Risk factors for donor cornea contamination: retrospective analysis of 4546 procured corneas in a single eye bank.

PURPOSE: Microbiological contamination is a common cause for elimination of organ-cultured donor corneas. The aims of the present study were to analyze contamination rates and identify risk factors for contamination. METHODS: Retrospectively, the contamination rates of 4546 organ-cultured corneas and the causative species were studied. The impact of sex, age, death-to-explantation interval, explantation technique, cause of death, and mean monthly temperature on contamination rate was analyzed. RESULTS: The median annual contamination rate was 5.3% (range: 3%-19%). Most contaminations were of fungal origin (61.9%), with Candida species (45%) being predominant. Bacterial contaminations (34.4%) were dominated by Staphylococcus species (12.8%). Sex, donor age, and mean monthly temperature had no statistically significant influence on the contamination rate. The median death-to-explantation interval of contaminated corneas (44 hours) was longer than that of sterile corneas (39 hours; P < 0.001; n = 4437). Cardiopulmonary failure was associated with the highest contamination rate (13.6%) of all death causes. The switch from whole globe to in situ excision was followed by a temporary increase in contamination rate (12.5%-19.4%). CONCLUSIONS: Although the genesis of donor cornea contamination seems to be multifactorial, resident species from physiological skin flora are the main contaminants indicating that the donor corpses could be the main source of microbiological contamination. A change in the explantation technique was followed by an increase in the contamination rate.

Thirty years of cornea cultivation: long-term experience in a single eye bank.

PURPOSE: To evaluate donor demographics, trends in donor tissue procurement and tissue storage over a long period. METHODS: A retrospective, longitudinal, descriptive analysis was undertaken of data from the Hamburg Eye Bank Data Base (HEB-DB) that had been collected between 1981 and 2010. Data on 54 parameters of cornea donors [including clinical history, age, death cause, gender and death-to-explantation interval (DEI)] and of cultivated corneas (endothelial quality and development in culture, cultivation period, microbiological contamination) were retrieved. These data were analysed statistically, focusing on the historical development of the eye bank. RESULTS: At the time of retrieval (June 2010), the HEB-DB contained data on 10 943 corneas (5503 donors). Most donors were men (65%) and had died from cardiopulmonary (n = 801)/cerebral (n = 261) failure or as the result of a polytraumatic accident/suicide (n = 602). Within these years, donor age, DEI and storage time increased. The percentage of stored corneas suitable for transplantation displayed a variable but increasing trend; in 2007, almost 75% of the stored corneas were transplanted. Between 1995 and June 2010, the median microbiological contamination rate was 5.3%. A change in the procurement procedure from enucleation to corneoscleral explantation in 2008 led to a briefly increased contamination rate. CONCLUSION: Donor demographic data run parallel to the general demographic development. Our analysis indicates a dynamic development of the eye bank over the last 30 years and emphasizes the need for an active quality management in coping with the challenges of modern eye banking.

Mesopic pupil size in a refractive surgery population (13,959 eyes).

PURPOSE: To evaluate factors that may affect mesopic pupil size in refractive surgery candidates. METHODS: Medical records of 13,959 eyes of 13,959 refractive surgery candidates were reviewed, and one eye per subject was selected randomly for statistical analysis. Detailed ophthalmological examination data were obtained from medical records. Preoperative measurements included uncorrected distance visual acuity, corrected distance visual acuity, manifest and cycloplegic refraction, topography, slit lamp examination, and funduscopy. Mesopic pupil size measurements were performed with Colvard pupillometer. Relationship between mesopic pupil size and age, gender, refractive state, average keratometry, and pachymetry (thinnest point) were analyzed by means of ANOVA (+ANCOVA) and multivariate regression analyses. RESULTS: Overall mesopic pupil size was 6.45 ± 0.82 mm, and mean age was 36.07 years. Mesopic pupil size was 5.96 ± 0.8 mm in hyperopic astigmatism, 6.36 ± 0.83 mm in high astigmatism, and 6.51 ± 0.8 mm in myopic astigmatism. The difference in mesopic pupil size between all refractive subgroups was statistically significant (p < 0.001). Age revealed the strongest correlation (r = -0.405, p < 0.001) with mesopic pupil size. Spherical equivalent showed a moderate correlation (r = -0.136), whereas keratometry (r = -0.064) and pachymetry (r = -0.057) had a weak correlation with mesopic pupil size. No statistically significant difference in mesopic pupil size was noted regarding gender and ocular side. The sum of all analyzed factors (age, refractive state, keratometry, and pachymetry) can only predict the expected pupil size in <20% (R = 0.179, p < 0.001). CONCLUSIONS: Our analysis confirmed that age and refractive state are determinative factors on mesopic pupil size. Average keratometry and minimal pachymetry exhibited a statistically significant, but clinically insignificant, impact on mesopic pupil size.

Traumatic wound dehiscence after penetrating keratoplasty: case series and literature review.

PURPOSE: Blunt trauma after penetrating keratoplasty (PK) is a high risk for wound rupture at the donor-recipient interface. We present 6 cases of traumatic wound dehiscence after PK; we describe the morphologic and functional outcome after surgical intervention and provide a review of the current literature. METHODS: Six patients with a traumatic wound dehiscence after PK were analyzed retrospectively from the files of the University Eye Hospital Hamburg-Eppendorf (1998-2009). In addition, a comprehensive literature review was performed. RESULTS: The indications for PK were keratoconus, corneal scars, and Fuchs endothelial dystrophy. The age range was 22-81 years; the time span between PK and globe rupture was 1 month to 27 years. The cause of the dislocation was a fall or blunt trauma, through a branch, airbag, fist, or finger. The corrected distance visual acuity (CDVA) pretrauma ranged between hand movement and 20/32. The CDVA after wound repair was 20/400 to 20/25 depending on the severity of the trauma. In 3 of the 6 cases, visual rehabilitation was superior to the pretrauma vision, whereas in 3 cases the pretrauma CDVA could not be reached. CONCLUSIONS: If a timely and adequate treatment of the traumatically dislocated transplant can be given, it is likely that the transplant will survive. Nevertheless, severely reduced visual acuity (i.e., < hand movement) and lens damage at the time of trauma are the most reliable predictors for the final visual outcome. A permanent loss of visual acuity is related rather to the intraocular damage (vitreous loss, vitreous bleeding, retinal tears, and retinal detachment) than to the readapted transplant itself.

Bilateral crystalline corneal deposits as first clinical manifestation of monoclonal gammopathy: a case report.

AIMS: To report the clinical and diagnostic findings of a patient with bilateral corneal deposits caused by an underlying monoclonal gammopathy. METHODS: Slit-lamp biomicroscopy, confocal microscopy and additional serological tests were performed on a 35-year-old man presenting with bilateral crystalline corneal deposits. RESULTS: The patient was diagnosed as having monoclonal gammopathy based on elevated levels of serum immunoglobulin G. Confocal microscopy showed highly reflective (protein) deposits throughout the entire cornea, with the highest density in the epithelium and anterior stromal keratocytes. CONCLUSIONS: Monoclonal gammopathy, a potential sign of a life-threatening disease, can lead to dense, bilateral corneal deposits. As such changes can occur long before ocular or systemic discomforts appear, an early diagnosis is crucial. Ophthalmologists should be aware of corneal deposits as potential warning signs of monoclonal gammopathy.