Long scleral tunnel technique to prevent tube exposure of Ahmed glaucoma valve
Reviewed by Jayavani Myneni

This retrospective study was done to evaluate the efficacy of long scleral tunnel technique and compare it with pericardium patch graft in preventing tube exposure of Ahmed glaucoma valve. Seventy-eight eyes of 73 patients were included. In group 1 patients, three parallel scleral incisions were made at 1.5-2mm, 6-8mm and 10-12mm away from limbus. A long scleral tunnel was prepared as two pockets one behind the other from these incisions. Paracentesis was done through the first scleral incision at the mouth of the tunnel. For group 2, pericardium patch graft was used to cover the tube. The mean age in both groups was comparable. Mean follow-up period in group 1 was 46.7 months and in group 2 was 43.6 months.Tube exposure was reported in one (2.5%) patient in group 1 at 25th month and three (7.9%) patients in group 3 at 21st, 27th and 30th months. The authors mention that the short follow-up period of the study is a limitation and suggest multicentre studies with longer follow-up periods. It is an interesting article highlighting the efficacy of an alternative approach to tube coverage which is very important to prevent endophthalmitis. 

Efficacy of long scleral tunnel technique in preventing Ahmed glaucoma valve tube exposure through conjunctiva.
Kugu S, Erdogan G, Sevim MS, Ozerturk Y.
SEMINARS IN OPHTHALMOLOGY
2015;30(1):1-5.