REFRACTIVE OUTCOMES IN COMBINED PHACO-VITRECTOMY FOR MACULAR HOLE OR EPIRETINAL MEMBRANE AND CATARACT

The most frequent complication of vitrectomy is cataract, with 50% patients requiring cataract extraction within one year. Moreover, many patients undergoing vitrectomy have co-existing cataract pre-operatively. Opting for a combined phaco-vitrectomy eliminates the need for a second procedure. There is a paucity of data in the literature regarding refractive outcomes after phaco-vitrectomy, and the optimal IOL formula. We therefore wished to determine the refractive outcomes for our patients who underwent combined phaco-vitrectomy.

Royal Victoria Eye and Ear Hospital. A tertiary centre for Ophthalmology in Ireland.

A retrospective chart review was carried out of patients who underwent combined phaco-vitrectomy for macular hole (MH) or epiretinal membrane (ERM) with concomitant cataract. Combined phaco-vitrectomy for other indications eg retinal detachment and were excluded. Pre- and post-operative visual acuity (VA) and refraction were recorded. Biometric data including IOL formula used and predicted refraction, axial length and K values were also noted. Post-op refractive success was defined as within ±1.0 dioptres (D) of target.

Data were available for 25 eyes of 23 patients who underwent combined phaco-vitrectomy. For 72% patients the indication for the procedure was MH with cataract, the remainder had ERM with cataract. Mean pre-op VA was 0.44 ±0.26 for ERM patients, and 0.56 ±0.15 for MH patients. Mean post-op VA was 0.3 ±0.26 for ERM patients and 0.21 ±0.15 for MH patients. Complete post-operative refraction was available for 76%. 94.7% patients achieved post-op refractive success within ±1D of target. 68.4% had an excellent refractive outcome within ±0.5D of target. AL <23 or >26 did not increase the risk of poor refractive outcome. SRK/T was used for 83% cases. The deviation of the post-op spherical equivalent from predicted refraction was on average +0.31D. Complications occurred in 11.5% patients, the most common being post-operative cystoid macular oedema.

Combined phaco-vitrectomy is a safe procedure with excellent visual outcomes. Our post-op VA and complication rates were in line with those in the literature. With regard to refractive outcome, 94.7% of our patients had a post-op refraction within ± 1.0D of target, which was comparable similar studies. The refractive outcomes for phaco-vitrectomy are similar to sequential vitrectomy and cataract extraction, but not as good as phacoemulsification alone. Whilst increased axial length and decreased pre-op VA have been identified as risk factors for poorer refractive outcome in phaco-vitrectomy, neither of these factors appeared to be associated with poor outcome in our study. SRK/T has been shown to be reliable for phaco-vitrectomy in both highly myopic and non-myopic eyes. Further data would be required to determine which IOL formula should be adopted routinely for these cases. In conclusion, there appears to be no refractive advantage to sequential vitrectomy and cataract extraction.