November 2018

COVER FEATURE

Treatment plan for corneal irregularities before cataract surgery


by Vanessa Caceres EyeWorld Contributing Writer


Slit lamp photograph of obvious ABMD, with a photograph of negative fluorescein staining
superimposed
Source: Joshua Teichman, MD


 

Assess carefully, consider potential postop visual outcome

Better management of ocular surface lesions before cataract surgery can help ensure better postop outcomes. However, surgeons must first decide which lesions need to be managed and which ones can be left alone.
A group of ophthalmologists recently shared with EyeWorld how they typically approach common ocular surface lesions and degenerations, such as pterygia, anterior basement membrane dystrophy (ABMD), and Salzmann’s nodules, before cataract surgery.

Managing pterygia

A pterygium in a patient who needs cataract surgery deserves special attention, said Joshua Teichman, MD, MPH, Department of Ophthalmology and Vision Sciences, Trillium Health Partners, University of Toronto, Canada. “I am more aggressive in removing a pterygium prior to cataract surgery, especially in patients who are hoping for spectacle independence after surgery,” he said.
Other surgeons concurred. “The pterygium should be removed if it is encroaching on the visual axis and/or the patient wants it removed,” said David Goldman, MD, Goldman Eye, Palm Beach Gardens, Florida. “In either of those cases, it should be removed prior to cataract surgery, with time for the cornea to heal and normalize.”
Dr. Teichman also will consider the presence of topographic changes, such as localized flattening, that may occur with smaller pterygia. This makes him more likely to remove the pterygium prior to surgery. He analyzes the topography, looking for asymmetry between the eyes.
“If the affected eye is substantially different than the contralateral eye, that should alert the examiner to the possibility of pterygium-induced corneal changes,” Dr. Teichman said.
Jeremy Kieval, MD, Lexington Eye Associates, Lexington, Massachusetts, said if there is a smaller pterygium, it can be left alone. However, he will let patients know that the refractive outcome can be more unpredictable and that the patient may have more significant postop astigmatism. “For the most part, topography is the most important of the criteria I use, looking for the typical flattening of the cornea where the pterygium is present and the corresponding steepening in the opposite meridian,” he said.
Another important consideration is the severity of the pterygium, said David Hardten, MD, Minnesota Eye Consultants, Minneapolis. When he removes a pterygium in a patient with milder cataract that isn’t the main vision issue, he will remove the pterygium and follow the patient until the cataract is visually significant. “In some eyes with severe pterygium with corneal scarring and irregular astigmatism that remains after the pterygium surgery, it may be a three-step or five-step procedure involving the pterygium surgery, followed by a PTK 6–12 months later, followed by the cataract surgery, then a YAG and another PTK,” he said. “In a patient with a longstanding pterygium that now has very dense cataract, I will sometimes remove the cataract, and the patient understands that his or her vision will still be slightly impaired from the pterygium as it had been before the cataract developed.”
Once a pterygium is removed, Dr. Teichman generally repeats the topography and biometry after 3 months. “There is evidence to suggest that the larger the pterygium, the more induced astigmatism and the longer the cornea will take to normalize. If I am ever unsure, I repeat the measurements and proceed once the measurements are stable,” he said.

ABMD and Salzmann’s nodules

The key step with ABMD is to spot it in the first place.
“I think most of us can look right through the cornea and start examining the cataract we will need to address, but if you stop and look closely, you can sometimes see subtle ABMD,” Dr. Kieval said. The use of retroillumination or a red-free filter can help find subtle disease, he said. Topography is also helpful.
“Subtle irregularities may be present on topography, and one should always inspect the rings image,” Dr. Teichman said. The use of negative fluorescein staining can be used, and surgeons can look out for a Shahinian’s sign—a scalloped line of tear film thinning—across the top third of the cornea, he explained.
A patient may benefit from a superficial keratectomy before cataract surgery if there is any irregularity in the central to mid-peripheral cornea, followed by topography and biometry 3 months later, Dr. Teichman said.
“Similar to the pterygium situation, it isn’t rare to need a YAG and another PTK for maximum vision recovery,” Dr. Hardten said. If it has been fairly stationary and the cataract is the main issue, he prefers to perform cataract surgery. “A PTK could be done later if their vision needs require,” he said.
“ABMD or Salzmann’s nodules do not always have to be removed prior to or during cataract surgery,” Dr. Goldman said. “If it is going to be addressed, it should be treated prior to cataract surgery. While I do corneal scrapings for ABMD in the office, for Salzmann’s nodules I will perform surgery in the OR. In the majority of these cases, you can undermine an edge of the nodule and peel them off. … I was trained that if you scrape the epithelium over the area of the nodule and start to use a blade to tease at the edge of the lesion, you can grasp the edge and peel the nodule off of the cornea.”
Dr. Teichman shared another pearl for Salzmann’s nodules. “Another important factor in treating them is identifying the underlying etiology. Often overlooked is chronic low-level inflammation from meibomian gland disease and dry eye. Simply removing the nodules may result in recurrence unless the underlying pathology is addressed,” he said.
Yet again, surgeons need to think about a patient’s visual goals and the size of the lesion. If the goal is to see better with glasses and it’s something small, Dr. Goldman will leave it alone.
Dr. Kieval added another circumstance when lesions may not need treatment. “I think it is reasonable, and more likely advisable, to leave well enough alone if the patient has poor visual potential due to other ophthalmic or neurological disease,” he said.

Toric lenses?

A patient with an ocular surface lesion is usually not the best fit for a toric IOL.
“I will not consider a toric lens in a patient undergoing cataract surgery who has a pterygium. In those cases, I’ll recommend pterygium surgery first, then determine if a toric lens is truly needed,” Dr. Goldman said.
“I have seen many patients with toric IOLs that had refractive surprises because of ABMD or a pterygium that wasn’t addressed prior to surgery, and I have seen patients who have those irregularities removed after phaco. They have refractive shifts that are very upsetting,” Dr. Kieval said. For this reason, he thinks it is crucial to see what the unadulterated cornea looks like and remove any deposits, degenerations, or lesions to maximize the potential postop outcome.

Surgical pearls

To help better manage pterygia, ABMD, or Salzmann’s nodules, the surgeons interviewed shared a few pearls.
1. Use hydroxypropyl methylcellulose. “This is useful to coat the cornea, improving visualization, and also to protect the epithelium,” Dr. Hardten said.
2. Consider dissection of the underlying Tenon’s for pterygium. Dr. Kieval recommends this along with placement of a conjunctival autograft and the use of mitomycin-C (MMC) on recurrent lesions—but not on primary pterygium. Dr. Teichman also uses MMC on aggressive recurrences that have occurred in the context of a previous conjunctival autograft.
3. Use a Tooke Corneal Knife. “I find this allows one to remove lesions at a plane that does not proceed too deeply yet allows the underlying scar to be removed well,” Dr. Teichman said.
4. Find your best fibrin glue choice. “I use conjunctival autograft in all cases and use fibrin glue to secure the graft,” Dr. Teichman said. “There is a study that demonstrated Tisseel [Baxter, Deerfield, Illinois] is likely a superior adhesive for pterygium surgery, and I have found that to be the case in my hands as well,” he said.
5. Be patient after treating a lesion. “Sometimes it can take months to achieve a stable state that can be reliably used for cataract surgery,” Dr. Kieval said.

Editors’ note: The physicians have no financial interests related to their comments.

Contact information

Goldman: david@goldmaneye.com
Hardten: drhardten@mneye.com
Kieval: jkieval@lexeye.com
Teichman: josh.teichman@gmail.com

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