Microscope-Assisted ab externo Surgery for the Treatment of Primary Rhegmatogenous Retinal Detachment - New Tech Meets Old Art

Aim: To report the outcomes of ab externo surgery using a surgical microscope, wide-angle viewing system, and chandelier endoilluminator (microscope-assisted ab externo surgery) for rhegmatogenous retinal detachment (RRD).

Methods: This was a retrospective study. Consecutive charts of patients with RRD who underwent microscope-assisted ab externo surgery were analyzed. The following demographic parameters were analyzed: age (years), gender (male/female), and eye (right/left). Clinical parameters were axial length (AL) measured in millimeters (mm), preoperative best-corrected visual acuity (BCVA) measured in logarithm of minimum angle of resolution (logMAR), intraocular pressure (IOP), and lens status (phakic/pseudophakic). The parameters of RRD were number and type of retinal breaks, location of retinal breaks, extent of retinal detachment (RD) (number of detached quadrants), and macular detachment (MD), as well as retinal breaks not detected preoperatively. Use of cryopexy, circumferential or segmental scleral buckle, drainage of subretinal fluid, injection of air or gas, and duration of surgery were recorded. The postoperative parameters analyzed were BCVA, IOP and recurrence of RD and postoperative complications. Follow-up was established at 3 months.

Results: A total of 213 eyes (97 right, 116 left) of 205 patients (114 males, 91 females) affected by primary RRD were included. Fifty-two eyes (24.4%) were affected by high myopia (AL >26.5 mm), and 160 patients (75.1%) were affected by RRD caused by a single retinal break and involving only one quadrant. The superior quadrant was the most frequently involved (49.3%). Forty-two eyes (19.7%) were affected by MD. In 13 eyes (11.3%), retinal breaks were not detected preoperatively. The duration of surgery was 75.5 ± 42 min. No significant BCVA changes were observed in the whole group, whereas a significant improvement of BCVA from the baseline (2.83 ± 0.87 logMAR) to each time point of follow-up was observed in the subgroup of patients affected by MD. Six eyes (2.8%) developed a recurrent RD, secondary to proliferative vitreoretinopathy (3 eyes) and secondary to a new retinal break (3 eyes). Two eyes developed a persistent vitreous hemorrhage, and one eye developed a macular hole after 1 week. PPV was performed for both.

Conclusion: Microscope-assisted ab externo surgery is effective and safe, it reduces discomfort, it allows the surgeon to work with both hands free, and provides an adequate visualization of each step being performed.