[Increased cataract rate and characteristics of Nd:YAG laser capsulotomy in retinitis pigmentosa].

BACKGROUND

Retinitis pigmentosa (RP) is associated with the development of a posterior subcapsular cataract (PSC). The development of posterior 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 incidence of PCO was evaluated in a group of 26 RP patients who underwent cataract surgery and IOL implantation. In a prospective analyse (part 2) PCO was quantified in 13 RP patients using the standardized photographic 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 controls were evaluated.

RESULTS

Part 1: The cumulative PCO rate in RP at the end of the first postoperative year was 14.6%, 26.8% in the second, 53.7% in the third and 70.7% after the third year. Nd:YAG laser capsulotomy was performed in 70% of eyes (after 18.4 +/- 14.7 months). In eyes with significant PCO development 70% had PSC preoperatively, while in eyes without PCO formation only 41.7% showed PSC. Part 2: The matched pairs analysis 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 RP-specific pathomechanisms are responsible for this needs further investigation.