Abstract
Purpose :
The diagnosis of glaucoma in almost all population-based studies has been centered on optic disc examination with or without visual field investigation. This study investigated the prevalence of glaucoma and retinal nerve fiber layer (RNFL) defects and their risk factors using diagnostic criteria based on neuroretinal rim thickness measured by optical coherence tomography (OCT) and RNFL assessment with RNFL optical texture analysis (ROTA).
Methods :
In an ongoing population-based study in Hong Kong (Hong Kong Southern District Eye Survey), residents of southern district (SD) aged 50 or above were consecutively recruited from a random sample between July 2021 to July 2022. All participants received a comprehensive ocular examination by ophthalmologists and OCT imaging of the optic disc (Cirrus HD-OCT, Carl Zeiss Meditec) and the RNFL (Maestro2, Topcon). Glaucoma was defined by having any part of the neuroretinal rim thickness below the 1st percentile with RNFL defects detected on ROTA. OCT images with a signal strength ≤6 or signal quality score ≤30 were excluded. The methodology of ROTA has been previously described (Leung CK et al., Nat Biomed Eng. 2022;6:593-604).
Results :
1189 subjects (2301 eyes) were examined. The mean age was 63.4 (95% CI: 63.1-63.7), the mean IOP was 14.0mmHg (95% CI: 13.9-14.2), and the average RNFL thickness was 94.1µm (95%CI: 93.7-94.5). The prevalence of glaucoma was 4.0% (95% CI: 2.9-5.2%); the prevalence of RNFL defects was 8.7% (95% CI: 7.1-10.4%). Factors associated with glaucoma included IOP (OR: 1.19, 95% CI:1.08-1.30, P<0.001) and age (OR: 1.05, 95% CI: 1.01-1.11, P=0.03). Likewise, IOP (OR: 1.10, 95% CI: 1.03-1.78, P=0.004) and age (OR: 1.07, 95% CI: 1.03-1.11, P<0.001) were also associated with RNFL defects. Hypertension, diabetes, and smoking status were neither associated with glaucoma nor RNFL defects.
Conclusions :
The prevalence of RNFL defects on ROTA was higher than the prevalence of glaucoma in a population aged ≥50 years. As RNFL defects can be detected prior to detectable neuroretinal rim loss and high IOP was associated with RNFL defects, our study highlights the importance of RNFL assessment for early detection and treatment of glaucoma.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.