Search

Purpose: To analyze the relationship between the central corneal thickness (CCT) and mid-peripheral corneal thickness (PCT) with the degree of myopia [axial length (AL) and spherical equivalent refractive error (SE)]. Methods: 175 right myopic eyes from 175 patients were divided according to the degree of SE: group #1 (n = 76, 12.00 D). The CCT and PCT (3 mm from the apex to the superior, inferior, nasal and temporal locations) were measured with the Orbscan-II. Relative peripheral index (RPI) was calculated by dividing the PCT by the CCT. The AL was measured with the IOL Master, and the SE was obtained with subjective refraction. Results: AL was 25.18 ± 1.16 mm, 26.59 ± 1.26 mm and 29.45 ± 2.58 mm and SE was −3.31 ± 1.40 D, −8.32 ± 1.64 D and −16.44 ± 4.48 D for groups #1, #2 and #3, respectively. Non-statistically significant differences in central and peripheral corneal thickness were found between groups (P > 0.05 ANOVA). Non-significant relationship was found between central and peripheral corneal thickness with the AL and SE in the three study groups and in the total sample (r 0.05). The RPI values were similar between groups without significant difference between groups (P > 0.05 ANOVA). Linear relationship was found between RPI superior location in group #2 (r = −0.23; P = 0.04) and RPI nasal location in group #3 with the EE (r = 0.41; P = 0.03). Conclusion: There are no significant differences among low, moderate and extremely myopic eyes related to the CCT and PCT. Corneal thickness is very similar in myopic eyes with small differences that are not clinically relevant to myopic patient management.

To evaluate the intra-test variability of ARK-30 handheld autorefractor and the agreement with subjective refraction and retinoscopy after uneventful cataract surgery.Prospective and non-randomized study that included 6 visits by patients undergoing uneventful cataract surgery at IOBA (Instituto de Oftalmobiología Aplicada) Eye Institute (University of Valladolid).The mean age of the 79 patients was 66.5years (range 23-90years). For the 124 eyes, the mean spherical equivalent of the sample at baseline visit was -3.59±6.28D (range -21.00D to +4.44D).Automated refraction was performed on follow-up visits 1day and weekly for 4weeks. Retinoscopy and subjective refraction were conducted at the Week 4 follow up.Automated refraction.Sphere, cylinder and mean spherical equivalent, J(0) and J(45) coefficient variabilities were low in all visits. Standard deviations and the limits of agreement were smallest for the last visit. Subjective refraction sphere and cylinder values were more positive than autorefraction by 0.12±0.53D (P=0.031) and 0.23±0.42D (P0.001), respectively. Comparison between autorefraction and retinoscopy showed a similar trend with the sphere and cylinder differences, 0.32±0.77D and 0.38±0.43D (P0.05), respectively.The ARK-30 is sufficiently accurate and repeatable for automated refraction after uneventful cataract surgery. This instrument may be useful for monitoring refractive outcome in these patients.

Purpose: To determine the inter-examiner agreement of the manual values of central and peripheral corneal thickness as measured by optical coherence tomography (AS-OCT Visante) and to assess the agreement between AS-OCT Visante pachymetry, Orbscan II and ultrasound pachymetry (USP). Methods: Central and peripheral (4.0 mm from the corneal centre to the superior, inferior, nasal and temporal areas) corneal thickness was analyzed in 30 eyes of 15 patients (mean age, 26.8 ± 6.8 years), with the AS-OCT Visante both automatically (Global-Pachymetry Map) and manually (Flap Tool). The Orbscan II and USP (Corneo-Gage Plus) pachymetry were also assessed. Inter-examiner reproducibility for the manual values of the AS-OCT Visante was calculated. Automatic and manual AS-OCT pachymetries were compared for all corneal locations. Results: Good inter-examiner agreement was obtained for the manual values of the AS-OCT Visante for all locations studied (p = 1.00). The automatic value was significantly different from the manual value for both central and inferior pachymetry (37 ± 10 μm and 27 ± 11 μm respectively; p