[Immunomodulation in penetrating keratoplasty. Current status and perspectives]

Adverse effects of low-dose systemic cyclosporine therapy in high-risk penetrating keratoplasty

PURPOSE

The purpose of this study was to investigate the adverse effects of low-dose oral cyclosporine (CsA) therapy following high-risk corneal transplantation.

METHODS

The medical records from 88 subjects who had undergone high-risk penetrating keratoplasties and had been administered oral CsA were retrospectively analyzed. High risk was defined as a history of graft rejection, three or more quadrants of vascularization, or the presence or history of intraocular inflammation. An initial CsA dose of 3-5 mg/kg per day was given for 3-7 days, followed by 2.5-3.5 mg/kg per day for approximately 1 month. The concentration of CsA was maintained at the target trough level of 120-150 ng/ml for at least 6 months or until serious complications developed. The relationship between the cumulative dose and duration of CsA administration and the adverse systemic effects, including the frequency of herpes keratitis, was evaluated. The incidence of herpes keratitis in the study subjects was compared with the incidence in 185 patients who had not received CsA therapy following penetrating keratoplasty.

RESULTS

The mean survival time of the grafts was 33.6 months. Adverse effects occurred in 81.8 % of subjects. Hypertension, elevated liver enzyme levels, elevated serum creatinine level, and decreased absolute neutrophil count (ANC) were observed in 14.8, 6.8, 5.7, and 5.7 % of subjects, respectively. Simvastatin-induced rhabdomyolysis also developed in one case. Some patients exhibited minor complications, with gastrointestinal problems and hypertrichosis recorded in 5.7 and 3.4 % of subjects, respectively. Hypertension and hepatotoxicity most frequently occurred after 4 to 8 weeks of medication, while ANC decrease and nephrotoxicity generally developed after 24 weeks of treatment, with incidence related to the cumulative dose. Herpes keratitis occurred more frequently (31.8 %) in the CsA-treated subjects than in subjects that did not receive CsA therapy (p = 0.005). Most of the adverse effects were reversed after discontinuation of CsA therapy.

CONCLUSION

The results of this study suggest that low-dose oral CsA therapy may induce various adverse effects, the most common of which are herpes keratitis and hypertension.

[Immunosuppressives to prevent rejection reactions after allogeneic corneal transplantation]

In order to prevent rejection of an allogeneic corneal transplant after perforating (high risk) keratoplasty, active agents from different classes of pharmacological substances are used, as with solid organ transplantation. In addition to glucocorticoids, antiproliferative agents, small molecule inhibitors and antibodies, those belonging to the group of macrolides with their many derivatives represent an interesting class of substances in this context. As a supplement to cyclosporin A (CSA) the most successful macrolide in transplantation medicine, animal experiments are currently being carried out to test newer macrolide derivatives, such as sanglifehrin A (SFA). This overview describes the classes of drugs and modes of action of currently administered standard medications in the clinical routine and new developments are presented.

Outcome of penetrating keratoplasty in corneal ulcer: a single-center experience

Background

Corneal ulcers often lead to scarring and astigmatism, and significant loss of vision is a common consequence.

Objective

To determine the rate of graft rejection, one of the most serious concerns with this procedure, and to evaluate the recovery of visual function in those patients for whom the operation was successful.

Methods

We describe a retrospective study of 33 corneal ulcer patients undergoing penetrating keratoplasty (PK) at the Tabriz Nikookari Eye Hospital.

Results

Mean age of the patients was 44 ± 14 years. Most common risk factors for active keratitis were trauma, dry eye, and malnutrition. Culture-positive results included bacterial keratitis (n = 15) and fungal keratitis (n = 5). Perforation was a significant risk factor for therapeutic failure (P < 0.05). Age or gender had no statistically significant effects on the PK outcome (P > 0.05). Postoperative visual acuity had a significant association with preoperative visual acuity (P < 0.01). Graft rejection rate (27.2%) was similar to that reported in the literature.

Conclusion

Although lamellar keratoplasty has recently been established, there are practical reasons for continuing the use of PK in centers such as ours, with due attention to the requirement for topical immunosuppression to diminish the rate of graft rejection and antimicrobial treatment to prevent postoperative infection.

Intrakamerale Applikation von Kortikosteroiden zur Therapie der schweren endothelialen Abstoßung nach perforierender Keratoplastik

Immune reaction is the main cause for graft failure following penetrating keratoplasty. Endothelial immune reaction is the most frequent and most dangerous subtype of rejection because destruction of the graft endothelium can lead to graft failure. "Acute" endothelial rejection is treated by administration of topical and systemic steroids. Intracameral application of corticosteroids by means of an anterior chamber flush is an adjunctive measure that can stop the immune reaction immediately. This measure is thus recommended in all intermediate and severe endothelial rejections.

Tacrolimus immunosuppression in high-risk corneal grafts

BACKGROUND

Unlike the immune privilege enjoyed by low-risk corneal grafts, high-risk corneal grafts experience rejection rates comparable to liver and kidney transplants. Systemic immunosuppression reduces the risk of rejection in high-risk corneal grafts.

METHODS

Systemic tacrolimus, a specific T cell inhibitor, was used at a mean daily dose of 2.5 mg to immunosuppress 43 patients undergoing high-risk corneal transplantation. Immunosuppression was continued for a period of 18-24 months after the high-risk corneal graft.

RESULTS

During a mean follow-up period of 33.7 months, clarity of the graft was maintained in 65% of patients. Eight patients experienced rejection episodes while on tacrolimus, and this led to graft failure in five patients.

CONCLUSION

Tacrolimus is relatively safe and effective in reducing rejection and prolonging graft survival in patients with high-risk keratoplasty compared with other series where similar immunosuppression was not used.

Klassifikation biomedizinischer Forschungsberichte als Grundlage evidenzbasierter Medizin in der Augenheilkunde

BACKGROUND

Evidence-based medicine requires careful appraisal of published data derived from experimental and clinical studies. Based on classification of biomedical research reports, evidence levels can be determined and recommendations for therapeutic decisions can be made.

METHODS

A classification system for clinical studies was developed. It was evaluated in classifying the reports published in Der Ophthalmologe during 2003-2004 (study design: descriptive cross-sectional study, case series).

RESULTS

In the 2-year interval, 70 longitudinal and 95 cross-sectional studies were published. The vast majority of the longitudinal studies were interventional cohort studies. Not considering case reports, 73% of the original articles were longitudinal prospective studies, 1% were retrospective (case-control) studies, and 26% were cross-sectional studies.

CONCLUSIONS

The study design of all published articles could be classified using the classification system. This classification system proves to be applicable in the context of clinical studies in ophthalmology and may be helpful in the process of critical appraisal of the literature and synthesis of clinical evidence and an evidence-based recommendation.

Stellenwert der systemischen Steroidtherapie nach Normalrisikokeratoplastik

BACKGROUND

The aim of this study was to evaluate the efficacy of sole application of topical steroids after normal-risk keratoplasty.

PATIENTS AND METHODS

This randomized prospective clinical study assessed 40 patients who had undergone penetrating normal-risk keratoplasty. Twenty patients were treated exclusively with prednisolone acetate 1% eye drops 5x/day for 6 months postoperatively. Another 20 patients additionally received systemic fluocortolone 1 mg/kg body weight per day tapered within 3 weeks postoperatively. The main outcome measures included clear graft survival, ratio of graft rejection, and side effects.

RESULTS

The mean postoperative follow-up was 18+/-9 months. Three graft rejections were observed in the group receiving only topical steroids. Two graft rejections were observed in the group administered combined systemic and topical steroid therapy. None of the patients has developed irreversible graft failure so far.

CONCLUSION

Sole topical steroid application seems to be an effective immune prophylaxis in patients undergoing penetrating normal-risk keratoplasty.