Comparison in conjunctival-Tenon's capsule thickness, anterior scleral thickness and ciliary muscle dimensions between Caucasians and Hispanic by optical coherence tomography.

PURPOSE: To investigate the differences in the dimensions of the anterior ocular segment, and specifically in conjunctival-Tenon's capsule thickness (CTT), anterior scleral thickness (AST) and ciliary muscle thickness (CMT), between Caucasian and Hispanic subjects using swept-source optical coherence tomography (SS-OCT). METHODS: Cross-sectional study including 53 Hispanic and 60 Caucasian healthy participants, matched by age, sex and refractive error, who underwent a complete ophthalmological examination. CTT, AST and CMT were manually measured in the temporal and nasal quadrants at 0, 1, 2 and 3 mm from the scleral spur using SS-OCT. RESULTS: Mean age and refractive error were 38.7 ± 12.3 years and -1.05 ± 2.6 diopters, and 41.8 ± 11.7 years and -0.50 ± 2.6 diopters for the Hispanic and Caucasians, respectively (p = 0.165 and p = 0.244). The CTT was increased in the temporal quadrant in the Hispanic group in the three studied regions (CTT1, CTT2 and CTT3; being the means 223.0 ± 68.4, 215.3 ± 66.4 and 203.8 ± 67.1 µm versus 190.8 ± 51.0, 189.4 ± 53.2 and 187.4 ± 55.3 µm respectively; p < 0.001). Larger AST values were observed in the temporal quadrant in the Hispanic group (AST2: 559.8 ± 80.8 µm and AST3: 591.6 ± 83.0 µm) compared to the Caucasian group (520.7 ± 50.1 and 558.9 ± 54.7 respectively; p ≤ 0.022). No differences were observed in the nasal quadrant for CTT, AST1 and AST3 (p ≥ 0.076). No differences emerged in the CM dimensions (p ≥ 0.055). CONCLUSION: CTT and AST measurements were thicker in the temporal quadrant of Hispanic patients compared to Caucasians. This could have implications for the pathogenesis of different ocular diseases.

Normative Topographic Anterior and Posterior Corneal Astigmatism: Axis Distribution and Its Relations with Ocular and Biometric Parameters.

Corneal astigmatism correction is a key factor when planning refractive treatment for ametropies with intraocular lenses. We aim to obtain normative anterior and posterior corneal astigmatism (ACA and PCA, respectively) data in a local population and to describe their axis distribution and their association with other parameters. A total of 795 patients with no ocular diseases were evaluated with corneal tomography and optical biometry. Only data of the right eye were included. Mean ACA and PCA were 1.01 ± 0.79 and 0.34 ± 0.17 D, respectively. Vertical steep axis distribution was 73.5% for ACA and 93.3% for PCA. Axis orientation between ACA and PCA matched best for vertical orientation (especially 90° to 120°). Vertical ACA orientation frequency decreased with age, with a more positive sphere and less ACA. Vertical PCA orientation frequency increased with higher PCA. Eyes with vertical ACA orientation were younger and showed a greater white-to-white (WTW) measurement, anterior corneal elevations, ACA and PCA. Eyes with vertical PCA orientation were younger and showed greater anterior corneal elevations and PCA. Normative ACA and PCA data in a Spanish population were presented. Steep axis orientations presented differences with age, WTW, anterior corneal elevations and astigmatism.

Dimensions of the limbus-ciliary sulcus region by OCT and correlation study in a large population.

PURPOSE: To assess the dimensions of the limbus-ciliary sulcus region measured by swept-source optical coherence tomography (SS-OCT) and conduct a correlation study in a large healthy population. SETTING: Centro Internacional de Oftalmología Avanzada, Madrid, Spain. DESIGN: Cross-sectional study. METHODS: The dimensions of the limbus-ciliary sulcus region were measured in the temporal and nasal quadrants using a SS-OCT. The limbus-sulcus distance (LSD), the posterior iris line-ocular surface to limbus distance (PIOLD), and the angle-to-sulcus distance (ASD) were measured. These distances were then assessed for correlations with factors such as age, sex, refractive error, anterior chamber angle (ACA), ciliary muscle thickness (CMT), conjunctival-Tenon capsule thickness (CTT), and anterior scleral thickness (AST). RESULTS: The mean age of the participants was 41.0 ± 18.2 years (range 5 to 86) and the mean refractive error -0.75 ± 3.3 diopters (range -10 to 7). The LSD could be measured in 93.2% of the participants (625 eyes out of 670 eyes), with a mean of 1.35 ± 0.12 mm (range 0.96 to 1.75) and 1.33 ± 0.12 mm (range 1.05 to 1.68) in the temporal and nasal quadrants, respectively, and a correlation of R = 0.616 (P < .001) between them. PIOLD measured 2.22 ± 0.31 mm (1.42 to 2.98), and ASD was 0.21 ± 0.05 mm (0.01 to 0.40). No correlation was observed between LSD with age, spherical error, sex, or ACA (P ≥ .247). However, LSD exhibited the highest correlation with AST (R = 0.466), followed by CTT (R = 0.309) and CMT (R = 0.259). CONCLUSIONS: The SS-OCT allowed for an accurate in vivo measurement of the dimensions of the limbus-ciliary sulcus region.

Impact of age, sex and refractive error on conjunctival and Tenon's capsule thickness dimensions by swept-source optical coherence tomography in a large population.

PURPOSE: To evaluate conjunctival and Tenon's capsule thickness (CTT) in a large healthy population using swept-source optical coherence tomography (SS-OCT), investigating the impact of age, sex and refractive error. METHODS: 630 healthy participants underwent a complete ophthalmological examination. CTT was manually measured in the temporal and nasal quadrants at 0, 1, 2 and 3 mm from the scleral spur using SS-OCT (CTT0, CTT1, CTT2 and CTT3, respectively). These dimensions were then assessed for associations in a multivariate regression model with age, sex, refractive error and anterior scleral thickness (AST). The reproducibility of the CTT measurements was determined in 30 individuals. RESULTS: CTT dimensions could be measured in 596 cases (94.6%); mean age was 42.6 ± 17.2 years (range 5-86). Mean CTT0 was 199.2 ± 33.8 and 192.9 ± 33.9 µm, mean CTT1 195.4 ± 38.0 µm and 199.9 ± 50.9 µm, mean CTT2 187.0 ± 38.4 and 194.8 ± 48.9 µm, and CTT3 180.5 ± 35.6 µm and 191.8 ± 43.7 µm, for the temporal and nasal quadrants, respectively. No difference in CTT was observed in the nasal versus temporal quadrant (p ≥ 0.106) except for the CTT0 and CTT3 (p = 0.001). Moderate correlation was observed between nasal and temporal CTT (R = 0.472, p < 0.001). In the multivariate model, no influence was observed by sex, refractive error and AST on CTT measurements (p ≥ 0.065). Negative association was observed between age and CTT (p < 0.005). The reproducibility was excellent (intraclass correlation coefficient ≥ 0.908). CONCLUSIONS: SS-OCT allows for in vivo CTT evaluation. Our data document a wide range of measurements, showing negative association between CTT and age.

Normative Pentacam anterior and posterior corneal elevation measurements: effects of age, sex, axial length and white-to-white.

PURPOSE: To provide normal corneal elevation data for a large Caucasian population and to determine the impacts on these data of age, sex, axial length (AXL) and horizontal white-to-white (WW). SETTING: Centro Internacional de Oftalmología Avanzada, Madrid, Spain. DESIGN: Retrospective, cross-sectional, observational. METHODS: In this retrospective, cross-sectional, observational study, anterior and posterior corneal elevations were measured in 789 right eyes of subjects with no ocular disease at the thinnest corneal location in relation to a fixed 8-mm best-fit sphere using the Pentacam, and AXL and WW were measured with the IOLMaster. A multiple linear regression model was used to assess the effects of age, sex, AXL and WW on the elevation data. RESULTS: Mean subject age was 50.5 ± 15 years (range 17-93 years); 64% were women. Mean anterior and posterior corneal elevations were 1.99 ± 1.75 µm (- 7 to 10 µm) and 7.70 ± 5.7 µm (- 6 to 28 µm). Anterior corneal elevations were higher by 0.165 µm and 0.033 µm for every mm reduction in AXL and every year reduction in age, respectively. Sex and WW were not significant predictors of anterior elevations (R2 = 7.7%). Posterior corneal elevation increased by 0.186 µm/year of age, 0.707 µm/mm reduction in WW and 0.819 µm/mm reduction in AXL. This variable was also 0.866 µm greater in men (R2 = 34.4%). CONCLUSION: Anterior corneal elevations decrease with age and are higher for shorter AXL but are not influenced by sex or WW. Posterior corneal elevations increase with age, decreasing AXL, decreasing WW and are higher in men.

Schlemm's canal measured by optical coherence tomography and correlation study in a healthy Caucasian child population.

PURPOSE: To measure the Schlemm's canal (SC) in vivo by Fourier-domain optical coherence tomography (FD-OCT) in a Caucasian paediatric population. METHODS: Participants of this cross-sectional study were 290 healthy children. In the right eye of each child, SC cross-sectional diameter and area measurements were made with the FD-OCT instrument RTVue® (Optovue Inc, Fremont, CA, USA) in the nasal and temporal quadrants. These SC variables were then assessed for correlation with the factors age, gender, refractive error, anterior chamber angle and trabecular meshwork (TM) metrics. Finally, the reproducibility of the SC measurements was assessed in 30 of the participants. RESULTS: Mean participant age was 10.7 ± 3.4 years (range 3-18). SC diameters could be measured in both quadrants in 70.6% and 70.4% of subjects, respectively. Mean SC diameters were similar (p = 0.125) for the temporal and nasal quadrants: 266.7 ± 84.1 µm (range 131-509) and 273.2 ± 77.3 µm (range 124-486), respectively. Mean SC areas were also similar (p = 0.167) for the two quadrants: 9975 ± 3514 µm2 (range 4000-23 000) versus 9688 ± 3297 µm2 (range 3000-24 000). No differences were detected in SC measurements according to gender, refractive error or angle and TM measurements (R ≤ 0.116; p ≥ 0.125). The exception was age which was directly correlated with SC size (p ≤ 0.041). The reproducibility of the SC measurements was excellent (intraclass correlation coefficients ≥0.936). CONCLUSION: FD-OCT allows the identification of the SC in children. Our data indicate an increase in SC size produced with age.