Transplantation of Suboptimal Corneal Donor Tissue: A Case Series Elsie Chan, FRANZCO Graeme Pollock, PhD Rasik B. Vajpayee, FRANZCO World Cornea Congress, 2015Financial interests: nil

Introduction Current standards for procurement and preparation of corneal donor tissue involves: – Extensive history from next-of-kin – Slit lamp biomicroscopy of the corneo-scleral button (where the tissue is examined in preservation medium in a bottle) – Serological and microbiological testing – Specular microscopy for endothelial cell structure and density There are limitations to the current screening methods, with cases of transplantation using suboptimal tissue (eg. previous refractive surgery) reported. 1-3

Aim and Methods Aim To present a series of patients who were observed to have corneal opacities in the donor corneal tissue immediately following corneal transplantation Study Design Retrospective case series Cases 4 transplants performed using corneal buttons from 3 donors in Melbourne, Australia in 2014 Donor tissues Prepared at a single eye bank service No history of surgery or other pathology in any of the donor corneas was reported based on clinical history from next-of-kin

Case 1 History 50 year old male History of keratoconus and previous penetrating keratoplasty Developed post-graft ectasia Underwent a repeat penetrating keratoplasty Post-operative finding Corneal opacity in mid-stroma, postulated to have been from previous trauma Outcome Patient happy with visual acuity, no further intervention required

Case 1 Photograph showing mid stromal opacity in the donor button (see arrow)

History 40 year old male History of keratoconus Underwent Dia-DALK 4 Post-operative finding Anterior stromal opacity across corneal button Outcome Repeat Dia-DALK performed Anterior Segment OCT (Zeiss HD-OCT 4000, Carl Zeiss Meditec, CA) image showing an anterior stromal opacity across donor tissue Case 2a

Case 2b History 20 year old male History of advanced keratoconus Underwent DALK (using Melles’ technique 5 ) Donor button Fellow eye of donor in Case 2a Post-operative finding Thin donor button measuring 470µm on anterior segment OCT 1 month post-operatively Outcome Patient happy with visual acuity, no further intervention required

Case 2b Thin donor button measuring 470µm on anterior segment OCT (Visante OCT, Carl Zeiss Meditec, CA). This is the fellow eye of Case 2a

Case 3 History 50 year old male History of keratoconus and previous penetrating keratoplasty Sustained blunt trauma leading to aphakia, aniridia, graft dehiscence and graft failure Underwent penetrating keratoplasty and insertion of aniridic IOL Post-operative finding 3 central corneal scars on the donor button consistent with a previous corneal foreign body Outcome Patient happy with visual acuity; no further intervention required

Case 3 Photograph showing three anterior stromal opacities in the donor tissue

Discussion Current techniques to screen donor corneal tissue for transplantation may not be sufficient to exclude pathologies including corneal scars and previous refractive laser surgery – History taking from the next-of-kin can be inaccurate or misleading 6 – Slit-lamp examination of donor corneo-scleral buttons is difficult – Subtle pathologies can be difficult to detect in donated eyes (secondary to post-mortem stromal oedema and epithelial changes) To decrease the number of suboptimal donor corneal tissue – Utilisation of more advanced imaging techniques including ocular coherence tomography 7, pachymetry and curvature maps 8 may be advantageous – Additional training of eye bank staff in recognising corneal pathology may also be helpful

References 1 Maharana P et al. Optom Vis Sci 2014; 91: e59. 2 Mendez Angulo E. Refract Corneal Surg 1989; 5: Michaeli-Cohen A et al. Cornea 2002; 21: Vajpayee R et al. JCRS 2014;40:276 5 Melles GRJ et al. BJO : Kang SJ et al. Cornea 2010; 29: Priglinger SG et al. Cornea. 2003;22:46. 8 Ousley PJ and Terry MA. Cornea. 2002; 21:181. ACKNOWLEDGEMENTS Medical Photography and Imaging Centre, Royal Victorian Eye and Ear Hospital, Melbourne, Australia and the Vision Eye Institute, Melbourne, Australia for the images used in this poster.