Deep sclerectomy in refractory congenital glaucoma

Abstract

We have a comment on the article on the risks profile of deep sclerectomy for treatment of refractory congenital glaucomas by Luke et al.The pressure-lowering effect of deep sclerectomy is independent of external filtration only when the superficial scleral flap is tightly secured, as described in Stegmann's viscocanalostomy. External filtration is also absent when the scarring process is so important that the pressure-lowering effect of the surgery is minimal. In the article by Luke et al, only one of the eyes that underwent deep sclerectomy alone, with or without perforations, developed a filtering bleb. It was, moreover, the only one that achieved intraocular pressure (IOP) control. This is the reason why, to optimize all the possible outflow mechanisms past the trabeculodescemetic membrane, we tie our superficial flap very loosely, provided no visible perforation is present.Of the 10 eyes in this series, only 2 had uneventful pure deep sclerectomy. In two eyes, percolation through the trabeculodescemetic membrane was weak, so the procedure was supplemented by a trabeculotomy. In another four eyes, identification of Schlemm's canal was not made, so no deep sclerectomy alone nor added trabeculotomy could be done, and the procedure was converted into a guarded filtering procedure. Finally, in two eyes an inadvertent visible perforation of the trabeculodescemetic membrane occurred. The report of a high percentage of conversion to perforating filtering surgery and potential associated postoperative complications differs from our own experience in refractory congenital glaucoma. After both pure deep sclerectomies, hyphemas were reported as complications, although trivial. These may further result from possible microperforations, with a resultant high and abrupt change in IOP. We agree that deep sclerectomy alone is not applicable in most cases with complicated refractory congenital glaucomas. We make small visible perforations of the trabeculodescemetic membrane with the tip of a 30-gauge needle. Our incidence of nonidentified Sclemm's canal in congenital refractory glaucomas, however, is low.Considering that only pure nonpenetrating filtering surgery is reported in this article, the IOP control after 19 months of follow-up was 50%, which, considering the high-risk failure rate for refractory congenital glaucoma, is not so bad. We have a comment on the article on the risks profile of deep sclerectomy for treatment of refractory congenital glaucomas by Luke et al. The pressure-lowering effect of deep sclerectomy is independent of external filtration only when the superficial scleral flap is tightly secured, as described in Stegmann's viscocanalostomy. External filtration is also absent when the scarring process is so important that the pressure-lowering effect of the surgery is minimal. In the article by Luke et al, only one of the eyes that underwent deep sclerectomy alone, with or without perforations, developed a filtering bleb. It was, moreover, the only one that achieved intraocular pressure (IOP) control. This is the reason why, to optimize all the possible outflow mechanisms past the trabeculodescemetic membrane, we tie our superficial flap very loosely, provided no visible perforation is present. Of the 10 eyes in this series, only 2 had uneventful pure deep sclerectomy. In two eyes, percolation through the trabeculodescemetic membrane was weak, so the procedure was supplemented by a trabeculotomy. In another four eyes, identification of Schlemm's canal was not made, so no deep sclerectomy alone nor added trabeculotomy could be done, and the procedure was converted into a guarded filtering procedure. Finally, in two eyes an inadvertent visible perforation of the trabeculodescemetic membrane occurred. The report of a high percentage of conversion to perforating filtering surgery and potential associated postoperative complications differs from our own experience in refractory congenital glaucoma. After both pure deep sclerectomies, hyphemas were reported as complications, although trivial. These may further result from possible microperforations, with a resultant high and abrupt change in IOP. We agree that deep sclerectomy alone is not applicable in most cases with complicated refractory congenital glaucomas. We make small visible perforations of the trabeculodescemetic membrane with the tip of a 30-gauge needle. Our incidence of nonidentified Sclemm's canal in congenital refractory glaucomas, however, is low. Considering that only pure nonpenetrating filtering surgery is reported in this article, the IOP control after 19 months of follow-up was 50%, which, considering the high-risk failure rate for refractory congenital glaucoma, is not so bad. Deep sclerectomy in refractory congenital glaucoma: Author replyOphthalmologyVol. 110Issue 9Preview Full-Text PDF