Use of the Choyce lens for IOL replacement

use of the choyce lens for IOL replacement ]. McHenry Nielsen, M.D. James P. Gills, M.D. New Port Richey, Florida Since the time of the first intracameral lens placement, problems have occasionally occurred that necessitated removal of the lens with the unhappy regression of the patient's vision to the status of aphakia and the problems of aphakic optical correction. The mere removal of the intraocular lens (IOL) in many cases alleviated the immediate medical difficulties but the optical problem remained. Once the offending lens was removed the hyphema, iritis or glaucoma often cleared up and the patient retained reasonable vision. However, the considerable advantages of intraocular lenses had been lost with the removal of the intraocular lens. The patient had won a battle but lost the war. It was felt in our clinic that if the offending lens could be removed and safely replaced with another lens, the patient would be better served. We thus undertook a study to determine the efficacy of removing offending intraocular lenses and replacing them with Choyce lenses. A Choyce Mark VIII anterior chamber lens· was selected because of its anterior location and angle fixation. It could be utilized in patients with previous intracapsular extractions where capsular fixation was now impossible and in cases with iris damage where iris fixation was no longer possible. Equally important reasons for the selection of the Choyce lens were the relative ease of its insertion and the lack of manipulation required. In 48 cases the problem intraocular lenses were removed and replaced by Choyce lenses in an attempt to restore the visual quality previously enjoyed by the patient (Table 1). The primary insertions were done by many surgeons, but lens removals and exchanges were performed by one surgeon using one technique. Offending lenses were removed anywhere from one month postoperatively to four years postoperatively, with a mean time of 27 months. The majority of lenses removed were of the metal loop style and were removed following the development of CME (primary surgery was intracapsular) or lens

·Manujactured by Rayner. Presented at the U.S. Intraocular Lens Symposium in Los Angeles, March 1978.

dislocation, iris atrophy and corneal edema (primary surgery was extracapsular) (Table 2). The time of follow-up postexchange ranged from two months to three years, with a mean time of 19 months. Postexchange visual outcome was used as the criteria for evaluation (Table 3). Although 25% of the cystoid macular edema cases continued to have a positive fluorescein angiogram, all other postoperative diagnoses were controlled or corrected following exchange surgery. Table l. Postoperative complications leading to IOL removal and replacement (sample size = 48 patients). Post-op Dx

Frequency

Chronic dislocation

22%

Cystoid macular edema (with fluorescein angiography)

42%

UGH syndrome

28%

Wrong lens power and/or size

8%

Table 2. Types of lenses removed. Frequency

Lens Type 4-loop metal

35%

3-loop metal

5%

2-loop metal

30%

I-loop metal

9%

Copeland

12% 9%

Choyce

Table 3. Postexchange results. Visual Quality Postexchange Post-op Dx

Improved

Same

Decreased

(~21ines)

Chronic dislocation

50%

40%

10%

Cystoid macular edema

75%

15%

10%

UGH syndrome

80%

20%

0%

Wrong lens power and/or size

100%

-.

These 48 cases of exchanged lenses demonstrate a possible alternative to mere removal of the offending intraocular lens. Our initial results show that 70% of the cases had vision improved by two or more lines, 24% had unchanged vision and only 6% had vision decreased after Choyce lens implantation.

AM INTRA-OCULAR IMPLANT SOC J-VOL. IV, OCTOBER 1978

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