Ocular hypertension and diabetes mellitus in the Beijing Eye Study

COUNTY-LEVEL ANALYSIS OF EYE EXAM ACCESS AND UTILIZATION IN THE UNITED STATES

PURPOSE

The eye exam is a critical tool for the prevention, screening, and diagnosis of ocular and systemic conditions. In this study, we characterize county-level variation in eye exam access and utilization for Medicare patients in the United States.

METHODS

This nationwide study uses the Medicare Physician & Other Practitioners - by Provider and Service dataset. We included all ophthalmologists and optometrists who performed eye exams on Medicare beneficiaries within a United States county in 2019. For every county where exams were performed, we calculated the number of practicing vision testing providers, percentage of providers classified as ophthalmologists, and the number of exams per 100 Medicare beneficiaries. Multiple linear regression was used to characterize associations between these variables and county characteristics, including measures of poverty, education, and income.

RESULTS

In 2019, 28937,540 eye exams were performed by 46,000 providers in 2,291 U.S. counties. In the median county, 34.9 eye exams were provided per 100 Medicare beneficiaries. The average county had 20.1 exam providers, 16.5% of whom were ophthalmologists. There were a median 6.6 eye exam providers for every 10,000 Medicare beneficiaries in the average county. The average provider performed 517.8 exams. Regression showed counties with lower median household incomes, higher poverty rates, or fewer high-school graduates had fewer eye exam providers per 10,000 Medicare beneficiaries and fewer eye exams performed per 100 Medicare beneficiaries.

CONCLUSIONS

We find significant county-level variation in eye exam utilization and provider availability. This reflects broader, well-recognized trends in socioeconomic health disparities in the U.S.

Environmental influences on ophthalmic conditions: A scoping review

BACKGROUND

Environmental factors have been implicated in various eye pathologies. The purpose of this review is to synthesise the published research on environmental effects on eye disease.

METHODS

Four databases were searched for terms relating to environmental exposures and ophthalmic disease. Titles and abstracts were screened followed by full-text review. Data was extracted from 118 included studies. Quality assessment was conducted for each study.

RESULTS

Air pollutants, including nitrogen dioxide, nitrites, sulphur dioxide, particulate matter, carbon monoxide, ozone and hydrocarbons are associated with ocular conditions ranging from corneal damage to various retinopathies, including central retinal artery occlusion. Certain chemicals and metals, such as cadmium, are associated with increased risk of age-related macular degeneration. Climate factors, such as sun exposure, have been associated with the development of cataracts. Living in rural areas was associated with various age-related eye diseases whereas people living in urban settings had higher risk for dry eye disease and uveitis.

CONCLUSION

Environmental exposures in every domain are associated with various ophthalmic conditions. These findings underscore the importance of continued research on the interplay between the environment and eye health.

Mendelian Randomization and Transcriptome-Wide Association Analysis Identified Genes That Were Pleiotropically Associated with Intraocular Pressure

BACKGROUND

Intraocular pressure (IOP) is a major modifiable risk factor for glaucoma. However, the mechanisms underlying the controlling of IOP remain to be elucidated.

OBJECTIVE

To prioritize genes that are pleiotropically associated with IOP.

METHODS

We adopted a two-sample Mendelian randomization method, named summary-based Mendelian randomization (SMR), to examine the pleiotropic effect of gene expression on IOP. The SMR analyses were based on summarized data from a genome-wide association study (GWAS) on IOP. We conducted separate SMR analyses using Genotype-Tissue Expression (GTEx) and Consortium for the Architecture of Gene Expression (CAGE) expression quantitative trait loci (eQTL) data. Additionally, we performed a transcriptome-wide association study (TWAS) to identify genes whose cis-regulated expression levels were associated with IOP.

RESULTS

We identified 19 and 25 genes showing pleiotropic association with IOP using the GTEx and CAGE eQTL data, respectively. RP11-259G18.3 (P_SMR = 2.66 × 10^-6), KANSL1-AS1 (P_SMR = 2.78 × 10^-6), and RP11-259G18.2 (P_SMR = 2.91 × 10^-6) were the top three genes using the GTEx eQTL data. LRRC37A4 (P_SMR = 1.19 × 10^-5), MGC57346 (P_SMR = 1.19 × 10^-5), and RNF167 (P_SMR = 1.53 × 10^-5) were the top three genes using the CAGE eQTL data. Most of the identified genes were found in or near the 17q21.31 genomic region. Additionally, our TWAS analysis identified 18 significant genes whose expression was associated with IOP. Of these, 12 and 4 were also identified by the SMR analysis using the GTEx and CAGE eQTL data, respectively.

CONCLUSIONS

Our findings suggest that the 17q21.31 genomic region may play a critical role in the regulation of IOP.

Sustained Inhibition of NF-κB Activity Mitigates Retinal Vasculopathy in Diabetes

This study investigated the effects of long-term NF-κB inhibition in mitigating retinal vasculopathy in a type 1 diabetic mouse model (Akita, Ins2^Akita). Akita and wild-type (C57BL/6J) male mice, 24 to 26 weeks old, were treated with or without a selective inhibitor of NF-κB, 4-methyl-N1-(3-phenyl-propyl) benzene-1,2-diamine (JSH-23), for 4 weeks. Treatment was given when the mice were at least 24 weeks old. Metabolic parameters, key inflammatory mediators, blood-retinal barrier junction molecules, retinal structure, and function were measured. JSH-23 significantly lowered basal glucose levels and intraocular pressure in Akita. It also mitigated vascular remodeling and microaneurysms significantly. Optical coherence tomography of untreated Akita showed thinning of retinal layers; however, treatment with JSH-23 could prevent it. Electroretinogram demonstrated that A- and B-waves in Akita were significantly smaller than in wild type mice, indicating that JSH-23 intervention prevented loss of retinal function. Protein levels and gene expression of key inflammatory mediators, such as NOD-like receptor family pyrin domain-containing 3, intercellular adhesion molecule-1, inducible nitric oxide synthase, and cyclooxygenase-2, were decreased after JSH-23 treatment. At the same time, connexin-43 and occludin were maintained. Vision-guided behavior also improved significantly. The results show that reducing inflammation could protect the diabetic retina and its vasculature. Findings appear to have broader implications in treating not only ocular conditions but also other vasculopathies.

Intraocular pressure and its relationship to ocular and systemic factors in a healthy Chinese rural population: the Handan Eye Study

PURPOSE

To describe the distribution of and factors related to intraocular pressure (IOP) in a healthy adult rural Chinese population in northern China.

METHODS

The Handan Eye Study is a cross-sectional, population-based study of eye diseases among 6,830 (90.4% response rate) rural Chinese persons aged 30+ years. Participants underwent an interviewer-administered questionnaire and a complete ocular examination, including standardized measurement of IOP with Perkins applanation tonometry.

RESULTS

After excluding persons with glaucoma, or those with diseases that have a marked effect on IOP or that preclude accurate IOP measurement, 6,101 persons were included in the current analysis. Mean IOP (mean ± standard deviation) of the study population was 15.0 ± 2.8 mmHg. Men had lower IOP than women (14.6 ± 2.8 mmHg versus 15.4 ± 2.7 mmHg, t = -8.37, P < 0.001). In the multivariate analysis younger age, female sex, presence of diabetes mellitus, higher blood pressure, higher body mass index, thicker central cornea and higher myopia were associated with higher IOP.

CONCLUSIONS

Mean IOP among persons living in rural northern China was similar to that recently reported in southern China. IOP appeared to be lower with increasing age in Chinese subjects, which contrasts with results in white populations.

Intraocular pressure in Japanese diabetic patients

Background

To determine whether the intraocular pressure (IOP) in diabetic patients is significantly different from that in nondiabetic patients.

Methods

The medical records of all patients who were initially examined in the Department of Ophthalmology, Kansai Medical University, Takii Hospital were reviewed. At the initial examination, patients had a detailed interview and underwent a comprehensive ophthalmic examinations. All patients were over 20 years of age and did not have glaucoma.

Results

A total of 703 patients were evaluated. The mean (±standard error) IOP of the diabetic patients was 15.5 ± 0.2 mmHg (n = 206), and was significantly higher than the 14.0 ± 0.1 mmHg (n = 497) in the nondiabetic patients (P < 0.0001). The IOP was negatively correlated with age (r = −0.202; P = 0.024) in the diabetic patients and was weakly but significantly correlated with the glycosylated hemoglobin (HbA_1c) level (r = 0.240; P = 0.015) in the group with diabetic retinopathy.

Conclusion

The significantly higher IOP in diabetic patients and positive correlation of IOP with HbA_1c levels in patients with diabetic retinopathy indicate that IOP in diabetic patients is higher, especially in those with poor control of diabetes.

Cerebrospinal fluid pressure in ocular hypertension

BACKGROUND

To assess the lumbar cerebrospinal fluid pressure (CSF-P) in ocular hypertensive subjects with elevated intraocular pressure (IOP) but without development of glaucomatous optic nerve damage.

METHODS

The prospective interventional study included 17 patients with ocular hypertension and 71 subjects of a nonglaucomatous control group. All patients underwent a standardized ophthalmologic and neurological examination including measurement of lumbar CSF-P. In the ocular hypertensive group, the IOP was corrected for its dependence on central corneal thickness (IOP(corrected) ). The trans-lamina cribrosa pressure difference (Trans-LCPD) was calculated as IOP(corrected) - CSF-P.

RESULTS

CSF-P was significantly (p < 0.001) higher in the ocular hypertensive group (16.0 ± 2.5 mmHg) than in the control group (12.9 ± 1.9 mmHg). CSF-P was significantly associated with IOP(corrected) (p < 0.001; r = 0.82). In multivariate analysis, CSF-P was significantly correlated with IOP(corrected) (p < 0.001) and marginally significantly with mean blood pressure (p = 0.05). Trans-LCPD was not associated significantly with blood pressure (p = 0.69).

CONCLUSION

Some ocular hypertensive subjects with increased intraocular pressure measurements (after correction for their dependence on central corneal thickness) had an abnormally high lumbar cerebrospinal fluid pressure. Assuming that lumbar cerebrospinal fluid pressure correlated with orbital cerebrospinal fluid pressure, one may postulate that the elevated retro-lamina cribrosa pressure compensated for an increased intraocular pressure. The elevated retro-lamina cribrosa pressure may have led to a normal trans-laminar pressure difference in the eyes with elevated intraocular pressure, so that glaucomatous optic nerve damage did not develop. Intraocular pressure, cerebrospinal fluid pressure and arterial blood pressure were correlated with each other.

The role of comprehensive eye exams in the early detection of diabetes and other chronic diseases in an employed population

The main objective of this study is to assess the cost benefit associated with comprehensive eye exams as a tool for the early detection of diabetes, hypertension, and high cholesterol. A retrospective, claims-based analysis was performed using U.S.-based employees and spouses from a large, national database. Individuals who received first notification of disease as a result of an eye exam were compared to individuals who did not receive early detection and presumably learned of their condition after further disease progression. Total health plan costs, lost time costs, and termination rates were calculated for the 12-month period after the index date. A sizable population first learned of their chronic condition through eye exams as no other claims-based evidence was found to suggest prior knowledge of the condition. All three disease cohorts with early detection during an eye exam had lower first-year health plan costs, missed fewer work days, and were less likely to terminate employment than the respective comparison groups. As employers strive to better manage health and business outcomes, comprehensive eye health exams can provide an opportunity for early disease detection and associated cost savings through referral to primary care providers and condition management programs.