Safety and Effectiveness Study of the MEL 80 Excimer Laser Using LASIK in the Treatment of Hyperopia

LASIK has become one of the most common refractive eye procedures performed in the country. In the hyperopia procedure, a steepening occurs on the corneal surface, rather than the flattening procedure (myopic treatment). The surgeon will produce a standard keratomileusis flap using a microkeratome, exposing the corneal stroma. Recontouring under the flap is then accomplished by the removal of tissue from the stroma with the laser. This recontouring results in an altering of effective lens power of the central cornea, measured in diopters (D). The MEL 80 Excimer Laser System will be evaluated for its ability to create accurate and stable hyperopic refractive correction results.

Inclusion criteria

• Naturally occurring hyperopia up to +6.0 D, with or without astigmatism of +0.50 D to +3.50 D at the spectacle plane, and MRSE ≤ +6.50 D;
• Have ≤ 0.75 D of latent hyperopia as determined by the difference between the preoperative MRSE and CRSE;
• A stable refraction for at least the last 12 months as documented by previous clinical records, i.e., the spherical and cylindrical portions of the manifest refraction have not progressed at a rate of more than 0.50 D during the year prior to the baseline examination in the eye to be treated;
• Hard contact lens wearers must have two central keratometry readings and two manifest refractions taken at least one week apart that do not differ by more than 0.50 D;
• Visual acuity correctable to at least 20/40 in both eyes;
• Operative eye must be targeted for emmetropia;
• At least 21 years of age;
• Willing and able to return for scheduled follow up examinations for 24 months after surgery;
• Sign and be given a copy of the written Informed Consent form.

Exclusion criteria

• A history of anterior segment pathology, including cataracts (in the operative eye);
• Severe dry eye syndrome unresolved by treatment;
• Residual, recurrent, active ocular or uncontrolled eyelid disease, corneal scars within the ablation zone or other corneal abnormality such as recurrent corneal erosion or severe basement membrane disease;
• Ophthalmoscopic signs of keratoconus (or keratoconus suspect);
• An ablation deeper than 250 microns from the corneal endothelium;
• Irregular or unstable (distorted/not clear) corneal mires on central keratometry readings;
• Blind in the fellow eye;
• Undergone previous intraocular or corneal surgery of any kind in the operative eye(s), including any type of excimer laser surgery for either refractive or therapeutic purposes;
• A history of ocular Herpes zoster or Herpes simplex keratitis;
• A history of steroid-responsive rise in intraocular pressure, glaucoma, or preoperative IOP >21 mm Hg;
• Diabetes, diagnosed autoimmune disease, connective tissue disease, or clinically significant atopic syndrome;
• Immunocompromised or use chronic systemic corticosteroid or other immunosuppressive therapy;
• Pregnant, lactating, or be of childbearing potential and not practicing a medically approved method of birth control;
• A known sensitivity to planned study medications;
• Participating in any other ophthalmic drug or device clinical trial during the time of this clinical investigation;
• At risk for angle closure or for developing strabismus postoperatively.
• For Fellow (Second) Eyes in Simultaneous Bilateral Treatment Procedures
• 1. Flap complications during the first eye's surgery such as a free cap, partial flap, thin flap, or irregular flap.
• 2. Epithelial defect exceeding 2 mm x 2 mm in dimension, or clinically significant debris in the interface between the flap and underlying stroma for the first eye.
• 3. Severe blepharospasm in the first eye that may have prevented or impeded the completion of the keratectomy and/or the laser ablation procedure.
• 4. Poor subject cooperation with instructions for the first eye's surgery and/or poor subject fixation on the laser fixation target.
• 5. Aborted LASIK procedure in the first eye or PRK was performed in the first eye because LASIK was not possible.