ABSTRACT.Purpose: To determine the critical value of the angle kappa in connection with a higher risk of photic phenomena for the AcrySof ReSTOR and Tecnis multifocal intra-ocular lens (MIOL) on a standardized pseudophakic eye model. To analyse the impact of biometric value changes on the critical angle kappa. Methods: Geometrical optic rules applied to a suitable optical model of the pseudophakic eye were used to calculate the critical value of the angle kappa for the Tecnis and three types of the AcrySof ReSTOR MIOLs. The angle kappa was defined as critical if the incident ray passed through the first ring's edge area. The influence of different positive optical corneal power (K), effective lens position (ELP) and axial length (AL) on the critical angle kappa (j c ) was investigated. The dependence of j c on one of the parameters was studied for standardized values of the remaining parameters. Results: The highest value of the critical angle kappa was evaluated for the Tecnis MIOL. The increase in ELP and K caused an increase in j c under the given conditions. On the contrary, an increase in AL led to lower values of j c . Conclusion: We demonstrated the dependence of the critical angle kappa on the central part of the MIOL and on biometric parameters of the eye, especially on the effective lens position. According to these results, we conclude that shallow anterior chamber depth in connection with a higher angle kappa is an important risk factor for pronounced photic phenomena after implantation of a diffractive MIOL.

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The aim of the study was to evaluate the progression of changes in the visual fields in patients with hypertensive glaucoma (HTG) and normotensive glaucoma (NTG) following administration of prostaglandins and beta blockers, as well as also in NTG without ophthalmological therapy. Methodos. The HTG group included 12 patients (mean age 66 years) with approximately the same changes in the visual field and central corneal thickness (CCT-568um) treated with prostaglandins, and 12 patients (mean age 60 years, CCT=544um) treated with beta-blockers. The IOP ranged from 12 to 18mmHg for the whole follow-up period. The NTG group consisted of three subgroups. The first subgroup consisted of 14 patients (mean age 58 years) who were treated with prostaglandins. The second subgroup consisted of 10 patients (mean age 57 years) who were treated with beta blockers. The third subgroup consisted of 18 patients (mean age 57 years) who underwent no ophthalmological therapy. IOP was within the range of 8-12 mmHg over the whole follow-up period. In all patients, we monitored the pattern defect (PD) and overall defect (OD) within a period of five years. The treatment was not modified during the treatment period. All patients were compensated for cardiovascular status and had no other internal or neurological disease. Visual acuity was 1.0 with a possible correction (less than 3 dioptres) in all patients. Results. There was no statistically significant difference in HTG during the treatment with prostaglandins in PD (P=0.35) and OD (P=0.09) or beta blockers (P=0.37 and 0.23, respectively). In NTG, the greatest changes occurred in PD (P=0.0001) in untreated patients. OD showed no statistically significant changes (P=0.25). Similarly, the patients on prostaglandins had a statistically significant difference in PD (P=0.04), while OD did not show statistically significant changes (P=0.4). We did not find statistically significant differences in progression in patients with NTG treated with beta blockers PD (P=0.7), OD (P=0.4). Conclusion. Treatment of glaucoma with prostaglandins and beta blockers has a significant importance in HTG. However, beta blockers have a higher protective effect on the visual field. This is not true in NTG, where we demonstrated this effect only following the administration of beta blockers.

Aim: To ascertain whether various therapeutic procedures in non-arteritic anterior ischaemic optic neuropathy (NAION) have an impact on the resulting visual acuity of the affected eye. To assess the prevalence of risk factors that accompany this disease according to the literature. Methods: The retrospective study enrolled 55 eyes of 53 patients (41 men, 12 women) with an age range of 46 to 85 years (mean 64.9; median 64.0) who were hospitalized at the Department of Ophthalmology of the Faculty of Medicine and Dentistry and the University Hospital in Olomouc with the diagnosis of NAION between 2005 and 2016, and who received systemic treatment with intravenous vasodilators, either alone or in combination with intravenous corticosteroids. Central visual acuity (CVA) prior to treatment and immediately after its termination was evaluated. CVA was measured using the Snellen chart and is presented in decimal values. Using medical history data and medical records, the presence of systemic disease, namely hypertension, type 2 diabetes mellitus, and hypercholesterolaemia, was studied in these patients and evaluated for a possible association with NAION. Results: In the group of patients who were treated with intravenous vasodilators, the resulting CVA improved by 0.083 on average. In the group of patients who, in addition to vasodilator therapy, also received treatment with corticosteroids, the resulting CVA improved by only 0.03 on average. Although there was a more prominent improvement in CVA in the group treated with intravenous vasodilators alone, this difference was not statistically significant. At least one risk factor was found in the vast majority of the patients (96%). Eighty percent of the patients had hypertension, 43.6% of them were treated for diabetes mellitus, and 72.7% of the patients took drugs for hypercholesterolaemia. A combination of all these conditions was found in 36.4% of the patients. The proportion of smokers and past smokers did not exceed that of non-smokers. Conclusion: The mean improvement in the resulting CVA in patients after systemic therapy with vasodilators alone was greater than in those treated with a combination of vasodilators and corticosteroids; however, this difference was not statistically significant. In most patients in the group, at least one systemic risk factor was noted, most frequently hypertension. The prevalence rate of systemic risk factors was comparable to that reported in the literature.