Abstract
Purpose :
Overlapping features between glaucoma and high myopia (HM) make glaucoma diagnosis in HM eyes challenging. Herein we evaluate the structure-function (SF) relationship of focal retinal layer thickness with visual field (VF) sensitivity in HM patients with glaucoma (HM-G) and highly myopic glaucoma suspects (HM-DS), comparing the superficial retinal layers (SRL) and deep retinal layers (DRL). We hypothesised that in HM-G, superficial retinal ganglion cell (RGC)-layers will exhibit stronger SF associations than deep non-RGC retinal layers, while in HM-DS, SRL and DRL will both exhibit strong SF associations.
Methods :
67 eyes from 49 HM-G subjects and 88 eyes from 61 HM-DS subjects were enrolled in this cross-sectional study. HM was defined as refractive error ≤-6 dioptres and/or axial length ≥26mm. HM-G eyes featured glaucomatous optic neuropathy with corresponding VF defects, while HM-DS eyes did not meet the criteria for glaucoma diagnosis. Subjects were evaluated using 10-2 Humphrey VF analyser and macular optical coherence tomography (OCT) scans. SF correlation between SRL/DRL thickness and VF pattern deviation (PD)/ total deviation (TD)/ total sensitivity (TS) were evaluated. P-value<0.05 was taken to be significant.
Results :
In HM-G eyes, SRL thickness in all sectors were positively correlated with VF, with significant correlations between inner plexiform layer (IPL)/ ganglion cell inner plexiform layer (GCIPL) and TD/TS (p<0.01). Strongest correlations were observed in the IPL, at the inferior-temporal (IT) sector (r=0.69). In contrast, in HM-DS eyes, SRL showed equivocal correlations, with significant correlation in GCIPL-PD and no significant correlation in all sectors in ganglion cell complex (GCC)-TD/TS and GCIPL-TD (p>0.05). Significant negative correlations were observed in all 4 sectors in the inner segment/ outer segment (IS/OS) layer of the DRL that was also strongest in the IT sector (r=-0.53, p<0.01).
Conclusions :
HM-G eyes show significant positive SF associations in all sectors of the SRL, with strongest correlations in the IPL layer of the IT sector. In HM-DS eyes, significant negative correlations were observed in the IS/OS layer of the DRL in all 4 sectors. Evaluation of the SRL and IS/OS SF relationship may be helpful in distinguishing HM-G from HM-DS eyes.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.