Antiglaucomatous drugs effects on optic nerve head flow: design, baseline and preliminary report.

PURPOSE: To determine the effect of the most frequent used antiglaucomatous drugs on the optic nerve head flow. To see the response of the autoregulation system in hypertensive, preperimetric and advanced perimetric glaucomas. MATERIALS: In this preliminary report, optic nerve head parameters and retinal perfusion values were measured in 25 healthy controls as well as in 72 glaucomatous optic nerve heads. The glaucomatous sample was divided into three groups: 24 eyes treated with Betaxolol, 24 with Brinzolamide and 24 treated with Brimonidine (each of these groups was conformed by 8 hypertensive glaucomas, 8 preperimetric glaucomas, and 8 perimetric glaucomas). METHODS: Patients were examined with scanning laser Doppler flowmetry (wave length 638 nm), and flow, volume and velocity indices were assessed in each report. Perfusion maps were analyzed with the new SLDF software, version 3.2 (automatic full field perfusion image analizer). Examinations were also performed with the Heidelberg Retina Tomograph (wave length 638 nm), using the new standard reference plane. Visual fields were performed with the Octopus 123 or 101 perimeters, programs Glx and G2, with 3 phases completed. Diurnal pressure curve with applanation tonometry and gonioscopy (for classification) were also performed. RESULTS: In this preliminary report, it was found that eyes in Hypertensive or preperimetric stages of glaucoma, seem to use their regulation systems in order to preserve their optic nerve head circulation, while advanced perimetric glaucomas seem not be able to preserve their optic nerve head flow. And that antiglaucomatous drugs were not able to increase optic nerve head flow neither. DISCUSSION: Optic nerve head blood supplies is regulated by an autoregulation system. This phenomenon may act in normals, hypertensive and preperimetric glaucomas, but it seems not be able to preserve blood flow in advanced glaucomas. Optic nerve head flow returns to normal values with treatment in glaucoma first stages, while it seems that it could not be restored in advanced glaucomas.

Glaucomatous optic nerve head changes with scanning laser ophthalmoscopy.

PURPOSE: To determine whether there are angiographic differences among normal, preperimetric and advanced glaucoma eyes using indocyanine green angiography with SLO. This method was chosen because of its sensibility to detect peripapillary capillary vessels. METHODS: Scanning laser opthalmoscopy was preformed on normal eyes, preperimetric glaucomas and advanced glaucomas. MATERIAL: The authors used a confocal SLO (Heidelberg Retina Angiograph-HRA) CONCLUSION: Several changes may be seen on peripapillary capillary vessels at the different glaucomatous stages. DISCUSSION: In normal subjects HRT shows preservation of the disc/cup area ratio; indocyanine green angiography shows normal prepapillary plexus pattern on the neuroretinal rim and cup. Subjects on glaucomatous preperimetric stage reveal a decrease in the disc/cup area ratio as a result of an increase of the cup area secondary to a reduction of the neuroretinal rim area. ICG at this hipertensive stage shows an increase in prepapillary plexus visualization, which may be a consequence of increased blood flow while autoregulation is still operative. Subjects with advanced glaucoma show prominent decrease in the disc/cup area ratio as well as marked capillary droupout in ICG angiography.

Scanning laser ophthalmoscopy for early diagnosis of vitreoretinal interfase syndrome.

PURPOSE: To describe the angiographic signs found using scanning laser ophthalmoscopy for the early diagnosis of vitreoretinal interface syndrome. This method is useful to visualize the inner retinal layers, being more sensitive than fundus biomicroscopy. MATERIAL: 61 patients with vitreoretinal interfase syndrome were evaluated. All of them had evidence of this disease using scanning laser ophthalmoscopy but four patients were referred without diagnosis of vitreoretinal interfase syndrome. These patients showed no biomicroscopic signs and diagnosis was made with SLO. METHODS: Confocal scanning infrared laser ophthalmoscope (Heidelberg Retinal Angiograph assembled by Heidelberg Engineering). This SLO uses an infrared diode laser source of 795 nm. CONCLUSION: Patients included were referred with another diagnosis and with this method the correct diagnosis was made. In conclusion scanning laser ophthalmoscopy allows early diagnosis of this pathology for follow-up and treatment.