POSTERIOR CAPSULE OPACIFICATION AND PROBL EMS OF ND-YAG LASER CAPSULOTOMY IN RETINITIS-PIGMENTOSA

Background: Retinitis pigmentosa (RP) is associated with the developme nt of a posterior subcapsular cataract (PSC). The development of poste rior capsule opacification (PCO) after cataract surgery and a decrease of central visual acuity is sometimes misinterpreted by the patients as natural course of RP. Therefore, therapeutic intervention is often delayed. Patients and methods: In a retrospective study (part 1) the i ncidence of PCO was evaluated in a group of 26 RP patients who underwe nt cataract surgery and IOL implantation. In a prospective analyse (pa rt 2) PCO was quantified in 13 RP patients using the standardized phot ographic technique and image analysis system introduced by Tetz et al. Matched pairs were formed with a control group of 13 patients without retinal disease who matched the RP group in terms of age distribution and postoperative follow-up time. In part 3 the parameters of Nd:YAG laser capsulotomy in 12 RP patients and 14 centrals were evaluated. Re sults: Part 1: The cumulative PCO rate in RP at the end of the first p ostoperative year was 14.6 %, 26.8 % in the second, 53.7 % in the thir d and 70.7 % after the third year. Nd:YAG laser capsulotomy was perfor med in 70% of eyes (after 18.4 +/- 14.7 months). In eyes with signific ant PCO development 70 % had PSC preoperatively, while in eyes without PCO formation only 41.7 % showed PSC. Part 2: The matched pairs analy sis showed a significantly higher PCO value for RP patients (2.11 +/- 1.42) than for the control group (0.89 +/- 0.72) (P = 0.038). Part 3: Average Nd:YAG laser energy levels were 12.8 +/- 11.2 MJ (RP) and 7.6 +/- 6.7 MJ (control). Some 25 % of RP patients required further laser treatment of regrown secondary cataract. Conclusions: Patients with RP showed a significantly higher incidence and density of PCO. Whether R P-specific pathomechanisms are responsible for this needs further inve stigation.