To examine the effects of presurgical corticosteroid treatment for normal-risk penetrating keratoplasty (NRPK), high-risk penetrating keratoplasty (HRPK), and high-risk penetrating keratoplasty plus lensectomy.
We used 3 corneal transplantation models (NRPK, HRPK, and high-risk penetrating keratoplasty plus lensectomy). For each model, we tried to compare the effect of corticosteroid treatment according to different timetables as follows: The first trial began with a corticosteroid injection given 2 weeks before the PK and continued until 4 weeks after the PK (group 1). The second trial started with a corticosteroid injection given on the day of the PK and continued for 4 weeks after the PK (group 2). The third trial started with a corticosteroid injection administered on the day of the PK and continued for 8 weeks after the PK (group 3). After harvesting and immunostaining of corneas, graft survival, neovascularization (NV), and lymphangiogenesis (LY) were compared among the groups. A P value <0.05 was considered as being statistically significant.
With respect to graft survival, group 1 had improved graft survival compared with that of group 3 in the HRPK model (P = 0.025). In all the 3 PK models, groups 2 and 3 demonstrated a similar graft survival (P > 0.05). With respect to NV and LY, in NRPK, group 1 showed less NV than did group 2 (P < 0.001) and group 3 (P = 0.016). In HRPK, group 1 also demonstrated less NV and LY than did group 3 (P = 0.045 and 0.044, respectively).
The initiation time point of the corticosteroid treatment is important for graft survival. Corticosteroid pretreatment is an effective means to increase graft survival for HRPK and to decrease NV and LY for both NRPK and HRPK.