Primary Open Angle Glaucoma | Protective Effect of Phenytoin on Glaucoma

Primary Open Angle Glaucoma research study

What is the primary objective of this study?

since glaucoma is considered an optic neuropathy, new treatments for glaucoma are being continuously investigated, including neuroprotection. Previous studies implied that phenytoin, a potent anti-convulsive drug, has a neuroprotective role, and Na+ channels blockage was suggested as a possible mechanism. This study predicts that glaucoma patients taking Phenytoin will have a less advanced glaucoma as compared to patients not taking the drug. Glaucoma severity will be determined by visual acuity, visual fields, optic disc cupping and nerve fiber layer thickness

Who is eligible to participate?

Inclusion Criteria: - Clinical diagnosis of glaucoma - chronic treatment with phenytoin for any indication Exclusion Criteria: - pregnancy - visual acuity less then 6/60

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Primary Open Angle Glaucoma

Secondary Open Angle Glaucoma

Narrow-Angle Glaucomas

Normal Tension Glaucoma

Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

1glaucoma patients who also suffer from epileptic disorder and receiving chronic oral Phenytoin treatment

2glaucoma patients who also suffer from epileptic disorder receiving anti-convulsant treatment other then Phenytoin

3glaucoma patients with no epileptic disorder and not receiving anti-convulsant treatment

Study Status

Unknown status

Start Date: November 2008

Completed Date: December 2010


Type: Observational


Primary Outcome: peripapillary RNFL thickness

Secondary Outcome: corrected pattern standard deviation in perimetric visual field

Study sponsors, principal investigator, and references

Principal Investigator: Omer Y Bialer, MD

Lead Sponsor: Rabin Medical Center


More information:

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Ates O, Cayli SR, Gurses I, Turkoz Y, Tarim O, Cakir CO, Kocak A. Comparative neuroprotective effect of sodium channel blockers after experimental spinal cord injury. J Clin Neurosci. 2007 Jul;14(7):658-65.

Podos SM, Becker B, Beaty C, Cooper DG. Diphenylhydantoin and cortisol metabolism in glaucoma. Am J Ophthalmol. 1972 Sep;74(3):498-500.

Naskar R, Quinto K, Romann I, Schuettauf F, Zurakowski D. Phenytoin blocks retinal ganglion cell death after partial optic nerve crush. Exp Eye Res. 2002 Jun;74(6):747-52.

Lo AC, Black JA, Waxman SG. Neuroprotection of axons with phenytoin in experimental allergic encephalomyelitis. Neuroreport. 2002 Oct 28;13(15):1909-12.

Hains BC, Waxman SG. Neuroprotection by sodium channel blockade with phenytoin in an experimental model of glaucoma. Invest Ophthalmol Vis Sci. 2005 Nov;46(11):4164-9.

Savini G, Bellusci C, Carbonelli M, Zanini M, Carelli V, Sadun AA, Barboni P. Detection and quantification of retinal nerve fiber layer thickness in optic disc edema using stratus OCT. Arch Ophthalmol. 2006 Aug;124(8):1111-7.

Carpineto P, Ciancaglini M, Zuppardi E, Falconio G, Doronzo E, Mastropasqua L. Reliability of nerve fiber layer thickness measurements using optical coherence tomography in normal and glaucomatous eyes. Ophthalmology. 2003 Jan;110(1):190-5.

Williams ZY, Schuman JS, Gamell L, Nemi A, Hertzmark E, Fujimoto JG, Mattox C, Simpson J, Wollstein G. Optical coherence tomography measurement of nerve fiber layer thickness and the likelihood of a visual field defect. Am J Ophthalmol. 2002 Oct;134(4):538-46.

Budenz DL, Chang RT, Huang X, Knighton RW, Tielsch JM. Reproducibility of retinal nerve fiber thickness measurements using the stratus OCT in normal and glaucomatous eyes. Invest Ophthalmol Vis Sci. 2005 Jul;46(7):2440-3.

Leung CK, Chan WM, Chong KK, Yung WH, Tang KT, Woo J, Chan WM, Tse KK. Comparative study of retinal nerve fiber layer measurement by StratusOCT and GDx VCC, I: correlation analysis in glaucoma. Invest Ophthalmol Vis Sci. 2005 Sep;46(9):3214-20.

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