Corneal topographic changes following trans-conjunctival 20 gauge sutureless vitrectomy (TC20V)

Abstract

PurposeTo assess the occurrence and magnitude of corneal topographic changes in phakic eyes undergoing Transconjuctival Cannulated 20 gauge Vitrectomy (TC20V) without scleral buckling or silicone oil tamponade.SettingProspective randomized controlled study done at Egyptian Eye Academy.MethodsForty eyes of 40 patients underwent TC20V for a variety of vitreo-retinal conditions over a 1 year follow-up period. Corneal keratometric readings were obtained using Oculus Pentacam before surgery, 1 week after, and 1 month after surgery; neither scleral buckling nor silicone oil tamponade were used in order to not affect the final corneal changes. Cases with postoperative hypotony were excluded.ResultsThe mean preoperative K1 (vertical keratometry) was 44.87 ± 3.55, the mean preoperative K2 (horizontal keratometry) was 44.57 ± 3.68; the mean postoperative K1 after 1 week was 45.1 ± 6.82 while the mean postoperative K2 after 1 week was 45.7 ± 3.97. Using paired t-test analysis, the P-value of the K1 change was 0.01 and P-value of the K2 change was 0.02. Both indicate minimally significant differences. One month postoperative the mean K1 was 45.2 ± 2.53 and the mean K2 was 45.1 ± 1.56 and P-values of both K1 and K2 changes after 1 month were >0.05, which indicates insignificant changes.ConclusionThe results showed that minimal corneal topographic changes were encountered with the use of TC20V owing to the tunnel configuration of the wound, and these changes also decrease within the first month.

The Effect of Strabismus Muscle Surgery on Corneal Biomechanics

“…Despite the fact that to our knowledge no recent studies have tackled the same variables, our hypothesis was inspired based on older studies which stated that, after strabismus surgery, corneal topographic changes were likely to occur [ 8 , 9 , 15 ]. In other studies, transient corneal topographic changes were found to occur after sutureless vitrectomy as well [ 11 , 12 ]. These changes occurred despite the lack of direct tissue continuity between the cornea and the vitreous body.…”

“…Recent studies found mild corneal topographic changes after sutureless vitrectomy as well, that most of these changes however, decayed with time [ 11 , 12 ].…”

Safety of 20-Gauge Transconjunctival Sutureless Vitrectomy

“…The primary advantages of sutureless vitrectomy are shorter operative times [16,17,18,19,20,21,22], less inflammation and pain postoperatively [15,17,19,20,23,24], and improvement in patient comfort [25,26,27]. Astigmatism following transconjunctival sutureless vitrectomy is uncommon [28,29,30,31] and, when present, is less important than in 20-gauge standard vitrectomy cases [32,33,34]. The fact that no sutures are placed in the sclera results in a reduction in postoperative astigmatism.…”