The purpose of this study is:

• To evaluate the safety of up to 3 additional courses of oral QLT091001 administered once daily for 7 days in subjects treated previously with a single 7-day course of QLT091001 in Study RET IRD 01
• To evaluate whether up to 3 additional courses of oral QLT091001 administered once daily for 7 days can maintain or improve visual function.

Inclusion Criteria:

• Subjects with LCA or RP due to RPE65 or LRAT deficiency who received a 7-day treatment course of QLT091001 and completed the Day 30 visit in Study RET IRD 01

• Subjects who meet any one of the following criteria at least 1 month after start of the 7-day treatment course in Study RET IRD 01:

  • no increase in GVF (in at least 1 eye): Follow-up GVF increased ≤20% from baseline or
  • decrease in GVF (in at least 1 eye): Follow-up GVF decreased below the highest previous response by ˃20% or
  • Considered a reasonable candidate for retreatment, based on the Investigator's discretion, in consultation with the independent DSMB and the Sponsor, based on regression or lack of response in other parameters of visual function (e.g., subjective reports of changes in color vision or adaptation to low light) but who do not meet other (GVF) criteria for study entry

Exclusion Criteria:

• Subjects with any clinically important abnormal physical finding at Screening.
• Subjects who have taken any prescription or investigational oral retinoid medication (e.g., Accutane,® Soriatane®) within 6 months of Day 0 and subjects who did not tolerate their previous oral retinoid medication will be excluded regardless of the time of last exposure.
• Subjects with liver failure, uncontrolled thyroid disease, hypersensitivity to retinoids, or hypervitaminosis A
• Subjects who have taken any supplements containing ≥10,000 IU vitamin A within 60 days of screening