Cataract surgery shows potential in retinitis pigmentosa management
Cataract surgery appears to safely and effectively improve visual acuity in patients with retinitis pigmentosa (RP), according to a recent study. Furthermore, the procedure does not accelerate disease progression.
The retrospective cohort study included 70 eyes of 40 RP patients who either underwent phacoemulsification with intraocular lens implantation or had no cataract surgery. Ellipsoid zone (EZ), which has been shown to be a reliable marker of RP severity, was measured using spectral domain optical coherence tomography (SD-OCT) at baseline and throughout follow-up (median, 768 days). RP progression was defined as the loss of EZ width over time.
Other data analysed included pre- and postoperative best-corrected visual acuity, incidence of macular oedema, posterior capsular opacification, epiretinal membrane, and intraocular lens subluxation.
Results showed no significant difference in RP progression between the cataract surgery and control groups (p=0.23). RP progression was associated with mode of inheritance, with autosomal recessive RP progressing at 148 microns/year and autosomal dominant RP progressing at 91 microns/year (p=0.003).
Visual acuity improved in 17/19 eyes that underwent surgery and remained stable in the remaining two eyes (89 vs 11 percent). Although the incidence of postsurgical posterior capsular opacification was high (18/19; 95 percent), no serious complications (ie, lens subluxation or endophthalmitis) were reported.
Cataract is among the major complications of RP. Although cataract surgeries have been demonstrated to achieve favourable results in RP patients, there are several risk factors that can potentially influence the outcome. In some cases, surgeries induce actual worsening of visual acuity as they may affect the status of asteroid hyalosis and cause visual disturbance especially in patients with visual field loss. [Case Rep Ophthalmol 2011;2:279–282]
Asteroid hyalosis, which commonly affects older individuals, is a usually asymptomatic, benign vitreous disease. The condition can sometimes lead to visual disturbances, which can be reversed by pars plana vitrectomy. [Ophthalmic Epidemiol 2003;10:331–335; Retina 2006;26:661–665]