Modified 360° retinopexy may avert retinal detachment in high-risk eyes

Creating a ‘second ora’ during vitrectomy for retained cataract fragments may reduce the need for additional surgical intervention.

A variation on 360° retinopexy performed during pars plana vitrectomy for retained cataract fragments may save the eye from further surgical intervention, according to a study.

Robert E. Morris

Correction of rhegmatogenous retinal detachment secondary to pars plana vitrectomy for retained cataract fragment, occurring in 4% to 36% of cases, represents a third surgical intervention for some patients. As well, late postoperative retinal detachment after surgery may cause poor visual outcome.

According to Robert E. Morris, MD, OSN Retina/Vitreous Board Member, prophylactic 360° retinopexy reduced the incidence of rhegmatogenous retinal detachment to 1.3% in 78 patients, compared with an average of 8.2% as reported in the literature.

“Prophylaxis benefits the patient and the eye that has suffered the complication of posterior cataract fragments — reducing by sixfold the chance that the patient must return to surgery yet a third time — because of retinal detachment,” Dr. Morris said in an interview with Ocular Surgery News.

“It is important to prevent retinal detachment as a complication of a vitrectomy that is itself performed to remedy a previous surgical complication. This is especially true in cataract patients who have very high expectations in the first place,” he said.

Retinopexy variation

According to Dr. Morris, encircling retinopexy has been under investigation for nearly 3 decades, with varying degrees of success. In large part, he said, the earlier forms of retinopexy failed because delivering encircling laser intervention via slit lamp was technically challenging.

However, the introduction of the indirect ophthalmoscope improves both safety and efficacy of laser intervention and should abate concerns over prophylactic retinopexy that may only be applicable to slit lamp delivery.

“Studies from the 1980s are still regularly cited as an argument against the concept of encircling prophylaxis, even though new forms of encirclement have subsequently been developed using the indirect ophthalmoscope,” Dr. Morris said.

In his interventional series, Dr. Morris performed a variation of retinopexy he refers to as “ora secunda cerclage” because it describes the intended outcome: “to produce, in effect, a ‘second ora,’ or ‘ora secunda,’ at approximately the equator, bonding the at-risk peripheral retina to the eye wall,” Dr. Morris said.

Failed focal laser prophylaxis due to new tear/rhegmatogenous retinal detachment in normal appearing retina elsewhere. (Reprinted with permission from Stephen F. Gordon.)	Slit lamp “fence” technique. Prophylaxis failure caused by a new tear anterior to encircling treatment, with rhegmatogenous retinal detachment extending through the laser fence into the central retina.
Completed ora secunda cerclage prophylaxis. The long posterior ciliary nerves at 9 o’clock and 3 o’clock meridians are spared to minimize impact on anterior segment innervation. Treatment extends to the ora serrata. Images: Gordon SF

The laser technique, developed by Dr. Morris and colleague C. Douglas Witherspoon, MD, and delivered through the indirect ophthalmoscope, has been shown previously to reduce fellow eye retinal detachment in patients with bilateral pseudophakia and a retinal detachment in one eye from about 21% to 1% after 3 years of follow-up. Dr. Morris said he is now preparing a report on 10-year data in these patients.

He has also used the technique in eyes with Marfan’s syndrome undergoing surgery, in cases of extreme myopia at high risk for retinal detachment, as well as in some forms of ocular trauma.

Retrospective case review

Dr. Morris and Jeffrey L. Shere, MD, recently reviewed 78 eyes of 78 patients presenting for vitrectomy to remove retained cataract fragments. Ora secunda cerclage was performed in all cases.

There was only one case of retinal detachment after vitrectomy, occurring less than 1 month after surgery. According to Dr. Morris, the detachment occurred before laser prophylaxis had attained full strength.

“This illustrates that no laser prevention is immediately effective, and it only becomes effective as the chorioretinal bond develops strength,” he said.

Because ora secunda cerclage or any laser prophylaxis is susceptible to early failure from retinal tears, intraoperative examination of peripheral retina at the conclusion of vitrectomy is important, and when necessary, a gas tamponade may be a useful intraoperative adjunct to achieve permanent closure of retinal defects, Dr. Morris said.

“In the one retinal detachment occurring in this study, the retinal defect was not felt to be associated with laser application, but rather to occur in spite of it,” he said.

The results of the study should only be taken as a proof of concept because despite the length of follow-up, data was collected in a retrospective fashion from a single center, Dr. Morris said.

He is currently developing a prospective, multicenter trial designed to answer whether ora secunda cerclage is a reasonable prophylaxis against retinal detachment in high-risk eyes. – by Bryan Bechtel

Reference:

• Morris RE, Shere JL, Witherspoon CD, et al. Intraoperative retinal detachment prophylaxis in vitrectomy for retained cataract fragments. J Cataract Refract Surg. 2009;35(3):491-495.

• Robert E. Morris, MD, can be reached at Retina Specialists of Alabama, 1201 11th Ave. S, #300, Birmingham, AL 35205; 205-933-2625; e-mail: rmorris@retinanetwork.com.