# Analysis of factors influencing retinal thickness in chronic obstructive pulmonary disease and hypertension: a cross-sectional study in a community-dwelling middle-aged and elderly population

## TL;DR

This study finds that hypertension and COPD are linked to changes in retinal thickness in older adults, with blood pressure and treatment affecting specific eye regions.

## Contribution

The study identifies region-specific effects of COPD and hypertension on retinal thickness in a community-dwelling population, including the differential impact of diastolic blood pressure and antihypertensive therapy.

## Key findings

- Hypertension is associated with retinal thinning in the temporal inner and superior outer regions.
- Diastolic blood pressure correlates with inner retinal thickness, but systolic blood pressure does not.
- Antihypertensive therapy reduces the effect of blood pressure on retinal thickness to specific regions.

## Abstract

Chronic obstructive pulmonary disease (COPD) and Hypertension are modifiable risk factors for premature mortality globally, with well-documented associations with retinal microvascular damage. Macular retinal thickness serves as a core quantitative indicator of macular structural integrity and ocular disease progression. However, existing studies primarily focus on retinal nerve layers in clinical populations, lacking investigations into full retinal thickness (RT) across all macular orientations in community-dwelling middle-aged and elderly individuals. This cross-sectional study aimed to measure RT in all macular regions using optical coherence tomography and identify hypertension as a key risk factor for retinal thickness abnormalities.

Participants aged ≥40 years were recruited from community physical examinations between January and December 2020. After excluding ineligible participants, 1,522 participants (2,977 eyes) were included. Demographic data, lifestyle factors, comorbidities, and ocular indicators (blood pressure and RT via iVue OCT using the ETDRS grid) were collected. Statistical analyses included-independent samples t-test, chi-square test, linear regression, and logistics regression (p < 0.05 for significance).

The mean age of participants was 70.04 ± 5.740 years (55.0% female), with 49.8% diagnosed with hypertension and 8.2% diagnosed with COPD. Age was associated with retinal thickness thinning in all regions except the central area (p < 0.05). Stratification by hypertension status revealed no association between COPD and retinal thickness across any regions in the hypertensive subgroup, whereas in the non-hypertensive subgroup, COPD was significantly linked to thinning in the central, inner nasal, inferior outer, and outer nasal regions (p < 0.05). History of hypertension was a risk factor for thinning in the temporal inner and superior outer regions (OR = 1.249, 95%CI:1.030–1.514; OR = 1.325, 95%CI:1.092–1.608). Diastolic blood pressure was positively correlated with inner retinal thickness (β = 0.186–0.202, p < 0.01), while systolic blood pressure had no significant effect. In hypertensive participants on medication, DBP’s positive correlation was limited to the superior inner region.

COPD and hypertension are independent risk factors for changes in retinal thickness, with heterogeneous effects across different retinal regions. DBP, but not SBP, independently correlates with inner retinal thickness, and antihypertensive therapy mitigates this effect to specific regions. These findings provide new insights for community ocular screening and retinal protection in hypertensive patients.