Modified Postoperative Regimen to Increase Retention of Keratoprostheses Juan Carlos Abad, MD Private practice, Medellín - Colombia Carolina Gómez Calle, MD Universidad de Antioquia Medellín-Colombia The authors have no financial interest in the subject matter of this poster Poster ID: 192

Purpose To compare the eight-year old experience with the new model (back plate with holes) Boston Keratoprosthesis (KPro) from a single Latin American center with published multi-diagnosis reports using the same keratoprosthesis, 1-4 and to evaluate the effect of a modified postoperative regimen in the retention rate of the device. 1.Zerbe, B.L. Results from the Multicenter Boston Type 1 Keratoprosthesis Study. Ophthalmology 2006;113:1779– Bradley, J.C; Hernandez, E.G; Schwab, I.R; Mannis, M.J. Boston Type 1 Keratoprosthesis: The University of California Davis Experience Cornea 2009;28:321– Chew, H. F; Ayres, B.D. et al. Boston Keratoprosthesis Outcomes and Complications. Cornea 2009;28:989–996 4.Aldave, A.J et al. The Boston Type I Keratoprosthesis Improving Outcomes and Expanding Indications. Ophthalmology 2009;116:640–651

Materials and Methods The charts of 19 patients who had undergone type I Boston KPro surgery from 2002 to 2009 were analyzed. Two patients required keratoprosthesis surgery both eyes. In these cases, only the right eye was analyzed. Since October 2008, we modified the postoperative regimen replacing topical prednisolone for topical medroxyprogesterone and four- generation quinolones for topical aminoglycosides and adding oral doxicycline and vitamin C for all patients based on the management of alkali corneal burns 1,2 and some studies about improved AlphaCor retention with postoperative medroxyprogesterone. 3 Compulsory usage of the bandage contact lens (BCL) was improved by lateral tarsorraphy and backup BCLs for all the patients. Topical diluted vancomycin was used before and after Oct Wagoner, M.D. Chemical injuries of the eye: current concepts in pathophysiology and therapy. Survey of ophthalmology. 41(4): , Brodovsky, S.C, McCarty C.A, Snibson, G; Loughnan, M; Sullivan, L; Daniell, M; Taylor, H.R. Management of Alkali Burns, An 11-year Retrospective Review. Ophthalmology 2000;107:1829– Hicks, C,R and Crawford G, J. Melting after Keratoprosthesis Implantation:The Effects of Medroxyprogesterone. Cornea 22(6): 497–500, 2003.

Preoperative Diagnosis

Results There were 12 male and 17 female patients Average age was 52 (±18) years old The average of follow up was 25 months (± 21,1) (Range:2.4 to 96.7) 1. Visual Acuity Preoperative best-corrected visual acuity (BCVA) ranged from 20/400 to light perception At last follow-up, postoperative BCVA was better than 20/200 in 68.4% of patients and was greater 20/50 in 53.8% of patients. The best visual result was observed in patients with atopic keratoconjunctivitis and ocular trauma.

Results - BCVA

Results 2. Kerathoprotesis Retention Months of f/u Case number

Results 2. Keratoprosthesis Retention The estimated time of survival of the keratoprosthesis was 55,9 months (CI 32,4 –76,3) Retention of the original KPro was 76,7% and of all KPros (including redos) 94,7%. Original KPro Corneal Melt around KPro

Results 3. Modified postoperative regimen effect Extrusion P value*ORCI 95% Yes n(%) No n(%) W/o Medroxyprogesterone5(41,7)7(58,3) 0,3334,286(0,386-47,625) With Medroxyprogesterone1(14,3)6(85,7) Conjunctival overgrowth

Traditional vs Modified PO Regimen 1.Traditional postoperative regimen 2.Modified posoperative regimen Other complications Eleven cases had glaucoma preop (57.8%) and 3 additional cases developed it after surgery (68.4%) Four cases of retroprosthetic membrane were encountered (21%) Two cases had sterile vitreitis (10.5%) There was one case of infectious keratitis and one of endophthalmitis (P.aeruginosa) (5.3% each)

Discussion Postoperative BCVA was greater than 20/200 and 20/50 in 68.4% and 53,8% of patients respectively, better than Zerbe’s study 1 (56% and 23% respectively), but similar to the University of California Davis’ report 2 (20/200 in 75% and 20/40 in 25% of eyes) In our analysis, the retention of the first KPro was 76,7%, similar to the 84 % retention rate found by Aldave. 3 The overall retention in our study was 94% like that observed by Zerbe et al. 1 (95%) We found a lower rate of retroprosthetic membranes (21%) than the report from Chew 4 (65%) The modified regimen in our population shows an initial trend to diminish corneal melt similar to the findings by Hicks et al. 5 1.Zerbe, B.L. Results from the Multicenter Boston Type 1 Keratoprosthesis Study. Ophthalmology 2006;113:1779– Bradley, J.C; Hernandez, E.G; Schwab, I.R; Mannis, M.J. Boston Type 1 Keratoprosthesis: The University of California Davis Experience Cornea 2009;28:321– Aldave, A.J et al. The Boston Type I Keratoprosthesis Improving Outcomes and Expanding Indications. Ophthalmology 2009;116:640–651 4.Chew, H. F; Ayres, B.D. et al. Boston Keratoprosthesis Outcomes and Complications. Cornea 2009;28:989–996 5.Hicks, C,R and Crawford G, J. Melting after Keratoprosthesis Implantation:The Effects of Medroxyprogesterone. Cornea 22(6): 497–500, 2003.

Conclusions The incidence of preoperative inflammatory conditions before keratoprosthesis surgery appears to be higher in a Third-world setting The clinical results seem to be similar to multi-diagnosis KPro series published from developed countries The modified postoperative regimen with medroxiprogesterone instead of prednisolone, avoiding 4 th generation quinolones and oral doxicycline and vitamin C seems to have decreased melts or at least their severity. Longer follow up is needed to confirm these findings. Our lower retroprosthetic membrane formation rate could be related to the fact that most patients were left aphakic during surgery.