The Far Nasal Part of the Visual Field - Part I.

AIMS: The aim of the study was to determine the limits of the far nasal part of the visual field. MATERIAL AND METHODS: Visual field examination was performed in 15 healthy subjects (30 eyes), specifically nine women aged 20-43 years and six men aged 22-35 years. All eyes were found to have physiological ocular findings and visual acuity of 1.0 with correction less than or equal to 3 diopters. The visual field was examined with a Medmont M700 instrument by shifting the fixation point 40 degrees temporally and simultaneously turning the head nasally, with a spatial accommodation program. A total of 89 examination points were included using flicker stimuli. RESULTS: The far nasal limit of the visual field reached 100° in 13.3% of eyes, 105° in 20% of eyes and up to 110° in 66.7% of eyes. CONCLUSION: The limit of the far nasal part of the field of vision reached 100-110 degrees (when nose shielding was eliminated).

The Far Nasal Part of the Field of Vision - Part II. Contribution to the Timely Diagnosis of Glaucoma.

AIM: The aim of this study was to examine possible changes in the conventionally undiagnosed nasal visual field in patients diagnosed with early primary open angle glaucoma. MATERIAL AND METHODS: Examination of the far nasal part of the visual field was performed in 30 patients (60 eyes) with early stage of primary open angle glaucoma (preperimetric stage of changes). The cohort consisted of 16 women (mean age 46.5 years) and 14 men (mean age 44.7 years). In all eyes, the glaucoma program (rapid threshold program of 50 degrees nasally and 22 degrees temporally) was performed with the Medmont M700 instrument to determine the physiological visual field. Visual acuity was 1.0 with a possible correction less than or equal to ±3 diopters and they had no other ocular defect except glaucoma disease. The visual field was subsequently examined with the same instrument by moving the fixation point 40 degrees temporally (spatially adaptive program) and simultaneously turning the head 10 degrees nasally. A total of 89 examination points were included using flicker stimuli and a range of 0-120 degrees nasally. RESULTS: The far nasal limit of the visual field reached 100° in 13.33% of eyes, 105° in 20% of eyes and up to 110° in 66.67% of eyes. CONCLUSION: In all eyes, depression of the distal periphery of the nasal part of the visual field was found to range from 50 to 95 degrees, with a normal visual field examined by the glaucoma program.

ANALYSIS OF CORNEAL ANTEROPOSTERIOR RATIO OF OPTICAL POWER USING OCT.

AIMS: The aim of the study was to analyse the values of the anteroposterior corneal optical power ratio (AP ratio), to compare the resulting values with those of theoretical models of the eye, and to define the effect of using an individual ratio value on the approximation of the total corneal power. MATERIAL AND METHODS: A total of 406 eyes were included. Each patient underwent an OCT (RTVue XR) examination, according to which the AP ratio of the cornea was determined, as well as the biometric parameters of the eye (Lenstar LS900). The correlation between the biometric parameters of the eye and the individual AP ratio values was evaluated using Pearsons correlation coefficient. In the analysis, the AP ratio results were compared with selected schematic models of the eye. Using Gaussian equations, a theoretical calculation of the total corneal optical power (KG) was performed, by fitting the AP ratio value and comparing it with the actually measured total corneal power (TCP). RESULTS: The mean value of the individually determined AP ratio was 1.17 ±0.02. The most frequently represented interval (33.74 %) was 1.17 to 1.18 AP ratio values, with the vast majority of eyes (79.56 %) in the range of 1.15 to 1.20. Individual values of total corneal optical power were statistically significantly different (p < 0.05) from the theoretical values of TCP (except in the Liu-Brennan eye model, where p = 0.06). The lowest mean difference of values was found for the Navarro schematic model. The dependence of the measured AP ratio values and biometric parameters reached a moderate negative correlation (r = -0.50 for p < 0.05) with the parameter corneal posterior surface curvature (Rp), as well as a weak negative correlation with limbal diameter WtW (r = -0.26 for p < 0.05) and a weak positive correlation with central corneal thickness CCT (r = 0.17 for p < 0.05). CONCLUSION: The assumption of a constant value of the AP ratio according to the selected schematic models of the eye is statistically significantly different from the actual measured values and was defined to have only a negative weak correlation with the size of the limbus diameter. Using the resulting average value of the determined AP ratio (1.17 ±0.02), a lower difference between real and calculated total corneal optical power was achieved.

VISUAL FIELD ASSESSMENT IN HYPERTENSION GLAUCOMA.

AIMS: The aim of the work is to verify the necessity of full-field perimetry test in incipient glaucoma. MATERIAL AND METHODS: The study included group of 16 incipient hypertension glaucoma (HTG group) patients without obvious changes in visual field and control group of 10 patients with normal ocular findings and value 1.0 of visual acuity. In both groups, full-field perimetry test was performed followed by a glaucoma perimetry test (rapid threshold strategy in both cases). Evaluated parameters were pattern defect (PD) and overall defect (OD) using Pearsons correlation coefficient. RESULTS: Strong correlation coefficient between PD (r = 0.74) and OD (r = 0.63) of both perimetry test were found in HTG group. Moderate correlation of PD (r = 0.54) and strong correlation of OD (r = 0.64) in control group. CONCLUSION: Results of the study shows, that expected changes of peripheral visual field will be recorded first in HTG group, but opposite is true. Perimetry glaucoma test is for incipient glaucoma sufficient to document the course and the examination of glaucoma disease.

OCT ANGIOGRAPHY, VISUAL FIELD AND RNFL WITH VARIOUS MEDICATIONS IN HYPERTENSIVE GLAUCOMAS.

AIM: The aim of the study was to determine whether hypertensive glaucoma (HTG) with different types of treatment leads to significant damage in any of the evaluated parameters. SAMPLE AND METHODOLOGY: The sample, consisting of 36 HTG patients (72 eyes), was divided into three subgroups: In the first group, patients were treated with combination therapy (latanoprost + timolol, latanoprost + dorzolamide + timolol, dorzolamide + timolol). The group consisted of seven women and five men, with an average age of 64 years (49-81). In the second group, patients were treated with beta-blockers (carteolol, betaxolol, timolol). The group consisted of five women and five men, with an average age of 62 years (27-77). In the third group, patients were treated with prostaglandins (latanoprost, bimatoprost). The group consisted of eleven women and three men, with an average age of 61 years (61-78). Criteria for inclusion in the study were visual acuity of 1.0 with a possible correction of less than ±3 dioptres, approximately the same changes in the visual fields of all patients, an intraocular pressure (IOP) of less than 18 mmHg, and no other ocular or neurological disease. The retinal nerve fibre layer (RNFL) on the optic nerve target and vessel density (VD) was measured using an Avanti RTVue XR from Optovue. We determined the values of VD in whole image (WI) and VD of peripapillary (PP). In both cases, we then measured all vessels (VDa) and small vessels (VDs). The visual field was examined by means of a fast threshold glaucoma program with a Medmont M 700 instrument. In addition to the sum of sensitivities in apostilbs (asb) in the range of 0-22 degrees, the overall visual field defect (OD) was also evaluated. The statistical analysis was carried out using a multivariate regression model with adjustment for age and gender. The measured values of the third group were taken as baseline. RESULTS: In the statistical analysis, we have found differences in visual field in the combination treatment group (p = 0.0006) and differences were recorded for RNFL in the beta-blocker group (p = 0.04).

OCT ANGIOGRAPHY AND DOPPLER ULTRASOUND IN HYPERTENSION GLAUCOMA.

AIMS: The main aim of this work was to find out if there is a correlation between vessel density (VD) and results of measured perfusion values in ophthalmic artery and in central retinal artery of the same eye in a group with hypertension glaucoma (HTG). MATERIALS AND METHODS: The file included 20 patients with HTG, thereof 13 women of average age 68.7 years (49-80 years) and 7 men of average age 58.4 years (27-81 years). Criteria for inclusion in the study: visual acuity 1,0 with possible correction less than ±3 diopters, approximately the same changes in visual fields in every patient, intraocular pressure (IOP) less than 18 mmHg, no other ocular or neurological diseases. VD was measured by Avanti RTVue XR by Optovue firm, perfusion parameters were measured using Doppler ultrasound with Affinity 70G machine by Philips firm. The peak systolic velocity (PSV) and end diastolic velocity (EDV) and resistance index (RI) were measured both in ophthalmic artery (AO) and in central retinal artery (CRA). Visual field (VF) was examined by quick threshold glaucoma program by Medmont M 700 machine. The sum of sensitivities in apostilbs (abs) was evaluated in the range 0-22 degrees of visual field. The results of sensitivities in visual field were compared to VD and perfusion parameters in CRA and AO of the same eye. RESULTS: Pearsons correlation coefficient (p = 0,05) was used to assess the dependency between chosen parameters. By comparing VF and VD from measured areas, strong correlation (r = 0.64, resp. 0.65) was revealed. It was then proved that VD (WI-VDs) correlates with RICRA weakly (r = -0.35) and moderately strongly (WI-VDa r = -0.4, PP-VDs r = -0.43 and PP-VDa r = -0.45). This means that with increasing resistance index in CRA the density in VD decreases. The other correlations between VD and perfusion parameters (PSV and EDV) in CRA and AO were not significant. CONCLUSION: Measured values showed that the vascular component of VD has a huge impact on the changes in visual fields in HTG. Weak to moderate influence exists between VD and RI in CRA. OCTA has proven to be more suitable than Doppler ultrasound for determining the condition of blood circulation in the eye.

Betaxolol, Brimonidin and Carteolol in the Therapy of Normal-Tension Glaucoma.

PURPOSE: The purpose of the study was to evaluate influence of betaxolol, brimonidine and carteolol in the progression of the visual field defects during time at patients with normotensive glaucoma (NTG). MATERIALS AND METHODS: This study included (60 eyes of) 30 patients with NTG. First group consisted of 20 eyes of 10 patients of the average age of 58.5 years, who were treated by betaxolol. Second group also consisted of 20 eyes of 10 patients of the average age of 62.6 years and they were treated by brimonidine. Third group had the same count of the eyes and patients, the average age was 61.1 years and these patients were treated by carteolol. Diagnose of NTG was based on the comprehensive ophthalmological examination including electroretinography and visual evoked potentials. Visual fields were examined by fast threshold glaucoma test using Medmont M700 device. We compared pattern defect (PD) in the visual field for 3 years. The including criteria were: similar visual field findings at the beginning of the study, stable eye therapy (treatment was not changed during the study), uncorrected or best corrected (up to +-3 D) visual acuity of 1,0 of ETDRS, intraocular pressure between 10-15 mm Hg, if present, then compensated cardiovascular disease, no other internal or neurological disorders. RESULTS: We didnt notice any statistically important difference of PD. The study revealed that brimonidin (p=0,99) and betaxolol (p = 0,81) had the best effect. CONCLUSION: Local therapy of betaxolol, brimonidine and carteolol has an essential clinical value in normotensive glaucoma. All the mentioned treatments had a protective effect on the visual field. However, local side-effects of brimonidinu are a question.

OCT ANGIOGRAPHY AND DOPPLER SONOGRAPHY IN NORMAL-TENSION GLAUCOMA.

AIMS: To investigate the dependence of blood vessel density and velocity in ophthalmic artery and arteria centralis retinae of the same eye in patients with normotensive glaucoma. METHODS: The sample consisted of 20 patients with normotensive glaucoma (NTG). There were 17 women (mean age 56.1) and 3 men (mean age 60 years). Inclusion criteria for study: visual acuity 1.0 with correction up to ±3 dioptres, approximately equal changes in the visual field, whereby it was incipient NTG and diagnosis was confirmed by electrophysiological examination, without further ocular or neurological disease. Parameters of vessel density (VD) were evaluated by Avanti RTVue XR (Optovue). Perfusion parameters such as peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) were evaluated for ophthalmic artery (AO) and arteria centralis retinae (ACR) using Doppler sonography (Affinity 70G Philips, probe 5-12 MHz). Visual field (VF) was evaluated by automated perimeter (Medmont M700) using fast threshold glaucoma strategy test. The sum of sensitivity levels in apostilb (asb) were evaluated in range 0-22 degrees of visual field. Resulting values of VF were compared with VD and perfusion parameters in AO and ACR at the same eye. RESULTS: Pearsons correlation coefficient was used to evaluate the dependence. Data shows, that changes in visual fields are mainly caused by peripapillary VD of small and all vessels, and vessels throughout measured image area also. Correlation of small vessels throughout measured image area was weak (r = 0.23). Moderate negative correlation was found for PSV in AO and peripapillary small VD (r = -0.46), all peripapillary VD (r = -0.49), VD in whole area (r = -0.45), then between EDV in AO and VD in whole area (r = -0.42). Other correlations between VD and perfusion parameter were insignificant. CONCLUSIONS: Study confirms, that changes of visual field in NTG patients are mainly caused by VD rather than perfusion parameters, especially in AO. Perfusion parameters in ACR are not significantly correlated with changes of VF in NTG patients.

OPTIC CHIASM WIDTH IN NORMAL-TENSION AND HIGH-TENSION GLAUCOMA.

PURPOSE: The aim of our study was to find out whether in patients with hypertensive glaucoma (HTG) and normotensive glaucoma (NTG), there is a change in the size of the chiasm depending on the changes in the visual field. Therefore, we retrospectively measured the width of the chiasm in the patients to whom we measured the size of the corpus geniculatum laterale in 2013. MATERIALS AND METHODS: The group consisted of two groups of patients. Nine with hypertensive glaucoma (HTG) and nine with normotensive glaucoma (NTG). The diagnosis was based on a complex ophthalmological examination and in NTG and electrophysiological examination. The visual field was examined by a rapid threshold program on the Medmont M700. The sum of the sensitivity from both visual fields in the range of 0-22 degrees was compared with the width of the chiasm obtained by the magnetic resonance imaging using the eight channel head coil. The measured values of all subjects were analyzed using a paired t-test and a correlation coefficient. RESULTS: We found a reduction in the chiasma width in both glaucoma groups. We found a statistically significant difference in the size of the chiasm (p = 0.0003) between the control group and the HTG group (p = 0.001). The narrowing of the chiasm showed a slight correlation in HTG with changes in the field of vision (r = 0.139) and in NTG a moderate correlation (r = 0.375). CONCLUSION: We found a reduction in the size of the chiasm in both HTG and NTG. The sum of sensitivities in the central parts of the visual field, however, more correlated with the reduction in the size of the chiasm in NTG. This finding shows that there are two different diagnostic groups.

VISUAL FUNCTIONS AFTER IMPLANTATION OF ACRYSOF MONOFOCAL INTRAOCULAR LENSES.

PURPOSE: The purpose of the study was to evaluate the visual functions after implantation of Acrysof monofocal intraocular lenses Alcon (SA60AT. MA50BM a SN60WF a SN6AT). MATERIALS AND METHODS: Four works are presented in the overview. The first work deals with the effect of eye length. corneal optic power and anterior chamber depth on the uncorrected near visual acuity (UNVA) after IOL implantation. The second work compares the effect of eye position (horizontal and vertical) on the final UNVA. The third work deals with the influence of the spherical lenses (SA and MA) and yellow aspherical lenses (SN) on UNVA. The later work examines the effect of pupil width on UNVA.    Results: The first work showed the dependence of eye axial length (the largest in eyes bellow 22.5 mm. r=0.36) on UNVA.  77.4 % of eyes with axial length below 22.5 mm had UNVA better than 0.5 and 70.49 % of all evaluated eyes had UNVA better than 0.5. Uncorrected far visual acuity (UDVA) better than 1.0 was in 97.54 % eyes in the whole group. In the second work we found a mean correlation in eyes shorter than 22.5 mm with UNVA in horizontal position (r=0.39) and in the vertical position (r=0.49). UNVA improved in these eyes in horizontal position from 0.53 to 0.58 in vertical position of the eye. In all eyes from the group UNVA changed from 0.51 to 0.56. The third work demonstrated the effect of sphericity and chromaticity on UNVA. Better than 0.5 in the group of eyes shorter than 22.5 mm in SA IOL in 67 % and in SN IOL in 60 %. In eyes with mean axial length was UNVA better than 0.5 in SA IOL in 86.5 %. in MA IOL in 81 % and in SN IOL in 75 %. In eyes longer than 23.5 mm was UNVA better than 0.5 in SA IOL in 100 % of eyes, in MA IOL in 60 % and in SN IOL in 33 % of eyes. In the fourth work the effect of pupil size was not demonstrated. CONCLUSION: The works showed excellent results of UNVA and UDVA after implantation of Acrysof monofocal lenses.

Late Functional and Morphological Findings after Methylalcohol Poisoning.

AIM: The aim of the study was to determine the morphological and functional findings in a patient after methanol poisoning. Examination methods: The patient (male, 38 years old) was suffered methanol poisoning in eight years ago (2012). The following tests and examinations were performed: neurological visual field XR test (Medmont M700), retinal nerve fibre layer (RNFL), ganglion cell complex (GCC) and peripapillary vessel density (all using Avanti RTvue, Optovue), pattern electroretinography (PERG) and pattern visual evoked potential (PVEP) examination according to ISCEV methodology (Roland Consult Instrument) and brain MRI examination (Philips Achieva Dstream 3 T). RESULTS: The biggest changes were found in RNFL and VD. PERG also showed damage to retinal ganglion cell axons. In left eye we determined decrease in oscillations (in comparison with contralateral eye) at N35-P50 and P50-N95. VEPs in both eyes were significantly reduced, almost inconspicuous in the left eye. Extension of latency time of P100 was not identified. Functional MRI showed a bilateral decrease in voxel activity with a greater decrease in the left eye. There were postmalatical changes in the dorsal parts of the putamen on MRI. The width of the optic nerve and chiasm was physiological. CONCLUSION: Asymmetric damaging of RNFL and cortical centres of the brain were determined. We registered large pathological changes in VD, which are probably responsible for the deepening of optic nerve excavation and further loss of nerve fibers of retinal ganglion cells, which have not yet been described in the literature. Following these results is possible to define direct damage of nerve structures and blood vessels by toxins of methanol metabolism in the acute stage and upcoming reparation processes in following periods.

[The Uncorrected Near Visual Acuity after the Monofocal Intraocular Lens Implantation]. / Nekorigovaná zraková ostrost do blízka po implantaci monofokální IOL.

Aim of the study was to evaluate retrospectively selected parameters, which influence the postoperative near visual acuity in a group of pseudophakic eyes of patients with Uncorrected Distance Visual Acuity (UDVA) and according to acquired results establish those, which mostly influenced good Uncorrected Near Visual Acuity (UNVA) after the implantation of monofocal IntraOcular Lens (IOL). Altogether, 122 pseudophakic eyes of 65patients were followed up, out of them in 57 patients both eyes were operated on. The frequency of visual acuity for three groups of operated eyes categorized according to the crucial parameter - eyes axial length (short, average, long) was evaluated. In each of groups, the average parameters (age, axial length, keratometry, and depth of the anterior chamber) were established, as well as relative frequency of postoperative uncorrected near visual acuity on conventionally used reading tables. The near visual acuity assessment for each eye separately was preformed in its horizontal position using the Zeiss table. The study did not confirm positive correlation of postoperative near visual acuity on the age of the patient, depth of the anterior chamber, nor the implanted IOL type. It was confirmed the presumption of optimal near visual acuity for eyes with axial length shorter than 23.5 mm, and in the process, between both parameters slightly negative correlation was found. On the other hand, middle positive correlation between uncorrected near visual acuity and central corneal power (in dioptres) in eyes with the axial length 22.5 - 23.5 mm was found. The study confirmed, that higher values of the central corneal power (in dioptres) and the high borderline value of the axial length up to 23.5 mm are the condition for optimal postoperative uncorrected near visual acuity after the implantation of monofocal intraocular lens.Key words: Uncorrected Near Visual Acuity (UNVA), monofocal intraocular lens, pseudoaccommodation.

Optimisation of the time of milk sample decontamination with 0.75% cethylpirydinium chloride upon identification of Mycobacterium avium subsp. paratuberculosis.

Isolation of MAP from biological material, including milk, is very difficult. No matter how the fresh milk is obtained, it contains a certain number of rapidly growing microorganisms. Therefore, the decontamination process is applied in the methods of MAP isolation. Investigations were therefore undertaken to determine the optimal time of milk sample decontamination with 0.75% CPC. The experiment was divided into two parts: determination of the survival time of M.smegmatis and E. coli in 0.75% CPC and determination of the time of raw milk decontamination. The results suggest that the optimal time of milk sample decontamination is 15 min.