CRYOPRESERVATION OF EXTRACTED CORNEAL LENTICULES AFTER RELEX SMILE FOR HUMAN USE

Primary purpose- To study the viability, safety, refractive efficacy and outcomes of cryopreserved donor lenticules obtained after ReLEx SMILE procedure ,for the correction of hypermetropia and aphakia in otherwise healthy patients.

Description of the hypothesis and methodology- ReLEx SMILE is a technique for the correction of myopia(short sightedness) whereby a lenticule is created in the patients cornea using the visumax femtosecond laser and subsequently removed through a 2mm incision. the technique is considered safe and effective and offers multiple advantages over conventional LASIK procedure which involves creation of  flap and sunsequent ablation of corneal tissue underneath the flap. Since SMILE is a flapless technique it does not have disadvantages of flap dislocation , infection , post operative dry eye etc.

The refractive lenticule which is removed after ReLEx SMILE procedure can be stored in cryopreservation and has been shown to remain viable for future use(study quoted). It can be used for the treatment of hypermetropic patients(far sightedness) by creating a pocket in their cornea with femtosecond laser and implanting this donor lenticule (which is matched for the refractive power). Before implanting the tissue into a patient, we shall be doing the serology test for HIV, HBV, HCV, Syphilis of the donor patient and a proper consent will be obtained from the donor for preserving their lenticules for use in other  patient. This technique is proposed to be a safer and effective alternative for hypermetropia correction compared to LASIK for hypermetropia, since it maintains the prolate shape of the cornea by additing tissue in the midperiphery  as against LASIK, which involves removal of tissue in midperiphery and creating a hyper prolate(abnormal) shape of cornea leading to aberrations and regression over a period of time. other advantages- it is a completely reversible procedure. Lenticule can be removed in the event of any adverse reaction if any. Chances of rejection are also extremely low, as the lenticule is a stromal tissue, which is mainly collagen tissue, and has the least antigens

Patients will be followed up at the periods of day 1, day 15, 1 month, 3 months and 6 months post operatively  and studied for clinical outcomes like visual acuity, slit lamp examination, Anterior segment OCT, specular microscopy, contrast sensitivity , aberrations and any adverse reaction.