Foldable IOLs found safe in eyes with uveitis

Study of various biomaterials reveals mostly comparable results.

Issue: July 1, 2000

BIRMINGHAM, United Kingdom — An evaluation of seven different foldable IOLs that were implanted in patients with various forms of uveitis found that the use of these lenses is safe. However, incidents of giant cells, scratch marks and, in a few cases, the need for laser capsulotomy underscore the fact that the optimal biomaterial has yet to be discovered.

“It’s safe to put any of these foldable IOLs in eyes of patients with uveitis,” said co-author Philip I. Murray, PhD, FRCOphth, a professor of ophthalmology at the University of Birmingham. However, “we found that the acrylic and hydrogel lenses were most susceptible to scratch marks, although this did not impact vision.”

The prospective study involved 49 consecutive patients (60 eyes) with four types of uveitis: anterior (20 eyes), posterior (one eye), panuveitis (37 eyes) and intermediate (two eyes). There were 26 males and 23 females, ages 9 to 83 years (mean of 48 years). All patients underwent phacoemulsification with foldable posterior chamber IOL implantation, and all eyes were free of active inflammation at the time of surgery.

Of the 60 lenses implanted, 30 were acrylic (29 Alcon [Fort Worth, Texas] MA60BM; one IOLTech [La Rochelle, France] Haptibag), 17 silicone (12 Allergan [Irvine, Calif.] SI40NB; three Allergan SI30NB; two Pharmacia [Peapack, N.J.] 912) and 13 hydrogel (11 Bausch & Lomb [Claremont, Calif.] H60M; two Optical Radiation Corporation U940 A, a mixed hydrogel). According to Bausch & Lomb, the H60M IOL has not been launched in the United States even though it has been approved for use in the United States.

Impressive visual acuity

The study, which was recently published in Ophthalmology, had a follow-up ranging from 1 month to 33 months, with a mean just over 17 months. At final follow-up, 93.3% (n = 56) of eyes had an improvement in visual acuity compared with preoperative levels. In the hydrogel group, 100% (13) showed an improvement, followed by 93.3% (28) in the acrylic and 88.2% (15) in the silicone group. An improvement equal to or greater than four Snellen lines also was achieved in 56.6% (34) of eyes (median group range of 53.8% to 58.8%) and equal or better than 20/30 in 75% (45) of eyes (70% to 82.3%).

In addition, the study found visually insignificant scratch marks produced by the lens-introducing forceps in 40% (24) of eyes, most commonly on the acrylic and hydrogel optics. Specifically, 61.5% (eight) of the hydrogel and 43.3% (13) of the acrylic had these scratch marks, compared with only 17.6% (three) of the silicone. Nonetheless, this difference between the three biomaterials was not significant. Although scratch marks could have resulted from a roughening of the surface of the lens when introducing forceps, they are well documented in a published paper from a few years ago.” Such a finding “in a way is unimportant because the scratch marks are not in the visual axis,” he said.

The study revealed a slightly statistical increase in anterior capsular phimosis (ACP) in the hydrogel group. “I found this surprising,” said Dr. Murray, who could not speculate on the reason. In total, ACP was observed in 35% (21) of eyes, with hydrogel accounting for 61.5% (eight) of the cases.

There was no statistical association between implant biomaterial and incidence of giant cells visualized on the optic. However, “during the first year of follow-up, there were more giant cells seen on the acrylic and silicone lenses compared with the hydrogel,” Dr. Murray said. Pigment cells on the optic at final follow-up also showed no statistical association with implant biomaterial. “Pigment cells were seen to a variable extent in 93.3% (56) of eyes,” he said.

Only 11.6% (seven) of eyes developed posterior synechiae: four acrylic, one silicone and two hydrogel. “Five of these cases were associated with giant cells on the optic,” Dr. Murray said.

YAG capsulotomy rare

Previous studies indicate that implant biomaterial appears to have some influence on the rate of posterior capsule opacification (PCO), with PMMA exhibiting the highest rate, less with silicone and minimal with acrylic. However, even though PCO occurred in 81.7% (49) of eyes in the current study, only 8.3% (five) of eyes required Nd:YAG capsulotomy: three acrylic, one silicone and one hydrogel. “In normal eyes, the Alcon MA60BM [hydrophilic], also known as the AcrySof, has previously been shown to minimize the incidence of PCO, but this may not hold true for uveitis eyes,” Dr. Murray said.

When Dr. Murray speaks to colleagues throughout the United Kingdom and in the International Uveitis Study Group, he discovers that “many of them are still opening up the wound and implanting a one-piece PMMA lens in these patients. What we’re trying to say is that you don’t have to open up the wound. You can insert a foldable IOL.” Moreover, the surgery “is less traumatic, requires a smaller wound, there are no sutures and visual recovery is quicker.”

Finally, “Although the study is about IOL material, the preoperative management and the postoperative management are probably the most important factors in predicting outcomes,” Dr. Murray said. “It really doesn’t matter what type of lens you use.”

For Your Information:

Philip I. Murray, PhD, FRCOphth, can be reached at Academic Unit of Ophthalmology, Division of Immunity and Infection, Birmingham and Midland Eye Centre, City Hospital NHS Trust, Birmingham B18 7QU, United Kingdom; (44) 121-507-6851; fax: (44) 121-507-6853; e-mail: p.i.murray@bham.ac.uk. Dr. Murray has no direct financial interest in any of the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

Alcon can be reached at 6201 South Freeway, Fort Worth, TX 76134; (800) 862-5266; fax: (817) 241-0677.

Allergan Inc. can be reached at 2525 Dupont Drive, Irvine, CA 92612; (800) 366-6554; fax: (800) 752-7006.

Bausch & Lomb Surgical can be reached at 555 W. Arrow Highway, Claremont, CA 91711; (800) 423-1871; fax: (909) 399-1525.

IOLTech Laboratories can be reached at Rue de la Désirée, 17000 La Rochelle, France; (33) 5-46-44-85-50; fax: (33) 5-46-44-85-60.

Pharmacia Corporation can be reached at 100 Route 206 N, Peapack, NJ 07977; (908) 901-8000; fax: (908) 901-8379.

Reference:

Rauz S, Stavrou P, Murray PI. Evaluation of foldable intraocular lenses in patients with uveitis. Ophthalmology. 2000;107:909-919.