Comparison of Visual Field Measurements in Glaucomatous Eyes using Oculus and Metrovision Perimeters.

Purpose: To investigate the agreement between the Oculus and Metrovision perimeters in the visual field evaluation of glaucoma patients. Methods: In this cross-sectional study, 41 consecutive glaucoma patients were enrolled. After detailed clinical examinations, visual field testing was performed for all patients using the Oculus and Metrovision perimeters. The interval time between the two visual field examinations was 30 min. Results: A total of 22 participants were male (53.7%) and the mean ± standard deviation (SD) age was 58.6 ± 9.1 years. The absolute average of the mean deviation (MD) in the oculus perimeter (8.24 ± 4.92 dB) was higher compared to the Metrovision perimeter (4.02 ± 4.62; P < 0.001). This difference was also evident in the Bland-Altman graph. The loss variance (pattern SD) values of Oculus perimeter (28.58 ± 16.40) and Metrovision perimeter (28.10 ± 28.45) were not significantly different; although based on the Bland-Altman plots in the lower MDs, the agreement is better and the data dispersion is lower, and in the higher MDs, the agreement is lower. The parameters of four visual field quadrants were also compared and showed poor correlations (P < 0.001). Conclusion: The Oculus and Metrovision perimeter devices have good agreement in lower MDs; however, they cannot be used interchangeably.

Seasonal variations in anterior segment angle parameters in myopes and emmetropes.

CLINICAL RELEVANCE: Seasonal variations are known to occur in a range of ocular parameters and in conditions including refractive error and glaucoma. It is of clinical importance to know if seasonal changes also occur in anterior segment angle parameters, given that they can influence these conditions. BACKGROUND: The study aimed to examine the seasonal variations in anterior segment angle parameters in healthy young adults. METHODS: Twenty-three emmetropic participants with a mean age of 26.17 ± 4.43 years and 22 myopic participants with a mean age of 27.27 ± 4.47 years completed four seasons of data collection. Anterior segment angle parameters were measured using swept-source anterior segment optical coherence tomography. Intraocular pressure (IOP) and objective refraction were also measured. Repeated-measures analysis of variance was used to determine the effect of season and refractive error on the various ocular parameters. RESULTS: A significant main effect of season was found for the majority of anterior segment angle parameters, including the angle opening distance at 500 and 750 µm from the scleral spur (p = 0.02, p = 0.006, respectively), angle recess area at 500 and 750 µm from the scleral spur (both p = 0.002), and trabecular iris space area at 500 and 750 µm from the scleral (p = 0.02, p = 0.008, respectively). However, measures of anterior chamber depth and trabecular iris angle did not exhibit statistically significant seasonal variations (all p > 0.05). A significant main effect of season was also found for the changes in IOP (p = 0.004) and objective refraction (p < 0.001). There was no season by refractive group interaction for any anterior segment angle parameter or IOP (all p > 0.05). CONCLUSION: There is a small but significant seasonal changes in the anterior segment angle parameters, refractive error, and IOP in healthy young adult males, in which the anterior segment angle dimensions are narrower, the IOP is higher, and the refraction is more myopic during winter.

Effect of cyclopentolate versus tropicamide on anterior segment angle parameters in three refractive groups.

CLINICAL RELEVANCE: Frequent clinical application of cycloplegia in clinical practice makes it essential to assess how this condition influences anterior segment angle parameters. BACKGROUND: This study aims to compare the effects of cyclopentolate and tropicamide on anterior segment angle parameters in three adult refractive groups. METHODS: Sixty healthy individuals were recruited and assigned into three refractive groups according to inclusion criteria. At baseline visit, anterior segment angle parameters were measured using anterior segment optical coherence tomography in the right eye. All measurements were repeated at two separate visits, one week apart, after administration of tropicamide 1% and cyclopentolate 1% at similar conditions. Main outcome measures were angle-opening distance, trabecular iris angle, trabecular iris space area and anterior chamber depth. Anterior segment angle parameters were recorded at temporal areas (180 degrees). RESULTS: Sixty participants (29 men and 31 women, age: 27.82 ± 4.71-years) completed the experiment. Baseline mean spherical equivalents were +1.52 ± 1.20 D, -0.04 ± 0.33 D and -1.91 ± 0.91-D in hyperopic, emmetropic and myopic groups, respectively. No statistically significant differences were found between tropicamide and cyclopentolate for all angle parameters in three refractive groups. Both drops induced an increase in all parameters in three refractive groups. Analysis between refractive groups revealed that a more hyperopic refraction was associated with less trabecular iris angle, angle-opening distance and anterior chamber depth parameters in baseline, after tropicamide and cyclopentolate instillations. CONCLUSIONS: Topical application of cycloplegic eye drops in healthy individuals leads to small but significant changes in anterior chamber depth and anterior segment angle parameters, regardless of refractive status. Moreover, lower values of anterior chamber depth and anterior segment angle parameters in hyperopic individuals after administration of cycloplegic drops should be taken into account during biometric measurement and phakic intraocular lens implantation. Due to shorter effect and recovery time and less ocular/systemic reaction of tropicamide versus cyclopentolate, tropicamide could be a recommended cycloplegic agent for diagnostic and therapeutic procedures.

Analysis of Age, Gender, and Refractive Error-Related Changes of the Anterior Corneal Surface Parameters Using Oculus Keratograph Topography.

PURPOSE: To assess refractive error, gender, and age-related differences in corneal topography of a normal population with Oculus Keratograph 4. METHODS: This cross-sectional study included a total of 500 normal eyes of 500 individuals with ages ranging from 10 to 70 years. All participants underwent detailed ocular examinations, including visual acuity measurement, slit-lamp examination, and refractive error evaluation. Slit-lamp examination was performed for all individuals to rule out apparent corneal diseases. Corneal topography parameters were assessed using Oculus Keratograph. The data were analyzed based on gender, refractive error, and age groups using independent sample t-test and one-way analysis of variance. RESULTS: Of a total of 500 participants (age: 29.51 ± 11.53 years) recruited for the present study, 66.4% were female, and 33.6% were male. The mean spherical equivalent of refraction was - 0.98 ± 1.65 diopters. Significant differences were noted in steep keratometry (P = 0.035) and corneal astigmatism (P = 0.014) between genders. Assessment of the data based on refractive error revealed significant differences in an index of vertical asymmetry (P < 0.001), index of height asymmetry (P = 0.003), and index of height decentration (P = 0.011). Considering age groups, significant differences were observed in flat keratometry readings (P < 0.001), mean corneal astigmatism (P = 0.02), minimum radius of curvature (P = 0.037), and apex power (P < 0.001). CONCLUSIONS: There was a prominent variation in some topographic parameters based on gender, age, and refractive error. The information on corneal parameters obtained with Oculus Keratograph from normal eyes provides a reference for comparison with diseased corneas.

Structure versus function in high myopia using optical coherence tomography and automated perimetry.

BACKGROUND: To examine the structure-function relationship between retinal thickness using spectral-domain optical coherence tomography and standard automated perimetry in high myopia. METHODS: The study population comprised 58 highly myopic individuals with no posterior abnormalities (mean spherical equivalent refraction ≤ -6.00 D and axial length ≥ 26.0 mm). All eyes underwent optical coherence tomography with the Spectralis spectral domain optical coherence tomograph and visual field evaluation with the Humphrey Field Analyzer II-i. Average macular layer thicknesses in each quadrant were calculated in a 6 × 6 mm area centred on the fovea. The visual field was assessed from 17 central locations (10°), approximately the equivalent of the area tested by optical coherence tomography in the macular scan. Linear correlations were made between different macular layer thicknesses and peripapillary retinal nerve layer thickness with their matched visual field sensitivities. RESULTS: Participant ages were 28.2 ± 6.4 years, mean spherical equivalent refractions were -8.20 ± 1.40 D and axial lengths were 26.7 ± 0.7 mm. There were significant positive correlations between layer thickness and corresponding visual field sensitivities as follows: ganglion cell layer in all quadrants, temporal quadrant of the nerve fibre layer with nasal quadrant of the visual field, inferior quadrant of the outer nuclear layer with superior visual field, and temporal-superior peripapillary nerve fibre layer with nasal-inferior visual field. CONCLUSION: The correlation between retinal layer thicknesses and visual field sensitivity could be explained by myopia-related losses due to lateral retinal stretching, with further research required to investigate this.

Visual field assessment in high myopia with and without tilted optic disc.

BACKGROUND: The aim was to evaluate the effect of the tilted optic disc on the visual field in highly myopic eyes. METHODS: A total of 58 eyes from 58 highly myopic individuals underwent detailed ophthalmic examination and were categorised into two groups according to the presence of a tilted optic disc. The visual field of 20 eyes (mean age of 28.95 ± 7.22 years) with tilted optic discs were compared with 38 eyes (mean age of 27.87 ± 6.08 years) of control subjects without tilted optic discs using the 30-2 SITA standard protocol with a Humphrey Field Analyzer - HFA II-i. Optic disc tilt was assessed from retinal photographs exported to Adobe Photoshop software. Disc ovality was assessed using the ratio of minimum to maximum disc diameter. A ratio of up to 0.80 was considered a tilted optic disc. RESULTS: Foveal threshold sensitivity showed no statistically significant difference between tilted and non-tilted groups (35.16 ± 2.71 dB versus 35.37 ± 2.35 dB, p = 0.76). The mean deviation was -3.29 ± 2.03 dB in the tilted group and -3.49 ± 2.56 dB in the non-tilted group (p = 0.77). Additionally, there were no significant differences in the average deviation between the two groups in four quadrants and four hemifields; however, the lowest average deviation was observed in the superotemporal quadrant in the tilted group (-4.54 ± 3.16 dB). In the non-tilted group, 29 per cent had no visual field defect, 24 per cent had an arcuate scotoma and 20 per cent had generalised depression. In the tilted group, 30 per cent had an arcuate scotoma, 30 per cent had generalised depression and 13 per cent had no visual field defect. Other visual field defects occurred at frequencies less than 15 per cent in both groups. CONCLUSIONS: The investigation of visual field patterns may be more appropriate than quantitative indices (for example, total mean deviation, foveal threshold sensitivity, average deviation) to assess the visual field in highly myopic patients with tilted optic discs.

Optical Coherence Tomography and Biometry in High Myopia with Tilted Disc.

PURPOSE: The purpose of this study was to compare retinal thickness and biometric parameters between highly myopic eyes with and without tilted optic discs. METHODS: A total of 60 eyes from 60 highly myopic individuals (defined as a mean spherical equivalent refraction of -6.00 D or greater and axial length ≥26 mm) underwent detailed ophthalmic examination. Twenty-one eyes (13 females and 8 males; mean age: 29 ± 7 years) with tilted optic discs were recruited and compared with 39 eyes (23 females and 16 males; mean age: 28 ± 6 years) of control subjects without tilted optic discs using spectral domain optical coherence tomography (OCT) and the Lenstar biometer. Disc ovality was assessed using the ratio of minimum to maximum disc diameter (index of tilt). A ratio of ≤0.80 was considered as a tilted optic disc. RESULTS: There were no significant differences in biometric parameters between two groups. However, myopia in the tilted disc group was significantly greater compared to the non-tilted group (-8.82 ± 1.58 D vs. -7.84 ± 1.22 D, p = 0.01). Comparison of OCT sectoral macular nerve fiber layer measurements between groups showed significant differences in inner ring thicknesses for the nasal (p = 0.01), inferior (p < 0.001), and temporal (p = 0.04) quadrants. A significant difference was also seen in outer ring macular nerve fiber layer thickness for the temporal quadrant (p = 0.03). No significant differences were demonstrated in optic disc peripapillary retinal nerve fiber layer (RNFL) thickness between the two groups. CONCLUSIONS: Mean spherical equivalent refractive error is strongly correlated with optic disc tilt; however, other biometric factors are independent of tilt. Structural examination of the eye using OCT can be employed to differentiate between eyes with tilted optic discs and those with normal discs. Peripapillary RNFL appears to be unaffected by tilted discs.