Structural and Microvascular Alterations in Macular Telangiectasia Type 2: The Diagnostic Value of Vessel Tortuosity

To investigate structural and microvascular changes in macular telangiectasia (MacTel) type 2 using optical coherence tomography (OCT) and OCT-angiography (OCTA) derived vascular parameters, and to examine their relationship in the macula.

A retrospective cross-sectional study included 27 MacTel type 2 patients and 54 age-and-gender-matched healthy controls. Participants underwent OCT, and OCTA imaging. Images from the superficial (SCP) and deep capillary plexuses (DCP) analyzed with OCTA Vascular Analyzer (OCTAVA) software to obtain different vascular parameters. Statistical analysis involved Mann-Whitney U tests, Spearman's correlations, and multivariate logistic regression; p <0.05 was considered significant after adjusting using the false discovery rate.

MacTel type 2 patients exhibited significant reduction in macular thickness in all inner ETDRS subfields (p < 0.05). Mean vessel tortuosity (mTort) in the DCP was significantly decreased in MacTel type 2 (p = 0.025). Macular thickness showed significant negative correlations with SCP-VD in the inner nasal region (r = -0.426, p = 0.034), and DCP-VD in the inner temporal region (r = -0.572, p = 0.003). Logistic regression identified central, inner nasal, and outer superior macular thickness, along with reduced mTort, as independent predictors of MacTel type 2 (p < 0.05).

This study highlights significant structural and microvascular changes in MacTel type 2, including macular thinning and reduced mean tortuosity. Additionally, the normal structural-vascular correlations were disrupted in MacTel Type 2, and different microvascular correlation patterns were observed in these patients. The identification of new vascular parameters may contribute to a better understanding of MacTel type 2.