[Appearance, recurrence and prognosis of immunological graft rejection after penetrating keratoplasty].

The aim of this study was to examine the patterns of immunological graft rejection reactions (IAR) after penetrating keratoplasty (KPL) and to assess the prognosis for preservation of transparency of the corneal graft. In the period from 2006 to 2015 a total of 190 IAR, which occurred in 120 eyes of 119 patients, were retrospectively analyzed. The underlying disease, number of previous KPL and IAR and measures of best corrected visual acuity (BCVA, logMAR) and pachymetry at the time points T1 = postoperatively, T2 = acute IAR, T3 = follow-up at 6 weeks and T4 = follow-up at 3-12 months were recorded. A successful treatment was defined as a lack of early recurrence (6-12 weeks after treatment) or the necessity for repeating the KPL. Data were compared using the χ The temporal analysis showed a median rejection-free interval of 19.3 months after the previous KPL (95% confidence interval, CI 14.7-26.6 months). In 138 out of 190 cases (72.6%) the IAR could be successfully treated, 12 (6.3%) suffered an early recurrence and 40 (21%) were irreversible. Despite a significant decrease of BCVA at T2 from 0.5 ± 0.4 at T1 to 0.7 ± 0.5 at T2 (p < 0.001), the comparison with the follow-up at 3-12 months (T1 vs. T4) showed no significant differences. The pachymetry at the thinnest point showed significant changes from T1 (535.4 ± 64.1 µm) to T2 (636.1 ± 102.1 µm; p < 0.001). Despite a significant reduction in thickness at T3 (607.3 ± 114.0 µm, p = 0.03), the corneal grafts were still significantly thicker in the follow-up at 3-12 months (591.8 ± 116.8 µm; p < 0.001; T1 vs. T4). With closely monitored aftercare following surgery IAR after KPL is rare. In most cases IAR typically occurs in the second postoperative year after KPL and under adequate treatment is reversible in approximately 75% of the cases. While BCVA showed a good recovery until the end of the follow-up period, the corneal grafts were still significantly thicker in the long-term after IAR (7.7-9.7%).