Are For-Profit Eye Banks a Good Idea?

ABSTRACT: For-profit eye banks have been advocated because they stimulate innovation and improve the quantity and quality of corneal tissue. The claims of for-profit eye banks do not stand up to scrutiny and promote discord in the recovery and distribution field. Commercialization can adversely affect public perception of corneal donation.

Effect of Graft Attachment Status and Intraocular Pressure on Descemet Stripping Automated Endothelial Keratoplasty Outcomes in the Cornea Preservation Time Study.

PURPOSE: To examine the association of donor, recipient, and operative factors on graft dislocation after Descemet stripping automated endothelial keratoplasty (DSAEK) in the Cornea Preservation Time Study (CPTS) as well as the effects of graft dislocation and elevated IOP on graft success and endothelial cell density (ECD) 3 years postoperatively. DESIGN: Cohort study within a multi-center, double-masked, randomized clinical trial. METHODS: 1090 individuals (1330 study eyes), median age 70 years, undergoing DSAEK for Fuchs endothelial corneal dystrophy (94% of eyes) or pseudophakic or aphakic corneal edema (6% of eyes). Recipient eyes receiving donor corneal tissue randomized by preservation time (PT) of 0-7 days (N = 675) or 8-14 days (N = 655) were monitored for early or late graft failure through 3 years. Donor, recipient, operative, and postoperative parameters were recorded including graft dislocation (GD), partial detachment, and pre- and post-operative IOP. Pre- and postoperative central donor ECD were determined by a central image analysis reading center. Proportional hazards, mixed effects, and logistic regression models estimated risk ratios and (99% confidence intervals). RESULTS: Three independent predictive factors for GD were identified: a history of donor diabetes (odds ratio [OR]: 2.29 [1.30, 4.02]), increased pre-lamellar dissection central corneal thickness (OR: 1.13 [1.01, 1.27] per 25µ increase), and operative complications (OR: 2.97 [1.24, 7.11]). Among 104 (8%) eyes with GD, 30 (28.9%) developed primary donor or early failure and 5 (4.8%) developed late failure vs. 15 (1.2%; P < .001) and 29 (2.4%; P = .04), respectively, of 1226 eyes without GD. 24 (2%) of 1330 study eyes had early acutely elevated postoperative IOP that was associated with a higher risk of graft failure through 3 years (hazard ratio: 3.42 [1.01, 11.53]), but not with a lower mean 3-year ECD (mean difference 61 (-479, 601) cells/mm2, P = .77). History of elevated postoperative IOP beyond 1 month was not significantly associated with 3-year graft success or ECD. CONCLUSIONS: Donor diabetes, increased donor corneal thickness, and intraoperative complications were associated with an increased risk of GD. Early acutely elevated postoperative IOP and GD significantly increased the risk for graft failure following DSAEK.

Safety of overnight orthokeratology for myopia: a report by the American Academy of Ophthalmology.

OBJECTIVE: To review the published literature to evaluate the safety of overnight orthokeratology (OOK) for the treatment of myopia. METHODS: Repeated searches of peer-reviewed literature were conducted in PubMed (limited to the English language) and the Cochrane Central Register of Controlled Trials (no language limitations) for 2005, 2006, and 2007. The searches yielded 495 citations. The panel reviewed the abstracts of these articles and selected 79 articles of possible clinical relevance for review. Of these 79 full-text articles, 75 were determined to be relevant to the assessment objective. RESULTS: No studies were rated as having level I evidence. Two premarket applications to the Food and Drug Administration were rated as having level II evidence. There were 2 studies rated as having level II evidence. The main source of reports of adverse events associated with OOK was 38 case reports or noncomparative case series (level III evidence). CONCLUSIONS: The prevalence and incidence of complications associated with OOK have not been determined. Complications, including more than 100 cases of infectious keratitis resulting from gram-positive and gram-negative bacteria and Acanthamoeba, have been described in case reports and case series representing observations in undefined populations of OOK users. Data collection was nonstandard. Risk factors for various complications cannot be determined. Because OOK puts patients at risk for vision-threatening complications they may not encounter otherwise, sufficiently large well-designed cohort or randomized controlled studies are needed to provide a more reliable measure of the risks of treatment and to identify risk factors for complications. Overnight orthokeratology for slowing the progression of myopia in children also needs well-designed and properly conducted controlled trials to investigate efficacy. Because of variations in orthokeratology practice, a wide margin of safety should be built into OOK regimens. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Central corneal opacification resulting from recent chemotherapy in corneal donors.

PURPOSE: Ocular surface disease following penetrating keratoplasty has been shown to increase patient morbidity and adversely affect graft survival. Five cases of dense central subepithelial opacification were noted in keratoplasty patients who received tissue from donors who had chemotherapy prior to death. Cancer-related deaths account for approximately 20% of the cornea donor pool. The purpose of this study was to identify the effect of recent systemic antimetabolite therapy on donor corneas. METHODS: Eye bank donor charts of 120 consecutive penetrating keratoplasty donors were retrospectively reviewed for cancer-related deaths. Donors who received chemotherapy prior to death were identified. Recipient records of those patients receiving tissue from donors that had recently undergone systemic chemotherapy were reviewed. Corneal clarity and postoperative ocular surface disease were noted by the surgeon. RESULTS: Twenty-nine of 120 cornea donors (24%) had a cancer-related cause of death. Five of these 29 donors (17%) had undergone systemic chemotherapy with antimetabolite drugs (which inhibit microtubule formation) within the previous 8 weeks. All 5 recipients postoperatively developed central subepithelial opacification in spite of temporary tarsorrhaphy performed at the time of keratoplasty. Central corneal opacification was severe enough in 3 patients to require regrafting for visual improvement. Histopathology showed abnormality of the central epithelial basement membrane, apoptosis of basal epithelial cells, and thinning of the epithelial cell layer. CONCLUSION: Corneas from donors who received a full course of recent systemic antimetabolite therapy are associated with central subepithelial scarring following keratoplasty. Corneal surgeons should be aware of the potential for severe ocular surface disease when using donor tissue from patients with metastatic cancer.

Effect of death-to-preservation time on donor corneal epithelium.

PURPOSE: Surface disease is one of multiple variables affecting the quality of the postkeratoplasty donor cornea. Trauma to Bowman's layer before and during harvesting can denude the donor epithelium and result in epithelial defects in the donor following penetrating keratoplasty. Eye banks use death-to-preservation (DP) time intervals as long as 18 hours. This study evaluates the effects of higher DP time on the donor epithelium in storage medium and immediately following keratoplasty. METHODS: Eighty-one consecutive corneas were procured by the University of Kentucky Eye Bank, rated by one technician (H.W.), and used by one surgeon (W.S.V.) for elective penetrating keratoplasty. Donor records were retrospectively reviewed for age, DP time, and epithelial condition. All corneas were harvested and evaluated according to Eye Bank Association of America standards. Donor charts were reviewed for DP time and for condition of the epithelium in storage. Recipient charts were reviewed for epithelial defects following keratoplasty. RESULTS: Average DP time of all 81 donor corneas was 6:18 hours (ie, 6 hours, 18 minutes). Average DP time of 13 corneas with epithelial sloughing was 7:02 (range, 2:01 to 12:25) hours, and nine (69%) had DP time longer than 6 hours. Average DP time of 68 corneas with no sloughing was 6:09 (range, 1:59 to 11:03) hours (P < .32). Average DP of 28 recipients with epithelial defect on day 1 was 8:01 (range, 3:41 to 12:49), and average DP in 53 patients with an intact epithelium on day 1 was 5:23 (range, 1:59 to 9:46) (P < .001). The percentage of postoperative patients with epithelial defects in the graft on day 1 rose from 14% when DP was less than 4 hours to 100% when DP was greater than 10 hours. Average DP in 13 donors under age 30 was 8.3 hours. CONCLUSION: DP time longer than 6 hours was more likely to result in sloughing of the donor epithelium. Care of donor epithelium prior to harvesting becomes increasingly important with DP times longer than 6 hours. Higher-than-average DP times occurred in donors under 30 years of age. Higher DP time results in an increasing likelihood of epithelial defects in the graft. Donor corneas with lower DP time may be important in penetrating keratoplasty ocular surface disease.

Spontaneous wound dehiscence after removal of single continuous penetrating keratoplasty suture.

PURPOSE: To determine the incidence and complications of spontaneous wound dehiscence after removal of a single continuous penetrating keratoplasty (PK) suture. DESIGN: Retrospective consecutive, noncomparative interventional case series. METHODS: Retrospective review of 324 consecutive continuous suture PKs performed between 1992 and 1999. RESULTS: Sixty-nine (21.3%) of 324 PKs reviewed had the continuous suture removed. The average interval for suture removal after PK was 24.5 +/- 15 months (range, 2.8-63.3 months). Five of the 69 eyes (7.2%) developed spontaneous wound dehiscence without direct eye trauma. In the five eyes that developed wound dehiscence, the continuous suture was removed at 24.6 +/- 10.3 months (range, 14-42 months). Dehiscence occurred at 11.6 +/- 6.5 (range, 3-18) days after suture removal. Significant history associated with wound dehiscence included coughing, yawning, falling without trauma to the eye, and spontaneous wound separation. The reasons for suture removal were astigmatism in four of five (80%) patients and a broken suture in one of the five patients. In four of five (80%) patients, the location of wound dehiscence correlated with the steep axis of corneal keratometry before suture removal. Surgical intervention preserved the presuture removal best-corrected visual acuity in four of the five eyes. No eyes with an intact suture spontaneously dehisced. CONCLUSIONS: The rate of spontaneous wound dehiscence after removal of a continuous suture in our series was 7.2%. All spontaneous dehiscences occurred within 2 weeks after suture removal. Older patients, who had PK for corneal edema with postoperative astigmatism and have been using corticosteroids drops for prolonged periods of time, are at higher risk of wound dehiscence. Patients should be monitored closely during the first 2 weeks after removal of a continuous suture for signs of wound separation, especially when suture removal is performed for astigmatism. Patients should be cautioned about the risk and symptoms of wound dehiscence before suture removal to facilitate early recognition and intervention for preservation of best visual potential.

Confocal microscopy: a report by the American Academy of Ophthalmology.

OBJECTIVE: To review the available evidence for the use of confocal microscopy in diagnosing infectious keratitis and for other applications for ophthalmic practice. METHODS: A MEDLINE search of the peer-reviewed literature for the years 1990 to 2001 yielded 94 citations. The search was limited to studies of human subjects published in English with abstracts. The Ophthalmic Technology Assessment Committee Cornea Panel evaluated these 94 articles for possible clinical relevance and selected 51 (54%) for content review by the panel members. Of these 51 articles, 24 were selected for the panel methodologist to review and rate according to the strength of evidence. RESULTS: Of the 24 articles, 21 (87.5%) were classified as case reports or case series and were rated as level III evidence. Three articles were classified as independent, masked, or objective comparisons performed in a narrow spectrum of patients or in a nonconsecutive series of patients and were rated as level II evidence. No studies were rated as level I evidence, defined as an independent masked comparison of an appropriate spectrum of consecutive patients. CONCLUSION: Confocal microscopy is a new technology with clinical applications in ophthalmology. Although confocal microscopy has been used in other fields of medicine, the optical transparency of the cornea and other structures of the eye provides a unique opportunity to apply this technology. The targeted literature review of 24 articles found no level I studies to support the use of confocal microscopy in the management of eye disorders. Three level II studies pertained to promising clinical applications of the confocal microscope and provided evidence that supports the use of confocal microscopy as an adjunctive modality for diagnosing Acanthamoeba keratitis. The remaining 21 articles, rated as level III evidence, focus on the use of confocal microscopy to facilitate the diagnosis of infectious keratitis, including amoebic and fungal, but currently there are no definitive studies of its role in the differential diagnosis of this condition. There are also level III studies that support the use of the confocal microscope in refractive surgery. Facilitating the diagnosis of infectious keratitis and applying the confocal microscope to refractive surgery may hold the greatest promise of this new technology.