Disclose retina risks of of intraocular refractive surgery

New Orleans-Patients undergoing intraocular refractive surgery with either refractive lens exchange (RLE) or phakic intraocular lens implantation need to be informed that there is a lifelong risk of retinal detachment, said Kirk H. Packo, MD, at the refractive surgery subspecialty day at the American Academy of Ophthalmology annual meeting.

Dr. Packo, a retinal specialist and professor and chairman, department of ophthalmology, Rush University Medical Center, Chicago, also recommended that in taking into account the retinal risks, refractive surgeons implant an acrylic IOL with a large diameter optic, suture the wound, create a large capsular opening, and be careful to avoid breaking the posterior capsule.

"Walk the line of performing the correct surgery for the patient while making any future retinal surgery easier to perform," Dr. Packo said. "And always remember primum non nocere. This is elective surgery, so don't harm a healthy eye."

One issue is the effect of YAG capsulotomy. Results of a landmark paper published more than a decade ago indicate that the incidence of retinal detachment is increased almost fourfold by YAG capsulotomy, and there are no data to show that varying the technique with respect to size of the capsular opening or energy delivered decreases the risk of retinal detachment.

"Despite new techniques for cataract removal and new IOL materials, we can expect this younger population undergoing RLE will eventually develop posterior capsule opacification requiring YAG capsulotomy," Dr. Packo said.

Other factors also exist to compound the risk for retinal detachment after RLE. First, lens removal itself causes biochemical alterations of the vitreous that can increase the detachment risk.

Available data indicate younger individuals are at greater risk than the elderly for retinal detachment after lens removal, and RLE is by its nature performed in younger patients.

In addition, patients with RLE also commonly have high myopia, which itself is associated with an increased baseline retinal detachment risk.

Natural history information indicates that 0.68% of eyes with ≥10 D of myopia develop rhegmatogenous retinal detachment (RRD) annually. Various papers have examined the risk of RRD after RLE with varying results.

In a study by Colin et al., following 52 eyes with ≥10 D of myopia for 7 years, 16% went on to develop posterior vitreous detachment, 61% required YAG capsulotomy, and 19% received additional laser treatment for retinal tears. RRD occurred in 2% of eyes at 4 years and in 8% at 7 years.

A study by Fernandez-Vega et al. that featured a mean follow-up of 4.8 years reported a retinal detachment rate of 2.1%, while a meta-analysis undertaken by Richard Packard, MD, of Eugene, OR, considering 13 papers and a total of about 1,800 eyes found a 1.5% rate of retinal detachment after a mean follow-up of 37 months.

"The varying risks reported in these papers partially reflect differences in follow-up periods, but patients continue to live beyond the end of the study," Dr. Packo said. "We need to know if the risk continues to increase with time. There is a lack of data on retinal detachment risk beyond 5 years after surgery, but recognize over half of retinal detachment patients do not recover vision better than 20/40. Do not downplay the risk."

There are also other retinal risks to consider in patients undergoing RLE, including cystoid macular edema and endophthalmitis. Currently, there are no data to suggest those complications are more likely in younger eyes undergoing RLE compared with the elderly cataract population.

"However, the risk still exists and patients need to be fully informed of the potential for these vision-threatening events," Dr. Packo said.

Phakic IOL risk low, not absent Retinal complications should be less likely after phakic IOL implantation relative to RLE since the lens and posterior capsule are not violated, but studies show they still can occur.

In one large series of more than 1,200 cases, Murat Oncel, MD, reported a retinal detachment incidence of 0.57%, while a rate of 4.8% was reported by Ruiz-Moreno et al. Also, Rizzo and colleagues described two cases of giant retinal tears that were difficult to fix.