Risk of cataract formation after DSEK rises sharply after 50 years of age

Surgical trauma, postoperative steroid use and narrow angle may contribute to the development of cataract up to 3 years after corneal transplantation.

Marianne O. Price

Rates of cataract formation and extraction after Descemet’s stripping endothelial keratoplasty were markedly higher in patients older than 50 years than in younger patients, a study found.

Cataract surgery is a viable option for patients at risk for developing visually significant opacities after undergoing DSEK, the authors said.

People younger than 50 years who are phakic reap more benefit by keeping their natural lens, because they can enjoy some accommodation for another few years, Marianne O. Price, PhD, the corresponding author, told Ocular Surgery News. “People who are older than 50 are losing accommodation, so there is less of a benefit to them to leave the lens in,” she said.

Patients need to be counseled about the potential risks of cataract formation after DSEK and the options of undergoing DSEK and cataract surgery concurrently or successively, Dr. Price and colleagues wrote.

“It is in the best interest of the patient, and it is important to have a discussion with the patient and explain all of the options,” Dr. Price said.

Results were published in the British Journal of Ophthalmology.

Patients, procedures

The retrospective study included 60 phakic eyes that underwent primary DSEK; only first-treated eyes in patients treated bilaterally were included. Median patient age was 52 years. Median graft diameter was 8.5 mm (range: 8 mm to 9 mm).

Patients received topical prednisolone acetate 1% for 7 or 8 months after corneal transplantation to forestall graft rejection. Some patients switched to loteprednol or fluorometholone to minimize IOP elevation.

The median follow-up interval after DSEK was 32 months.

Study results showed that 22 eyes (37%) underwent cataract surgery after DSEK. Mean patient age at the time of cataract surgery was 57 years.

Grafts remained clear during the median follow-up period of 18 months after cataract surgery.

Six eyes underwent regrafting surgery. Cataract surgery and DSEK were performed concurrently in four eyes and consecutively in two eyes.

Kaplan-Meier analysis showed that the probability of undergoing cataract surgery after DSEK was 20% within 1 year, 31% within 2 years and 40% within 3 years in this cohort.

Among 20 patients no older than 50 years at the time of DSEK, the probability of undergoing cataract surgery after DSEK was 0% after 1 year and 7% after 3 years.

Among 40 patients older than age 50 years, the probability of having cataract surgery after DSEK was 31% at 1 year and 55% at 3 years. The between-age difference in probability was statistically significant (P = .0005).

The reported rate of cataracts is 3% to 4% among the overall U.S. population aged 43 to 64 years. The rate of cataracts reported in the study for that age range was 21 of 50 eyes (42%) that underwent DSEK, the authors said.

Risks, complications

The results showed no association between graft size and cataract formation or complications during cataract surgery.

“We didn’t have any complications associated with the cataract extraction in these eyes, even though about half of them had a 9-mm graft,” Dr. Price said. “Even with having a large graft in there, there wasn’t any problem with extracting the cataracts.”

Investigators said that any decrease in endothelial cell density after cataract surgery was statistically insignificant.

“Endothelial cell counts have an inherently high standard deviation, so it takes a certain amount to be able to detect a statistically significant difference,” Dr. Price said. “It’s good that we were not able to detect a difference, which means that if there was a difference, it was small.”

Cataract formation after DSEK can be attributed to multiple factors, such as surgical trauma, use of postoperative steroids and narrow angle, Dr. Price said.

She suggested that lens removal be considered for some patients with narrow angle.

“A DSEK graft actually adds some tissue to the back of the cornea, so you don’t want to risk any graft-iris touch,” she said. “In someone who has a very narrow angle, it may be just as well to go ahead and take the lens out.” – by Matt Hasson

Reference:

• Price MO, Price DA, Fairchild KM, Price FW Jr. Rate and risk facrtors for cataract formation and extraction after Descemet stripping endothelial keratoplasty. Br J Ophthalmol. 2010;94(11):1468-1471.

• Marianne O. Price, PhD, can be reached at Cornea Research Foundation of America, 9002 N. Meridian St., Suite 212, Indianapolis, IN 46260; 317-814-2990; e-mail: marianneprice@cornea.org.
• Disclosure: Dr. Price has no financial disclosures.

This retrospective study by Dr. Marianne Price and colleagues reports on the largest series (n = 60) of phakic DSEK cases to date and looks at the risk factors for development of cataracts after surgery. The finding of a lower risk for patients younger than age 50 is clinically relevant, especially because many DSEK surgeons advocate lens extraction for every DSEK case, regardless of lens clarity. If the surgery and postoperative steroid use are the same for both old and young patients, then why should there be a difference in the rate of cataract formation?

We have observed that the corneal changes in young Fuchs’ dystrophy patients who require surgery are often morphologically different than those found in older eyes. The central cornea is often more severely involved, often with bullae and a confluence of guttata, while the midperipheral cornea can at the same time look pristine with no guttata. In older eyes, the guttata are usually more generally distributed. Are the lenses of young Fuchs’ eyes also different and more resistant to cataract formation or is it just a matter of time?

The study should give pause to surgeons considering automatic lens removal in young Fuchs’ eyes (especially those that still have some accommodation) and likely will enjoy years without cataract formation.

– Mark A. Terry, MD
Director Corneal Services, Devers Eye Institute Professor, Oregon Health Sciences University
Portland, Ore.
Disclosure: Dr. Terry receives a small royalty from Bausch + Lomb for the instruments he designed for endothelial keratoplasty surgery.