Cataract surgery in patients with retinitis pigmentosa
Reviewed by KC Madhusudhana

Retinitis pigmentosa (RP) is the commonest inherited cause of retinal degeneration. Posterior subcapsular cataract (PSC) develops in 41% to 90% of these patients by age 40 years. In this retrospective study, the authors have evaluated surgical outcomes in patients with RP undergoing phacoemulsification (n=87 eyes of 47 patients). Data on best-corrected visual acuity (BCVA), lens and zonular status, use of capsular tension ring (CTR), incidence of posterior capsular opacification (PCO) and YAG laser capsulotomy, and surgical complications were recorded. Average age was 48.9 years (range, 31-78 years) with a mean follow-up period of 23.3 months. Most (97.5%) of these patients had PSC. Mean BCVA improved from 20/340 to 20/129 within three months of surgery (p<0.0001). Eyes with a preoperative vision of 20/40 to 20/200 (47 eyes) improved from a mean 20/81 preoperatively to 20/43 (p<0.0001), postoperatively. PCO occurred in 82.5% of cases while YAG capsulotomy was required in 52.5% at an average 10.8 months postoperatively. Signs of phacodonesis were seen in 18.8% of eyes. One patient developed bilateral in-the-bag intraocular lens (IOL) dislocation more than five years after surgery. The authors conclude that cataract surgery improves visual acuity in a majority of RP patients with a preoperative vision of 20/200 or better. However, patients with a preoperative BCVA of 20/400 or worse have limited visual improvement objectively, owing to the macular pathology, but still report noticeable subjective improvement. A high prevalence of zonular weakness is noted in these patients warranting careful evaluation preoperatively and to use appropriate techniques to minimise zonular stress. The placement of standard CTRs alone may not prevent late in-the-bag IOL dislocations and hence alternative means of IOL fixation should be considered in cases with advanced or progressive zonular weakness. 

Cataract extraction outcomes and the prevalence of zonular insufficiency in retinitis pigmentosa.
Dikopf MS, Chow CC, Mieler WF, Tu EY.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2013;156(1):82-8.e2.