[Differences of optic disc appearance between normal tension and high tension glaucoma patients].

INTRODUCTION: The term glaucoma is used to cover a wide range of diseases, whose main feature is optic neuropathy. According to the level of intraocular pressure (IOP), the open angle glaucoma is arbitrarily divided into high tension glaucoma (HTG) and normal tension glaucoma (NTG). OBJECTIVE: The aim of this study was to investigate the differences of optic disc cup appearance between patients with NTG and HTG. METHODS: Prospective study included 30 patients (60 eyes) with NTG and 30 patients (60 eyes) with HTG. IOP was measured by Goldmann applanation tonometry. Examination of optic disc head was performed by indirect ophthalmoscopy with Volk 90 D superfield lens through a dilated pupil to observe qualitative and quantitative parameters. Visual fields were examined in all patients with the Octopus program G1, full threshold strategy (Octopus 500 EZ, Interzeag, Switzerland). RESULTS: Vertical form of optic disc cup was present in 11 eyes with NTG (18.3%) and three eyes with HTG (5%) (p < 0.05). A disc with localized tissue loss (polar notching) on the inferior pole was observed in eight eyes with NTG (13.3%) and in one eye with HTG (1.7%) (p < 0.01). Uniformly enlarged, round cup was more frequent in patients with HTG than NTG: 93.3% and 68.3% respectively (p < 0.05). CONCLUSION: The perceived differences indicate a complex multifactorial nature of glaucoma disease and a possible existence of two pathophysiological ways of optic disc changes within the same basic disease.

[Prevention of intraocular pressure elevation after argon laser trabeculoplasty in primary open angle glaucoma].

INTRODUCTION: Argon laser trabeculoplasty (ALT) is an intraocular pressure lowering method that is overall safe and powerful, but often complicated by transient postoperative intraocular pressure rises. In prevention of this complication, we frequently use two potent alpha-adrenergic agonists--brimonidine and apraclonidine. OBJECTIVE: The aim of this study was to compare brimonidine 0.2% and apraclonidine 0.5% efficacy and safety in prevention of intraocular pressure elevation after ALT. METHODS: This was a prospective, randomized, double-masked and comparative study. This study included 27 POAG patients, 15 received 0.2% brimonidine, and 12 received 0.5% apraclonidine before laser surgery (22 eyes in both groups). Intraocular pressure readings were taken 1, 2, 3, 24 hours and 7 days after ALT. Student's t-test was used to analyse data between two groups, and chi2 test to compare data within groups. Value p less than 0.05 was considered statistically significant. RESULTS: We found statistically significantly lower IOP in eyes that received 0.2% brimonidine at readings taken 1 hour after ALT (p = 0.001). There were no statistically significant differences in other IOP readings between two groups. CONCLUSION: A single preoperative drop of brimonidine 0.2% had similar efficacy and safety as apraclonidine 0.5% in preventing transient IOP elevations after ALT.