Posterior synechia formation after phacovitrectomy - Predicting factors and the role of short-acting mydriatics.

Purpose: To evaluate the influence of topical short-acting mydriatics on the formation of posterior synechia after phacovitrectomy surgery of pars plana vitrectomy and phacoemulsification with intraocular lens implantation.

Methods: A prospective randomised controlled trial. Fifty-seven adult (>18 years old) patients (57 eyes) who underwent phacovitrectomy surgery at a single tertiary hospital, were randomly divided into two groups. The control group (29 eyes) received standard postoperative treatment (topical antibiotics and steroids). The study group (28 eyes) received short-acting mydriatics together with standard therapy. Patients were followed until 24 months after surgery. The primary outcome measure was the formation of posterior synechia during the follow-up period.

Results: A total of 7 patients developed posterior synechia during the follow-up period (12%), 3 in the study group (11%) and 4 in the control group (14%). There was no statistical difference between the groups. Significant associations for the development of posterior synechia were surgery for retinal detachment, longer surgery duration (>93 min) and the use of tamponade, in particular silicone oil.

Conclusions: The use of topical short-acting mydriatic drops after phacovitrectomy surgery, in addition to standard post-operative treatment, did not reduce the formation of posterior synechia. However, we identified several factors that may influence or act as predictors for the development of posterior synechia: surgery for retinal detachment, using silicone oil tamponade and a longer surgery duration. Our findings may aid in the standardisation of post-phacovitrectomy surgery treatment and define potential at-risk patients who should be monitored more closely.