Global metrics on ocular biometry: representative averages and standard deviations across ten countries from four continents

Severe Spontaneous Tilt of Scleral-Fixated Intraocular Lenses

PURPOSE

To report and evaluate a multicenter series of 18 cases of severe, spontaneous IOL tilt involving the flanged intrascleral haptic fixation technique (FISHF).

DESIGN

Clinical study with historical controls.

METHODS

We report a cross-sectional study of 46 FISHF cases using the CT Lucia 602 IOL at a single academic center over a period of 24 weeks to determine the incidence of severe rotisserie-style rotational tilt. These rates were then compared with the same time-frame the prior year to help determine if this is a new phenomenon. Additional cases of severe tilt were solicited from another 4 academic centers.

RESULTS

Among 46 FISHF cases at a single center, 5 developed severe tilt. No clear pattern in surgical technique, ocular history, or ocular anatomy was evident in these cases compared with controls, although the involved IOLs clustered within a narrow diopter range, indicative of a batch effect. In the same 24-week interval the year before, 33 FISHF cases were performed, none of which exhibited severe rotational tilt. In our multicenter dataset, 18 cases of tilt were identified. Surgeons included fellow and early-career physicians as well as surgeons with multiple years of experience with the Yamane technique. A variety of surgical approaches for FISHF were represented. In at least 8 of the cases, haptic rotation and/or dehiscence at the optic-haptic junction were documented.

CONCLUSIONS

The identification of haptic rotation and dehiscence intraoperatively in several cases may reflect a new stability issue involving the optic-haptic junction.

Ocular parameters and anthropometry in Indo-Trinidadians

To assess ocular parameters and their association with anthropometric measurements in Indo-Trinidadians adults. This was a clinical, descriptive, cross-sectional study of ocular parameters and anthropometry in adults Trinidadians of South Asian descent (Indo-Trinidadian). Ocular parameters were measured using optical coherence tomography, intraocular lens master biometer, and an autorefractor. Weight, height, and body mass index (BMI) were measured by anthropometry. Univariable and multivariable linear regressions were used to determine the association between demographic variables, anthropometric and ocular parameters. A total of 149 participants (298 eyes) comprising of 90 females (60.6%) and 59 males (39.4%). Aged 18 to 67 participated in the study. Males were taller, heavier, and had longer axial lengths than females which were statistically significant (P < .05). Age was negatively correlated with central corneal thickness (CCT) (r = -0.353, P = .044) and retinal nerve fiber layer thickness (r = -0.348, P = .047) but positively correlated with lens thickness (R = 0.881, P < .001). Education level was positively associated with CCT (R = 0.408, P = .018) but negatively associated with lens thickness (r = -0.521, P = .002). Weight was negatively correlated with corneal topography (r = -0.427, P = .013). Height was negatively correlated with cup-to-disc ratio (r = -0.410, P = .018), CCT (r = -0.382, P = .028), and corneal topography (r = -0.453, P = .008). There was no correlation between BMI, ocular parameters and CCT. There was a significant difference in the ocular parameters between males and females of South Asian descent in Trinidad and Tobago. Weight was negatively associated with the corneal topography. Height was negatively associated with the cup-to-disc ratio, central corneal thickness, and corneal topography. BMI had no statistically significant association with the ocular parameters investigated.

Gender- and Age-Related Differences of Ocular Biometric Parameters in Patients Undergoing Cataract Surgery in Bosnia and Herzegovina

Purpose

The aim of the study is to determine the distribution and mutual relationship of ocular biometric parameters, as well as to evaluate gender- and age-related differences in patients undergoing cataract surgery in Bosnia and Herzegovina.

Materials and Methods

It was a retrospective cross-sectional study of consecutive patients who underwent cataract surgery between January 2017 and December 2021 in a tertiary care clinic. All biometric measurements were performed using the optical biometer OA-2000 (Tomey, Nagoya, Japan).

Results

The study evaluated 1278 eyes from 1278 consecutive cataract patients. The average age of all included patients was 69.4 ± 9.98 (range 40-96). A total of 672 eyes (52.58%) were from females. The mean axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and mean keratometry were 23.46 ± 1.18 mm, 3.17 ± 0.40 mm, 4.54 ± 0.48 mm, and 43.42 ± 1.55D, respectively. Corneal astigmatism of ≥1D, >2D and >3D was found in 33.4%, 7.8% and 2.5% patients, respectively. Females were found to have shorter AL (p < 0.0001), shallower ACD (p < 0.0001) and steeper corneas (p < 0.0001). In both genders, AL, ACD and with the rule astigmatism showed a decreasing trend (p = 0.0001), while keratometry, the average cylinder, and against the rule astigmatism showed an increasing trend (p = 0.0001) with increasing age. Furthermore, in both genders, there was an increasing trend in ACD (p = 0.0001), and a decreasing trend in keratometry (p = 0.0001) and LT (p = 0.0001) with increasing AL.

Conclusions

This study provides useful reference data on ocular biometry for cataract surgeons in Bosnia and Herzegovina. Female patients tend to have steeper corneas, shorter AL and shallower AC than males, and these differences are independent of age or AL.

Comparison Between Ocular Biometric Parameters and Intraocular Pressure With and Without Contact Lenses

OBJECTIVES

To compare the values of central corneal thickness, anterior chamber depth (ACD), lens thickness (LT), vitreous length (VL), axial length (AL), and corneal-compensated intraocular pressure performed with and without contact lenses (CL).

METHODS

Forty volunteer participants (16 men and 24 women, 24.2±2.9 years) were recruited. In a single visit, participants underwent autorefraction, keratometry, biometry, topography, pachymetry, and tonometry with the naked eye (without CL). Then, biometry, pachymetry, and tonometry were repeated twice wearing two CL (somofilcon A and nesofilcon A) fitted in a random order.

RESULTS

Many of the ocular biometric values were affected by the use of CL during measurements (paired t test; all P ≤0.003), except for LT and VL (Wilcoxon test; both P ≥0.272). Corneal-compensated intraocular pressure was also affected by contact lens wear during measurements, obtaining lower values when wearing them (Wilcoxon test; all P ≤0.001).

CONCLUSIONS

Central corneal thickness, ACD, AL, and corneal-compensated intraocular pressure measurements cannot be performed while wearing CL. However, LT and VL measurements were not affected by any contact lens use. In addition, it was observed that ACD results from both devices are not interchangeable either when measured with the naked eye or using any contact lens.

Distribution and Characteristics of Ocular Biometric Parameters among a Chinese Population: A Hospital-Based Study

INTRODUCTION

This study aimed to describe the distribution and characteristics of ocular biometric parameters among a large Chinese population.

METHODS

This retrospective cross-sectional study included 146,748 subjects whose ocular biometric parameters were measured at the ophthalmology clinic of West China Hospital, Sichuan University, and recorded in the hospital database. Ocular biometric parameters, including axial length, anterior chamber depth, corneal keratometry, and keratometric astigmatism, were recorded. Only monocular data for each subject were analyzed to avoid bias.

RESULTS

Valid data from 85,770 subjects (43,552 females and 42,218 males) aged 3-114 years were included in this study. The mean axial length, mean anterior chamber depth, average corneal keratometry, and mean keratometric astigmatism were 24.61 mm, 3.30 mm, 43.76 D, and 1.19 D, respectively. The stratification of the ocular parameters by age and gender showed significant inter-gender and inter-age differences.

CONCLUSIONS

Analysis of a large population of subjects in western China aged 3-114 years showed that the distribution and characteristics of ocular biometric parameters, including axial length, anterior chamber depth, corneal keratometry, and keratometric astigmatism, differed by age and gender. This study is the first to describe ocular biometric parameters in subjects aged > 100 years.

Nonhuman Primate Eyes Display Variable Growth and Aging Rates in Alignment With Human Eyes

Purpose

To assess age-related biometric changes of the eye in nonhuman primates (NHPs), to and decipher the growth and aging rates and their comparability with humans.

Methods

Ocular anatomic measurements were performed on 341 macaca fascicularis aged 0.5 to 23 years via multimodal approaches including IOLMaster 700. Linear or polynomial regression models were simulated to determine the best fitted age-related function. The metrics were compared with human equivalents in published reports.

Results

Macaques exhibited a postnatal eye growth pattern similar to humans, characterized by continuous eye extension coordinated with dramatic reshaping of the lens but not the cornea. The age-related growth of lens thickness (LT), anterior chamber depth (ACD), and axis length (AL) exhibited nonlinear and bipolar patterns. The inflection points were 10 to 12 years old for LT and ACD and 13 to 15 years old for AL in macaques, which were comparable in chronological age at a ratio of ∼1: ratio with that in humans. In contrast, the speed of aging, including the increase in lens density and the decrease in retinal nerve fiber layer thickness, was comparable in relative age at a ratio of ∼1:3 according to the differences in lifespan between macaques and humans. Lens density was a robust indicator for the aging process.

Conclusions

Macaque eyes recapitulated the age-related process of human eyes to varying extents with different growth and aging rates. Chronological age or relative age should be considered in different scenarios when macaques are included in preclinical studies.

3D bioprinting of corneal models: A review of the current state and future outlook

The cornea is the outermost layer of the eye and serves to protect the eye and enable vision by refracting light. The need for cornea organ donors remains high, and the demand for an artificial alternative continues to grow. 3D bioprinting is a promising new method to create artificial organs and tissues. 3D bioprinting offers the precise spatial arrangement of biomaterials and cells to create 3D constructs. As the cornea is an avascular tissue which makes it more attractive for 3D bioprinting, it could be one of the first tissues to be made fully functional via 3D bioprinting. This review discusses the most common 3D bioprinting technologies and biomaterials used for 3D bioprinting corneal models. Additionally, the current state of 3D bioprinted corneal models, especially specific characteristics such as light transmission, biomechanics, and marker expression, and in vivo studies are discussed. Finally, the current challenges and future prospects are presented.