Effect of Increasing Povidone-Iodine Exposure on Corneal Epithelium and Impact on Donor Rim Cultures.

PURPOSE: The purpose of this study was to assess the effect of a second povidone-iodine (PVP-I) application at the time of donor tissue recovery on overall tissue quality and to analyze the rate of positive fungal and bacterial rim cultures before and after implementing increased PVP-I exposure. METHODS: The left cornea was recovered after a single application of PVP-I, while the right cornea was recovered after double PVP-I application in research-consented donors. The epithelial cell death rate was estimated using viability assay in corneal whole mounts under 10× objective (n = 5). Clinical characteristics of epithelium, stroma, and endothelium; positive rim culture rate; and incidences of infectious postoperative adverse reactions were compared for a period of 14 months before and after implementation of increased PVP-I protocol. RESULTS: The average epithelial cell death rate was unaltered between single and double PVP-I exposure groups. We observed a modest 10% increase in the number of tissues with mild edema after implementation of increased PVP-I exposure. Nonetheless, the percentage of tissues with moderate or severe edema was unaltered. The average positive rim culture rate decreased from 1.17% to 0.88% (P = 0.075) after implementation of the double PVP-I soak procedure. There has been only one report of infectious postoperative adverse reactions since this procedure change. By contrast, there were 5 reports for a period of 14 months before implementation of this protocol. CONCLUSIONS: These results indicate that new donor preparation methods with an additional 5 minutes of PVP-I exposure do not affect tissue quality, reduce positive rim cultures, and lead to lower incidence of postoperative infection.

Patient-Reported Outcomes After Corneal Transplantation.

PURPOSE: To characterize vision-related quality of life after penetrating keratoplasty (PKP), deep anterior lamellar keratoplasty (DALK), Descemet stripping automated endothelial keratoplasty (DSAEK), and Descemet membrane endothelial keratoplasty (DMEK) using the National Eye Institute Visual Function Questionnaire (NEI-VFQ 9). METHODS: Using the Sight Outcomes Research Collaborative ophthalmology electronic health record repository, questionnaire responses were obtained from 103 PKP patients, 24 DALK patients, 42 DSAEK patients, and 50 DMEK patients undergoing postoperative examination. No exclusions were made based on preoperative diagnosis, age, complications, or comorbidities. Associations between clinical characteristics and vision-related quality of life were analyzed using nonparametric and linear regression methods. RESULTS: Patients were surveyed an average of 1.5 years postoperatively (range 24 d to 4.4 yrs). Participants who had undergone DALK, DMEK, DSAEK, and PKP had median composite VFQ scores of 77.8, 84.2, 76.1, and 70.6, respectively (P= 0.002). There were no significant differences in VFQ scores between patients treated with DMEK versus DSAEK (P = 0.440) or between patients treated with PKP versus DALK (P = 1.000). Higher postoperative acuities in the operative and fellow eyes were associated with higher VFQ scores (P < 0.001 and P < 0.001). When controlling for postoperative acuity by regression modeling, surgery type was not associated with patient-reported composite VFQ scores. CONCLUSIONS: In this study, patient-reported vision-related quality of life was similar among DMEK and DSAEK participants and also among DALK and PKP participants. When controlling for postoperative acuity, vision-related quality of life was similar among all study participants, irrespective of the keratoplasty technique.

Corneal donor tissue preparation for endothelial keratoplasty.

Over the past ten years, corneal transplantation surgical techniques have undergone revolutionary changes. Since its inception, traditional full thickness corneal transplantation has been the treatment to restore sight in those limited by corneal disease. Some disadvantages to this approach include a high degree of post-operative astigmatism, lack of predictable refractive outcome, and disturbance to the ocular surface. The development of Descemet's stripping endothelial keratoplasty (DSEK), transplanting only the posterior corneal stroma, Descemet's membrane, and endothelium, has dramatically changed treatment of corneal endothelial disease. DSEK is performed through a smaller incision; this technique avoids 'open sky' surgery with its risk of hemorrhage or expulsion, decreases the incidence of postoperative wound dehiscence, reduces unpredictable refractive outcomes, and may decrease the rate of transplant rejection. Initially, cornea donor posterior lamellar dissection for DSEK was performed manually resulting in variable graft thickness and damage to the delicate corneal endothelial tissue during tissue processing. Automated lamellar dissection (Descemet's stripping automated endothelial keratoplasty, DSAEK) was developed to address these issues. Automated dissection utilizes the same technology as LASIK corneal flap creation with a mechanical microkeratome blade that helps to create uniform and thin tissue grafts for DSAEK surgery with minimal corneal endothelial cell loss in tissue processing. Eye banks have been providing full thickness corneas for surgical transplantation for many years. In 2006, eye banks began to develop methodologies for supplying precut corneal tissue for endothelial keratoplasty. With the input of corneal surgeons, eye banks have developed thorough protocols to safely and effectively prepare posterior lamellar tissue for DSAEK surgery. This can be performed preoperatively at the eye bank. Research shows no significant difference in terms of the quality of the tissue or patient outcomes using eye bank precut tissue versus surgeon-prepared tissue for DSAEK surgery. For most corneal surgeons, the availability of precut DSAEK corneal tissue saves time and money, and reduces the stress of performing the donor corneal dissection in the operating room. In part because of the ability of the eye banks to provide high quality posterior lamellar corneal in a timely manner, DSAEK has become the standard of care for surgical management of corneal endothelial disease. The procedure that we are describing is the preparation of the posterior lamellar cornea at the eye bank for transplantation in DSAEK surgery (Figure 1).