Anatomic Success of Pars Plana Vitrectomy for Rhegmatogenous Retinal Detachment during the Changeover from 20 to 23 Gauge - A Study on 313 Consecutive Cases

Background: The aim of this investigation was to evaluate the effect on the anatomic surgical success with the changeover from 20 Gauge (G) (n = 206) to 23 G (n = 107) pars plana vitrectomy (PPV) in rhegmatogenous retinal detachment. Methods: 313 consecutive patients were retrolective-prospectively analysed. Several parameters including lens status, number of retinal breaks, extent of retinal detachment, proliferative vitreoretinopathy (PVR) and refractive error were examined. Primary success rate was defined as anatomic success after a minimum follow-up of 6 months. The secondary success rate was determined as anatomic success after one further operation if necessary. Moreover recurring retinal detachment after initial success was registered. In additional to the analysis over all patients, cases were grouped according to the severity of the pre-operative baseline situation. Results: Primary success rate was 87.4% for 20 G PPV and 87.9% for 23 G PPV, secondary success rate was 95.6% for 20 G PPV and 94.4% for 23 G PPV. 13.9% (20 G) and 7.4% (23 G) of patients with initially reattached retina after one surgery developed recurrent retinal detachment in the followup and were successfully treated in 17/25 and 7/7 cases. With 20 G PPV a primary success rate of 85% was obtained in phakic eyes and 89.6% in pseudophakic eyes, respectively. However, primary success rate with 23 G PPV was 90.4% for phakic eyes and 85.5% for pseudophakic eyes. For simple, medium and severe cases, the primary success rate decreased from 97.1 to 92.4 and 74.2% in 20 G PPV, whereas no obvious tendency appeared for 23 G PPV (93.9, 83.7, 88%). In 20 G PPV surgery the lens status had no influence on the primary success rate (p > 0.05), for medium and severe cases in 23 G PPV better results were obtained in phakic eyes (88.5 and 93.3%) compared to pseudophakic eyes (78.3 and 80%, n.s.). Conclusion: 20 G PPV as well as 23 G PPV are good surgical techniques in rhegmatogenous retinal detachment. Overall the miniaturisation of surgical instruments seems to be without any disadvantage for the surgical success.