Deep sclerectomy with a collagen implant using the excimer laser.

We describe a new technique of nonpenetrating glaucoma surgery that uses the excimer laser to reduce the risk of perforating the trabeculo-Descemet's membrane. With this technique, the ablation is precise and homogeneous. A collagen device is sutured over the scleral bed to create an outflow pathway for aqueous humor drainage. After a superficial scleral flap is dissected with a diamond knife, the sclera, under direct visualization, is ablated with the excimer laser over Schlemm's canal until aqueous humor percolates through from the anterior chamber. A collagen device is placed over the sclera to allow the aqueous humor to flow from the anterior chamber through the trabeculo-Descemet's membrane. The preliminary results show a drop in intraocular pressure to the middle teens.

Arterial narrowing as a predictive factor in glaucoma.

PURPOSE: To evaluate whether retinal arteriolar widths change in normal patients and in different glaucoma types. We measured the arteriolar width at the merge in the optic nerve (MD), at the edge of the optic nerve (ED) and at the peripapillary area (1 disc diameter distance) (disc distance D). HRT software 1.11, Interactive Means program was used. One hundred forty three eyes of seventy-two patients divided in four subgroups normal, low-tension glaucoma (LTG), primary open angle glaucoma (POAG) and ocular hypertensive (OH). No statistically significant was found in each studied group. The normal patients showed no changes in the retinal arteriolar width compared with all the glaucoma groups.

Papillary drusen and ocular hypertension.

PURPOSE: To evaluate if the changes in the peripapillary and papillary retinal nerve fiber layer, in a young girl who presents papillary drusen and ocular hypertension in both eyes. METHODS: We studied this case with retinography, Humphrey Visual Field, HRT, GDx, and diary curve tonometry. RESULTS: After three years of follow up, no changes were observed in the drusen at the peripapillary and papillary retinal nerve fiber layer. CONCLUSION: In a well controlled ocular hypertensive patient there is no evidence of changes at the optic nerve head and RFNL related to the drusen or to the high pressure. All the diagnosis methods were correlationated with the clinical evolution over time.

Purification and characterization of a new kappa-carrageenase from a marine Cytophaga-like bacterium.

A bacterial strain able to degrade various sulfated galactans (carrageenans and agar) was isolated from the marine red alga Delesseria sanguinea. From the cell-free supernatant of cultures grown on crude lambda-carrageenan, a kappa-carrageenase was purified by ammonium sulfate fractionation, gel filtration on Sephacryl S 200 HR and ion-exchange chromatography on DEAE--Sepharose-CL6B. The purified kappa-carrageenase was detected as a single protein upon SDS/PAGE. Its molecular mass was estimated at 40 kDa. Activity was observed against kappa-carrageenan over the pH range 5.0-8.5 and was optimal at pH 7.2 in Tris buffer or 7.0 in Mops buffer. The enzyme activity remained stable at 30 degrees C, but only for up to 1 h at 40 degrees C. Analysis of the degradation products of the kappa-carrageenase by gel filtration and 13C-NMR spectroscopy indicated that the enzyme degrades kappa-carrageenan down to the level of the kappa-neocarratetraose sulfate. The properties of this new enzyme are compared with those of previously characterized carrageenases.