Abstract
Purpose: :
To analyze the results of total deviation (TD) measured by standard automated perimemtry in patients with early (preperimetric) glaucoma.
Methods: :
Fifty seven patients with early glaucoma who have retinal nerve fiber layer (RNFL) defect in red free photograph but normal standard automated perimetry (SAP) and sixty one normal controls were enrolled. TD plot in Humphrey visual field was divided into six sectors according to the optic disc-VF mapping (Garway-Heath, Ophthalmology 2000) and compared the mean threshold of each sector between early glaucoma and control. Subjects in each group were classified into normal TD group and abnormal TD group by the presence of visual field defect in TD plot, and the proportions of the TD abnormality were calculated. Finally, peripapillary RNFL thickness was measured using Stratus optical coherence tomography (OCT) and compared between normal TD group and abnormal TD group of early glaucoma patients.
Results: :
Compared with controls, mean TD thresholds of early glaucoma were significantly low in inferonasal, inferotemporal, superonasal sectors (P<0.05). TD abnormalities were found in 25 out of 57 glaucoma eyes (43.86%) ; 20 out of 52 eyes (38.50%) when excluding 5 eyes whose TD abnormal points did not correspond to RNFL defect, while 4 out of 61 eyes showed TD abnormality in controls (6.58%). In early glaucoma, RNFL thickness was significantly lower in abnormal TD group (25 eyes) than normal TD group (32 eyes) at eleven o’clock (P=0.037, 112.60 ± 19.49µm, 126.53 ± 27.72µm, respectively)
Conclusions: :
In patients with early glaucoma of preperimetric stage, 38.50% have glaucomatous VF defect in TD plot and RNFL thickness was significantly low in TD abnormal glaucoma eyes. So the importance of TD plot should be considered in practice. It is necessary to study about the ability of TD plot to predict the development of definite VF defect in patients with preperimetric glaucoma.