NON PENETRATING DEEP SCLERECTOMY ASSOCIAT ED WITH COLLAGEN DEVICE IN PRIMARY OPEN-ANGLE GLAUCOMA - MIDDLE-TERM RETROSPECTIVE STUDY

Purpose To evaluate the middle term tonometric results of a new filter ing procedure, the non penetrating deep sclerectomy with collagen devi ce, in primary open-angle glaucoma. This technique aims to eliminate o r minimize the complications of classical trabeculectomy. Material and method This procedure has been developed by Koslov et al. Under a lim bal-base conjunctival flap and a superficial scleral flap, the ablatio n of a deep scleral flap takes away the external wall of Schlemm's can al, leaving only the Descemet membrane. A visible filtration across th e opened Schlemm's canal and Descemet membrane is obtained. To improve the aqueous filtration, a cylindric collagen device, made from biocom patible porcine scleral tissue, known for its high water content, is f ixed in the deep scleral bed with a 10/0 nylon suture. This device pro vides a support for the elimination route of aqueous humor and acts li ke a sponge, carrying the liquid by capillary action. It is sterilized by irradiation. Full guarantee against viral contamination is provide d. This procedure ends in one suture (10/0 nylon) of superficial scler al flap and conjunctival closing suture. We conducted a retrospective study. Our material included 159 patients (92 males, 65 females), 219 eyes. The mean age was 65 years (11-91). The mean follow-up : 8 months (3-20). The types of glaucoma were: POAG: 183 eyes; juvenile POAG: 18 eyes; pigmentary glaucoma : 11 eyes; capsular glaucoma : 7 eyes. 58 e yes (40 patients) presented one or several risk factors of failure for filtering surgery. Results The mean pre-operative IOP was 24mmHg +/- 6.60; 15.7 +/- 5.30 at the end of the follow-up (Delta average IOP: 9. 1 +/- 7.1). The probability success rate (IOP less than or equal to 20 mmHg), according to the Kaplan-Meier Method, was 89 % at six months, 75.6 % at 16 months. With monotherapy with beta blockers, 79 % at 16 m onths. It was better in the without risk factors group. The mean chang e in visual acuity was inferior to 0.1 at the end of the follow-up. Ex cept several hyphemas, no complications of the trabeculectomy were obs erved. The reelevation of IOP was due to an internal obstruction (goni osynechiae or bad filtration), it was treated with Nd-Yag laser with a 2/3 of success rate. External obstruction was treated by 5FU injectio ns into the bleb. Conclusion Non penetrating deep sclerectomy with col lagen device can be an excellent alternative to trabeculectomy in open and wide angles. It does not modify visual actuity. It carries less c omplications than trabeculectomy and the use of antimitotic agents is safer.