INTRAOCULAR-PRESSURE AND CENTRAL VISUAL-FIELD OF NORMAL-TENSION GLAUCOMA

Aim-To study whether damage in the central 30 degrees field of normal tension glaucoma (NTG) is relatively heterogeneous or homogeneous with respect to intraocular pressure (IOP) related damage. Methods-Using t he results of Humphrey perimeter examinations, the central 30 degrees field was divided into four subfields; superior and inferior hemifield s excluding the caecocentral field (30-2 program) and superior and inf erior 10 degrees hemifields (10-2 program). In 103 NTG cases, the intr aindividual bilateral difference in the mean of total deviations (mean TD) in the four subfields was analysed by multiple linear regression to correct the effects of factors other than IOP. Explanatory variable s were the intraindividual bilateral difference in the mean of clinic IOP (IOPmean), that in the ratio of area of peripapillary atrophy corr esponding to each subfield to disc area, and that in myopic refraction . Results-The intraindividual bilateral difference in the mean TD was significantly and negatively correlated with that in IOPmean in three of the above four subfields (p<0.005) and correlation tended to be neg ative (p=0.07) in the superior 10 degrees hemifield. Conclusions-Diffu se IOP related damage was suggested in the central 30 degrees field of NTG; greater extent of the damage in the above four subfields was cor related with higher mean IOP. The present findings may have clinical i mplications.