Contents:

• Retinal Detachments
• Viterectomy Surgery
• Face-Down Postoperative Positioning
• High-Speed ICG Angiography Case Study
• Fact Sheet for Patients with Macular Degeneration
• Intraocular Kenalog Injection
•  
• Glossary of Terms

Retinal Detachments

Retinal detachments are rare, occurring at a rate of about 1 in 10,000 people per year.  Until several years ago, detached retinas were a common source of blindness.  Previous ocular surgery, injury, certain medical conditions and some genetic disorders can sometimes predispose a person to a retinal detachment, but often there is no preceding event or trigger.

A retinal detachment is caused when the vitreous gel inside the eye collapses creating tension on the retina resulting in a retinal tear.  It is through this break or tear that fluid begins to accumulate underneath the retina.  This progressive blister of fluid enlarges around the retinal break to extend more posteriorly and can involve the central retina, resulting in decreased vision.  Once this blister of subretinal fluid becomes large enough, it is called a retinal detachment and side vision may be lost.

The natural course of retinal detachments is progressive and leads to complete blindness if left untreated.  Retinal detachments never repair themselves, although some progress rapidly and others very slowly.

If caught at a very early stage of their development, some retinal detachments can be treated with laser photocoagulation or a freezing technique known as cryoretinopexy.   At later stages of development, a gas injection may sometimes be chosen to repair selected retinal detachments.  This gas injection is called pneumatic retinopexy and is combined with laser photocoagulation and/or cryoretinopexy applied at the same or a later date.  As an in-office procedure, a gas bubble is injected into the eye and the patient is instructed on the proper head positioning to hold the gas bubble over the break and close the hole.  As long as the hole is closed, sub-retinal fluid will absorb.  When the retina is flat, laser photocoagulation or cryoretinopexy is used to permanently hold the retina in place.  The single surgery success rate is lower (70-80%) than other techniques (i.e.,80-90% for a scleral buckle), but when successful, the final vision is often better than with other techniques.  If it fails and other techniques are needed, there is no vision penalty-“no bridges have been burned.”  The gas bubble will absorb on its own in 1-3 weeks.

Many times, however, a scleral buckle procedure is required to repair the retinal detachment and may be the first choice of treatment for the detachment.  This involves placing a belt of medical grade silicone plastic around the eye in the operating room.  The indentation closes the break from outside the eye.  Sometimes it is necessary to drain the sub-retinal fluid, and/or put some gas inside the eye, but these decisions are made at the time of surgery.  Every effort is made to do all that is necessary to achieve retinal re-attachment.  The goal of surgery is to close the break, reduce retinal traction, and then postoperatively allow some time to pass for the retina to become firmly attached to the outer layers in its normal position.  Approximately 1 in 10 patients require an additional procedure following the initial procedure.  Sometimes pars plana vitrectomy, with or without a scleral buckle, is needed, and is often the first choice in selected patients.  This is a procedure where the vitreous is removed from inside the eye to relieve traction or to remove opacities that obscure the surgeon’s view of the retinal tear that is the cause of the detachment.  Overall, 95-98% of all retinal detachments can be successfully reattached, but 2-5% fail in spite of out best and sometimes multiple efforts.  There is a great deal of research being done in the area of failed retinal detachments.  Unfortunately, there is no 100% cure.

The final visual outcome is sometimes unpredictable pre-operatively.  Even though a retinal detachment might be fully reattached and “successfully” repaired, the visual acuity may be less than what it had been before the detachment occurred.  If the macula (the area of the retina that provides the most sensitive vision) is detached, it will continue to heal for several months after surgery, but still may be permanently damaged by the original detachment and limit the final vision recovery.  If there is no improvement in straight ahead vision following successful retinal detachment surgery, the restoration or preservation of peripheral vision alone makes surgery worthwhile.  Even if the visual acuity prior to retinal detachment surgery was not involved, the vision may be limited post-operatively for a number of reasons, including:  fluid within the retina, cataract, membranes distorting the retina, and occasionally a hole in the macula.  These possible complications can sometimes be treated with further surgery or medications.

Besides failure to reattach the retina and possible limited vision after surgery, other complications could include infection, migration or erosion of the plastic band, hemorrhage, cataract (or dislocated lens-if an implant is in place) and glaucoma.  Most of these complications can generally be successfully dealt with, but not always.  Potentially blindness or loss of an eye can occur.  Fortunately, this is rare.  Considering the natural course of the disease where there is 100% chance of blindness without surgery, these  risks are acceptable, low, and should not dissuade you from surgery.

The scleral buckling surgery generally takes about an hour and is often done under general anesthesia, that is, with the patient fully asleep. Vitrectomy surgery may be done with general anesthesia also as an outpatient procedure.   Both procedures may rarely require overnight hospitalization.  It takes 2-4 weeks for the retina to maximally bond to its proper position.  Most of this bonding, however, is complete within the first week.  Limited activity or special positioning (link to “face-down postoperative positioning” article below) will be required for approximately 5-10 days following surgery.  In particular, it will be necessary to reduce activities such as reading and driving where rapid eye movements could create new retinal traction and/or allow fluid to re-collect underneath the retina causing a re-detachment.  Follow-up arrangements and instructions for postoperative care will be given at the time of your discharge.

If you have any additional questions, please feel free to discuss them with me at anytime.

David V. Poer, M.D., F.A.C.S.
Vitreo-Retinal Consultants

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Viterectomy Surgery

Vitrectomy surgery was developed in the early 1970’s. Now, with highly refined instruments, vitrectomy surgery has come of age.

Vitrectomy surgery is extremely useful in the treatment of numerous ocular conditions and the list continues to grow. The first vitrectomy was for intraocular hemorrhage due to diabetic retinopathy and is still a very common reason for vitrectomy. In addition, preretinal and subretinal membranes can be removed with these techniques. Repair of retinal detachments, closure of macular holes, removal of foreign bodies and retained lens fragments, release of vitreous strands, removal of scar tissue, and improvement of many retinal vascular conditions, including diabetic macular edema, are among the common indications for this extremely useful procedure. Vitrectomy surgery often improves or stabilizes vision by removing blood or other debris, membranes, etc. that by themselves, or secondarily through traction on the retina, decrease the vision.

The surgery is done (with the eye left in place) under a microscope with an infusion line to maintain intraocular pressure and volume. A hand held light source and hand held instrumentation are placed through the pars plana. This anatomical area is uniquely designed for surgical access to the posterior structures of the vitreous and the retina. Incisions are made just behind the iris.

There are numerous instruments that are complimentary to the vitrectomy cutter, i.e. forceps, picks, irrigators, cannulas, laser probes, and various other instruments uniquely designed for manipulation of intraocular structures.

Vitrectomy surgery is sometimes done under general anesthesia, but increasingly it is done with local anesthetic and IV sedation. Surgery often takes an hour to an hour and a half or more. The recovery time and restoration of vision will depend upon the indications for surgery.

After the vitreous is removed, a salt solution is usually used as a replacement, but gas is sometimes used. Vitrectomy surgery is sometimes accompanied with placement of intraocular gas or air, after which the patient may be in a face down position to keep the retina in the proper position during healing. Laser photocoagulation is often applied during vitrectomy surgery and sometimes will be applied postoperatively. Other volume expanding materials can be used, such as silicone oil, which have some advantages over gas in that positioning is much less restrictive and visibility is greater; however, it generally requires removal several weeks or months following surgery.

The risks of vitrectomy surgery are real, but generally small and acceptable when indications are strong. Vision can sometimes be improved significantly, but seldom to normal. Improvement of vision often takes weeks or even months following surgery. Postoperative bleeding is common and often clears within several days, weeks, or sometimes months. A progressive cataract is common in patients over 50 years of age. We expect that 50 percent of these patients will require future cataract surgery within two years. Intraocular lenses are well tolerated in patients who require vitrectomy surgery and generally do not impede or alter our success rates. Infection, retinal detachment, recurrent membranes, or reopening of macular holes can occur. Glaucoma and even blindness can occur, but are rare. Most of the complications associated with vitrectomy are manageable. Though vitrectomy is common and routine, it is not trivial. A full discussion of all the risks, complications, alternatives, and postoperative expectations are to be discussed prior to surgery, but any time is appropriate.

The indications for vitrectomy surgery are increasing and the instrumentation continues to improve. We are deeply indebted to the pioneers of ophthalmology who have brought this procedure to modern medicine.

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Face-Down Postoperative Positioning

Intraocular gas is often used to occlude the offending retinal hole and to speed retinal detachment repair and other select conditions. Inactivity and head positioning are essential during the healing process. Here are some tips that other patients have found helpful. Face-down furniture is also available for purchase or rent and makes positioning more tolerable.

1. Lean over the kitchen table like a student asleep at his desk.
2. Use an ironing board-it is soft and its height is adjustable.
3. Use a ring pillow-either a hernia cushion or an inflatable beach ring wrapped in a soft cloth (i.e. Kerlex from a drug store).
4. Remove a leaf from a dining room table and pad the sides to maintain a face-down position within the enlarged crack.
5. Turn furniture upside down and pad the legs- a TV table, or a stool can be used in such a way.
6. Put several pillows under your chest and stomach and rest with face down in bed-with some support at your chin or forehead. A “travel” or C-shaped “neck pillow” is often helpful.
7. Put a mirror at your feet to watch TV or listen to the radio. Talking books and free Bible on cassette tapes are available. Use it as an opportunity to improve and refine your “inner” life. Make lemonade out of lemons.
8. You may discover other solutions. Be creative. Let us know what works so we can share these ideas with other patients.

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High Speed ICG Angiography Case Study

This patient, a 92-year old white female, presented with a long history of glaucoma and macular degeneration, failing vision for 1-2 months, a best corrected visual acuity of 20/400 in the right eye, and hand motion in the left eye with an old macular scar.

High-speed indocyanine green angiography (HS-ICGA) was done in an attempt to reveal any feeder vessels. The Heidelberg Engineering SLO was used to acquire images at the rate of 12.3 frames per second following an injection of 0.3 ml of ICG dye (fluorescein angiography is typically done at one frame per second). This small amount of dye normally fades after twenty minutes, allowing another injection after laser treatment to see if the feeder vessel was successfully treated.

HS-ICGA was repeated 11 days later showing inactivity of the CNV membrane. A fluorescein angiogram done one month post-laser confirmed this. The patient’s visual acuity at three months post-laser had improved to 20/100. Follow-up continues.

* Ophthalmoscopy of the right eye revealed pigment atrophy and localized pigment hyperplasia, eith subretinal fluid present suggesting submacular choroidal neovascularization.

*Early FA: Classic subfoveal CNV membrane (arrow).

*Late FA: Spread of dye within serous elevation (arrow).

*Early HS-ICGA: Filling of choroidal and retinal vessels.

*Midphase HS-ICGA: Branching pattern of the subfoveal CNV membrane visible with single feeder vessel (arrow).

*Immediate post-laser HS-ICGA: Feeder vessel was successfully treated with dye red laser. CNV membrane does not fill with dye (arrow), fovea spared.

*- retinal imaging by Thomas Egnatz, CRA

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In October 2001, the research group of The Age Related Eye Disease Study reported on the results of a ten-year study of approximately 4,700 patients with “dry” macular degeneration who were given nutritional supplements. The study revealed that in some patients with dry macular degeneration, the other eye benefited from the following nutritional supplements:

• Antioxidants of:
  • Vitamin C (500mg)
  • Vitamin E (400i.u.)
  • Beta Carotene (15mg)-combined with Zinc Oxide (80mg with 2mg of Copper to reduce the risk of Zinc induced anemia).

Three things you can do to reduce your risk of catastrophic vision loss due to macular degeneration are:

1. Do not smoke. Smoking has been found to increase the risk of vision loss.
2. Take high dose nutritional supplements.
   (Note: Smokers should not take beta carotene because of the concern of an increased risk of lung cancer.)
3. Check the Amsler grid (http://www.garetina.com/Amslergrid.htm) regularly and report new vision loss of distortion.

For a small group of patients with dry macular degeneration, sub-threshold diode grid laser photocoagulation has also been shown to be of benefit and may reduce the risk of abnormal vessels growing under the retina and also improve vision.

After many decades, this study has now provided reliable data to support the use of nutritional supplements and offers more hope to patients with macular degeneration. This report, combined with advances the treatment of the wet form of macular degeneration, is indeed good news.

If you have additional questions or concerns, please talk with me further.

Examples of AREDS proven formulas:

• ICAPS AREDS FORMULA
• OCUVITE PRESERVISION AREDS FORMULA
• Generic Brands available

David V. Poer M.D., F.A.C.S.

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INTRAOCULAR KENALOG INJECTION

Topical, periocular, and systemic steroids have been used in medicine, and ophthalmology in particular, for over 40 years. We have a long experience with these drugs, and they have been extremely useful in reducing, controlling, and sometimes eliminating intraocular inflammation. The list of side effects, limitations, and potential complications is well known. More recently, we have been using intraocular steroids for control of intraocular inflammation, resolution of macular edema, and inactivation of subretinal neovascular membranes. The indications for intraocular steroid injection are growing.

There are potential risks of steroids, however delivered, that accompany their significant potential benefits. The injection of steroids, as with any intraocular procedure, has a chance for significant complications. Intraocular procedures, though common and routine, are never considered trivial. The most common complications of intraocular steroids include limited benefit or failure to work as desired. Also, 20% of patients experience a pressure rise, which can lead to glaucoma. Usually, topical drops are sufficient to control the glaucoma, but surgery is sometimes necessary. The intraocular steroid typically wears off in three to four months, and the need for ongoing pressure control medication usually subsides. Other less common, but potentially serious, complications include sterile, or even infectious, endophthalmitis (infection of the eye) with potential devastating vision loss. It is uncertain as to how frequently this occurs, but it is probably on the order of 1 in 500 or 1 in 1000 injections. Even so, many of these patients can be treated satisfactorily with a significant improvement in vision. Cataracts, and less commonly, retinal detachments, intraocular hemorrhages, and even blindness can occur. Extraocular, subconjunctival, or even lid swelling or bruising commonly occurs, but this is of little or no visual consequence.

The shot itself is minimally uncomfortable and is done with topical and local anesthesia. Postoperatively, ten days of topical antibiotics are useful to reduce the rate of complications. Follow-up appointments are necessary to look for any potential complications and treat them accordingly. The patient usually returns within a few days of the intraocular injection, and then again in about two weeks and one to two months to judge the effects and to detect late complications of treatment if any. The benefits may be seen in a few days, weeks, months, or not at all.

There are new drug delivery systems on the horizon that may replace intraocular injections. For now, however, intraocular injection of steroids is often a very useful means of applying the steroid where it is most needed. Typically, this has little or no affect on the blood sugars of diabetics because the steroids are contained within the eye. As mentioned earlier, steroids have been present for many years and have long since gone through the FDA approval process. Unfortunately, however, they were not officially approved for intraocular injection, and though they are commonly used nationally and are a national standard of care, it is an “off-label” use. If you have additional questions or concerns, please feel free to discuss them with me.

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