advertisement
Impressions of the 1999 American Academy of Ophthalmology Annual Meeting
Orlando, FL, USA, October 24-27, 1999
Theodore Krupin
Orlando, Florida, was the site of the 1999 Joint Meeting of the 103rd Annual Meeting of the American Academy of Ophthalmology and the XXII Congress of the Pan-American Association of Ophthalmology. The new and massive Orlando Convention Center provided excellent lecture halls, meeting rooms, and exhibitor space. Unfortunately, many satellite meetings were held away from the Convention Center, which presented problems because of Orlando's poor road system with complicated traffic jams, and lack of sufficient taxi cabs. This observation is from a person who lives in Chicago! However, the meeting was well attended and a time to renew friendships with colleagues from around the globe.
For the past few years, the Academy's Annual Meeting 'begins' two days early with Subspecialty Day Programs and Special Meetings and Events. These meetings may have larger attendance than some of the symposia during the Annual Meeting. The Glaucoma Subspecialty Day is presented in conjunction with the American Glaucoma Society. Robert N. Weinreb, MD and Jeffrey M. Liebmann, MD created a well-organized program: Glaucoma 1999: Concepts and Controversies, which was aimed to provide clinicians with practical information that can be used to treat glaucoma. Drs Weinreb and Liebmann not only put together a superb program, but also assembled a first-class group of presenters from South America, Europe, and the USA. Case presentations were added to this year's program for discussing specific patient problems. Cases related to the use of target intraocular pressure, pigmentary glaucoma (including laser iridotomy), exfoliative glaucoma, glaucoma associated with pseudophakia, management of shallow anterior chamber, and complications of glaucoma drainage devices, were presented. I particularly enjoyed these segments which provided a 'grand rounds' flavor to the program. The remainder of the day-long program covered all the critical and timely topics important to the clinician taking care of glaucoma patients, as well as 'hot' topics for the future (e.g., neuroprotection, genetics, and new approaches to medical therapy). As a glaucoma practitioner, I thoroughly enjoyed this glaucoma day.
The Joint Meeting glaucoma presentations contributed new information relating to glaucoma surgery. Dr Kuldev Singh communicated results from a randomized comparison of mitomycin-C (MMC) (0.4 mg/ml for two minutes) or 5-fluorouracil, (5-FU) (50 mg/ml for five minutes) application during primary trabeculectomy. Both treatments were equally effective short-term, 91% of eyes with intraocular pressure of less than 18 mmHg, and had similar postoperative complications. This paper is interesting because it is my clinical impression that long-term bleb complications may be greater with MMC usage. Equal antifibrotic efficacy confirms my avoidance of MMC for low-risk eyes undergoing primary (initial) trabeculectomy. Dr Lindsey Harris presented a technique for repair of late bleb leaks by placing a free conjunctival patch graft over the existing de-epithelialized bleb. Their results were very impressive, with leaks persisting in only two of 47 treated eyes! Intraocular pressure increased from 6.6 to 11.9 mmHg. This technique is less invasive than surgically excising a leaking bleb and advancing a replacement conjunctival flap. I will use their method when the situation indicates.
Papers were presented on non-penetrating deep sclerectomy to achieve pressure control. Dr F.F. El Sayyad performed deep sclerectomy in one eye and trabeculectomy in the fellow eye of 39 primary open-angle glaucoma patients. At one year, intraocular pressure reduction was 12.4 mmHg after deep sclerectomy and 14.1 mmHg after trabeculectomy. A similar percentage of eyes (92.4% versus 94.9%) had pressures <=21 mmHg. However, a greater number of eyes in the trabeculectomy group had lower pressures. Transient flat/shallow chamber occurred more often when the anterior chamber was entered (trabeculectomy). I was surprised to hear that internal iris incarceration occurred in two deep sclerostomy eyes (without presumed entrance into the chamber). I thought Dr R.G. Carassa made the best presentation on viscocanalostomy at the Saturday Glaucoma Update meeting. He expanded his results previously presented at the 1998 AAO and 1999 ARVO meetings, comparing 25 eyes undergoing either primary viscocanalostomy or trabeculectomy with postoperative 5-FU injections. The trabeculectomy eyes had more transient postoperative complications: hypotony with choroidals in three eyes and pressure spike in two eyes that required suture lysis. Three of nine eyes that received postoperative 5-FU injections had punctate keratopathy. These trabeculectomy-associated events required more postoperative visits than the viscocanalostomy group. Both procedures lowered intraocular pressure; however, final levels were lower in the trabeculectomy (12.0 mmHg) than the viscocanalostomy (15.1 mmHg) eyes, with the disparity possibly increasing with longer postoperative time. The probability of success, defined as pressure <=16 mmHg, was greater after trabeculectomy. In another presentation, Dr G. Sunaric-Megevand reported an 86% success (20% with medications) for achieving pressures <=20 mmHg in a mixed group of eyes undergoing viscocanalostomy. While I had some difficulty with this paper, it was apparent that the technique was not effective in eyes that I consider at high risk for trabeculectomy failure without antifibrotic medications (e.g., scarred conjunctiva). These and other reports at this year's meeting continue to highlight that deep sclerectomy and viscocanalostomy are effective surgical techniques in chosen glaucoma patients. Continued investigations are needed to determine the role of these surgeries in various types of glaucoma. In my opinion, both these techniques are in evolution. Glaucoma and its therapy is a life-long condition. Time will show the long-term success and magnitude of pressure reduction, as well as possible late complications, with these procedures.
The Annual Meeting Scientific Poster sessions presented a mixture of intellectually stimulating glaucoma topics and the opportunity for one-to-one discussions with the authors. Drs J.W. Doyle and M.F. Smith reported an increase in the cost of maximum medical therapy in the USA associated with the wider array of medical therapies: up to $1700/year. Cost of medical treatment is a world-wide issue. Dr P. Gelman (San Paulo, Brazil) found that when patients were able to discontinue antiglaucoma medications (a successful laser trabeculoplasty), they chose to stop one of the newer, more costly agents rather than the lower cost pilocarpine that has more frequent side effects. Dr P.A. Wren, using psychological testing on newly diagnosed glaucoma patients, confirmed the clinically-known adverse emotional impact that occurs when the disease is first discovered. This poster from the Collaborative Initial Glaucoma Treatment Study (CIGTS) found that younger (35-55 years old) and employed patients were more likely to experience psychological distress, and recommended the need to tailor counselling and educational efforts for these groups of patients. I think their recommendations are also valid for all glaucoma patients in whom the chance of possible blindness is stressful. A poster comparing trabeculectomy with and without antifibrotic medications in low-pressure glaucoma was presented by Mr W.L. Membrey. Pressure reductions were greater when antifibrotic agents were used. Intraoperative MMC was associated with a greater incidence of late hypotony, bleb leak, and reduced acuity than perioperative 5-FU. A poster by Dr D.M. Albert presented histopathological findings on iridectomy specimens from eyes receiving latanoprost, a medication that can increase iris pigmentation. There was no morphological difference between latanoprost-treated and control iris specimens.
Space restraints limit discussion of the many other worthy presentations and posters at the 1999 meeting. As a reminder, future Annual Meetings of the American Academy of Ophthalmology are October 22nd-25th, 2000, in Dallas, Texas, and November 11th-14th in New Orleans, Louisiana. See you there.
