Corneal Diameter Research Articles

Analysis of Asphericity and Corneal Longitudinal Spherical Aberration of 915 Chinese Myopic Adult Eyes.

To analyze the corneal asphericity, longitudinal spherical aberration (LSA), and related factors in Chinese myopic adult eyes. This was a retrospective study of myopic adult patients. The corneal asphericity and LSA were measured at 3.0, 4.0, 5.0, 6.0, and 7.0 mm diameter apertures using corneal tomography. Age and refractive power were recorded for correlation analysis. In total, 531 females and 384 males were included. At the above five diameter settings the corneal asphericity values (Q) of the anterior surface were -0.09±0.21, -0.14±0.16, -0.15±0.13, -0.17±0.11, and -0.20±0.11, and those of the posterior surface were 0.23±0.49, 0.06±0.29, -0.01±0.22, -0.07±0.16, and -0.08±0.15, respectively. The anterior corneal LSA values at these diameters were 0.39±0.19, 0.63±0.27, 0.97±0.36, 0.90±0.30, and 0.83±0.29 D, respectively and the whole corneal values were 0.26±0.20, 0.44±0.27, 0.70±0.36, 0.66±0.30, and 0.59±0.28 D, respectively. Corneal asphericity and peripheral LSA showed no or weak correlation with age or spherical equivalent (all r < 0.2). Corneal anterior and posterior Q values in myopia patients are negatively correlated with corneal diameter. Corneal anterior and whole corneal LSA increased significantly with diameter up to 5 mm, then decreased slightly with diameter. Corneal asphericity and peripheral LSA showed very weak or no correlation with age or spherical equivalent. ChiCTR1800015985.

Adaptive Features of the Eye to the Ecological Habit of the Short-Eared Owl Asio flammeus and Japanese Scops Owl Otus semitorques

In this study we investigated the eye morphology and retinal topography of two owl species in relation to their visual environment. Although Short-eared Owl Asio flammeus is larger and weighs more than Japanese Scops Owl Otus semitorques, its eye dimensions (weight, corneal diameter, and axial length) are all smaller than the scops owl's. Owl retinas were examined in Nissl-stained whole-mount preparations. The total number of retinal ganglion cells (RGCs) was greater in the Japanese Scops Owl (4,703.0×103 cells) than in the Short-eared Owl (2,346.8×103 cells). The eye morphology of, and the number of RGCs in the Japanese Scops Owl indicate that it is more adapted to a nocturnal habit. An area of high-density RGCs was horizontally distributed in the temporal retina of the Short-eared Owl, with a peak density of 17.4×103 cells/mm2. In the Japanese Scops Owl's temporal retina, there was an oval-shaped arrangement with a peak density of 23.1×103 cells/mm2. These distributions indicate that whereas Short-eared Owl is adapted to open habitats, Japanese Scops Owl is adapted to enclosed habitats. The RGCs of both species were classified into three categories (small, medium, and large) based on the size and appearance of somas. In both species, medium-sized cells predominated, and the proportion of large-sized cells was smallest. The distribution and high-density areas differed among these groups, suggesting adaptation to the visual environment. The high-density areas of these groups cover the nasal visual fields, which include the overlap for binocular vision.

Childhood glaucoma profile in a tertiary centre in Egypt according to the childhood glaucoma research network classification.

To describe the prevalence and clinical characteristics of a large cohort of childhood glaucoma patients that presented to a tertiary Egyptian children's hospital using the childhood glaucoma research network (CGRN) classification. A retrospective review of the medical records of all patients ≤ 14 years with a diagnosis of childhood glaucoma or glaucoma suspects who presented to Children's Hospital between January 2014 to December 2019 was conducted. Data collected included age at the time of diagnosis, gender, laterality, prenatal history, parental history, including consanguinity, intraocular pressure, horizontal corneal diameter, and cup-to-disc ratio. A total of 1113 eyes of 652 patients with diagnoses of either childhood glaucoma or glaucoma suspects were included in the study. Six hundred and sixteen patients (94%) were born full-term. A history of positive parental consanguinity was identified in 334 patients (51.2%). Almost 60% of patients were males. Primary congenital glaucoma (PCG) was the most prevalent diagnosis (68.2%), followed by glaucoma suspects (10.4%) and glaucoma following cataract surgery (GFCS) (8.4%). Juvenile open-angle glaucoma was the least prevalent category (0.3%). Other categories including glaucoma associated with non-acquired systemic disease, glaucoma associated with non-acquired ocular disease, and glaucoma associated with acquired conditions represented 5.8%, 4.7%, and 1.9%, respectively. PCG is the most common form of glaucoma in Egypt. More than half of the pediatric glaucoma patients had a positive history of parents' consanguinity.

Using Artificial Intelligence to Quantify Sexual Dimorphism in Aesthetic Faces: Analysis of 100 Facial Points in 42 Caucasian Celebrities.

Sexual dimorphism has been studied in the faces of average populations and worldwide celebrities; however, a focused analysis of attractive Caucasian faces has not been conducted. The study harnesses the power of artificial intelligence (AI) to efficiently analyze these facial patterns in attractive Caucasian male and female celebrities. Twenty-one male and 21 female Caucasian celebrities were selected based on popular editorial rankings, modeling agencies, and casting directors from 2017 to 2022. Frontal photographs of celebrities aged 23 to 42 without facial animation were selected. One hundred facial landmarks were identified using semi-automatic image analysis software consisting of modified Apple Vision (Cupertino, CA) machine-learning algorithms with additional custom landmarks. Measurements were converted to absolute distances by fixing subjects' white-to-white corneal diameters to the validated average in Caucasians. Attractive females had significantly greater upper and middle facial proportions, more uniformly divided facial thirds, and greater canthal tilt compared with males. Attractive males had significantly greater facial height, bizygomatic and bigonial widths, medial and total brow lengths, and alar width than females. The golden ratio (1.618) was observed in the ratio of facial height to bigonial width in females (1.613), and attractive males closely approximated that ratio (1.566). There were no significant differences in interpupillary distances, eyebrow angles, or horizontal palpebral fissure lengths. No faces in either sex exhibited scleral show. The study is the first to utilize AI in quantifying key sexual dimorphisms among Caucasian celebrity faces. Identifying these contemporary patterns may provide valuable considerations in planning facial aesthetic and gender affirmation surgery.

Comprehensive comparisons of ocular biometry: A network-based big data analysis

PurposeTo systematically compare and rank ocular measurements with optical and ultrasound biometers based on big data.MethodsPubMed, Embase, the Cochrane Library and the US trial registry (www.ClinicalTrial.gov) were used to systematically search trials published up to October 22nd, 2020. We included comparative studies reporting the following parameters measured by at least two devices: axial length (AL), flattest meridian keratometry (Kf), steepest meridian keratometry (Ks), mean keratometry (Km), astigmatism (AST), astigmatism vectors J0 and J45, anterior chamber depth (ACD), aqueous depth (AQD), central corneal thickness (CCT), corneal diameter (CD) and lens thickness (LT). A network-based big data analysis was conducted using STATA version 13.1.ResultsAcross 129 studies involving 17,181 eyes, 12 optical biometers and two ultrasound biometers (with both contact and immersion techniques) were identified. A network meta-analysis for AL and ACD measurements found that statistically significant differences existed when contact ultrasound biometry was compared with the optical biometers. There were no statistically significant differences among the four swept-source optical coherence tomography (SS-OCT) based devices (IOLMaster 700, OA-2000, Argos and ANTERION). As for Ks, Km and CD, statistically significant differences were found when the Pentacam AXL was compared with the IOLMaster and IOLMaster 500. There were statistically significant differences for CCT when the OA-2000 was compared to Pentacam AXL, IOLMaster 700, Lenstar, AL-Scan and Galilei G6.ConclusionFor AL and ACD, contact ultrasound biometry obtains the lower values compared with optical biometers. The Pentacam AXL achieves the lowest values for keratometry and CD. The smallest value for CCT measurement is found with the OA-2000.

Clinical and diagnostic imaging profile of three anterior segment dysgenesis disorders presenting with infantile corneal opacities.

To describe three anterior segment dysgenesis disorders with infantile corneal opacities, namely, congenital hereditary endothelial dystrophy (CHED), primary congenital glaucoma (PCG), and Peters anomaly (PA) in terms of clinical characteristics, histopathology, genetic association, and diagnostic imaging profiles using imaging modalities such as ultrasound biomicroscopy (UBM) and microscope-integrated intraoperative optical coherence tomography (i-OCT). Seventy-four eyes with 22 eyes of CHED, 28 eyes of PA, and 24 eyes of PCG were clinically evaluated and underwent imaging using UBM and i-OCT. Corneal buttons of 16 operated patients underwent histopathological analysis, while genetic analysis was done in 23 patients using whole-exome sequencing. Corneal diameters (CD) and UBM parameters like anterior chamber depth (ACD), iris thickness (IT), and ciliary body (CB) thickness revealed a statistically significant difference between the three categories. In PA, 9 eyes had a third rare phenotype with only a posterior corneal defect with no iris adhesions. Genetic mutations were seen in all tested patients with CHED, in 83.3% of patients with PCG, and in 80% of patients with the third type of PA. i-OCT helped in the characterization of corneal opacity, identification of posterior corneal defects, iridocorneal adhesions, and contour of Descemet's membrane. Overlapping phenotypes of the above disorders cause a diagnostic dilemma and parameters like CDs, UBM ACD, IT, and CB thickness help differentiate between them. i-OCT can help in classifying the diseases in a high resolution, non-contact manner, and can better delineate corneal characteristics. The rare third type of PA phenotype may have a genetic association.

Repeatability of new optical biometer and agreement with 2 validated optical biometers, all based on SS-OCT.

To evaluate the repeatability of the measurements provided by a new optical biometer (EyeStar 900) based on swept-source optical coherence tomography (SS-OCT) and their agreement with the measurements given by 2 validated biometers based on the same technology, the IOLMaster 700 and Argos. IRCCS G.B. Bietti Foundation, Rome, Italy. Prospective evaluation of diagnostic test. In a series of unoperated eyes, 3 consecutive scans were acquired with the EyeStar 900, and 1 with the IOLMaster 700 and the Argos. The following biometry parameters were analyzed: axial length (AL), keratometry (K), corneal astigmatism, central corneal thickness, corneal diameter (CD), anterior chamber depth (ACD), lens thickness (LT), and lens tilting. Repeatability was assessed using test-retest variability, the coefficient of variation (CoV), and the intraclass correlation coefficient (ICC); agreement was based on the 95% limits of agreement. 56 eyes of 56 patients were analyzed. High repeatability was achieved for all measured parameters, as the CoV was <1% in most cases and ICC was >0.95 for all parameters. Good to high agreement was found among the measurements of the 3 optical biometers, although some statistically significant differences were detected between the EyeStar 900 and Argos (mean K, ACD, LT, and CD were higher with the Argos). The Argos measured a shorter AL in eyes >25 mm. The new generation SS-OCT EyeStar 900 optical biometer produces highly repeatable measurements that are in good agreement with those provided by 2 previously validated instruments.

The inflammatory cytokine profiles and ocular biometric characteristics of primary angle-closure glaucoma.

To investigate the pathogenesis of primary angle-closure disease (PACG) by measuring the anatomical structures of the anterior and posterior segments of the eye and inflammatory markers in the peripheral blood. This case-control study enrolled patients diagnosed with acute PACG (APACG) and chronic PACG (CPACG). It also enrolled control subjects without PACG. The anterior and posterior anatomical features were measured in all study participants. The levels of interleukin (IL)-6, tumour necrosis factor-α and the neutrophil-to-lymphocyte ratio (NLR) in the peripheral blood were measured. This study analysed a total of 99 eyes: 34 eyes from 34 patients with APACG, 28 eyes from 28 patients with CPACG and 37 eyes from 37 control patients with senile cataract. The axis length, corneal diameter, anterior chamber depth and anterior chamber volume were significantly smaller in the APACG and CPACG groups compared with the controls. The level of IL-6 in the peripheral blood of patients with PACG was significantly lower than that of the controls. The NLR in the peripheral blood of patients with PACG was significantly greater than that of the controls. Changes in the ocular anatomy and some inflammatory markers might be involved in the pathogenesis of PACG.

The Agreement of the Nomogram Tool and Ultrasound Biomicroscopy Images in Calculating Ultrasound Cycloplasty Probe Model in Chinese Patients

Purpose: The aim of the study was to compare and explore the agreement between the nomogram tool and ultrasound biomicroscopy (UBM) images method to calculate the ultrasound cycloplasty (UCP) probe model in Chinese glaucoma patients. Methods: Retrospective analysis of Chinese glaucoma patients who visited Zhongshan Ophthalmic Center in Guangzhou from January to December 2019 and were eligible for UCP surgery. Visual acuity, intraocular pressure (IOP), ocular axial length (AL), and horizontal corneal diameter (white to white [WTW]) were measured. UBM images with clear ciliary body imaging and AL and WTW data were sent to trained personnel for probe model measurements. The data calculated by both methods were analyzed using unweighted and weighted κ statistics. The level of agreement refers to Landis and Koch’s guideline for the strength of agreement indicated with weighted κ values. Results: 1,061 eyes of 642 patients were involved, with a mean age of 61.66 ± 11.66 years. Their best-corrected visual acuity converted to logarithm of minimal-angle-of-resolution (logMAR) scores of −0.18–3.00 with a mean value of 0.69 ± 0.77. IOP was 22.0–60.0 mm Hg with a mean of 27.97 ± 5.66 mm Hg. The mean AL and WTW were 22.88 ± 1.33 (19.15–32.14) mm and 11.52 ± 0.49 (10.00–12.90) mm, respectively. The agreement between the two methods was fair (weighted κ = 0.299), matching in 62.86% of eyes (weighted κ = 0.299, κ = 0.264). The agreement in primary open angle glaucoma, acute primary angle-closure glaucoma, chronic primary angle-closure glaucoma, and secondary glaucoma patients was 60.85% (weighted κ = 0.336, κ = 0.301), 65.06% (weighted κ = 0.146, κ = 0.127), 62.26% (weighted κ = 0.204, κ = 0.184), and 57.97% (weighted κ = 0.332, κ = 0.280) of eyes, respectively. Conclusion: The agreement between UBM images and the nomogram tool to calculate the UCP probe model of Chinese patients is at a fair level. The nomogram tool prefers to use larger probes. Improvements to the nomogram tool, such as including data from more ethnic groups and being able to calculate separately for different types of glaucoma, are needed to improve accuracy. The inclusion of parameters or images from more directions of the eye may help measure probe models more accurately for both the nomogram tool and the UBM image measurement.

Large deletion of cyp1b1 in a case of primary congenital glaucoma identified with mlpa

Primary congenital glaucoma (PCG) is an inherited ocular abnormality that is caused by mutation in CYP1B1 gene. Report of large deletion or gene copy number variants of CYP1B1 in PCG is uncommon. In this case report we describe a rare case of PCG with whole CYP1B1 deletion with implication for changes in detecting mutation of CYP1B1 gene. Clinical, ophthalmological, genetic, and pedigree information of the proband is described and discussed in detail in this case report. The deletion was identified using the Multiplex ligation-dependent probe amplification (MLPA) method. Whole deletion of CYP1B1 was identified using MLPA. Intra ocular pressure (IOP) of the right eye was 38mmHg and that of the left eye was 35mmHg. Corneal diameters of both eyes were 13mm horizontal and 12mm vertical. The patient underwent a total of five operations with the first operation performed when he was 2.5 months old. Further investigation revealed that the patient’s grandfather was exposed to a large quantity of 2,3,7,8-tetrachlorodibenzo-p-dioxin. CYP1B1 deletion albeit rare can cause Primary Congenital Glaucoma with poor prognosis and MLPA should be used to detect large deletion and gene copy number variation when sequencing method fails to detect mutations.

Evaluation of a Protocol for Diagnosis and Treatment of Primary Congenital Glaucoma in Tanta University Eye Hospital

Background: Primary congenital glaucoma is the most common type of glaucoma in infancy. It manifests within the first few years of life and is not associated with any other systemic or ocular abnormalities. This study aimed to evaluate a protocol for diagnosis and treatment of primary congenital glaucoma at Tanta University Eye Hospital.&#x0D; Methods: The study was prospective interventional on 60 eyes of 36 infants and children who presented between December 2018 to March 2021 at Tanta University Eye Hospital in Egypt. All patients were presented with primary congenital glaucoma and were managed according to specific diagnostic, therapeutic and follow up regimen. Pre- and Post-operative clinical data were recorded, and results were studied.&#x0D; Results: The mean of age±SD (range) at first presentation was 11.33±21.76 (0.5-120) months and of follow-up period was 7.85±2.71 (4-13) months. The mean of pre-operative IOP, corneal diameter, C/D ratio and AxL was 24.1±5.9 (12–41.5) mmHg, 12.97±0.69 (11–14.5) mm, 0.57±0.18 (0.2–0.9) and 21.87±1.28 (19.1–26.8) mm respectively, and post-operatively was 14.4±3.09 (8.5–20.5) mmHg, 12.71±0.89 (11–14.5) mm, 0.48±0.22 (0.2–1) and 22.16±1.53 (19–25.9) mm respectively. Surgical interventions included 1ry surgeries (trabeculotomy in 21 eyes and CTT with MMC in 39 eyes), 2ry surgeries (CTT with MMC in four eyes) and 3ry surgery (Ahmed valve implantation in one eye). Complete success was achieved in 38 eyes (63.3%) and qualified success in 22 eyes (36.7%).&#x0D; Conclusions: The current protocol applied at Tanta University Eye Hospital for diagnosis and treatment of primary congenital glaucoma proved efficacy and safety. Primary surgical intervention in the form of trabeculotomy (for mild cases) and combined trabeculotomy-trabeculectomy with MMC (for moderate to advanced cases) is a successful regimen for management of these eyes.

Retinal injury identified by overhead-mounted optical coherence tomography in two young children with infantile-onset glaucoma

PurposeTo report and characterize unexpected retinal findings identified by imaging with overhead-mounted optical coherence tomography (OCT) in 2 young children with infantile-onset glaucoma. MethodsChildren with glaucoma were imaged during clinically indicated examinations under anesthesia using overhead-mounted HRA+OCT Spectralis with Flex module (Flex-OCT, Heidelberg, Germany) from February 2017 through February 2022. Imagers prioritized scans of the peripapillary retinal nerve fiber layer (pRNFL), optic nerve head, and macula. Children imaged before age 2 years with images adequate for evaluation were included. Age at glaucoma diagnosis, glaucoma type, highest intraocular pressure (IOP), corneal diameter (CD), and axial length (AL) were recorded. ResultsA total of 41 children (71 eyes with glaucoma) were imaged before age 2 years. Macular imaging identified both inner and outer retinal thinning in 3 eyes of 2 young children (both eyes of a child with newborn primary congenital glaucoma (PCG) and 1 eye of a child with glaucoma following cataract surgery), which remained stable over time. These findings were present in 2 of 41 children (4.9%) and 3 of 71 eyes (4.2%) imaged with Flex-OCT. Neither highest IOP, CD, nor AL at imaging differentiated the 3 eyes with retinal changes from the larger group. ConclusionsThree eyes of 2 young children with refractory glaucoma of different etiologies and highly elevated IOP demonstrated areas of inner and outer retinal thinning, consistent with retinal injury from probable prior macular ischemia. Unexpected retinal pathology identified on Flex-OCT imaging in infantile-onset glaucomas highlights the need for continued study of the pathophysiology of this disease.▪

White to white cornea diameter and mesopic pupil size in patients with keratoconus

Objectives: Keratoconus is characterized by the abnormal cornea structure and it is manifested by changes in anterior segment parameters responsible for ocular high order spherical aberrations. The aim of the study is to investigate cornea horizontal white to white diameter and mesopic pupil size in patients with keratoconus. Methods: The medical records of each participant were reviewed. The horizontal white to white cornea diameter and the mesopic pupil size were measured with the Sirius Topography System in 215 eyes of 123 subjects. Two groups were formed, the first group included 113 eyes with keratoconus and the second group is composed of 102 healthy eyes. Differences in sex, age, cornea diameter and mesopic pupil size between two groups were analyzed statistically. Results: There were no statistically significant differences in sex and age distribution between the two groups (p&gt;0.05). The average horizontal corneal diameter was 11.98±0.33 mm in the 1st group and 11.81±0.24 mm in group 2. It was significantly higher in patients with keratoconus than in healthy subjects. (p=0.04) The mean mesopic pupil size was 3.64±0.12 mm in group 1 and it was 3.73±0.14 mm in group 2. The mesopic pupil size was significantly higher in healthy subjects than in patients with keratoconus (p=0.03). Conclusion: This study showed that while the horizontal white to white diameter of the cornea increases in keratoconus, the mesopic pupil size decreases. In clinical practice, these two parameters should be considered in treatment procedures of patients with keratoconus.

Outcomes of early versus delayed trabeculotomy for primary congenital glaucoma.

In patients with primary congenital glaucoma (PCG), elevated intraocular pressure (IOP) causes abnormal eye growth. This study compared the outcomes of children with PCG who underwent ab externo trabeculotomy (TROC) at age ≤ 6months (early TROC) and of those who underwent TROC at age > 6months (delayed TROC). Intraocular pressure, horizontal corneal diameter (HCD), central corneal thickness (CCT) and axial length (AL) were compared before TROC and at 1-, 3-, 6- and 12-month follow-up visits between the groups of children who underwent TROC until or after 6months of age. The ALs of these groups were also compared with the ALs of healthy age-matched eyes examined under the same conditions. Trabeculotomy was performed in 43 children: 18 (33 eyes) aged 6months (group 1) and 25 (37 eyes) aged >6months (group 2); the mean ages were 86.56 ± 53.64 and 504.48 ± 448.14 days, respectively. The mean pre- and 12-month postoperative IOP values were 15.97 ± 4.78/16.62 ± 4.85 and 9.77 ± 2.88/10.93 ± 4.83 mmHg, respectively. Delayed TROC was associated with abnormal AL in 31 (88.6%) out of 37 eyes, while after early TROC, only 13 (41.9%) out of 33 eyes had abnormal AL (chi-square, 8.00; p= 0.03). In multivariable analysis, each 1-mmHg increase in preoperative IOP was associated with a 0.25-mmHg increase at 12 months (p= 0.04). On average, the mean IOP of the delayed TROC group was higher than that of the early TROC group by 3.72 mmHg at postoperative month 12 (95% CI=0.44-6.99; p= 0.02). Compared with delayed TROC, early TROC is associated with reduced IOP and substantially reduced incidence of abnormal AL at postoperative month 12.

Association between Refractive Errors and Ocular Biometry in an Elderly Population.

The anterior chamber depth in hyperopic eyes is significantly deeper than that in myopic eyes, and this finding is independent of the axial length. This study aimed to determine the relationship between and refractive errors and ocular biometric components in a geriatric population 60 years and older. The present population-based cross-sectional study was performed using a multistage random cluster sampling method in Tehran, Iran. After selecting the samples, visual acuity measurement, autorefraction, subjective refraction, and slit-lamp examination were performed for all participants. Ocular biometric indices were measured with Pentacam AXL (Oculus, Wetzlar, Germany). The correlation coefficients of spherical equivalent with axial length, corneal radius of curvature, axial length/corneal radius of curvature ratio, and anterior chamber depth were -0.40, 0.14, -0.63, and -0.18, respectively, after controlling the effects of age, sex, and nuclear cataract. The axial length (24.84 vs. 21.21 mm), the anterior chamber depth (2.74 vs. 2.34 mm), the ratio of the axial length to the corneal radius of curvature (3.35 vs. 2.71), and the anterior chamber volume (138.59 and 105.54 mm 3 ) were the highest and lowest in myopic and hyperopic individuals, respectively (all P < .001). In the first model, axial length and nuclear cataract were significantly inversely related to the spherical equivalent. However, corneal radius of curvature, anterior chamber depth, central corneal thickness, and corneal diameter had a significant direct relationship with the spherical equivalent. In the second model, the axial length/corneal radius of curvature ratio and cataract showed an inverse relationship with the spherical equivalent, whereas anterior chamber depth and corneal diameter had a direct relationship with the spherical equivalent. Among the biometric components, the axial length/corneal radius of curvature ratio has the strongest relationship with refractive errors. The anterior chamber depth is lower in myopes compared with hyperopes after controlling the effect of axial length.

Changes in corneal diameter in myopic children during 18 months randomly assigned to orthokeratology lenses or single‐vision spectacles

AbstractPurpose: Orthokeratology lenses (OKL) have been shown to reduce axial length elongation in myopic children. OKL are costume fit, reverse geometry lenses. One of the parameters used to ensure lens fitting is the corneal diameter. The purpose of this study was to investigate changes in corneal diameter during 18 months in myopic children randomized to OKL or single‐vision spectacles (SVS).Methods: This study was an 18‐month 1:1 randomized, controlled trial of Danish myopic children aged 6–12 years with myopia ranging from 0.5 to 4.75 diopters (D) spherical component and refractive astigmatism ≤2.5 D. The intervention was orthokeratology lenses (OKL), while the control group received SVS. The outcome measure was corneal diameter (Pentacam HR, Oculus, Wetzlar, Germany).Results: A total of 37 right eyes were included, 23 (13 female) in the control group and 14 (9 female) in the intervention group. We found a significant change in corneal diameter in both the control group (difference in medians of 0.20 mm, p &lt; 0.001, Wilcoxon signed‐rank test) and the intervention group (difference in medians of 0.175 mm, p &lt; 0.001, Wilcoxon signed‐rank test). Furthermore, when comparing our 2 groups, we saw a significantly smaller increase in corneal diameter in the intervention group compared to the control group (difference in medians of 0.025 mm, p = 0.03, Mann–Whitney rank‐sum test).Conclusions: The corneal diameter significantly changes during 18 months in Danish children in both groups, however, the difference is significantly less during OKL treatment. The latter needs further clarification at this point. We can conclude, that to ensure correct OKL fitting in children close monitoring during OKL treatment is necessary.

Correlation between biomechanical and endothelial corneal properties in myopic children

AbstractPurpose: The purpose of the study is to investigate the endothelial layer and biomechanical properties of the cornea, in a group of low‐moderate myopic children.Methods: This prospective study included only the right eye from myopic patients younger than 18. We performed a complete ophthalmologic examination, including autorefractometry under cycloplegia (to determine the spherical equivalent ‐ SE), slit lamp and fundus examination, visual acuity and ocular tonometry. Furthermore, the patients were examined with the Aladdin biometer (Topcon, Tokyo, Japan) to determine central corneal thickness (CCT) and axial length (AL), with the Specular Microscope (Nidek, Gamagori, Japan) to determine number (Num) and density (CD) of endothelial cells, and with the Ocular Response Analyser (Reichert Ophthalmic Instruments Inc., Depew, NY) to determine corneal hysteresis (CH) and resistance factor (CRF). IBM SPSS Statistics 26 was used for statistical analysis.Results: Our study included 64 right eyes from 64 patients (51.56% male, 48.44% female). The average age was 14.27 years (standard deviation 2.71). The average SE is −2.57 (SD 1.62), AL 24.69 (SD 1.15), CCT 0.565 (SD 0.036), CH 12.32 (SD 1.88), CRF 12.64 (SD 2.24), Num cell 175.17 (SD 38.55), CD 3126.86 (SD 192.74). There are significant correlations between the biomechanical properties of the cornea and the characteristics of the endothelial layer. We found a statistically significant moderate positive correlation between CH and CD in this paediatric myopic population (Pearson's r of 0.353, p 0.004), and also between CRF and CD (Pearson's r of 0.2557, p 0.041). Between AL and the number of cells, there is a significant negative correlation (Pearson's r of −0.287, p 0.025). There are no significant correlations between the number of endothelial cells and CH, CRF, SE or CCT, or between CD and AL, CCT, SE.Conclusions: Our study reveals that in children with myopia, the endothelial cell count is higher in corneas with a higher hysteresis and resistance factor. Moreover, the relationship between the axial length and the number of endothelial cells suggests an impact of myopia on the endothelial layer and warrants further studies, including a larger number of patients and more corneal properties, such as corneal diameter and curvature.

The association between ocular biometric components and corneal aberrations in elderly

AbstractPurpose: To determine the association between ocular biometric components and corneal aberrations in individuals aged 60 years and older.Methods: In a cross‐sectional study, multi‐stage cluster sampling was performed in Tehran, the capital of Iran. After selecting the samples, all study participants underwent ophthalmic examinations including visual acuity, refraction, anterior and posterior segment examination using slit‐lamp biomicroscopy as well as corneal imaging by Pentacam AXL. The corneal aberrations were measured for a sub‐sample.Results: This report analysed 644 eyes of 415 individuals after applying the inclusion and exclusion criteria. Of these, 236 (56.9%) were females. The mean age of participants was 66.36 ± 4.70 years (range: 60–79 years). According to the generalized estimation equation (GEE), the root mean square (RMS) of higher‐order aberrations (HOA) was related to age (β = 0.081, p = 0.002), crystalline lens thickness (β = 0.08, p &lt; 0.001), and corneal diameter (β = −0.04, p = 0.014). The RMS of total Coma aberration was directly related to the intraocular ocular pressure (β = 0.001, p = 0.044), female sex (β = 0.02, p = 0.05), and crystalline lens thickness (β = 0.06, p &lt; 0.001). There was a direct relationship between the RMS of third‐ and fourth‐order HOAs and crystalline lens thickness (p &lt; 0.001). Spherical aberration was directly related to the male sex (β = −0.02, p = 0.004), axial length (β = 0.05, p &lt; 0.001), central corneal thickness (β = 0.001, p = 0.025), and inversely related to anterior chamber depth (β = −0.07, p = 0.031) and crystalline lens thickness (β = −0.25, p &lt; 0.001).Conclusions: The results of this study showed that ocular biometric components are related to corneal aberrations in the elderly. It is necessary to pay attention to this finding in the clinical affairs of the elderly.

Microspherophakia and megalocornea with or without secondary glaucoma: A case series

AbstractPurpose: To report a case series of 6 eyes of 3 children diagnosed with microspherophakia and megalocornea with or without secondary glaucoma (MSPKA) and to discuss its clinical features and management.Methods: We reviewed 3 cases of a boy (case 1) and 2 sisters (cases 2,3) diagnosed with MSPKA from two consanguineous families. Ultrasound biomicroscopy was performed in 2 eyes and anterior‐segment swept‐source optical coherence tomography in 6 eyes.Results: Mean corneal diameter was 13 mm. Lens equatorial diameters were, in case 1, 6.2 mm in the right eye (RE) and 6.1 mm in the left eye (LE); in case 2, 7.4 mm (RE) and 7.7 mm (LE). Systemic work‐up was unremarkable.Case 1: A 6‐year‐old boy presented with bilateral lens subluxation and advanced secondary angle‐closure glaucoma (SACG). Best‐corrected visual acuity (BCVA) was 20/200 (RE) and was limited to counting fingers (LE). We performed phacoemulsification, anterior vitrectomy and retro‐pupillary iris‐claw intraocular lens implantation (RPIC‐IOL) in both eyes. At 5 months follow‐up, BCVA was 20/50 (RE) and 20/100 (LE). Intraocular pressure (IOP) decreased to 14 mmHg in both eyes.Case 2: Ophthalmologic examination in a 5‐year‐old girl showed in both eyes: a BCVA of 20/50, megalocornea, normal IOP and iridophacodonesis. Surgery with scleral fixation of the capsular bag will be considered.Case 3: An 8‐year‐old girl was referred after a bilateral lensectomy following spontaneous luxation of the lens into the anterior chamber in her RE. Examination showed bilateral megalocornea, aphakia and normal IOP. Secondary RPIC‐IOL implantation and amblyopia management were planned.Genetic testing for the Latent Transforming Growth Factor Beta Binding Protein 2 (LTBP2) gene mutation was performed in both sisters.Conclusions: MSPKA is a rare condition that can be associated with extraocular manifestations. Patients are at a high risk of lens dislocation and SACG. Surgical management remains challenging and should not be delayed.

Ocular biometric dimensions according to gender. Are they different?

AbstractPurpose: To analyse ocular biometric parameters in men and women in a population of cataract surgery candidates and determine whether statistically significant differences exist.Methods: A cross‐sectional study of 5034 eyes of 2671 patients was performed. Biometric parameters of the eyes were measured by Zeiss IOLMaster 700. The axial length (AL), mean anterior radio (aR), mean posterior radio (pR), central corneal thickness (CCT), anterior chamber depth (ACD) (epithelium to lens), lens thickness (LT), and White to White corneal diameter (W2W) were evaluated. These data represent normative biometric values for the Valencian population.Results: The mean age in the male group was 73 ± 9.6 years, the mean age in the female group was 73.8 ± 8.3 years. The male/female ratio was 0.84. The male–female difference, with a 95% confidence interval (CI) in AL, ACD, and LT were 0.65 mm [0.57; 0.73] (p &lt; 0.01), 0.17 mm [0.14; 0.2] (p &lt; 0.01), and 0.031 mm [0.005; 0.5] (p &lt; 0.05), respectively. Differences (95% CI) in W2W and CCT were 0.18 mm [0.15; 0.20] (p &lt; 0.01), and 4.89 μm [2.55; 7.23] (p &lt; 0.01). Differences (95% CI) in aR and pR were 0.137 mm [0.12; 0.153] (p &lt; 0.01) and 0.122 mm [0.106; 0.139] (p &lt; 0.01). All biometric eye parameters (AL, aR, pR, CCT, ACD, LT, W2W) measured, were lower in females than in males, with a statistically significant difference.Conclusions: Statistically significant differences between genders were found in all the biometric parameters evaluated. In our population, women's eyes are smaller than men's in all biometric parameters that shape them. Gender must be taken into account in the biometric evaluation of the eye. These results may be relevant in intraocular lens power calculation and in the evaluation of refractive error.