Macular ganglion cell complex (mGCC) and peripapillary retinal nerve fiber layer (ppRNFL) thickness can be used as structural parameters for detecting preperimetric glaucoma, reveals a study in the Journal of Glaucoma.

The investigation, led by Dr S.T. Takagi, Department of Ophthalmology, Toho University School of Medicine Faculty of Medicine, Tokyo, Japan, was held in a single institution and included 50 eyes of 50 glaucoma patients with visual field defects limited to the superior or inferior hemifield.

There were also 25 eyes of 25 control participants matched for age, sex and refractive errors. Thickness was measured in three areas using the automatic algorithm of a spectral-domain optical coherence tomography system.

Defective and normal hemifield values were compared, along with the correlation between OCT parameters and the total deviation values of the parameters in the Humphrey visual field.

mGCC thickness in the normal hemifield in glaucomatous eyes was significantly lower than in the control eyes. However, there was no significant difference in total thickness of the macular retinas between glaucomatous eyes and control eyes. In the normal hemisphere the mGCC and ppRNFL thicknesses were significantly correlated with total deviation in the visual field paramters.