Purpose
Valved-cannulas were recently introduced to small gauge pars plana vitrectomy (PPV) systems and offer stable intraoperative fluidics. To our knowledge, there are no systematic reports in the literature on outcomes and safety of valved cannulas for retinal detachment (RD) repair.
Methods
Retrospective case control study of 163 eyes who underwent PPV for RD repair with valved cannulas between 07/2012 - 02/2013 or non-valved cannulas between 07/2011 - 02/2012 at the Duke Eye Center. Only eyes receiving temporary perfluorocarbon (PFC) to drain subretinal fluid and/or flatten the retina were included.
Results
104 eyes underwent PPV with valved cannulas and 59 eyes with non-valved cannulas. Baseline demographics, visual acuity (VA), and lens status were similar between the two groups without significant differences. Proportion of eyes presenting with chronic, recurrent, macula-off and early proliferative vitreoretinopathy (PVR) RD were similar, but there were fewer eyes with preoperative grade C PVR in the valved vs non-valved group (35% vs 53%, p=0.031). There were no significant differences in the proportions of eyes undergoing adjuvant scleral buckle, relaxing retinectomy, octafluoropropane (C3F8) gas, sulfur hexafluoride (SF6) gas or silicone oil tamponade. Mean follow up was 335.5 days in the valved group and 540.5 days in the non-valved group. Single surgery success, defined as attached retina at the final visit after one surgery, was achieved in 87% in the valved and 86% in the non-valved group (p=1.0). Visual improvements (final VA compared to preoperative VA) were also not different, with a change of -0.50 logMAR (SD=1.01) in valved eyes vs -0.38 logMAR (SD=0.95) in non-valved eyes (p=0.584). Similarly, no significant differences were identified in intraocular pressure or presence of anterior chamber fibrin at postoperative day 1 and retained subretinal or intraocular PFC in the postoperative course.
Conclusions
This is the first study, to our knowledge, rigorously investigating the use of valved vs non-valved cannulas during small gauge PPV for retinal detachment repair. In this mixed study cohort with simple and complex retinal detachments, anatomical and functional outcomes as well as complication rates were not different in valved compared to non-valved cannulas.