EXAMINATION OF THE OPTIC NERVE HEAD WITH HEIDELBERG RETINA TOMOGRAPHY IN EYES WITH LARGE OPTIC NERVE HEAD CUP AND NORMAL VISUAL FIELD

Objective: To evaluate optic nerve head (ONH) topographic measurements with Heidelberg Retina Tomography in eyes with large ONH cup and (C/D ratio> 0.4) normal standard visual field. Materials and methods: Sixty-four eyes of 32 patients with large, physiologic ONH cups and normal standard visual fields were included in the study. The white-on-white visual fields (program 30-2) were obtained with Humphrey perimeter (Model 750). Intraocular Pressure (IOP) and Central Corneal Thickness (CCT) were measured with Goldmann applanation tonometer and ultrasonic pachymeter respectively. HRT with the software version 1.01 was used to evaluate the ONH topographic measurements Results: The mean age of patients were 44.25 +/- 14.0 years. Mean CCT was found 558.33 +/- 33.27 ae m. Mean IOP of the patients was 16.15 +/- 2.42 mmHg. We evaluated 32 eyes as normal (group 1) and 32 eyes as glaucoma (group 2) according to ONH analysis with HRT. Strong correlation was found between C/D ratio and glaucoma group with Mann Whitney U statistical analysis. Conclusion: The C/D ratio was found significantly smaller in normal group than in glaucoma group (p< 0.05). HRT reported 50% of the eyes whose clinical findings were normal, as having glaucoma. HRT may be useful for detection of glaucomatous change in subjects with large ONH cups in the long term followup. However, HRT results alone may be misleading in the diagnosis of glaucoma.