Tips to diagnose corneal lumps and bumps

Tips to diagnose corneal lumps and bumps

 by Ellen Stodola EyeWorld Senior Staff Writer

Physicians share some of their methods to diagnose and address corneal lumps and bumps prior to cataract surgery

When performing cataract surgery, it’s important to diagnose and treat any other conditions prior to

performing surgery to ensure the best outcome. Sumit “Sam” Garg, MD, vice chair of clinical oph- thalmology and medical director, Gavin Herbert Eye Institute, Irvine, California, Lawrence Hirst, MD, the Australian Pterygium Centre, Brisbane, Australia, and Christo- pher Rapuano, MD, director of the cornea service, Wills Eye Hospital, Philadelphia, discussed some possi- ble corneal lumps and bumps that patients may present with, when to treat these conditions, and what technologies they use.

Best way to diagnose, treat “There’s no simple answer of how to diagnose lumps and bumps on the cornea,” Dr. Hirst said. “But the cornea has a limited range of condi- tions that occur on the surface.”

Salzmann’s nodules, he said, are a common condition and degenera- tive change that can occur in older patients. Generally, these patients may be asymptomatic, he said, and the nodules often occur in the pe- riphery. If they start to become more central and affect the vision, they can cause irregular astigmatism and visual distortion. If the Salzmann’s nodules are not in the central area, you don’t need to do anything with them, Dr. Hirst said. He recom- mends removal if the patient clearly has some visual changes that can be related directly to the Salzmann’s nodules. The simplest way to re- move these is to strip them off the cornea, he said.

Dr. Hirst also discussed epithe- lial basement membrane dystrophy (EBMD), which he said does not usually cause a discernable change in the surface contour of the eye in the deeper levels of the epithelium, but he said that occasionally it can be a precursor of erosive episodes on the surface of the eye and may cause some visual disturbance when in the visual axis.

He added that phototherapeu- tic keratectomy (PTK) is an option for everything except for dysplastic conditions. However, he said that he finds that Salzmann’s nodules are easily removed by mechanical means.

Dr. Garg said that he relies heavily on slit lamp exam, especially with the use of retro-illumination. He added that topography and to- mography are also vital. “Depending on the severity, I start with aggres- sive lubrication and offer superficial keratectomy (at the slit lamp),” he said. “I find that superficial kera- tectomy is generally effective at improving the ocular surface.”

Dr. Rapuano stressed the im- portance of a good slit lamp exam. He added that corneal topography is also key, and you want to have a normal corneal topography map. It’s important to look at not just the col- ors on the corneal topography map, he said, but also the rings. If you just look at the colors, this can blend in some of the abnormalities and may not show the whole picture.

Each diagnosis will be treated somewhat differently, depending on whether the physician is dealing with EBMD, Salzmann’s nodules, or another condition.

There are many people with EBMD, Dr. Rapuano said. It’s a common condition, particularly as patients get older. If it’s not causing an irregularity in the tear film or on the topography, you could probably just follow it along and not treat

it, he said. However, Dr. Rapuano noted that if it is causing negative staining, which can be seen on the slit lamp with fluorescein dye, then it’s probably affecting the vision and should be treated.

Dr. Rapuano recommended a debridement for significant EBMD. He added that if there’s significant basement membrane left once you take the epithelium off, you can do diamond burr polishing. PTK may be used in cases where there is also stromal haze or scarring, and he added that he uses mitomycin C at the time of PTK to reduce the risk of scarring.

In the case of Salzmann’s nodules, those can be mild as well, he said. These can be left alone if they’re in the periphery but should be treated if they seem to be affect the visual axis. Dr. Rapuano added that distortion of rings will show up as astigmatism, and he cautioned the importance of recognizing this in the overall treatment plan. If a physician sees this and doesn’t know what’s going on in cornea, they may treat the astigmatism, he said, and they could use a toric lens or other correction option. However, if the nodule is later treated, this would leave the patient with the initial astigmatism fix. It’s important to know whether you’re dealing with regular astigmatism or astigmatism that is secondary to something else, he said.

Dr. Rapuano will treat Salzmann’s nodules with excimer laser PTK with mitomycin C.

 

Pterygium—remove or leave it?

Many people have a pterygium, and Dr. Rapuano said that if it is small, peripheral, hasn’t changed, and isn’t causing a problem for the patient, then cataract surgery can be done, and the pterygium can be dealt with later. However, if the pterygium is causing a lot of astigmatism or if the physician is considering the use of a toric lens, then it may be a good idea to treat the pterygium prior to cataract surgery.

If the pterygium is inducing astigmatism and the patient is interested in decreasing that astig- matism/spectacle independence, Dr. Garg prefers to stage the pterygium and cataract surgeries. “I often wait several months in between the two,” he said, until it’s possible to get stable, repeatable, and reliable measurements. pterygia because there’s a high risk of recurrence,” he said. It’s estimated that recurrence is between 5% to 15%, he added. However, Dr. Hirst will remove pterygium more fre- quently and even if they are small, as he has found that his preferred re- moval technique has a close to zero chance for recurrence (1/2500) and a near normal appearance to the eye.

Currently, Dr. Hirst’s whole practice addresses pterygium only. “Most people are wary of removing “In the context of cataract and refractive surgery, I believe signif- icant pterygia must be removed first,” he said. “And I wouldn’t undertake calculations for cataract and refractive procedures for at least

3 or 4 months after removal of the pterygium.”

 

IOL calculations

It’s important to wait an adequate amount of time after treating the corneal surface to ensure accuracy of calculations. Dr. Rapuano said that he generally waits at least 6 weeks as that is usually how long it takes to get stable, reproducible K readings, but he also noted that this can de- pend on the patient. Some patients may heal slower than that, he said.

“Depending on the extent of the pathology and the desired refrac- tive outcome, I will wait anywhere between 1 to 2 months,” Dr. Garg said. “I like to wait for the surface to improve and for reliable (and repeat- able) measurements.”

 

Helpful technologies

Dr. Garg uses both topography and tomography for these patients. “It is important to determine how much irregular astigmatism is present and whether the pathology is responsible for it,” he added. “This helps make the decision on whether to pro-

ceed with removal.” Dr. Garg uses several topographers, including the OPD III (Nidek, Fremont, California) and iTrace (Tracey Technologies, Houston). He also routinely uses the Pentacam (Oculus, Arlington, Washington).

Dr. Garg said he uses ORA (Al- con, Fort Worth, Texas) and noted that the accuracy really depends on how “clean” the removal is. “If there is a smooth corneal surface after removal, I find that the aberrometry is accurate,” he said.

Dr. Rapuano generally uses the slit lamp and corneal topography when deciding whether to remove a corneal lump or bump. He said he does not use intraoperative aberrom- etry and cautioned to make sure that the IOL calculations are correct be- cause some of these lumps or bumps may distort the aberrometry. EW

Editors’ note: Drs. Garg, Hirst, and Rapuano have no financial interests related to their comments.

 

Contact information Garg: gargs@uci.edu

Hirst: lawrie@tapc.net.au

Rapuano: cjrapuano@willseye.org

A moderately large pterygium can be seen nasally in this right eye. An iron line (Stocker line) can be seen near the leading edge, indicating chronicity.

Map and dot changes of epithelial basement membrane dystrophy (EBMD) are apparent centrally, which can cause irregular astigmatism.

Several small midperipheral Salzmann’s nodules are noted. While not involving the visual axis, they often cause irregular astigmatism and affect vision and keratometry readings.

Moderate central map changes with subepithelial fibrosis are apparent centrally in this eye with epithelial basement membrane dystrophy (EBMD).