Macular structure-function relationship at various spatial locations in glaucoma

Abstract

Background/aims: To study whether the structure-function (S-F) relationship in glaucoma differs according to macular location using spectral-domain optical coherence tomography (SD-OCT) and standard automated perimetry 10-2 and 24-2 visual fields (VFs).

Methods: We enrolled 151 eyes of 151 healthy, preperimetric and perimetric glaucomatous subjects. Macular ganglion cell-inner plexiform layer thicknesses at different parafoveal locations were measured using Cirrus SD-OCT. The mean sensitivity of 10-2 and 24-2 VFs was recorded in the decibel and 1/L scales. The topographic relationships between structure and function were assessed at different parafoveal and hemimacular locations using 'weighted' correlation coefficients. The strength of S-F relationships between macular ganglion cell-inner plexiform layer thickness measurements and VF mean sensitivity in various parafoveal locations and in superior and inferior hemimacula was compared using Steiger's test.

Results: The temporal parafoveal sector showed a significantly greater S-F relationship in each hemimacula compared with other parafoveal sectors (p<0.05). The inferior hemimacula showed a significantly greater S-F relationship than superior hemimacula (p<0.001).

Conclusions: The strength of the S-F associations at the temporal parafoveal location is significantly greater than that of the central or nasal parafoveal location in each hemimacula. The strength of the S-F association is significantly greater in the inferior hemimacula than in the superior hemimacula.

Keywords: Field of vision; Glaucoma; Macula.