Abstract
Purpose::
To assess and compare outcomes of 25-gauge and 20-gauge vitrectomy surgeries, including visual recovery, rate of cataract formation, and complications.
Methods::
A retrospective, case-control study was performed comparing 25-gauge vitrectomies (between January 2002 and August 2004) to 20-gauge vitrectomies (between January 2003 and December 2003). Cases with prior vitrectomies by either method, diagnoses not seen as primary diagnoses for the 25-gauge vitrectomies, or cases without at least 3 months of follow-up were excluded from analysis. Analyses were performed with the Fisher’s exact test, Wilcoxon rank sum test, and Kaplan-Meier.
Results::
Inclusion criteria were met by 71 and 68 cases of 25-gauge and 20-gauge vitrectomies, respectively. The mean visual acuity at the 3-month post-operative visit improved significantly from the mean pre-operative visual acuity for both groups (p<0.001 for 25-gauge and p=0.002 for 20-gauge). At the 3-month post-operative visit, the visual acuity was significantly better for those eyes which underwent a 25-gauge vitrectomy (p=0.013), though there was no difference at the final visit. The rate of cataract extraction at one year was 63.4% for the 25-gauge group and 68% for the 20-gauge group by Kaplan-Meier analysis (p=0.700). Regardless of vitrectomy technique, pseudophakic patients for the epiretinal membrane (ERM) and macular hole (MH) groups at the last post-operative visit had visual acuities that were better than those who were still phakic (ERM p=0.01; MH p=0.005). Low intraocular pressures (<6 mmHg) on post-operative day one were more commonly noted in the 25-gauge group (p=0.028), while high intraocular pressures (>21 mmHg) were found more often in the 20-gauge group (p=0.004). Retinal tears were seen in 1 and 12 cases of 25-gauge and 20-gauge vitrectomies, respectively.
Conclusions::
Twenty-five gauge vitrectomies appear to provide faster visual acuity recovery, though the final visual acuity outcomes are similar. Complication profiles between the two groups differ when evaluating intraocular pressure on post-operative day one and incidences of retinal tears. The rate of cataract formation after 25-gauge and 20-gauge vitrectomies do not differ.
Keywords: vitreoretinal surgery • cataract • visual acuity