 3. Presence of any substantial ocular disease other than diabetic retinopathy or central retinal vein occlusion that may compromise vision in the study eye and or confound interpretation of the data; e.g. substantial cataracts, advanced glaucoma, optic neuritis, optic neuropathy or atrophy, marked macular atrophy, history of retinal detachment, uveitis, viral or other forms of chorioretinitis, etc. 