Comparative efficacy of different treatment modalities in the management of macular oedema in retinitis pigmentosa: a systematic review and network meta-analysis.

OBJECTIVE

To compare the efficacy of current treatments for retinitis pigmentosa (RP)-associated macular oedema using network meta-analysis (NMA).

METHODS AND ANALYSIS: Electronic databases were searched for studies reporting changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT). A frequentist NMA was performed and treatment hierarchies were estimated using the surface under the cumulative ranking curve.

RESULTS

12 studies were included to compare the following: oral acetazolamide 500 mg/day, oral methazolamide 50-100 mg/day, topical dorzolamide 2% three times daily, topical ketorolac 0.5% four times daily, intravenous umbilical cord mesenchymal stem cells (UCMSCs; single administration of 3×10⁶ cells), intravitreal dexamethasone implant (DEXi) 0.7 mg, intravitreal triamcinolone acetonide (IVTA) 4 mg, sub-Tenon TA (STTA) 20 mg, intravitreal bevacizumab 1.25 mg and intravitreal ranibizumab 0.5 mg. Regarding changes in BCVA at 3-4 months, oral carbonic anhydrase inhibitors (CAIs) showed greater BCVA improvement compared with anti-vascular endothelial growth factor (anti-VEGF) therapies; however, no intervention demonstrated statistically significant superiority in BCVA at 12 months. At 3-4 months, DEXi, acetazolamide, methazolamide and dorzolamide demonstrated comparable CMT reduction and outperformed anti-VEGF therapies, IVTA, STTA, intravenous UCMSC and control. By 12 months, dorzolamide (vs acetazolamide: -169.50 µm (95% CI -331.83 to -7.17) and vs methazolamide: -185.49 µm (95% CI -354.35 to -16.63)) and DEXi (vs acetazolamide: -147.00 µm (95% CI -206.58 to -87.42) and vs methazolamide: -162.99 µm (95% CI -238.56 to -87.42)) provided significantly greater CMT reduction than acetazolamide and methazolamide.

CONCLUSIONS

CAIs and DEXi demonstrated the greatest long-term anatomical benefit for RP-associated macular oedema, whereas durable BCVA gains remained limited across available therapies. While oral and topical CAIs showed comparable short-term efficacy, topical dorzolamide and DEXi provided greater long-term CMT reduction than oral CAIs. Given the limited number of studies and small sample sizes, these findings should be interpreted cautiously and validated in larger randomised controlled trials.