Effect of donor parameters on primary graft failure and the recovery of acuity after keratoplasty

Effect of Donor Graft Quality on Clinical Outcomes After Penetrating Keratoplasty for Keratoconus

PURPOSE

To evaluate the effect of donor and eye bank characteristics on graft rating and clinical outcomes after penetrating keratoplasty (PK) for keratoconus.

METHODS

This retrospective interventional case series included 252 keratoconic eyes which underwent PK. Donor data included age and sex, cause of death, death-to-preservation time, preservation-to-surgery time, epithelial and stromal status, endothelial cell density (ECD) and morphology, and graft rating. Postoperative outcomes included visual acuity, refractive error, epithelial problems, suture-related complications, graft rejection, and graft transparency. Multivariate regression analysis assessed correlations between donor and eye bank characteristics and graft quality, and postoperative outcomes.

RESULTS

Mean recipient and donor age was 29.7 ± 10.0 and 26.2 ± 8.8 years, respectively and mean follow-up period was 66.7 ± 38.5 months. Death-to-preservation time was significantly associated with the presence of graft epithelial sloughing (P = 0.005) and stromal cloudiness (P < 0.001). Donor age significantly influenced ECD (P = 0.02), mean cell area (P = 0.04), and hexagonality (P = 0.01). The presence of epithelial defects on postoperative day 1 correlated significantly with death-to-preservation time (P = 0.004). Graft stromal edema on postoperative day 1 was significantly associated with graft epithelial sloughing (P < 0.001). Postoperative visual and refractive outcomes, complications, and graft survival were not correlated with any donor or eye bank factors.

CONCLUSION

Donor and eye bank variables affected the quality of donor corneas and early postoperative course. However, their long term effect on clinical outcomes, complications, and graft survival were insignificant.

Primary graft failure : a clinicopathologic and molecular analysis

OBJECTIVE

Primary graft failure (PGF) corneal tissues were analyzed for herpes simplex virus (HSV) and varicella-zoster virus (VZV).

DESIGN

Retrospective, noncomparative case series.

MATERIALS

Formalin-fixed, paraffin-embedded tissue of 21 donor corneas and 14 recipient corneas of PGF cases, as well as 10 control corneas.

METHODS

Clinical, histologic, immunohistochemical, polymerase chain reaction (PCR), and, in selected cases, transmission electron microscopic characteristics were studied.

MAIN OUTCOME MEASURES

Evidence of HSV or VZV in donor tissues.

RESULTS

Median patient age was 65 years, and median donor age was 48 years. Donor cornea parameters, including endothelial cell counts, death-to-preservation time, and time in storage, were generally within accepted standards. Stromal edema was found in all 21 donor corneas with PGF. Eighteen donor corneas demonstrated severely reduced or absent endothelium and mild to moderate lymphocytic infiltration without necrosis. Three donor corneas (14%) had necrotizing stromal keratitis (NSK) with keratic precipitates. Positive immunohistochemical staining of keratocytes for HSV was present in two of two donor corneas with NSK and was negative in 18 other donor corneas. Polymerase chain reaction analysis revealed the DNA of HSV type 1 (HSV1) in all donor corneas with NSK and in four donor corneas without NSK (33%). Recipient corneal tissue was negative for HSV1 DNA in three patients with NSK and positive in two of the four other PCR-positive patients. Transmission electron microscopy analysis showed viral particles in two donor corneas with NSK. Polymerase chain reaction analysis revealed no evidence of HSV type 2 or VZV in any cornea. All control corneas were negative for viral DNA. Sixteen corneas remained clear and two had failed after regraft for PGF, with a median follow-up of 3.6 years.

CONCLUSIONS

Herpes simplex virus type 1 DNA was present in 33% of patients of PGF. Herpetic stromal keratitis was found in some failed corneas; the lack of HSV in the paired recipient suggests importation within the donor cornea. The overall prognosis for regrafting after PGF is good.