Protective Effect of Phenytoin on Glaucoma

The study will examine adult patients who suffer from glaucoma and epileptic disorders on the same time. the study group will include glaucoma patients, being treated with oral Phenytoin for their epileptic disorder. The study group will be compared to 2 control groups: * Glaucoma patients with epileptic disorder,receiving different medication than Phenytoin * Glaucoma patients with no epileptic disorder. 4 parameters will be evaluated for all groups: 1. Best corrected visual acuity 2. Optic disc cupping 3. visual fields and general perimetric indices 4. peripapillary retinal nerve fiber layer. Every participant in the study,after giving his informed consent, will be evaluated by a senior ophthalmologist in a single office appointment. The appointment will include a visual acuity, complete ophthalmic examination,Humphrey perimetric visual field testing and peripapillary RNFL thickness measurement by OCT. no drug or other treatment will be given to the participants after data collection, average +/-Standard deviation for the 4 parameters will be compared between the 3 groups. Student T-test and one- way ANOVA will be used for statistical analysis.