Treatment Study for Ischemic Optic Neuropathy With Opthalmic Timolol Maleate 0.5%

Non-arteritic anterior ischemic optic neuropathy (NAION) currently has no widely accepted acute treatment to improve recovery or prevent progression in the first month. It causes monocular vision loss with potential second eye involvement in 15% at 5 years. This leads to significant disability. It is the most common acute optic neuropathy in patients over 55 years of age. The final mechanism of injury is believed to be ischemic. Increasing perfusion of the optic nerve may reduce damage and prevent progression. Reduction in intraocular pressure has been shown to increase optic disc perfusion in animal models. Timolol maleate is a widely used medication for Glaucoma that reduces intraocular pressure. Treatment with Timolol maleate may improve optic disc perfusion in NAION and reduce ischemic damage from this condition. This study aims to enroll and treat patients with Timolol maleate 0.5% within 48 hours of symptom onset to assess feasibility of the study design and potential benefit of rapid intraocular pressure reduction.

• Timolol maleate (Drug), also known as Timoptic., Timolol., Timolol maleate.: Timolol 0.5% 1 drop twice daily to the effected eye for 4 weeks.

Primary outcomes

• Recruitment Rate of patients during the one year study to assess feasibility of a larger study [12 months]: This is to define the feasabilty of the study design for a larger study.
• Number of patients with adverse events [12 months]

Secondary outcomes

• Change in visual acuity at enrollment and three month follow up using a logMAR scale. [Enrolment, Within 48 hours of enrollment , 1 month, 3 months.]: This will evaluate the change in visual acuity as a measure of visual function.
• Change in the mean deviation of actual versus predicted sensitivity of the visual field. [48 hours after enrollment, 1 month, 3 months]: Using a a Haag-Streit Octopus 900 with white on white TOP 30-2 visual field program, the mean deviation will be compared at various time points to assess for improving visual function as it relates to the field of vision.
• Change in Colour vision as measured by HRR colour plates. [Within 48 hours of enrollment, 1 month, 3 months]: The total number of colour plates seen will be counted and compared to baseline as a measure of visual recovery as it effects colour vision.
• Change in contrast sensitivity will be measured using the Pelli-Robson contrast sensitivity chart. [48 hours from enrollment, 1 month, 3 months.]: The Pelli-Robson contrast sensitivity chart is another method to assess visual function. The change in total number of plates seen will be compared at the various time points.

Sex: All, ages: 41 Years to any

Inclusion Criteria:

* Age >40
* Sudden, painless monocular vision loss with edema of the optic disc
* Clinical diagnosis is Non-Arteritic Anterior Ischemic Optic Neuropathy
* Relative Afferent Pupil Defect (RAPD) at first study visit

Exclusion Criteria:

* Onset of vision loss >48 hours from time of enrollment
* History of Asthma or COPD
* History of Heart Block or Sinus Bradycardia
* Allergy to any beta blocker
* History of Multiple Sclerosis or optic neuropathy
* Active Ocular Inflammation on examination
* Currently being treated for Cancer or systemic vasculitis
* History of Glaucoma or use of medications that lower IOP
* Symptomatic cataract, retinopathy, macular disease or amblyopia in the symptomatic eye
* IOP of <10 at baseline
* Ocular surgery in past three months
* Women who are pregnant, breast-feeding or may become pregnant
* Inability to provide informed consent or follow up at three months
* Currently enrolled in any other study drug trial or previously enrolled in this study

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• Martin A SuttonBrown, MD, Principal investigator, Fraser Health Region