Natural History Study in Inherited Retinal Disease Subjects Caused by Mutations in RPE65 or LRAT

This is a retrospective, uncontrolled, multicenter, case history study to determine the
natural history of visual function in patients with IRD phenotypically diagnosed as LCA or
RP caused by autosomal recessive mutation in RPE65 or LRAT.

Up to 60 subjects will be enrolled in this study at approximately 12 study centers in
Canada, the US and Europe.

Inclusion Criteria:

- Male or female subjects aged 8 or older with IRD (LCA or RP) caused by inherited
autosomal recessive mutation in either RPE65 or LRAT.

- Subjects who have at least 2 documented kinetic visual field assessments of the same
isopter(s) in at least one eye performed at least 2 years apart on the same type of
equipment when the subject was between the ages of 6 and 65 years.

- If applicable, subjects who provide informed consent for the study (the requirement
for informed consent may be applicable to all sites or may be waived by the IRB
and/or local regulations). The parent or guardian must sign an approved informed
consent form for the study for subjects younger than the age of majority.

Exclusion Criteria:

- Subjects, who in the Investigator's opinion, have any severe acute or chronic medical
condition, psychiatric condition, physical examination finding or laboratory
abnormality that may interfere with the interpretation of their visual function data.

- Subjects with concomitant bilateral ocular disorders that may affect visual acuity or
visual fields (e.g., advanced glaucoma, optic neuritis, anterior ischemic optic
neuropathy, advanced cataract, intraocular surgery).