Allergan Medical Research Articles

Discoloration of a Silicone Intraocular Lens 6 Weeks After Surgery-Reply

In Reply. —The communication from Dr Watt is extremely timely and significant; he must be congratulated on his clinical finding of a discolored IOL 6 weeks after surgery. Dr Watt's report is also significant because it now demonstrates that the behavior of silicone as an IOL material in the human eye is not isolated to the two manufacturers originally reported by me in theArchives, but also involves another major manufacturer of IOLs. In a recent Ocular Surgery News teleconference on discolored IOLs, Patricia Knight, PhD, of Allergan Medical Optics, Irvine, Calif, confirmed that there were reports of 1% hazing or discoloring of some IOLs in early clinical studies and 0.7% discoloration in later studies. I believe that some IOLs can discolor very early after implantation. The discoloration of the IOL occurring within 6 weeks of implantation does not surprise me, because a retrospective examination

Discoloration of a Silicone Intraocular Lens 6 Weeks After Surgery-Reply

In Reply. —This letter is in response to Dr Watt's letter concerning discoloration of an IOL model SI-18NGB manufactured by Allergan Medical Optics (AMO), Irvine, Calif. We appreciate the opportunity to address Dr Watt's concerns and will be sending a clinical researcher to observe this lens firsthand. In the meantime, we have consulted the manufacturing records of this IOL and found that 34 other lenses from the same batch have been implanted with no report of discoloration. Dr Watt's description of a centrally located discoloration appears similar to our observations made during Food and Drug Administration core studies in 1987. Several investigators reported that under slit-lamp examination, eight subjects (1.6%) in the cohort were found to have a slight haze in the center of their SI-18B implant. However, all three investigators believed this haze to be clinically insignificant and noted no visual disturbance. In addition, all three investigators noted that

Comments on Silicone Intraocular Lens Discoloration

To the Editor. —We read with interest the letter by Milauskas1and also his reply2to the correspondence by Kershner3and Ziemba.4We congratulate Dr Milauskas for detailing his findings and for providing a notification of possible problems with silicone as an intraocular lens (IOL) biomaterial. These letters provide an alert to the ophthalmic community and the Food and Drug Administration. We wish to communicate our experience with explanted silicone lenses that were submitted to the Center for Intraocular Lens Research (Salt Lake City, Utah, and Charleston, SC) between July 1987 and July 1991. Of a total of approximately 5000 explanted IOLs studied in our laboratory, 24 were silicone lenses, of which 11 were manufactured by STAAR Surgical Co (Monrovia, Calif) and 13 by Allergan Medical Optics (AMO; Irvine, Calif). The implant duration of these IOLs ranged from 7 days to 34 months (mean, 16 months).

Silicone Intraocular Lens Implant Discoloration in Humans-Reply

In Reply. —Dr Milauskas has described his experience with 15 silicone IOL implantations of two lens materials and styles from two separate manufacturers. I have clinical experience with several hundred patients in whom silicone IOLs from three manufacturers have been implanted (STAAR Surgical lenses, IOLAB LI-30U, and the Allergan Medical Optics [Irvine, Calif] SI18, SI20, and SI22 NB series of silicone lenses). I have reviewed the medical records of my patients, all of whom were exposed to the high-intensity UV sun exposure of Southern Arizona, and none was found to have discolored IOLs. I have spoken with the manufacturing representatives of both Allergan Medical Optics and IOLAB; neither one has received an official report of discolored silicone IOLs after up to 5 years of postoperative experience. Several investigators in the IOLAB LI-3OU original core study have reviewed the photographs supplied by Dr Milauskas and none has been able to detect

Keratometric cylinder and visual performance following phacoemulsification and implantation with silicone small-incision or poly(methyl methacrylate) intraocular lenses

Silicone and poly(methyl methacrylate) (PMMA) intraocular lenses from Allergan Medical optics were implanted in the posterior chamber of 96 cataract patients with small or standard incisions following phacoemulsification. Significantly less keratometric cylinder (astigmatism) and better uncorrected visual acuity were observed during the six week postsurgical follow-up in the patients who received the small incision silicone lens than in those who received the standard PMMA lens.

Preliminary Evaluation of the Koziol-Peyman Teledioptric System for Age-Related Macular Degeneration

Allergan Medical Optics has recently developed a bioptic optical implant with central minus and peripheral positive components (AMD-100B) that is used in conjunction with specially constructed bi-element spectacles to improve visual performance in patients with age-related macular degeneration. The Koziol-Peyman Teledioptric R system has been evaluated in both the laboratory and a limited clinical trial and found to be capable of producing a magnified image of high resolution, accompanied by enhanced visual perception in the absence of any apparent postoperative complications.

Advantages and limitations of current soft intraocular lenses

We report our clinical experience with six soft intraocular lenses: (1) STAAB silicone, (2) CooperVision/Schlegel silicone, (3) IOLAB silicone, (4) Allergan Medical Optics (AMO) silicone, (5) Fyodorov silicone, and (6) Alcon hydrogel (IOGEL). We found that these soft intraocular lenses have several common design problems. The singlesize design of five of the six soft lenses can lead to a windshield-wiper decentration effect in lenses too small for larger eyes. We observed several instances in which the one-piece lenses became decentered, subluxed, and vaulted anteriorly against the iris or posteriorly away from the iris as postoperative capsulozonular changes occurred. We found that the insertion methods for these soft lenses need refining to reduce the risk of intraocular damage and wound stretching if the lenses are to be folded and inserted through a small 3.0 mm to 3.5 mm incision. The surface and physical characteristics of these lenses may also require further study. We observed folding grooves, sebacium deposits, and rust from the insertion instrument on some lenses inside the postoperative eye and pigment dispersion associated with hydrogel lenses. We conclude that small diameter polymethylmethacrylate implants are the best choice for small incision cataract surgery at this time.