This study is a phase 1, open label, non-randomized, multi-center, pilot study to evaluate the safety and tolerability of NT-501 implants in 5-7 study participants with Mactel.

Protocol for Extended Follow-up of a Phase 1 Multicenter Open Label Safety and Tolerability Clinical Trial of Ciliary Neurotrophic Factor (CNTF) in Patients with Macular Telangiectasia Type 2 (MacTel)

Inclusion Criteria:

• The participant must be offered sufficient opportunity to review the informed consent form, agree to the form's contents and sign the protocol's informed consent;
• The participant must have bilateral MacTel;
• Women of childbearing potential and all men must agree to use an effective form of birth control during the study;
• Participant must be medically able to undergo ophthalmic surgery for ECT implant;
• The participant's best-corrected visual acuity 64 letters or better (20/50 or better) in the study eye;

Exclusion Criteria:

• Participant is < 21 years of age;
• Participant is medically unable to comply with study procedures or follow- up visits;
• Participant has evidence of ocular disease other than MacTel that may confound the outcome of the study (e.g., diabetic retinopathy with manifest macular edema, uveitis, etc.);
• Participant has a chronic requirement (e.g., ≥ 4 weeks at a time) for ocular medications and/or has a diagnosed disease, that in the judgment of the examining physician, may be vision threatening or may affect the primary outcome (artificial tears are permitted);
• Participant has evidence of subretinal neovascularization in either eye;
• Participant has evidence of central serous chorio-retinopathy (CSR) in either eye;
• Participant has evidence of pathologic myopia in either eye;
• Participant has had a vitrectomy, penetrating keratoplasty, trabeculectomy or trabeculoplasty;