Abstract
Abstract: :
Purpose:To estimate the probability of IOP control at 2 years after one treatment episode with transscleral diode laser cyclophotocoagulation(cyclodiode) in patients with recalcitrant glaucoma.To estimate the risk of later onset hypotony after one treatment episode and to compare with the risk after retreatment. Study design/Method: Retrospective interventional case series of first treatments in all patients undergoing their first cyclodiode treatment at one specialist glaucoma unit in a tertiary referral centre during a 12 month period. Methods:210 eyes (age 53 ± 23 years,mean ± S.D.) underwent a first cyclodiode treatment for glaucoma during the study period April 2001 – March 2002. The responses to 132 first treatments and 52 retreatments were analysed at 6 months, one year and two years. The probability of IOP control (<22mmHg) with or without medication, occurrence of hypotony, and retreatment rate was measured at each time–point. Results: The mean preoperative IOP was 33.3 mmHg on mean 2.5 medications. The mean treatment energy 147 ± 54J. 70, 58 and 49 eyes were still attending 6 months, 12 months and 2 years after one cyclodiode laser treatment respectively. 37 (53%), 30 (52%), 30 (61%) were controlled at these respective time–points on 2.5 ± 0.4, 2.3 ± 0.4 and 2.3 ± 0.4 mean ± S.D. medications and 8 (11%), 8 (14%), and 6 (12%) were controlled without medication and without further cyclodiode treatment episodes. 52 patients required re–treatment a mean of 169 ±195 days after the initial treatment and 16 required a third treatment. Hypotony (IOP < 6mmHg on two consecutive out–patient visits) occurred after 7 (5%) of first treatments and 10 (19%) of retreatments (p<0.01, Chi–square). 10 eyes developed hypotony in the first 3 months (early), though late onset hypotony was observed in 7 eyes (later than 3 months after treatment). Conclusions: The probability of IOP control <22mmHg after 2 years without medication after one cyclodiode treatment episode was very low (12%), though 61% controlled on medication is similar to that at earlier time–points and in keeping with previous reports that had shorter follow–up. Cyclodiode is a very useful technique for short–term IOP control but the chance of medium–term success (2 years) is modest. Although the risk of hypotony is low (5%) after the first treatment episode, this increases with retreatment. In view of the higher than expected rate of occurrence of later hypotony (41% of episodes occurring more than 3 months after the treatment episode) retreatment should be approached with caution.
Keywords: laser • clinical (human) or epidemiologic studies: outcomes/complications • ciliary body