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Microbial keratitis following penetrating keratoplasty
Purpose:
To investigate the prevalence of microbial keratitis, predisposing risk factors and treatment modalities in patients who developed keratitis following penetrating keratoplasty (PK).
Patients And Methods:
The records of 285 patients who had undergone PK between January 1991 and December 1995 in a tertiary care center were reviewed. Patients who developed postoperative microbial keratitis were evaluated for predisposing risk factors, microbiological etiology, response to broad spectrum antibiotic therapy and subsequent PK. Patients were mainly treated with fortified topical antibiotics with or without repeat PK.
Results:
Of the 285 patient records reviewed, microbial keratitis developed in 21 eyes of 21 patients (7.4%). Seventy-one percent of infections occurred within 6 months after grafting. Keratitis initially began from the donor-recipient border in 16 cases (76.2%) and were central or paracentral in 5 patients. Predisposing risk factors included loose or exposed suture (9), suture removal (1), persistent epithelial defect (3), graft failure (3), contact lens wear (1), Stevens-Johnson syndrome (1). Fifteen (71.4%) patients were culture-positive consisting of Streptococcus pneumoniae (7), Staphylococcus aureus (5), Pseudomonas aureginosa (2), and Hemophilus influenzae (1). Forty-three percent of patients were successfully treated with medical therapy only. Seven patients underwent second PK for visual rehabilitation and 4 for tectonic purposes. After medical and surgical therapy, graft clarity was achieved in 17 (81%) of patients.
Conclusions:
The microbial keratitis following PK is a major postoperative problem affecting the long term prognosis. Careful selection of patients, and preoperative and postoperative control of risk factors, may decrease the frequency of this complication. Several factors, including loose or exposed sutures, epithelial defects, ocular surface disorders, and graft failure, may predispose patients to develop microbial keratitis following PK.
Insights
Microbial keratitis after penetrating keratoplasty (PK) affects graft prognosis. Risk factors like suture issues and epithelial defects increase infection risk, necessitating careful patient selection and management.
Area of Science:
- Ophthalmology
- Microbiology
- Transplantation Science
Background:
- Postoperative microbial keratitis is a significant complication following penetrating keratoplasty (PK).
- Understanding the prevalence, risk factors, and treatment outcomes is crucial for improving patient prognosis.
Purpose of the Study:
- To determine the incidence of microbial keratitis post-PK.
- To identify predisposing risk factors for this complication.
- To evaluate treatment strategies and outcomes for microbial keratitis after PK.
Main Methods:
- Retrospective review of 285 patients undergoing PK between 1991 and 1995.
- Analysis of predisposing factors, causative microorganisms, and treatment responses.
- Evaluation of outcomes including graft clarity and visual rehabilitation.
Main Results:
- Microbial keratitis occurred in 7.4% of patients, with 71% within 6 months post-grafting.
- Common risk factors included loose sutures, epithelial defects, and graft failure.
- Streptococcus pneumoniae and Staphylococcus aureus were the most frequent pathogens; 43% resolved with medical therapy alone.
Conclusions:
- Microbial keratitis following PK is a serious complication impacting long-term outcomes.
- Controlling risk factors such as suture integrity and ocular surface health is vital.
- Prompt medical and surgical interventions can restore graft clarity in most cases.
