Cystoid macular edema (CME) and cataract are the most common vison-compromising complications in managing retinitis pigmentosa (RP). Although cataract surgery is a common procedure in most patients, when a patient has been diagnosed with RP, it is considered a high-risk procedure. Furthermore, practitioners have limited evidence-based information regarding prognosis after cataract surgery.
To address this gap in knowledge, Ahmed Sallam, MD, PhD, FRCOphth, and colleagues conducted a retrospective clinical cohort study to determine visual acuity (VA) outcomes and intraoperative and postoperative complications in patients with RP who have undergone isolated cataract surgery.
The results of the study were published in the American Journal of Ophthalmology.
Evolving Therapeutic Landscape
When asked about the importance of this research, Dr. Sallam explained, “The therapeutic landscape of retinitis pigmentosa [RP] is rapidly evolving, with multiple ongoing clinical trials of novel therapeutics, many of which show promising preclinical or early clinical efficacy signals.”
He went on to describe the importance of surgical intervention in this evolution of care.
“These novel therapeutics include gene therapy products developed for subretinal delivery, leading to an expected increase in the number of vitrectomy surgeries in younger individuals with RP, thereby increasing the need for subsequent cataract surgery at a younger age. However, the evidence to inform patients with RP about their prognosis after cataract surgery has been limited.”
To address this limitation, the study identified 113,389 eyes that underwent cataract surgery. Of these, 72 eyes were diagnosed with RP prior to the procedure. The study participants with diagnosed RP had a mean age of 57±15 compared to 75±10 in the control group (ie, those participants without RP or any other ocular comorbidity; P<0.001). Forty-six percent of the RP group and 60% of the control group were female (P=0.06).
Preoperative VA (mean logarithm of the minimum angle of resolution [LogMAR]=1.03 vs 0.59, P<0.001) and postoperative VA (LogMAR= 0.71 vs 0.14, P<0.001) were poorer in the RP group. The study results showed a mean VA gain of 0.25±0.60 LogMAR in the RP group versus 0.43±0.48 LogMAR in the control group (P<0.001). The researchers noted no significant differences in the rate of intraoperative pupil expansion use, posterior capsular tears, or zonular dialysis between the RP and control groups.
In terms of postoperative CME, 6.9% of RP eyes developed this condition, whereas 1% of control eyes (P<0.001) developed this condition. Yttrium aluminum garnet (YAG) posterior capsulotomy was significantly higher (P<0.001) in patients with RP compared to the control group (13.9% vs 3%) within the first six months after surgery.
Advantages of Cataract Surgery
“Cataract surgery can improve vision in eyes with RP and cataract, albeit significantly less than after routine cataract surgery,” Dr. Sallam says. “Intraoperative complications are similar to control eyes; however, eyes with retinitis pigmentosa experienced more frequent postoperative CME and YAG capsulotomy by 7- and 5-fold, respectively.”
According to Dr. Sallam, there is more work to be done in this field of study.
“Surrogate markers of RP severity, such as optical coherence tomography structural changes, the extent of retinal atrophy, disease duration, and visual field data, should be explored in future studies. Also, molecular confirmation and genotypic data can further investigate the complication rates for specific genotypes or inheritance modes.”
