Mustafa Onat

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.

Repeat penetrating keratoplasty: indications and prognosis, 1995-2005

Purpose To evaluate the data of penetrating keratoplasty over a 10-year period and to compare indications and outcomes of eyes undergoing single graft with those of eyes requiring regrafting. Methods A total of 652 eyes of 613 patients required single graft (Group I). Sixty-one regrafts were performed on 53 eyes (Group II). The mean follow-up time was 23.4±21.3 months (range 6–132 months). The results were evaluated for the following criteria: primary indications, allograft reactions, graft clarity, final postoperative visual acuity, and complications leading to reduction in vision. Results The most common indication was keratoconus (228 eyes; 35.0%) in Group I, and vascularized corneal scar (12 eyes; 22.6%) in Group II. Allograft reactions occurred in 96 eyes (14.7%) in Group I, and 17 eyes (32.0%) in Group II (p=0.001). At the end of the study period, 76.4% of patients in Group I had entirely clear grafts, whereas 45.3% of patients in Group II had entirely clear grafts (p=0.000). The main causes of corneal graft failure were irreversible allograft reaction, endothelial failure, and graft infection, which were all seen in higher percentage in the regraft group. A best-corrected visual acuity of 20/100 or better was achieved in 377 eyes (57.8%) in Group I and 11 eyes (20.7%) in Group II (p=0.000). Conclusions The complications of repeated surgery may reduce final graft clarity and visual acuity; the disease process necessitating regrafting may carry a poorer prognosis for sight.

Results of Therapeutic Penetrating Keratoplasty

PurposeBy a retrospective study of patients in the Ankara Hospital Eye Clinic, to determine the anatomical and visual results of therapeutic penetrating keratoplasty (PK) and its role in the management of corneal disease.MethodsTherapeutic PK was performed in 36 patients (37 eyes) who had corneal perforation due to corneal disease (23 eyes) or eyes in which perforation was imminent (14 eyes). Initial indications for grafting were nonperforated descemetocele without inflammation (six eyes, 16.2%); nonperforated bacterial corneal ulcer (five eyes, 13.5%); nonperforated herpetic keratitis with active stromal inflammation (two eyes, 5.4%); acanthamoeba keratitis (one eye, 2.7%); perforation due to herpetic keratitis (13 eyes, 35.2%); perforation due to persistent epithelial defect (8 eyes, 21.6%); or perforation due to bacterial corneal ulcer (two eyes; 5.4%). The results were evaluated for each of the following criteria: anatomical integrity of the eye, cure of the disease, complications, graft clarity, and visual acuity.ResultsAnatomical integrity was achieved in 21 of the 23 eyes (91.3%) perforated from corneal disease. Therapeutic PK cured the disease in all bacterial keratitis cases. The proportion of clear grafts was 60.9% in the 23 eyes perforated from corneal disease, and 57.1% in the 14 eyes in which perforation was imminent. Fifteen eyes (40.5%) obtained a final visual acuity of 20/100 or better; five of these eyes were not yet perforated before the PK.ConclusionsTherapeutic PK is effective in the management of the eye with active uncontrolled infection or perforation from corneal disease. Approximately half of our patients maintained a clear graft at the last visit. Without therapeutic surgery, these eyes would have been lost.

Prospective Comparison of Two Suturing Techniques of Amniotic Membrane Transplantation for Symptomatic Bullous Keratopathy

PURPOSE To determine the outcomes of a modified amniotic membrane transplantation (AMT) suturing technique for pain and discomfort relief in patients with symptomatic bullous keratopathy (BK). DESIGN Randomized, double-blind controlled clinical trial. METHODS setting: Ankara Research and Training Hospital 1st and 2nd Eye Clinics, Ankara, Turkey. study population: This prospective study included 39 eyes (39 patients) with BK presenting with intractable pain or discomfort and poor visual potential. intervention: Patients were randomly assigned into two groups: in group 1 (21 patients), patients underwent a modified AMT suturing technique; a groove was prepared by vacuum trephine on the recipient cornea and the edges of the punch-shaped amniotic membrane (AM) were sutured to this groove with the basement membrane side up. In group 2 (18 patients), patients underwent the standard AMT suturing to the cornea. main outcome measure: During a mean follow-up of 27.3 +/- 8.5 months (standard deviation) (range, 12 to 36 months), epithelial healing, persistence of AM, pain relief, and visual changes were analyzed and were compared between groups. RESULTS The mean age (P = .15), the mean follow-up (P = .73), and the mean preoperative visual acuity (P = .53) were similar in both groups. With the modified suturing technique, the postoperative visual acuity was better (P = .03), epithelialization time was shorter (P < .001), and the AM remained longer (P < .001). Successful epithelialization was achieved in 20 eyes (95.3%) in group 1, and in 16 eyes (88.9%) in group 2 (P = .586). The pain scores of patients in group 1 remained stable (P = .223) over time, however increased from the first week to the third month postoperatively in group 2 (P = .046). CONCLUSIONS The modified AMT suturing technique has a similar epithelialization rate to standard AMT suturing to cornea. Though technically more demanding, shorter epithelialization time, longer persistence of AM, and stable pain scores in the postoperative period makes this a promising method for the treatment of symptomatic BK.