The use of pattern electroretinogram (PERG), automated static perimetry and selected parameters of clinical examination in early diagnosis of glaucoma

98^th Annual Meeting DOG 2000

V 427

The use of pattern electroretinogram (PERG), automated static perimetry and selected parameters of clinical examination in early diagnosis of glaucoma

A. Palacz

Purpose: To evaluate sensitivity and specificity of automated static perimetry compared to PERG and value of selected parameters of clinical examination medical history, intraocular pressure, cup/disk ratio in early diagnosis of glaucoma.

Patients and methods: in glaucoma suspected patients referred from outpatient clinic the following studies were performed: complete ophthalmologic examination as well as pattern electroretinography PERG (Utas E-1000, LKC System, Inc, USA), automated static perimetry (programm G1X, Octopus 1-2-3, Interzeag). Results of the PERG examinations were subjected to Fourier (FFT) analysis and obtained that way amplitudes of PERG were classified as within or out of previously established norms. Visual field abnormalities were assesed as significant based on Glaucoma Laser Trial criteria.

Results: 40 patients (80 eyes) were examined. On the basis of decreased PERG amplitude glaucoma was diagnosed in 30 patients (51eyes), that is 75% of examined patients. On the basis of static automated perimetry glaucoma was diagnosed in 20 patients (29 eyes), that is 50% of examined patients. The study showed, that perimetry didnt detect 10 glaucoma patients (18 eyes) who were revealed by PERG. In all but 2 eyes (in 2 patients) abnormalities in perimetry were corresponding with those detected by PERG. The 2 discordant were assesed as false positive. Specificity and sensitivity were calculated as 89,66% and 58,82% respectivly. Analysis of "cold hands and/or feet" were significantly more frequent in patients with NTG. Values of IOP and c/d ratio showed wide dispersion in both glaucoma and non-glaucoma patients.

Conclusions: 1) Symptoms of vascular abnormallities (cold hands and/or feet) seem to be a significant risk factor for glaucoma, 2) IOP and c/d ratio have limited value in differentiating glaucoma and non-glaucoma patients, 3) The final glaucoma diagnosis must be supported by additional investigations such as automated static perimetry or PERG, that last being more effective in detecting early glaucoma changes.

I^st Eye Clinic of Pomeranian Medical Academy in Szczecin

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