Serially Checked Spherical Aberration Can Evaluate the Anti-Myopia Effect of Orthokeratology Lens in Children.

We aimed to investigate the changes in higher-order aberrations (HOAs) after wearing orthokeratology (OK) lenses in myopic patients. The study included 15 eyes from ten myopic patients, whose refractive error was myopia less than -4.5 diopters (D) and astigmatism less than 1.5 D. Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) were measured, and Zywave® aberrometry was performed at baseline and 1, 3, and 6 months following OK lens wear. The mean age was 11.5 years (range: 9-15 years). There was a significant improvement in UCVA (p ≤ 0.001) and a decrease in the spherical equivalent measured with auto-refraction at 6 months (p ≤ 0.001). Total HOAs significantly increased after OK lens wear (p ≤ 0.001), with spherical aberration increasing approximately 3.9-fold (p = 0.05). Spherical aberration demonstrated statistically significant positive correlations with the change in spherical equivalent at 3 and 6 months (p = 0.007 and 0.003, respectively). After wearing properly prescribed OK lens, all subjects had significantly improved UCVA and decreased myopic spherical equivalent, with increased total HOAs and positive spherical aberration at 1 month, and the changes were maintained at 6 months. Serially checked spherical aberration could evaluate the anti-myopia effect of the orthokeratology lens in children.

Validity of Tono-pachymetry for Measuring Corrected Intraocular Pressure in Non-surgical and Post-photorefractive Keratectomy Eyes.

PURPOSE: To assess the validity of central corneal thickness (CCT) and corrected intraocular pressure (IOP) values obtained by tono-pachymetry in non-surgical and post-photorefractive keratectomy (PRK) eyes. METHODS: For the study, 108 young healthy participants and 108 patients who had PRK were enrolled. Measurements were randomly performed by tono-pachymetry, ultrasonic (US) pachymetry, and Goldmann applanation tonometry (GAT). CCT measurement by tono-pachymetry was compared to that of US pachymetry. The corrected IOP value obtained by tono-pachymetry was compared to that obtained by US pachymetry and GAT. The corrected IOP from US pachymetry and GAT was calculated using the identical compensation formula built into the tono-pachymetry. Bland-Altman plot and paired t-test were conducted to evaluate the between-method agreements. RESULTS: The mean CCT measurement using tono-pachymetry was significantly greater by 7.3 µm in non-surgical eyes (p < 0.001) and 17.8 µm in post-PRK eyes (p < 0.001) compared with US pachymetry. Differences were significant in both Bland-Altman plotand paired t-test. The mean difference of corrected IOP values obtained by tono-pachymetry and calculated from measurements by US pachymetry and GAT was 0.33 ± 0.87 mmHg in non-surgical eyes and 0.57 ± 1.08 mmHg in post-PRK eyes. The differences in the Bland-Altman plot were not significant. CONCLUSIONS: The CCT measurement determined using tono-pachymetrywas significantly thicker than that of US pachymetry. The difference in CCT was greater in post-PRK eyes than in non-surgical eyes. However, the corrected IOP value obtained by tono-pachymetry showed reasonable agreement with that calculated from US pachymetry and GAT measurements.

Lamina cribrosa depth according to the level of axial length in normal and glaucomatous eyes.

PURPOSE: To compare the lamina cribrosa (LC) depth of the optic nerve head in normal and glaucomatous eyes over a wide range of axial length (AXL). METHODS: A total of 402 eyes, including 210 normal and 192 glaucomatous eyes, were imaged by spectral domain optical coherence tomography. Normal and glaucomatous eyes were each divided into three subgroups according to the level of AXL; long (> 26 mm), mid-level (23-26 mm), and short (< 23 mm). Visual field mean deviation (VF MD), LC thickness, and LC depth were compared between normal and glaucomatous eyes in each of the AXL subgroups. These parameters were also compared between normal and glaucomatous eyes in the three AXL subgroups. Factors associated with LC depth in each AXL subgroup were evaluated by univariate and multivariate regression analyses. RESULTS: A comparison of the three AXL subgroups in normal eyes showed that the LC was thinnest in the long AXL subgroup (short; 189.7 ± 24.1 µm, mid-level; 179.9 ± 34.3 µm, long; 149.2 ± 36.2 µm, p < 0.001), but LC depth did not differ significantly in the three subgroups (short; 527.1 ± 144.4 µm, mid-level; 578.2 ± 163.5 µm, long; 594.4 ± 187.5 µm, p = 0.144). In glaucomatous eyes, glaucoma severity assessed by VF MD did not differ significantly among the three AXL subgroups (short; -6.99 ± 8.50 dB, mid-level; -6.40 ± 7.64 dB, long; -4.61 ± 5.22 dB, p = 0.168). However, LC depth was greater in the long than in the short AXL subgroup (679.5 ± 192.7 µm and 555.9 ± 134.1 µm, respectively, p = 0.004), although neither subgroup differed significantly in LC depth from the mid-level AXL subgroup (611.8 ± 162.3 µm, p = 0.385, p = 0.090). LC thickness was significantly different between normal and glaucomatous eyes (p < 0.001). LC depth was not different between normal and glaucomatous eyes in both short and mid-level AXL subgroups (p = 0.297, 0.222), but differed in the long AXL subgroup (p = 0.022). The presence of glaucoma was associated with greater LC depth only in the long AXL subgroup (p = 0.012). CONCLUSIONS: LC depth may vary according to the level of AXL in glaucomatous eyes with a similar level of glaucoma severity, with the greatest LC depth found in eyes with long AXL. Those findings suggest that glaucomatous optic disc cupping would manifest differently according to the level of AXL.