Experience with the Choyce-Tennant Implant

EXPERIENCE WITH THE CHOYCE-TENNANT IMPLANT To the Editor: I was pleased to see the paper "Long-term Results with Choyce-Tennant Anterior Chamber Intraocular Lens Implants" by John E. Downing, M.D., and Carolyn Parrish, M.D., in the September 1986 issue and congratulate the authors on their generally excellent results. It is right to refer to the lens they used as the Choyce-Tennant AC implant. The Choyce Mark VIII (made by Rayner in England, and Coburn in the U.S.A.) and the Tennant modification (Precision Cosmet) are so alike that I cannot tell the difference until I look at the eye on the corneal microscope and see a planoconvex as opposed to a biconvex optic. Back in 1963, I considered providing the Mark VIII with a similar optic but decided to continue with the biconvex format because I wished to have maximum clearance between the anterior optical surface and the endothelium. Although the Tennant optic reduces that clearance by 0.2 mm for a + 19 diopter lens, more in the higher powers, it does not seem to have resulted in a significant amount of corneal edema, only one case (0.5%) being noted by Downing and Parrish. In the discussion thev refer to Pearce's findings on my patients published in 1975. Please note that the actual survey took place in 1972. All the patients were secondary implants and in many cases the antecedent cataract surgery had not been straightforward; many of the aphakias so treated were the result of trauma. Although I used alpha chymotrypsin where appropriate, neither the cryoprobe nor sodium hyaluronate (Healon®) were available in the 1960s. They list pupil block and glaucoma as the most serious complications and record a high (86.5%) cumulative incidence of ovaling of the pupil. This mirrors my experience with the Mark VIII and justifies the changes I made in it in 1977, resulting in the Mark IX, also made by Rayner and Coburn. The incidence of pupil block with the Mark IX in my fi;-st 1,000 cases was low (1%); of glaucoma, 2%. Ovaling of the pupil (defined as the ratio oflong axis to short axis> 2:1) was no more than 7.5%. Other factors such as the routine use of Healon® may account in part for the marked diminution of ovaling. Many thousands of Mark IXs have been used in North America and I should like to see a survey similar to that of Downing and Parrish for the Mark IX, which is the ultimate expression of the original Strampelli principle of the one-plane, one-piece, one-material anterior chamber implant. Looking at their results as a whole there is a complete absence ofYAG capsulotomies, subluxations and dislocation, phacoanaphylactic uveitis, sunset and sunrise syndromes, and other complications associated

with ECCE/PC lens implantation techniques. For not the first time, I wonder why so many physicians undertook this conversion when the old-fashioned ICCE/AC implant technique works so well-up to 7112 years (Downing and Parrish), 23 years (my Mark VIII cases) and 8112 years (the Mark IX). D. P. Choyce, M.S., F.R.C.S.

Westcliff-on-Sea, England

CHARGING MEDICARE PATIENTS MORE THAN NON-MEDICARE PATIENTS To the Editor: It has come to my attention that there have been flat fees set by hospitals for cataract surgery. The hospitals have established a flat fee, but it appears to be a twotier fee. One fee for non-Medicare patients and a higher fee for Medicare patients. This is called "no cost cataract surgery." The Medicare patients are charged an insurance rate. The patients without insurance are charged a flat rate. For example, if the hospital charge for cataract surgery with an implant is under $850 (unlikely), the patient is charged up to $850, or the balance. If Medicare pays over $850, the patient is charged nothing. With the strong emphasis by the federal government to cut the surgeon's fee, is it fair for Medicare to be paying $2,200 to $2,800 for one to two hours in the hospital, while the government is planning to cut the surgeon's fee to one-half of what the hospital is charging? The hospital has one to two hours of care, or less. The surgeon has six months' care to give and if any type of complication occurs, a much longer period of care. After being discharged from the hospital, the postoperative responsibility of the hospital is zero-to the surgeon it just begins. Is it legal and is it right for the hospital to charge Medicare patients more than non-Medicare patients? Alvan Balent, M.D.

Fort Lauderdale, Florida

USING THE ARGON LASER TO CUT SUTURES To the Editor: We read with interest the letter to the editor by Drs. I. Allen Chirls and John W. Norris in the March 1986 issue regarding the use of the argon laser to cut sutures. We would like to refer them to a letter to the editor, "u se of the Argon Laser in Suture Removal After Cataract Surgery," in the American Journal ofOphthalmology in March of 1984 in which we described this technique and its applications. Dennis Metz, M.D. Jacob Ackerman, M.D. Irwin Kanarek, M.D. Brooklyn, New York

J CATARACT REFRACT SURG-VOL 13, JANUARY 1987

85