FAQs

ACHROMATOPSIA
ADJUSTABLE SUTURES IN STRABISMUS SURGERY
ALBINISM
AMBLYOPIA
ANATOMY
ANESTHESIA FOR CHILDREN HAVING EYE SURGERY
ANIRIDIA
ANISOCORIA AND HORNER SYNDROME
BELL PALSY
BLOWOUT FRACTURE

ACHROMATOPSIA

What is Achromatopsia?   This is a visual disorder leading to reduced vision, and particularly the absence of color vision.

How common is Achromatopsia?
This condition affects approximately one in 40,000 persons, with varying presence in different parts of the world, particularly in the eastern Pacific islands of Pingelap (see the book, ‘The Island of the Colourblind’ by Oliver Sacks, MD). Because there is a genetic link, chromatopsia is also more common where there is a higher rate of consanguineous marriages (e.g., between first cousins).

What causes Achromatopsia?  Achromatopsia is caused by an abnormality of the retina, the “film” portion of the eye responsible for “making the picture”. Three types of retinal cells (cone subtypes) are responsible for normal color vision: the red cones, the green cones, and the blue cones. A balanced distribution of these cells is necessary for normal color vision.

An achromatopsic child may be born with a total or reduced complement of cones (partial or incomplete achromatopsia). Achromatopsia is an inherited condition and so far three genes (genetic markers found on chromosomes) are known to be associated with this condition: CNGA3, CGNB3, and GNAT2. The three chromosomes that may have changes associated with achromatopsia are chromosome 14, chromosome 8q21- q22, and chromosome 2q11.

What are the chances of having more children with Achromatopsia? Achromatopsia is a recessively inherited disease, meaning that both parents contribute abnormal genes to the affected offspring. The parents themselves do not show signs of the disease, because only one functioning gene need to be present for normal cone development (autosomal recessive inheritance). This gives a family with one affected child about a 25% (1in 4) risk of each pregnancy resulting in another affected child.

How does Achromatopsia affect vision? Achromatopsia is sometimes called ‘Day Blindness’, as these children see better in subdued light. Children with complete achromatopsia will have a poorer vision (20/200 or less) to the presence of sensitivity to light (photophobia) and the presence of nystagmus (wobbly eyes). Children with incomplete or partial achromatopsia will have a better vision (20/120 to20/80).

How is the diagnosis made? The diagnosis will be made by your eye doctor. The affected child will not be able to perform the screening tests to check for color blindness. The diagnosis can be confirmed by electrical tests called electroretinography (ERG), which specifically records the electrical response of cones to light stimulation.

What treatment is available for Achromatopsia? Children should be checked for refractive errors (need for glasses). Prescribing glasses to correct refractive conditions such as farsightedness (hyperopia), nearsightedness (myopia) and astigmatism can improve the vision somewhat, but will not restore normal levels of vision. Magnifying devices (low vision aids) may be helpful for reading as may the use of large print books.

What type of glasses should my child wear? Dark-tinted glasses will help reduce the sensitivity to light.

How will this condition affect my child’s schooling?  With adequate help from teachers for the visually impaired, children with achromatopsia are usually able to attend mainstream schools. More severely affected individuals may benefit from more intensive services available schools specifically designated for the visually impaired.

Is there an Achromatopsia support group? http://www.achromat.org

 

ADJUSTABLE SUTURES IN STRABISMUS SURGERY

What is an adjustable suture in strabismus surgery?

Adjustable suture surgery is a technique that allows for a change in eye muscle position in the immediate postoperative period, with the goal of improving the chance for desired eye alignment.

The operation is performed in two steps:
First, the eye muscle is repositioned in standard fashion by disinserting the attachment to the globe and then loosening (recession) or shortening (resection) it. The suture holding the muscle in place is then tied in a “releasable” fashion (somewhat akin to a bow know rather than a square knot).

Second, after the patient is awakened from anesthesia, the eye alignment is checked, and the knot untied, so the muscle position can be moved or “adjusted”. If no adjustment is needed the stitches are permanently tied and trimmed. Topical anesthetic numbing drops are used to help patients tolerate this suture adjustment.

Who can have adjustable suture surgery?

Cooperative adults and teenagers are often able to tolerate a suture adjustment. Occasionally, even young children have adjustments done in the operating room under light anesthesia.

Is the patient asleep or under anesthesia during the suture adjustment?

Usually not. Most adults have the muscles adjusted on the same day or the day after surgery. The adjustment may take place in the operating room itself, in the recovery room shortly after surgery, or in the doctor’s office later the same day or the next day. Topical anesthetic drops are used to numb the eye.

Is suture adjustment painful?  Usually, there is some discomfort during the adjustment; the numbing drops help a lot, though there is maybe pressure or pulling sensation when the muscle is moved.

Is adjustable suture surgery new?  An adjustable suture technique was first described in 1941; popular use became more widespread after 1975.

What are some of the benefits of adjustable suture surgery?  Theoretically, adjustable sutures give the surgeon the ability to fine-tune surgical outcomes, to reduce the reoperation rate, and to improve success in more complicated surgery such as re-operations, trauma, and patients with thyroid eye disease.

What are the disadvantages of adjustable suture surgery?  The attachment site of the muscle can vary with healing – muscles can both slip back farther than desired or “creep” forward after the adjustment period. Changes in eye alignment can occur during the healing period with adjustable and non-adjustable techniques.

What are some possible complications of adjustable suture surgery?

Blurred vision and pain can limit the patient’s ability to cooperate with both the measurements and the adjustable procedure.

Breakage of the suture or cutting of the knot can occur during an adjustment. If this happens, some patients will need to go back to properly secure the muscle.
Sometimes the muscle won’t move forward or backward as desired. This can be due to the healing of the muscle to the sclera, especially for late adjustments, restricted or scarred muscles, or muscles that have lost elasticity.

The heart rate can slow down (bradycardia) in some people when an eye muscle has tension put on it, and some people feel faint and nauseous. These reactions are usually very short-lived and not serious or severe.

The most common problem with adjustable suture surgery is knowing where to place the muscle. Measurements of the eye position are often quite variable immediately after surgery, so it’s difficult to know what the eye alignment measurement will be, once the muscle heals.

Do all strabismus surgeons use adjustable sutures?  No. Some physicians use this on all cooperative patients, some rarely or never. At Ticho Eye Associates, we have extensive experience with this surgical technique, though Dr. Ticho reserves adjustable sutures for very specific clinical situations.

 

ALBINISM

What is albinism?  Albinism refers to a group of inherited conditions affecting the production of melanin, the major pigment giving color to our skin and eyes.

How common is albinism?  One person in 17,000 has some type of albinism, affecting people of all races. Most children with albinism are born to parents who have normal hair and eye color for their ethnic backgrounds.

What are the two different types of albinism?  Oculocutaneous albinism involves decreased pigment in the eyes, hair, and skin. Another form of albinism (often termed ocular albinism) affects only the eyes primarily, while the skin and hair show normal or near-normal coloration.

What causes albinism?  Albinism is passed from parents to their children through genes.

How is albinism inherited?  For most types of albinism, both parents must carry an albinism gene to have a child with albinism. Parents may have normal pigmentation but still, carry the gene. When both parents carry the gene, and neither parent has albinism, there is a one-in-four chance at each pregnancy that the baby will be born with albinism. This type of inheritance is called autosomal recessive inheritance.

What is X-linked ocular albinism?  In X-linked inheritance, the gene for albinism is located on an X chromosome. Females have two X chromosomes, while males have one X chromosome and one Y chromosome. X-linked ocular albinism appears almost exclusively in males. The albinism gene is passed to male offspring from their mothers (who carry one normal gene and one abnormal albinism gene without developing clinical problems). The mothers have subtle eye changes that an ophthalmologist could identify, but they generally have normal vision. For each son born to a carrier mother, there is a one-in-two chance of developing X-linked ocular albinism.

What are the visual symptoms of albinism?

The symptoms of albinism begin in early childhood and may include decreased vision, sensitivity to bright lights, a jittery movement of the eyes (nystagmus), and eye misalignment (strabismus). Vision can range from normal, for those minimally affected, to legal blindness for those with more severe forms of albinism. Near vision is often better than distance vision. Generally, patients who have the least amount of ocular pigment have the poorest vision.

These eye problems result from abnormal development of the fovea, which is the retinal area normally responsible for producing the sharpest visual images. If the fovea is poorly developed, the eye cannot produce sharp images, even with corrective lenses. This is analogous to a smartphone camera with only limited megapixels — even if the image is well- focused (ie., even with glasses), the resulting photo will be grainy and not sharp.

How is albinism treated?

Albinism is a lifelong condition. Although there is no way to cure poor or absent pigment production or to correct the visual development, proper eye evaluation and management can be useful. Eye misalignment can be treated with glasses or surgery. Glasses can be prescribed to improve vision and reduce light sensitivity. Magnifying glasses for reading and low vision aids for distance vision can also be helpful.

Genetic counseling of affected individuals and their families is recommended. Counselors can provide a detailed explanation of the disorder including the chances of future children being affected.

What lifestyle adjustments does albinism usually require?

The reduced visual acuity associated with albinism may result in difficulty in school, such as the inability to read what is written on a chalkboard except when very close, and difficulty with certain sports. It may also result in the inability to drive, and place limitations on vocational choice.

Students, parents, and teachers should work as a team to consider seating, lighting, optical aids, and support for social and emotional growth.

What optical aids are useful in albinism?

The use of optical aids depends on the individual. Some children may do well with ordinary glasses. For older children and adults, glasses with small telescopes mounted on the lenses may help with both close and distant vision. Contact lenses work satisfactorily for many albinism patients.

What non-medical approaches can help a patient with albinism?

Children and adults with albinism can benefit from participation in peer support groups – for gathering information and dealing with the emotional aspects of having associated life challenges. These groups may help the individual to feel less isolated, to learn positive attitudes and coping skills from others with low vision, and to discover valuable governmental and other resource information.

Where can I find more information about albinism?

For more information contact:

National Organization for Albinism and Hypopigmentation (NOAH) 1530 Locust Street, #29
Philadelphia, PA 19102-4415
1-800-473-2330

AMBLYOPIA

What is amblyopia?  Amblyopia, or “lazy eye,” causes more vision loss in children than all other ocular conditions put together. Amblyopia is a failure of visual development in the brain which can happen even when there is no problem with the eye structure itself. The decrease in vision results when one or both eyes send a blurry image to the brain. The brain then “learns” to only see blurry with that eye, and the brain areas normally responsible for 20/20 vision fail to develop. Only children can get amblyopia; unfortunately, if untreated, amblyopia causes permanently reduced vision.

What kinds of amblyopia are there?  The three main types of amblyopia are Strabismic, deprivation, and refractive amblyopia. The end result of all forms of amblyopia is reduced vision in the affected eye(s).

What is strabismic amblyopia?  Strabismic amblyopia develops when the eyes are not straight. One eye may turn in, out, up, or down. When this happens, the brain “turns off” or ignores visual input from the eye that is not straight.

What is deprivation amblyopia?  Deprivation amblyopia develops when cataracts or similar conditions “block” or deprive young children eyes of visual experience. Because cataracts, corneal scars, and similar conditions may be present on both sides, deprivation amblyopia sometimes affects the vision of both eyes.

What is refractive amblyopia?  Refractive amblyopia happens when there is a large or unequal amount of refractive error (glasses strength) in a child’s eyes. Usually, the brain will “turn off” the eye that has more farsightedness or more astigmatism. Parents and pediatricians may not be aware there is a problem because the non-amblyopia “good” eye may have normal vision, so visual behavior may appear normal. Frequently, in refractive amblyopia, the child’s eyes may stay straight, so this kind of amblyopia in children may not be detected until the child has a formal vision test.

Will glasses help a child with amblyopia to see better?

Frequently, but glasses often do not correct vision all the way back to 20/20. With amblyopia, the brain gets accustomed to seeing a blurry image and cannot interpret the clear image that the glasses produce. With time, however, the brain may “relearn” how to see and the vision may increase. Remember, glasses alone do not increase the vision all the way to 20/20, as the brain is used to seeing blurry with that eye. For that reason, the non-amblyopic eye is treated (with patching or atropine eyedrops) to make the amblyopic (weak) eye stronger.

What can be done if my child has equal high amounts of farsightedness and/or astigmatism and is diagnosed with bilateral amblyopia?
Bilateral amblyopia is usually treated with consistent, early glasses, and or contact lenses with follow-up over a long period of time. If asymmetric amblyopia (one eye better than the other) occurs, then patching or atropine eye drops may be added.

When should amblyopia be treated?

Early treatment is always best. If necessary, children with refractive errors (nearsightedness, farsightedness, or astigmatism) can wear glasses or contact lenses when they are as young as one week old. Children with cataracts or other “amblyogenic” conditions are usually treated promptly in order to minimize the development of amblyopia.

How old is TOO old for amblyopia treatment?

Dr. Ticho participated in the groundbreaking studies, sponsored by the National Eye Institute and National Institutes of Health, which confirmed that SOME improvement in vision can be attained with amblyopia therapy initiated younger teenagers (through age 14 years). Better treatment success is achieved when treatment starts early, however.

How can I get early detection for amblyopia?  Some forms of amblyopia, such as those with associated eye-crossing, may be easily detected by parents. Other types of amblyopia (from high refractive error) might cause a child to move very close to objects of squint their eyes. Still, other forms of amblyopia may NOT be obvious to parents and therefore must be detected by Vision Screening. At Ticho Eye Associates we recommend early screening by primary care doctors at all “well-child” checkups and mandatory exams by a qualified eye doctor by 5 years of age.

In families with a history of any early childhood eye or vision problems, we suggest this exam be performed by age 3. The doctors and orthoptist at Ticho Eye Associates are uniquely trained to find amblyopia even in infants, using such techniques as Forced Preferential Looking tests.

How is amblyopia treated?  One of the most important treatments of amblyopia is correcting the refractive error with consistent use of glasses and/or contact lenses. Other mainstays of amblyopia treatment are to enable as clear an image as possible (for example, by removing a cataract), and forcing the child to use the non-dominant eye (via patching or eye drops to blur the better-seeing eye).

When should patching be used for amblyopia treatment?  Patching should only be done if recommended by an eye doctor qualified in examining and treating children. Regular checks are important to assess how the patch is affecting the child’s vision. Although sometimes difficult, patching usually works very well if started early enough and if the parents and child follow the patching instructions carefully. It is important to patch the dominant eye to allow the weak eye to get stronger.

Are there different types of patches?  The classic patch is an adhesive “Band-Aid” which is applied directly to the skin around the eye. These may be available in different sizes for younger and older children. For children wearing glasses, both cloth and semi-transparent stickers (Bangerter foils) may be placed over or onto the spectacles. “Pirate” patches on elastic bands are especially prone to “peeking” and are therefore only occasionally appropriate.

Is there an alternative to patching to treat amblyopia?

Sometimes the stronger (good) eye can be blurred or “penalized” to help the weaker eye get stronger. Blurring the vision in the good eye with atropine drops encourages the child to use the amblyopic eye. Atropine drops may be easier for some children and families to use than eye patches because once the eye drops are administered, the most difficult part of the treatment is done, whereas patching requires regular parental monitoring to ensure that the patch remains in place.

Multiple studies performed by the Pediatric Eye Disease Investigator Group (PEDIG) over the past twenty years have shown that patching or eye drops may be similarly effective in many amblyopia conditions. Dr. Ticho was a co-author for many of these PEDIG studies, which now help guide treatment decisions for children with amblyopia.

Do atropine drops work for all amblyopic children?  Not all children benefit from eye drop treatment for amblyopia. Penalizing eye drops generally work best for children who are far-sighted and less well when the stronger eye is nearsighted.

How many hours per day patching is enough when treating amblyopia?  Patching of the dominant (good) eye may be recommended either full or part-time during waking hours. PEDIG studies suggest that 2-4 hours of patching often achieve similar results as longer amounts in patients with moderate amounts of amblyopia.

How long does amblyopia patching therapy take to work?  Although vision improvement frequently occurs within weeks of beginning patching treatment, optimal results often take many months. Once your vision has been improved, part-time (maintenance) patching or periodic use of atropine eye drops may be required to keep the vision from slipping backward or deteriorating. This maintenance treatment may be advisable for several years.

During which activities should patching be performed?  The particular activity is not terribly important, compared to the need to keep the patch on during the allotted time. As long as the child is conscious and has his or her eyes open, visual input will be processed by the amblyopic eye. On the other hand, the child may be more cooperative, or more open to bargaining, if patching is performed during certain, desirable activities (such as watching a preferred television program or hand-held computer games). PEDIG studies have not suggested that specific visual tasks are more effective in treating amblyopia than general eye use.

Should patching be performed during school hours?

In many instances, school is an excellent time to patch, taking advantage of a nonparental authority figure. Patching in school hours gives the class an opportunity to learn valuable lessons about accepting differences between children. While in most instances, children may not need to modify their school activities while patching, sometimes adjustments, such as sitting in the front row of the classroom, will be necessary.

If the patient, teacher, and classmates are educated appropriately, school patching need not be a socially stigmatizing experience. On the other hand, frequently a parental or another family figure may be more vigilant in monitoring patching than is possible in the school setting. Parents should be flexible in choosing when to schedule patching.

What if my child refuses to wear the patch?

Many children will resist wearing a patch at first. Successful patching may require persistence and plenty of encouragement from family members, neighbors, teachers, etc. Children will often throw a temper-tantrum, but then they eventually learn not to remove the patch. Another way to help us is to provide a reward to the child for keeping the patch on for the prescribed time period. Atropine penalization eyedrops may be a useful alternative for certain children.

Can surgery be performed to treat amblyopia?

Surgery on the eye muscles is a treatment for strabismus – it can straighten misaligned eyes. By itself, however, surgery does not usually or completely help the amblyopia. Surgery to make the eyes straight can only help enable the eyes to work together as a team. Children with strabismic amblyopia still need close monitoring and treatment for the amblyopia, and this treatment is usually performed before strabismus surgery is considered.

Children who are born with cataracts may need surgery to take out cataracts. After surgery, the child will usually need vision correction with glasses or contact lenses and patching.

What are the appropriate goals of amblyopia treatment?

In all cases, the goal is the best possible vision in each eye. While not every child can be improved to 20/20, most can obtain a substantial improvement in vision. Although there are exceptions, patching does not usually work as well in children who are older than 9 years of age.

What happens if amblyopia treatment does not work?

In some cases, treatment for amblyopia may not succeed in substantially improving vision. It is hard to decide to stop treatment, but sometimes it is best for both the child and the family. Children who have amblyopia in one eye and good vision only in their other eye can wear safety glasses and sports goggles to protect the normal eye from injury. As long as the good eye stays healthy, these children function normally in most aspects of society.

 

ANATOMY

What are the extraocular muscles?

They are six muscles that are present in the eye socket and attach to the eye to move it. These muscles work to move the eye up and down and side to side and to rotate the eye.

What is the superior rectus?

The superior rectus is an extraocular muscle that attaches to the top of the eye. It moves the eye upward primarily, but also moves it out and rotates the eye inward to the nose.

What is the inferior rectus?

The inferior rectus is an extraocular muscle that attaches to the bottom of the eye. It moves the eye down primarily, but also moves it out and rotates the eye outward.

What is the medial rectus?

The medial rectus is an extraocular muscle that attached to the outside of the eye near the nose. It moves the eye toward the nose primarily.

What is the lateral rectus?

The lateral rectus is an extraocular muscle that attaches to the eye on the side near the temple. It moves the eye outward primarily.

What is the superior oblique?

The superior oblique is an extraocular muscle. It comes from the back of the eye socket then attaches to the top of the eye near the nose. The superior oblique muscle rotates the eye down and inward.

What is the inferior oblique?

The inferior oblique is an extraocular muscle. It attaches to the eye socket in the front of the eye socket near the nose and travels outward and backward in the eye socket before attaching to the bottom part of the eyeball. It rotates the eye up and outward.

What is the conjunctiva?

The conjunctiva is a transparent mucous membrane that covers the inner surface of the eyelids and the surface of the eye.

What is the lacrimal gland?

The lacrimal gland produces tears that lubricate the eye. It is located under the brow in the eye socket toward the outside.

What is Tenon’s capsule?

Tenon’s capsule is a layer of tissue that lies between the surface of the eye and the conjunctiva.

What is the sclera?

The sclera is the white outer wall of the eye. It covers nearly the entire surface of the eyeball. It is a strong layer made of collagen fibers. The tendons of the extraocular muscles attach to the sclera

What is the cornea?

The cornea occupies the front center part of the outer wall of the eye. It is made of collagen fibers in a very special arrangement so that the cornea is clear. One looks through the cornea to see the iris and pupil. The cornea bends light coming into the eye so that it is focused on the retina.

What is the anterior chamber?

The anterior chamber is a fluid-filled space on the inside of the eye. The cornea lies in front of the anterior chamber and the iris and the pupil are behind it.

What is the iris?

The iris is the colored part of the eye that surrounds the pupil. It is disc-shaped with a hole in the middle (the pupil). Muscles in the iris cause the pupil to constrict in bright light and to dilate in dim light. The change in pupil size regulates the amount of light that reaches the posterior part of the eye.

What is the lens?

The lens of the eye is located directly behind the pupil. The lens bends light coming into the eye to help focus it on the retina. The lens changes shape to help the eye focus to see objects clearly at near. The lens is suspended from the wall of the eye by many small fibers (zonules) that attach to its capsule.

What is the ciliary body?

The ciliary body is attached to the outer edge of the iris near the wall of the eye. The ciliary body produces the fluid that fills the eye and nourishes its structures. It also helps to change the shape of the lens when focusing occurs.

What is the vitreous?

The vitreous is a cavity that lies between the lens and the retina and fills the majority of the space inside the eye. It is a transparent tissue that plays an important role in nourishing the inner structures of the eye. The light that comes into the eye through the pupil and passes through the vitreous to be projected on the retina.

What is the retina?

The retina is a thin, transparent structure that covers the inner wall of the eye. The eye works like a camera and the retina is similar to the film in the camera. It is where images are first projected before they are transmitted through the optic nerve to the brain. It is a very complex structure with 10 layers of specialized cells including the photoreceptor cells (rods and cones).

What are photoreceptors?

Photoreceptors are highly specialized cells of the retina that receive light impulses and change them into chemical energy that can be transmitted by nerve cells to the brain. The two types of photoreceptors are rods and cones. Rods perceive black and white and serve night vision primarily. Cones are responsible for color perception and central vision.

What is the macula?

The macula is a small specialized area of the retina that has very high sensitivity and is responsible for central vision. It is the area in the posterior retina that is bordered by two branches of blood vessels that come from the optic nerve and head toward the side of the eye that is away from the nose.

What is the retinal pigment epithelium?

The retinal pigment epithelium is a layer of cells deep to the retina. This single layer of cells helps maintain the function of the photoreceptor cells in the retina by processing vitamin A products, turning over used photoreceptor segments, absorbing light, and transporting nutrients in and out of the photoreceptor cells.

What is the choroid?

The choroid is a tissue layer that lies between the retina and the wall of the eye or the sclera. The choroid has a rich supply of blood vessels that nourish the retina.

What is the uveal tract?

The uveal tract is a pigmented component of the eye that is comprised of 1) the iris, 2) the ciliary body, and 3) the choroid.

What is the optic nerve?

The optic nerve connects each eye to the brain. It is a structure that sends the picture seen by the eye to the brain so that it can be processed. The optic nerves end in a structure called the optic chiasm. In an adult, the optic nerve is about the diameter of a pencil. There are over 1 million individual nerve cells in the optic nerve.

What is the optic chiasm?

The optic chiasm is the place in the brain where the two optic nerves meet. The individual nerve fibers from each nerve are sorted in the chiasm. The sorting occurs in such a way that the right side of the brain controls the view of objects in the left visual space and the left side of the brain controls the view of objects in the right visual space.

What is the visual cortex?

This is an area of the brain in the posterior occipital lobe to which the neurons in the retina ultimately give visual information. The visual cortex helps to process information regarding the image such as its color, composition, and relation in space to other objects. This information is then sent to other parts of the brain that serve higher visual functions.

 

ANESTHESIA FOR CHILDREN HAVING EYE SURGERY

What types of anesthesia are appropriate for children having eye surgery?
Either general or local anesthesia is indicated during eye surgery to reduce or eliminate pain. Local anesthesia, which blocks sensation to one area of the body but does not affect general consciousness, is occasionally used for children having eye surgery. General anesthesia, which puts the whole body “to sleep” and eliminates the possibility of movement, is more commonly used. Occasionally, general anesthesia may be required to perform a complete eye examination on a child, even if no invasive surgery
is planned.

How is anesthesia administered to children?
General anesthesia is typically administered in two stages. First, a relaxing drug is delivered as a gas through a scented face mask causing the child to drift off to sleep. An intravenous (IV) line is usually placed in a vein of the arm or leg after a young child is asleep from the mask. Older children may have the IV line placed before going to sleep.

After the child is asleep, a mask may be held over the child’s mouth and nose for a brief procedure (such as opening blocked tear ducts). For other eye procedures, however, a breathing tube is placed in the windpipe to allow the anesthesiologist to control the child’s breathing and maintain anesthesia during surgery. Anesthetic agents (inhalation agents) delivered through the tube or medications are given intravenously to maintain the anesthesia. The breathing tube is removed at the end of the surgery before the child is fully awake. The IV can be removed in the recovery period when the child is drinking well.

How is anesthetic “sleep” different from normal sleep?
Anesthetic “sleep” is quite different from normal sleep because the potent medications affect every organ of the body. Achieving and maintaining the desired effect requires continuous monitoring and adjustment. Your anesthesiologist has the experience and knowledge to decide which agents are best for your child and to administer them in a safe manner as possible.

How should you prepare a child for surgery?
Parents should tell children old enough to understand why they are having surgery. Your hospital may provide tours to show its facilities and explain its procedures to the child. Most children are inquisitive and may be fascinated by all the machines in the operating room. They should be encouraged to ask questions. The staff, nurses, and doctors will try to make the hospital experience a positive one.

Is a medical examination needed for children before undergoing general anesthesia?
Before surgery, medical history and physical examination may be performed to be sure your child is sufficiently healthy for anesthesia.

Do anesthesia complications tend to run in families?
It is important to know if any blood relatives had serious problems with anesthesia such as a high fever (malignant hyperthermia) or not breathing, as some of these rare problems can be hereditary. Relatives may have had nausea with anesthesia. Nausea is also common after strabismus surgery but medications to ease the discomfort are available.

What can a child eat or drink prior to general anesthesia?
In general, your child should not eat food or drink baby formula for eight hours or drink anything, even water or breast milk, for four hours before surgery. The stomach must be empty to avoid possible anesthesia complications. The hospital staff will give you specific instructions about what time your child must stop eating and drinking.

Can a sedative be given to calm a child before going into surgery?
Children may receive a liquid sedative prior to surgery to help ease any apprehension. A sedative comforts children as they await their surgery, reduces anxiety as they move into the operating room, and helps them forget the events immediately associated with their surgery.

Isn’t general anesthesia dangerous?
Although strabismus surgery is usually quite routine, children are extensively monitored by the anesthesiologist while they are asleep. Serious reactions to anesthesia are extremely rare. All precautions are taken to ensure children’s safety while they are asleep.

What is a laryngeal mask airway?
Modern anesthesia techniques also often include special breathing tubes (called laryngeal mask airways) that reduce irritation to the windpipe during surgery and lessen sore throats afterward.

What happens during the recovery from general anesthesia after
surgery?

Once the surgery is complete, the tube is removed and normal breathing resumes. The child is then transferred from the operating room to the recovery room and over the next hour or so gradually wakes up. During this time children are often groggy and confused but receive supportive care and reassurance from the recover room staff who are also monitoring the child’s heart rate, blood pressure, and respiration. During the next few hours, the child will still be sleepy, sometimes cranky, and may have a lowered tolerance for discomfort or pain.

Additional reassurance and the use of mild pain medications are helpful when needed. Most children are back in many normal activities by the next day. Occasionally a child will sleep for hours, especially after a long surgical procedure or if sedating pain medications are required.

What are the side effects of anesthesia?
Children may be nauseated or vomit after eye surgery, particularly muscle surgery. Although nausea may last for hours, it is rarely serious. Everything possible should be done to reassure the child and make him or her comfortable. Medication is sometimes helpful.

What are the risks of anesthesia?
Serious anesthesia complications, such as brain damage or death, are exceptionally rare. Generally, healthy children tolerate anesthesia at least as well as adults. Whenever possible, elective eye surgery should be avoided when a child is ill. Anesthesiologists and surgeons should be informed of all medical conditions and all medications the child is taking. They should also be informed of any anesthetic problems the child or any blood relative has experienced, as there are some rare hereditary conditions, which are associated with a greater risk. Dr. Ticho operates only at institutions well-versed in the care of children.

Will my child wake up during the anesthesia?
The anesthesiologist monitors with the concentration of inhaled anesthetic vapors to assure that your child will not be aware of pain or other aspects of the surgery.

Can strabismus surgery in pediatric patients be done with topical or
local anesthesia?
Some strabismus surgery in teenagers and adults can be done with a local anesthetic. Unlike its use in adult cataract surgery, topical anesthesia, consisting of numbing eye drops to the surface of the eye, may not provide sufficient patient comfort to be used during eye muscle surgery.

Strabismus surgery typically requires 30 minutes or longer to complete. The patient must be still and comfortable during this period to avoid potentially serious complications that may result from sudden unexpected movements. As most children cannot be expected to remain still for the time necessary to complete the surgery, nearly all children require general anesthesia in order for eye muscle surgery to be performed safely and comfortably.

Summary
Anesthesia for children is generally safe. Complications may be minimized
by avoiding food and drink before general anesthesia and postponing
elective surgery if the child is ill. Modern anesthesia allows surgery or
examinations to be performed without pain or anxiety.

 

ANIRIDIA

What is Aniridia?  Aniridia means an absence of the iris or the colored part of the eye. Usually, a small rim of iris may be present, though sometimes this may only be visible to the eye doctor who may see the small rim of iris using a special magnifying instrument. The pupil is large and the condition is present in both eyes.

How common is Aniridia?  In the general population, this may vary from region to region and has been reported to be present in 1 per 50,000 to 1in 100,000 people.

What causes Aniridia?  Normally the iris forms during the 12 to 14th week of pregnancy. In aniridia, the failure of this development is due to a gene defect in chromosome 11p. The gene that causes Aniridia is called PAX6.

What are the chances of having another child with Aniridia?  If a parent has Aniridia he or she may have a 50% chance of an affected offspring for each pregnancy, this is known as autosomal dominant transmission. Aniridia may occur for the first time in the family without affected parents (called the sporadic type of Aniridia) and this affected child has a 50% chance of having an affected offspring for each pregnancy. In a rare, autosomal recessively inherited form of Aniridia, the parents have a 25% chance of an affected child for each pregnancy; this type may also.be associated with mental retardation.

How does Aniridia affect vision?

Some children with aniridia may have very good vision (20/30 or better) and some may have vision poorer than 20/200. Different parts of the eye are affected in aniridia, causing a variety of vision problems. The lack of iris tissue usually causes significant problems with glare. Light scatter and light sensitivity may be increased by cornea scarring or cataract. Occasionally the lens in the eye may be shifted out of its normal place (subluxated). The fovea, which is the central part of the retina, is often underdeveloped, leading to eye shaking (nystagmus). Vision loss may be exacerbated by optic nerve maldevelopment. Finally, 50% of children will develop glaucoma at some stage of their life.

Is Aniridia associated with other health problems?

Aniridia may occur on its own with no other systems of the body being affected. However, aniridia has also been described with other syndromes (a group of signs which occur consistently together). In sporadic cases (where there is no definite family history), aniridia may be associated with a kidney tumor called a Wilms tumor (or nephroblastoma) or WAGR syndrome which stands for Wilms tumor, Aniridia, Genital abnormalities and Retardation (mental). Gillespie’s syndrome is a combination of aniridia, mental retardation, and balance problems (ataxia).

What treatment is available for aniridia?

Children with aniridia need regular eye exams to assess their vision and glasses measurements. They should be monitored regularly for possible development and treatment of glaucoma and cataract. In certain cases, an artificial iris may be surgically implanted, to improve eye appearance and reduce light sensitivity.

Genetic counseling and examination of family members for subtle iris changes is important for establishing the mode of inheritance. Genetic tests of the chromosomes can also assess the risk of tumor development.

What type of glasses should my child wear?  The eye doctor will check your child’s prescription and prescribe appropriate glasses to improve vision and to protect the eye from sunlight and injury (polycarbonate lens). Magnifying aids (low vision devices) may make reading easier.

What about contact lens use in Aniridia?  Special colored soft contact lens is available to improve the pupil appearance, reduce glare, and occasionally improve vision beyond that obtainable from glasses. Because aniridia often affects the cornea, however, contact lens wear should be monitored regularly.

How often and how long will my aniridic child need to be seen?  Once aniridia is diagnosed your child will require regular eye examinations for life. The frequency of these examinations depends on age and presence/severity of associated ocular problems.

How will the diagnosis of aniridia affect my child’s schooling?  Most children with aniridia will do well in the usual school setting, though modifications may be needed to adjust to specific visual needs. The school should regularly assess what assistance is appropriate for a given child’s visual status.

Are there any Aniridia support groups?  www.aniridia.org

 

ANISOCORIA AND HORNER SYNDROME

What is the pupil?
The colored donut-shaped part of the eye is called the iris. The pupil, the hole in the center of the iris, controls how much light to enter the eye, by constricting or dilating. This pupil size change is controlled by the iris sphincter and dilator muscles, respectively.

My child’s pupils are different sizes. Is this normal?

Normally the size of the pupil is the same in each eye with both eyes dilating or constricting together. The term anisocoria refers to pupils that are different sizes at the same time. The presence of anisocoria can be a normal variation (physiologic), or it can be a sign of a medical condition.

When is anisocoria normal?

Approximately 20% of the population has some degree anisocoria. Anisocoria that is NOT associated with or due to an underlying medical condition is called physiologic anisocoria. Typically physiologic pupil asymmetry does not exceed one millimeter between the two eyes.

How does the doctor determine whether my child’s anisocoria is due to an underlying medical problem?
Your doctor will ask questions, which may include when the anisocoria was first noted, whether you believe it is more noticeable in bright or dim illumination, and whether or not there was a preceding event that could be related to such recent trauma. The doctor will evaluate how the size of the pupils and how they react to bright and dim lighting. Careful evaluation of the eyelids and the internal structures of the eye also help guide diagnosis. Based on the evaluation, the doctor may wish to perform tests with eyedrops or perform laboratory or radiologic testing.

How does the doctor know if the big pupil is ‘too big’ or the small pupil is ‘too small’?
One of the most important parts in the evaluation of anisocoria is determining which pupil is abnormal. If the difference in size between the pupil’s increases in the dark, then the smaller (miotic) pupil may not be dilating well. Conversely, if the difference in pupil size increases in bright lighting, then the larger (mydriatic) pupil may be the abnormal one because it is not constricting as expected.

What are some causes of an abnormally large (dilated or mydriatic) pupil?

After a trauma to the eye, the iris tissue can be injured causing the pupil to not constrict to bright light normally. Another possible cause is Adie’s tonic pupil syndrome. This is a condition most common in young adult females, which usually begins in one eye. The pupil is sluggish to react to light. Many people with Adie’s pupil also have diminished deep tendon reflexes and may have trouble focusing at near. The condition is usually not associated with any more serious conditions.

Some eyedrops have a dilating effect on the pupil, so a careful history is important to determine if there has been any inadvertent exposure to these drops. Finally, an abnormality of the third cranial nerve (which controls eyelid position, most eye movements, as well as the iris sphincter muscle) can cause the pupil to dilate.

What are some causes of an abnormally small (miotic) pupil?

Inflammation within the eye, whether from trauma or another cause, can make the pupil “sticky” keeping it from dilating properly. Horner syndrome also produces a small pupil in the affected eye.

What are the signs of Horner syndrome?

In Horner syndrome, the pupil in the involved eye is smaller and does not dilate symmetrically. Drooping (ptosis) of the upper lid and slight elevation of the lower eyelid (known as inverse ptosis). Because the upper eyelid is slightly lower than normal, and the lower eyelid is slightly higher than normal, the eye may appear smaller than the other side. If present very early in life, Horner syndrome may result in asymmetric eye color (heterochromia) and decreased sweating of the skin on the face on the affected side (anhydrosis).

What are the causes of Horner syndrome in children?

Horner syndrome can be divided into congenital (from birth) and acquired causes. Congenital Horner can result from neck trauma during birth and can be seen in association with an armpit (brachial plexus) injury (Klumpke’s palsy). Often, however, there is no apparent cause for congenital Horner syndrome.

Acquired cases can be due to neck trauma, neck surgery, or an abnormality in the chest, neck, or brain. Although rare, the risk of a tumor called neuroblastoma should be considered in children with Horner syndrome.

What tests may be considered when Horner syndrome is suspected?

When clinical findings point towards a diagnosis of Horner syndrome, additional investigation, including special eyedrops tests, may be warranted to confirm the diagnosis. When Horner syndrome is diagnosed in a child, the doctor may order urine tests and/or radiologic studies to search for neuroblastoma.

 

BELL PALSY

What is Bell palsy? Bell palsy is a weakness of the muscles of the face also known as idiopathic facial palsy (“idiopathic” means of unknown cause and “palsy” means paralysis). Although more common in adults, Bell palsy can occur in children.

What is the Facial Nerve?
The facial nerve comes directly from the brainstem, traveling through the skull bones to activate the facial muscles. The facial muscles include the orbicularis oculi muscle, which closes the eyelid, and the risorius muscle, which is involved in smiling.

How did Bell palsy get its name?
Sir Charles Bell was a Scottish surgeon who described the nerve supply to the facial muscles over 200 years ago.

How is Bell palsy diagnosed?
Eyelid drooping and difficulty closing one (or both) upper eyelids are classic findings in Bell palsy. Asymmetric or incomplete smiles, decreased forehead wrinkling, nasal stuffiness, and mild difficulty with speaking are also common signs. Frequent early symptoms include abrupt onset of dry eye and tingling around the mouth, with progression to more complete facial palsy occurring within one to several days.

What causes Bell Palsy?
Although the cause is unknown, there is some suggestion that Bell palsy might be caused by a virus. Children with facial paralysis should see their pediatrician or pediatric ophthalmologist to exclude other possible causes for the weakness. Lyme disease is an example of another cause for facial paralysis and should be considered, especially if you live in an area where Lyme disease is common. Brain imaging (such as MRI or CT scanning) should be considered, especially if the weakness does not begin to improve in a few weeks.

Can Bell palsy be transmitted from one person to another? No, Bell palsy is not contagious.

Who is at risk to get Bell palsy?
Most persons with Bell palsy are otherwise healthy. However, older individuals, persons with immune deficiency, diabetics, and women in the last trimester of pregnancy are at higher risk for developing Bell palsy. Men and women are affected at similar rates, and there is an approximately equal incidence of the disease in different races. The severity and duration of Bell palsy also is not significantly affected by gender or race.

How common is Bell palsy?
Bell palsy affects about 0.2% of the world’s population or about 1 in 5000 people. About 40,000 Americans are affected every year.

Can both sides of the face be affected by Bell palsy?
Bilateral Bell palsy is rare, affecting <1% of patients with the condition.

Are there other symptoms besides the facial weakness?
Some patients complain about pain around the ear, facial numbness, sensitivity to sound, or numbness of the tongue. Since there is a decrease in the ability to blink, dry spots may develop on the surface of the eye, causing pain or a feeling of dryness. Because the tear drainage system requires normal muscle tone, overflow tearing may also be a problem.

Is the weakness of the face permanent?
In almost all cases, the weakness caused by Bell palsy starts to improve after a few weeks. Recovery is usually full; however, there may be some permanent signs of the condition, such as twitching of the muscles around the mouth when blinking.

What is the treatment for Bell palsy?
Most cases of Bell palsy recover without the use of medications, using supportive care alone. Lubricating eye drops and ointments may prevent drying of the ocular surface. Anti-viral medications or steroid medication are occasionally prescribed.

How long does it take for Bell palsy to recover?
On the average, recovery from Bell palsy takes between a few weeks and several months, though some recovery may continue for over six months following the onset.

Can Bell palsy come back after my child has recovered?
In the vast majority of cases, Bell palsy happens only once, but recurrence may even years after the first episode. The risk of recurrence is elevated in patients with immune system diseases, such as HIV-AIDS or sarcoidosis.

What type of eye lubrication is best for Bell palsy?
In general, there are artificial tear drops and artificial tear ointments. The ointments will generally last longer, and frequently give more thorough protection against dryness than drops. However, because of their increased thickness, artificial tear ointments cause significant blurring of vision, which usually persists several minutes after administration. Some artificial lubricants (gels) are formulated to be intermediate between regular tear drops and ointments.

Both artificial tear drops and ointments come in preserved and non- preserved formulations. Around 15% of the general population may develop a sensitivity to preservatives used in many eye drops.

 

BLOWOUT FRACTURES

What is a “blowout” fracture?

A blowout fracture is a fracture of the bones below the eye (the orbital floor).

What is the orbit?

The orbit refers to the bones surrounding the eye. If one were to look at a skull, the orbit is the cone-shaped opening in the skull surrounding the eye.

What is the “floor” of the orbit?

The bones on the bottom of the orbit are referred to as the floor. The bones on the top are called the roof. The bones on the side are the walls. (There are no windows or doors ☺)

What is the function of the orbit?

In a general sense, the orbit holds your eye in the correct position. The orbit also protects your eye. Because the bones surrounding the eye extend beyond the eye, projectiles tend to hit the bones of the orbit rather than the eye itself.

What causes a blowout fracture?

Blowout fractures result from trauma to the orbital bones. When an object hits the orbital bones (usually the eyebrow and upper cheekbone) the force is transmitted to the bones. If the force is great enough it will cause the bones to buckle and break.

What are the common causes of blowout fractures?

Any large object with force or speed can cause a blowout fracture. Typical causes include motor vehicle accidents, balls used in sports, fists, and elbows.

What are the symptoms of an orbital blowout fracture?

The most common symptoms include bruising and swelling around the eye, soreness in the area of the impact, redness of the eye, bruising on the surface of the eye, or nose bleeds. These symptoms are usually transient and not necessarily worrisome.

Symptoms that may indicate a more serious injury include pain on eye movement, double vision, air under the skin around the eye, or numbness of the cheek/mouth/nose on the side of the injury.

If the trauma is severe enough other damage may be present including fractures of other facial bones, actual injury to the eye, or injuries to the skull/brain. These injuries would require other treatments not discussed in this handout.

How do you know if there is a fracture?

X-rays and CAT scans of the orbit and face are used to make the definitive diagnosis.

Are there different types of blowout fractures?

Blowout fractures are classified on several features including:

-size (big or small)

-location (front or back)

-bone-in place or displaced

-tissue/muscle entrapped in fracture

-accompanying symptoms (double vision, pain, eye position)

A “simple” fracture is one where it is minimal or no double vision; minimal or no interference with eye movements; and minimal fracture size.

What can be done for a simple blowout fracture? Most simple blowout fractures will heal without any lasting problems. Treatment consists of:

-ice to decrease swelling

-antibiotics to prevent the spread of bacteria from the adjacent sinuses

-decongestants to aid in the drainage of blood and fluid accumulating in the sinuses

-avoidance of nose blowing to prevent pressure from propelling the sinus contents into the orbit

-oral steroids in some cases to decrease swelling and scarring

When should surgical repair of blowout fractures be considered?

Fractures where there are persistent symptoms, usually double vision or pain, require surgical repair. The timing of the repair varies but usually is within two weeks of the injury. Initial repair may consist of any of the following:

-exploration of fracture site and repositioning of bone

-release of trapped tissue from the fracture site

-covering of fracture site with synthetic material

What long-term problems may develop following blowout fractures?

The majority of fractures, whether treated medically or surgically, heal without any long- term effects. Further surgery may be necessary if there is a persistent double vision. In these cases, strabismus surgery (eye muscle surgery) is required in order to alleviate the symptoms. Occasionally the persistent double vision can be treated with non-surgical methods (prism glasses or botulinum toxin injections).

 

 

Medical Disclaimer

The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. All content, including text, graphics, images, and information, contained on or available through this web site is for general information purposes only

Note: The Frequently Asked Questions are adaptations of material prepared by Dr. Benjamin Ticho for the American Academy of Pediatric Ophthalmology and Strabismus (AAPOS) when he served as the chairperson of the AAPOS Public Information Committee many years ago,. The FAQ section of the AAPOS website remains an excellent source of information for parents and others seeking information about pediatric eye conditions.  Similarly, the public information sections of the American Academy of Ophthalmology website contain much useful material to increase awareness of a variety of eye diseases,.