Cover Feature: Retina co-morbidity for the anterior segment surgeon
January 2012

by Michelle Dalton
EyeWorld Contributing Editor

Family history and refractive error are but two risk factors that increase the risk of a retinal detachment. Here, retinal experts discuss when—or if—to treat tears and holes

Retinal detachments (RD) are more likely to occur in patients with higher myopia, and the risk increases if there’s a family history of RD or if a patient’s fellow eye has had one. In these patients, retinal specialists recommend extra vigilance when looking at the peripheral retina during normal pre-op exams before cataract surgery. Refractive lens exchange patients undergoing an IOL exchange are also at a higher risk. Complicated cataract surgery—cases involving vitreous loss or capsular rupture—also puts the patient at an increased risk of developing an RD. Another patient group at risk is people who have undergone refractive surgery and no longer consider themselves myopic. Anatomically, those eyes are still longer and at risk, retina specialists said.

Sometimes, regardless of how meticulous the surgeon is, an RD may still occur.

Educating the patient about the signs and symptoms of RD can go a long way toward catching a tear before it becomes a full-blown detachment, experts said.

“If patients are aware of the signs and symptoms of RD, they’ll be less likely to ignore floaters,” said David S. Boyer, M.D., clinical professor of ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles.

“Wound integrity is crucial as well. If someone has a clear corneal cataract surgery and you see vitreous in the wound, that’s a risk factor for retinal tears,” said Andrew A. Moshfeghi, M.D., assistant professor of ophthalmology, and medical director, Bascom Palmer Eye Institute, Palm Beach Gardens, Fla.

Likewise, if patients do have increased risk factors, silicone IOLs and multifocal IOLs can make treatment of a detachment more difficult because visualization is hampered, said Amani Fawzi, M.D., associate professor of ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago.

Lastly, a younger patient age can also increase the risk, said Jay M. Stewart, M.D., associate professor of ophthalmology, School of Medicine, University of California, San Francisco. “A study by Ripandelli and co-workers published in Ophthalmology in 2007 found that younger patients had a higher likelihood of developing a retinal detachment following cataract surgery, and most post-operative posterior vitreous detachments occurred in young patients.”¹

Patients who seek treatment “too late in the course of the disease because they’re unfamiliar with the symptoms” are most likely to have poor visual outcomes as well, Dr. Stewart said. “Once central vision has been impacted by an RD, the outcomes are not as good.”

Dr. Fawzi agreed, noting anterior segment surgeons should educate patients to pay attention to any floaters, flashing light, or curtain/veil coming across their visual field in the first few weeks after cataract surgery.

What to treat and when

Any suspicious lesion in the retinal periphery bears examination and investigation, Dr. Stewart said. Retinal tears should be treated before the patient undergoes cataract surgery, and Dr. Boyer recommended allowing the tear to heal for “several weeks” before any other surgery.

“Tears put patients at a marked increased risk of developing a detachment. It takes about 17–18 days to get an 80% bond if you’re using lasers to treat,” he said.

Most horseshoe retinal tears need to be treated immediately, Dr. Moshfeghi said, unless there’s adequate pre-existing retinal scarring.

Drs. Fawzi and Stewart are slightly more cautious, noting they’ll follow rather than treat asymptomatic patients. “In most cases, the incidental finding of a hole in an asymptomatic patient with no strong family history or no underlying medical conditions (for example, Marfan’s) probably doesn’t need treatment,” Dr. Stewart said.

Everyone agreed, however, that tears are more worrisome than full-on holes, regardless of geography.

“People can go their entire life with an atrophic round hole and never need treatment,” Dr. Moshfeghi said.

What about lattice?

Lattice—one of the most common peripheral retina changes—may or may not cause an RD, and hence its treatment is controversial.

“Lattice is commonly found in eyes that harbor RD, but may not be a causative agent. And 10–15% of the normal population has lattice,” Dr. Moshfeghi said.

Lattice puts a patient at a “slightly greater risk” for RD, Dr. Boyer said. Lattice is autosomal dominant, with a variable degree of expressivity. “About one-third of all RDs will have a patch of lattice in it, and many times—about 18-20% of the time—lattice will have holes in it,” he said.

For Dr. Stewart, the decision point on treatment is multifactorial—if the patient has lattice degeneration and has had a posterior vitreous detachment, “then the patient has a lower risk of getting a detachment from the cataract surgery. If there’s lattice but no PVD, then there’s greater concern,” he said. If biomicroscopy doesn’t help clarify if there’s been a PVD, he recommended using B-scan ultrasound.

Treatment strategies

Three main treatments—scleral buckle, pneumatic retinopexy, and vitrectomy (with or without accompanying buckle)—remain the standard of care in treating a full-blown detachment.

“Which of the three procedures is used to correct the problem depends on where the pathology is,” Dr. Boyer said. “Most retinal specialists lean toward doing a vitrectomy in a pseudophakic patient.”

Studies in Europe show pseudophakes do better after vitrectomy and phakics do better after scleral buckling procedures, Dr. Stewart said. “There’s not a lot of extra benefit to adding a buckle to the vitrectomy,” he said. Pneumatic is not as successful in pseudophakes simply because of the increased difficulty in getting the full periphery in that patient group, making it easier to miss small tears.

“If you don’t know where the tears are, you can’t treat them. So it’s possible to get secondary tears after pneumatic,” he said.

Dr. Moshfeghi said he’s not likely to perform vitrectomy in a phakic patient.

“First, you’re likely to create a worse cataract with a vitrectomy,” he said. “Primary scleral buckle is the historical and still practiced way to fix it.” Additionally, scleral buckle generally does not make the cataract worse, nor will it “guarantee a cataract will form earlier, unlike a vitrectomy.”

Scleral buckles change the length of the eye, which in a phakic patient is not terribly crucial, as the subsequent IOL calculations will take that into account. In a pseudophake, however, “scleral buckle can render the IOL almost worthless as buckles can change refraction by as much as 2 or 3 D,” Dr. Moshfeghi said.

Unfortunately, “a lot of fellows are graduating now without learning how to perform scleral buckles, so it may be a dying art,” Dr. Fawzi said. “I personally think there is a role for it in patients who are young, myopic, who are phakic, and don’t present with PVD. If we do a vitrectomy on them, we’re guaranteeing them a cataract off the bat.”

Because the technology in both phaco machines and IOLs has become so sophisticated, more and more retinal specialists are performing straight vitrectomy and discounting the potential for worsening the cataract in phakic patients. Post-phaco, retina specialists suggest cataract surgeons encourage patients to come in if any sign or symptom of a potential tear or detachment is noticed.

“The more patients are aware, the more likely they’ll come in if they start noticing an increase in floaters,” Dr. Stewart said.

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References

1. Ripandelli G, Coppe AM, Parisi V, et al. Posterior vitreous detachment and retinal detachment after cataract surgery. Ophthalmology. 2007;114(4):692-7. Epub 2007 Jan 17.

Editors’ note

The doctors interviewed have no financial interests related to this article.

Contact information

Boyer: vitdoc@aol.com
Moshfeghi: amoshfeghi@med.miami.edu
Stewart: stewartj@vision.ucsf.edu