Segmental analysis of macular layer thinning in patients with unilateral primary open-angle glaucoma.

Abstract

 

Purpose

 

To measure the thicknesses of the inner layers of the macula in both eyes of patients with unilateral primary open-angle glaucoma (POAG) and compare them with normal control eyes.

 

Methods

 

This prospective, cross-sectional pilot study enrolled patients with unilateral POAG, who had visual field defect in only one eye, and controls with a normal eye exam. Horizontal and vertical B-scan images centered on the fovea were obtained using Spectral domain optical coherence (SD-OCT, Heidelberg Engineering GmbH, Heidelberg, Germany). Semi-automatic delineation and segmentation of the inner layers of the retina were performed to evaluate macular retinal nerve fiber layer (mRNFL), ganglion cell complex (GCC) and ganglion cell-inner plexiform layer (GC-IPL) thicknesses. Mean, superior, inferior, nasal, and temporal inner macular layer thicknesses were compared between affected eyes, fellow eyes without field defect and control eyes.

 

Results

 

Nineteen patients with unilateral POAG and 14 normal control eyes were enrolled. In the affected POAG eyes, thinning of the mRNFL, GCC, and GC-IPL layers on horizontal and vertical scans were significant when compared to controls (P<0.05), particularly on vertical scans (P<0.001). The mean regional macular GCC and GC-IPL were most severely thinned in the inferior and temporal perifoveal regions. The unaffected eye of patients with unilateral POAG showed significant thinning of the mRNFL only in the vertical scan when compared with normal controls (P<0.05).

 

Conclusions

 

SD-OCT detected significant thinning of the mRNFL, GCC and GC-IPL in the affected eyes of patients with unilateral POAG. Fellow eyes showed early structural changes only in the vertical mRNFL scans when compared with normal controls.  

 

Visual field and spectral-domain optical coherence tomography (SD-OCT) scans for both affected and fellow eyes of a patient with glaucoma and unilateral visual field loss. Comparing the horizontal macular scans in (A) to (B) demonstrates significant macular retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer thinning in the affected left eye (B) vs. unaffected right eye (A). Also shown are the SD-OCT peripapillary RNFL circle scans and thickness profiles for both eyes.