Visual function correlates with foveal slope, retinal and choroidal thickness on optical coherence tomography in type 2 Macular Telangiectasia

ABSTRACT

Purpose

To correlate the foveal slope angle (FSA), retinal (RT) and choroidal (CT) thickness measured using optical coherence tomography (OCT) across different stages of type 2 macular telangiectasia (MacTel) with best-corrected visual acuity (BCVA).

Methods

A cross-sectional study of 182 gradable quality macular OCT images of 49 patients with type 2 MacTel was carried out. RT was measured on the Spectralis OCT machine from ETDRS (Early Treatment Diabetic Retinopathy Study) retinal thickness map and later used for calculating FSA. RT and CT were measured at 500-µm intervals up to 1500 µm from foveal centre manually. The change in RT, CT and FSA across five stages of type 2 MacTel was assessed. The measurements were correlated with BCVA.

Results

The FSA, RT and CT were calculated quadrantwise and stagewise. The FSA and RT showed a significant negative correlation with disease stage and BCVA (p < .05) in all four quadrants. No significant correlation was noted between CT and BCVA. Multivariate linear regression analysis identified the temporal FSA to correlate best with BCVA.

Conclusion

BCVA correlates best with temporal FSA. Smaller the temporal FSA, poorer the vision.

KEYWORDS:

• Macular telangiectasia
• foveal slope angle
• retinal thickness
• choroidal thickness
• optical coherence tomography

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Ethics approval and consent to participate

Approval was obtained from Narayana Nethralaya Institutional Review Board and Ethics committee (C-2021-03-003).

Authors’ contributions

RV, JC, NKY – conceptualising the study, data acquisition, analysing the data, statistics and results, interpreting the findings, writing & reviewing the manuscript NR, PRM, SAM, DSM – Data acquisition and analysing the data

Additional information

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.