Longitudinal associations of ocular biometric parameters with onset and progression of diabetic retinopathy in Chinese adults with type 2 diabetes mellitus.

To investigate the associations of ocular biometric parameters with incident diabetic retinopathy (DR), incident vision-threatening DR (VTDR) and DR progression. This community-based prospective cohort study recruited participants with type 2 diabetes aged 35-80 years from 2017 to 2019 in Guangzhou, China. Refractive error and ocular biometric parameters were measured at baseline, including axial length (AL), axial length-to-corneal radius (AL/CR) ratio, corneal curvature (CC), lens thickness (LT), anterior chamber depth (ACD), lens power and corneal diameter (CD). A total of 1370 participants with a mean age of 64.3±8.1 years were followed up for two consecutive years. During the follow-up period, 342 out of 1195 (28.6%) participants without DR at baseline had incident DR, 15 out of 175 (8.57%) participants with baseline DR had DR progression and 11 of them progressed to VTDR. After multiple adjustments, a longer AL (OR=0.76; 95% CI, 0.66 to 0.86; p<0.001) and a larger AL/CR ratio (OR=0.20; 95% CI, 0.07 to 0.55; p=0.002) were associated with significantly reduced risks of incident DR but were not associated with incident VTDR or DR progression. Refractive status and other ocular biometric parameters investigated, including ACD, CC, CD, lens power and LT were not associated with any of the DR outcomes (all p>0.05). A longer AL and a larger AL/CR ratio are protective against incident DR. These parameters may be incorporated into future DR risk prediction models to individualise the frequency of DR screening and prevention measures.

Wang W ，Chen Y ，Xiong K ，Gong X ，Liang X ，Huang W ... -  《-》

Association between ocular biometrical parameters and diabetic retinopathy in Chinese adults with type 2 diabetes mellitus.

The influence of myopia and ocular biometry parameters on diabetic retinopathy (DR) needs further clarification. We aimed to investigate the association between ocular biometrical parameters and DR in Chinese people with diabetes mellitus (DM) without any ocular intervention. This cross-sectional study recruited type 2 DM patients with no history of ocular treatment in Guangzhou, China. The ocular biometrical parameters were obtained by Lenstar (LS900, Haag-Streit AG, Koeniz, Switzerland), including corneal diameter, central corneal thickness (CCT), corneal curvature (CC), anterior chamber depth (ACD), lens thickness (LT) and axial length (AL). The lens power and axial length-to-cornea radius ratio (AL/CR ratio) were calculated. Spherical equivalent (SE) was determined by auto-refraction after pupil dilation. Multivariate logistic regression analyses were performed to explore the associations of ocular biometry with any DR and vision threatening DR (VTDR). A total of 1838 patients were included in the final analysis, involving 1455 (79.2%) patients without DR and 383(20.8%) patients with DR. After adjusting confounding factors, any DR was independently associated with AL (odds ratio (OR) 0.84 per 1 mm increase, 95% confidence interval (CI): 0.74, 0.94) and AL/CR ratio (OR 0.26 per 1 increase, 95%CI: 0.10, 0.70). Similarly, the presence of VTDR was independently related to AL (OR 0.67 per 1 mm increase, 95%CI: 0.54, 0.85) and AL/CR ratio (OR 0.04 per 1 increase, 95%CI: 0.01, 0.25). The lens power may not be significantly correlated with presence of any DR or VTDR. The CC, corneal diameter and refractive status were not significantly correlated with presence of DR or VTDR. Longer AL and higher AL/CR ratio may be protective factors against the occurrence and progression of DR. Further longitudinal studies are warranted to verify if refractive status and AL-associated parameters contribute to the occurrence and progression of DR in type 2 DM.

Wang L † ，Liu S † ，Wang W ，He M ，Mo Z ，Gong X ，Xiong K ，Li Y ，Huang W ... -  《-》

Lens Power, Axial Length-to-Corneal Radius Ratio, and Association with Diabetic Retinopathy in the Adult Population with Type 2 Diabetes.

To calculate crystalline lens power and to determine the relationship between ocular biometry and diabetic retinopathy (DR) in an adult population with type 2 diabetes mellitus (T2DM). Cross-sectional, population-based study. Patients with T2DM from the Beixinjing community, Changning district, Shanghai. Random clustering sampling was used to identify adults with T2DM in the Beixinjing community. Spherical equivalent (SE) was determined by subjective refraction that achieved the best corrected vision. Axial length (AL), corneal power (CP), and anterior chamber depth (ACD) were measured using the IOLMaster. Diabetic retinopathy and diabetic macular edema (DME) were assessed according to the international DR classification. The crystalline lens power was calculated using the Bennett-Rabbetts formula. The AL-to-corneal radius ratio (AL/CR ratio) was defined as the axial length divided by the mean corneal radius of curvature. A total of 4011 eyes of 2057 subjects with T2DM were included in the analysis. In multivariate logistic models adjusting for age, sex, duration of diabetes, glycosylated hemoglobin A1c, serum creatinine, body mass index, systolic blood pressure, and cataract, after categorizing values into quartiles, there were trend associations between lens power and any DR (P = 0.01), between AL/CR ratio and any DR (P = 0.02), and between AL and any DR (P = 0.03), between lens power and moderate DR (P = 0.02), and between AL and moderate DR (P = 0.02); eyes with higher AL/CR ratio were less likely to have any DR (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.24-0.78; P = 0.01 per 1 increase) and moderate DR (OR, 0.44; 95% CI, 0.21-0.93; P = 0.03 per 1 increase), eyes with longer AL were less likely to have any DR (OR, 0.88; 95% CI, 0.81-0.95; P = 0.002 per millimeter increase) or moderate DR (OR, 0.89; 95% CI, 0.80-0.98; P = 0.02 per millimeter increase), and eyes with higher SE were more likely to have any DR (OR, 1.08; 95% CI, 1.03-1.13; P = 0.003 per diopter increase). In persons with T2DM, lens power, AL/CR ratio, and AL were associated with the presence of any DR and moderate DR. These findings suggested that globe elongation plays a major role in protective effects against DR, with contributions from lens power and other refractive components.

He J ，Xu X ，Zhu J ，Zhu B ，Zhang B ，Lu L ，He X ，Bai X ，Xu X ，Zou H ... -  《-》

Longer axial length is protective of diabetic retinopathy and macular edema.

To assess the association of ocular biometric parameters and refractive error with diabetic retinopathy (DR) and diabetic macular edema (DME) in persons with diabetes. Cross-sectional, clinic-based study. Patients with diabetes aged 18 years or more from the Royal Victorian Eye and Ear Hospital, Victoria, Australia. Spherical equivalent (SE) refraction was assessed using objective autorefraction. Axial length (AL), corneal curvature (CC), and anterior chamber depth (ACD) were measured using the IOLMaster (Carl Zeiss Meditech AG, Jena, Germany). Diabetic retinopathy was graded from 2-field retinal photographs using the modified Airlie House classification system. Diabetic macular edema was defined as absent or present from fundus photographs and confirmed by optical coherence tomography (Stratus, Carl Zeiss Meditech AG). Severity of DR was grouped as no DR, mild DR (Early Treatment of Diabetic Retinopathy Study [ETDRS] = 20), moderate DR (ETDRS = 31-43), and severe DR (ETDRS >43). Diabetic macular edema severity was classified as mild, moderate, or severe. A total of 208 of 630 eyes (33.0%) had DR. In multivariate models, eyes with longer AL were less likely to have mild (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.41-0.83; P = 0.006 per mm increase), moderate (OR, 0.73; 95% CI, 0.60-0.88; P = 0.002), and severe DR (OR, 0.67; 95% CI, 0.53-0.85; P=0.01), and had a lesser risk of mild (OR, 0.70; 95% CI, 0.56-0.86; P < 0.001) and moderate DME (OR, 0.72; 95% CI, 0.56-0.93; P=0.002) but not severe DME. No association was found for SE, ACD, and CC with DR. In persons with diabetes, eyes with longer ALs are less likely to have DR and DME.

Man RE ，Sasongko MB ，Sanmugasundram S ，Nicolaou T ，Jing X ，Wang JJ ，Wong TY ，Lamoureux EL ... -  《-》

Are myopic eyes less likely to have diabetic retinopathy?

Eyes with myopia may be less likely to develop diabetic retinopathy (DR). The relationship between refractive error, ocular biometry, and DR therefore was investigated. Population-based, cross-sectional study. Persons with diabetes from the Singapore Malay Eye Study (SiMES). Diabetes mellitus was defined as random glucose of 11.1 mmol/l or more, use of diabetic medication, or a physician diagnosis of diabetes. Spherical equivalent refraction (SE) was assessed using an autokeratorefractometer and subjective refraction. Axial length (AL) and anterior chamber depth (ACD) were measured by IOLMaster (Carl Zeiss Meditec AG, Jena, Germany). Diabetic retinopathy was graded from retinal photographs. Any DR was defined by characteristic lesions defined by the Early Treatment Diabetic Retinopathy Study (ETDRS); moderate DR by ETDRS retinopathy severity scores of 43 or higher; and vision-threatening retinopathy by severe nonproliferative retinopathy, proliferative DR, or clinically significant macular edema. Of 3280 adult Malay participants (78.7% response), 629 persons with diabetes contributed to this analysis. In multivariate analyses adjusting for age, gender, education, height, cataract, hypertension, hemoglobin A1c, and other factors, eyes with myopic SE were less likely to have any DR (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.84-0.96; P = 0.002, per 1-diopter [D] decrease), moderate DR (OR, 0.83; 95% CI, 0.73-0.93; P = 0.001, per 1-D decrease), and vision-threatening DR (OR, 0.77; 95% CI, 0.67-0.88; P<0.001, per 1-D decrease). Eyes with longer AL were less likely to have any DR (OR, 0.86; 95% CI, 0.75-0.99; P = 0.041, per 1-mm increase), moderate DR (OR, 0.80; 95% CI, 0.62-1.05; P = 0.11, per 1-mm increase), and vision-threatening DR (OR, 0.63; 95% CI, 0.40-0.99; P = 0.044, per mm increase). Eyes with deeper ACD were less likely to have moderate DR (OR, 0.32; 95% CI, 0.16-0.64; P = 0.001, per 1-mm increase) and vision-threatening DR (OR, 0.14; 95% CI, 0.06-0.36; P = 0.001, per 1-mm increase). Myopic refraction and longer AL are associated with a lower risk of DR, particularly vision-threatening retinopathy, without any evidence of a threshold.

Lim LS ，Lamoureux E ，Saw SM ，Tay WT ，Mitchell P ，Wong TY ... -  《-》