Microvascular alterations of the ocular surface and retina in connective tissue disease-related interstitial lung disease
Authors:   Department of Rheumatology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China, Chen Li-Ming , Wang Jun-Yi ,   The First School of Clinical Medicine of Nanchang University, Jiangxi Medical College of Nanchang University, Nanchang 330000, Jiangxi Province, China, Xu San-Hua ,   Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China, Chen Cheng ,   Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China, Wei Hong ,   Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China, Ling Qian ,   Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China, He Liang-Qi ,   Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China, Zou Jie ,   Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China, Wang Yi-Xin ,   School of Optometry and Vision Science, Cardiff University, Cardiff, CF24 4HQ, Wales, UK, Chen Xu ,   Ophthalmology Centre of Maastricht University, Maastricht 6200MS, Limburg Provincie, Netherlands, Ying Ping ,   Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China, Huang Hui ,   Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China, Shao Yi ,   Department of Ophthalmology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China; Department of Ophthalmology, Eye &amp; ENT Hospital of Fudan University, Shanghai 200030, China, Wu Rui ,   Department of Rheumatology, the First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi Province, China
Published: September 2024

AIM: To examine the disparities in macular retinal vascular density between individuals with connective tissue disease-related interstitial lung disease (CTD-ILD) and healthy controls (HCs) by optical coherence tomography angiography (OCTA) and to investigate the changes in microvascular density in abnormal eyes.
METHODS: For a retrospective case-control study, a total of 16 patients (32 eyes) diagnosed with CTD-ILD were selected as the ILD group. The 16 healthy volunteers with 32 eyes, matched in terms of age and sex with the patients, were recruited as control group. The macular retina’s superficial retinal layer (SRL) and deep retinal layer (DRL) were examined and scanned using OCTA in each individual eye. The densities of retinal microvascular (MIR), macrovascular (MAR), and total microvascular (TMI) were calculated and compared. Changes in retinal vascular density in the macular region were analyzed using three different segmentation methods: central annuli segmentation method (C1-C6), hemispheric segmentation method [uperior right (SR), superior left (SL), inferior left (IL), and inferior right (IR)], and Early Treatment Diabetic Retinopathy Study (ETDRS) methods [superior (S), inferior (I), left (L), and right (R)]. The data were analyzed using Version 9.0 of GraphPad prism and Pearson analysis.
RESULTS: The OCTA data demonstrated a statistically significant difference (P<0.05) in macular retinal microvessel density between the two groups. Specifically, in the SRL and DRL analyses, the ILD group exhibited significantly lower surface density of MIR and TMI compared to the HCs group (P<0.05). Furthermore, using the hemispheric segmentation method, the ILD group showed notable reductions in SL, SR, and IL in the superficial retina (P<0.05), as well as marked decreases in SL and IR in the deep retina (P<0.05). Similarly, when employing the ETDRS method, the ILD group displayed substantial drops in superficial retinal S and I (P<0.05), along with notable reductions in deep retinal L, I, and R (P<0.05). In the central annuli segmentation method, the ILD group exhibited a significant decrease in the superficial retinal C2-4 region (P<0.05), whereas the deep retina showed a notable reduction in the C3-5 region (P<0.05). Additionally, there was an observed higher positive likelihood ratio in the superficial SR region and deep MIR. Furthermore, there was a negative correlation between conjunctival vascular density and both deep and superficial retinal TMI (P<0.001).
CONCLUSION: Patients with CTD-ILD exhibits a significantly higher conjunctival vascular density compared to the HCs group. Conversely, their fundus retinal microvascular density is significantly lower. Furthermore, CTD-ILD patients display notably lower superficial and deep retinal vascular density in comparison to the HCs group. The inverse correlation between conjunctival vascular density and both superficial and deep retinal TMI suggests that detecting subtle changes in ocular microcirculation could potentially serve as an early diagnostic indicator for connective tissue diseases, thereby enhancing disease management.