Integrating Clinical Data and Tear Proteomics to Assess Efficacy, Ocular Surface Status, and Biomarker Response After Orthokeratology Lens Wear.

Purpose: This study evaluated the efficacy and ocular surface status of Breath-O Correct, novel orthokeratology (OK) lenses, worn overnight for 3 months. Lens-induced changes in the tear proteome were evaluated. Methods: Thirty-one subjects, aged 19 to 26 years with refractive error from -1.00 to -5.00 D, were randomly assigned 1:1 to the treatment or control group. Refraction, visual acuity, corneal integrity, biomechanics and endothelial health, ocular surface changes, and subjective symptoms were assessed at the baseline, one-month, and three-month visits. The tear proteome was characterized over time using sequential window acquisition of all theoretical ion spectra mass spectrometry. Results: Lenses improved uncorrected visual acuity and reduced spherical powers with similar efficacy to other OK lenses. Significant reductions (P < 0.05) in corneal hysteresis (11.12 ± 1.12 to 10.38 ± 1.36 mm Hg) and corneal resistance factor (11.06 ± 1.32 to 9.90 ± 1.45 mm Hg) were observed in the treatment group after one month of lens wear, whereas other assessed factors remained unchanged. Thirteen and eight differentially expressed proteins were found after one month and three months of lens wear, respectively. Two proteins (proline-rich protein 27 and immunoglobulin V regions) were differentially expressed at both visits. Conclusions: Over a three-month period, Breath-O Correct lenses were overall safe, well tolerated, efficacious in refractive power reduction, and comparable with other OK lenses. Furthermore, their use caused only minor noninflammatory protein expression changes in the tear proteome. Translational Relevance: This study investigated the safety of orthokeratology contact lenses on the ocular surface in molecular aspects and standard clinical parameters.

Dynamic contour tonometry over silicone hydrogel contact lens.

PURPOSE: This study compared the measurements of intraocular pressure (IOP) and ocular pulse amplitude (OPA) using the Dynamic Contour Tonometry (DCT) over silicone hydrogel contact lenses of different modulus. Corneal biomechanics were also measured using the Ocular Response Analyzer (ORA). METHODS: Forty-seven young (mean age 22.3 years, standard deviation 1.2 years) subjects had IOP, OPA, corneal hysteresis (CH) and corneal resistance factor (CRF) measured without lens and with two brands of silicone hydrogel contact lenses. Each eye wore one brand followed by another, randomly assigned, and then the lenses switched over. Difference and agreement of IOP and OPA with and without silicone hydrogel contact lens were studied. RESULTS: The right and left eyes had similar corneal curvatures, central corneal thicknesses, IOP, OPA and corneal biomechanics at baseline. No significant difference was found in CH and CRF when they were measured over different contact lenses. IOP demonstrated a greater difference (95% limits of agreement: 2.73mmHg) compared with no lens when it was measured over high modulus silicone hydrogel lenses. Agreement improved over low lens modulus silicone hydrogel lenses (95% limits of agreement: 2.2-2.4mmHg). 95% limits of agreement were within 1.0mmHg for OPA. CONCLUSIONS: This study demonstrated the feasibility of DCT over silicone hydrogel lenses. Low lens modulus silicone hydrogel contact lens in situ has no clinical effect on DCT.

Pentacam anterior chamber parameters in young and middle-aged Chinese.

BACKGROUND: The aim was to compare the anterior segment of two groups of Chinese using the Pentacam system. METHODS: Fifty young (median age 21 years) and 50 middle-aged (median age 46 years) subjects with equal numbers of males and females had their axial length measured with the IOL Master. Their axial anterior chamber depth, anterior chamber volume and temporal and nasal anterior chamber angles were measured using the Pentacam and comparisons were made between the two groups. RESULTS: Both groups shared similar axial lengths (unpaired t-test: p = 0.37) but young subjects had significantly deeper anterior chamber by 11 per cent (3.60 ± 0.40 mm) compared with middle-aged subjects (3.24 ± 0.34 mm) (analysis of variance: p < 0.001). The anterior chamber volume was significantly greater in young subjects by 24 per cent (200.12 ± 35.59 mm(3)) than the middle-aged subjects (161.03 ± 37.79 mm(3)). The associations of anterior chamber depth and anterior chamber volume with axial length were significant (R(2) from 0.16 to 0.50) and similar in both groups. Young subjects had wider anterior chamber angles (mean differences: 4.60° and 6.07° at temporal and nasal, respectively) than middle-aged subjects. Among middle-aged subjects, females had significantly shorter axial length but anterior chamber depths were similar between the two sexes. Females had significantly smaller anterior chamber volumes. CONCLUSIONS: Middle-aged subjects had more crowded anterior chambers than young subjects with similar axial lengths. Anterior chamber volume may be a more sensitive parameter to reveal this difference than a linear measurement of the anterior chamber depth.