Lamellar corneal patch grafts in the management of corneal melting.

PURPOSE: To evaluate the clinical indications and results of reconstructive (tectonic) lamellar keratoplasty in corneal melting. METHODS: A nonrandomized, uncontrolled retrospective case series of 64 consecutive patients (80 eyes) who underwent lamellar keratoplasty for corneal melting at our institution over a 17-year period. We reviewed the (a) clinical indications, (b) visual acuities, (c) postoperative corneal clarity, and (d) post-operative complications. Comparisons in visual acuity were made between central and peripheral corneal melts. The statistical influence of patient age, diagnosis, and corneal graft size on pre- and postoperative visual acuity values also was studied. RESULTS: Although reconstructive lamellar keratoplasty for active corneal melting was effective in saving the integrity of the globes in all but four patients, the postoperative visual acuity remained poor in the majority of cases because of the often devastating nature of the underlying ocular diseases. Only 14 patients had best postoperative visual acuities of 20/100 or better. Repeated lamellar keratoplasties were necessitated by corneal opacification, infection, or progressive postoperative corneal dissolution in 14 cases. Subsequent vision-restoring surgeries, consisting of penetrating keratoplasties or cataract extractions, were done in 11 eyes with modest improvement of visual acuity. Postoperative visual acuity was significantly better in peripheral corneal melts than in central melts (p = 0.004). CONCLUSION: Lamellar keratoplasty is an effective method of restoring the integrity of the eye ravaged by corneal melting. It is less invasive and consequently safer than penetrating keratoplasty in actively inflamed and unstable eyes. The primary purpose for this surgery is to salvage the integrity of the globe during the acute phase of disease and not so much to achieve visual improvement per se. It allows time for systemic immunosuppression to take effect and for the eye to quiet down before possible future vision-restoring surgery.

Central lamellar keratoplasty for optical indications.

PURPOSE: This study aims to evaluate the results of lamellar keratoplasty (LKP) for optical (nontectonic) indications over the past 19 years at our institution, noting the advantages and pitfalls of the procedure. METHODS: The study is a retrospective review of 52 central LKPs in 37 patients. Snellen visual acuity, preoperative clinical indications, and postoperative status of the cornea (donor graft, graft-host interface, and recipient cornea) were assessed. RESULTS: Postoperative follow-up ranged from 3 months to 18 years (median, 3 years). In descending order of frequency, corneal dystrophies, aniridic keratopathy, corneal scars, and keratoconus were the most common indications for surgery. After surgery, 38% of the eyes were able to achieve 20/50 or better visual acuity. The two most common causes of poor visual acuity were (1) opacification and/or blood vessel growth in the graft-host interface or on the graft surface and (2) high astigmatism. Persistent epithelial defects occurred in 21% of the eyes after LKP. CONCLUSION: Although LKP provides a safer alternative to penetrating keratoplasty, it is limited by vision-reducing graft-host interface problems, astigmatism, and difficult surgical technique. We postulate that the current results of LKP may be improved by (1) removing as much recipient corneal stroma as possible (e.g., dissecting down to Descemet's membrane) or, alternatively, using an automated microkeratome and (2) raising the currently used qualitative eyebank standards for accepting LKP donor tissue.

Assessment of health-related quality of life after corneal transplantation.

PURPOSE: To determine the extent to which commonly used clinical measures of corneal transplantation outcome are related to aspects of visual function and health-related quality of life. METHODS: In a cross-sectional validation study, ophthalmic examination information was collected by chart review of, and health-related quality of life information was collected by telephone contact with, patients (n = 77) undergoing routine follow-up examinations at least 1 year after corneal transplantation. A questionnaire that included the VF-14 and SF-36 instruments was completed for each participant. Associations between clinical and questionnaire outcomes were evaluated using analysis of variance and regression analyses. RESULTS: When the best-corrected visual acuity of both eyes was evaluated, there was a positive association (P < .0001) of visual acuity with the VF-14 score and with the following SF-36 scales: role limitations because of emotional problems (P = .04), emotional well-being (P = .08), and social functioning (P = .02). Those with a high degree of keratometric astigmatism showed an impact on social functioning (P = .005). Upon regression analysis, the single most important factor associated with the patients' reported visual function was their visual acuity in the better eye, followed by the extent of keratometric astigmatism. CONCLUSIONS: These findings demonstrate a high degree of criterion validity in using the VF-14 instrument to assess the outcome of corneal transplantation. Application of the more generic SF-36 measure shows effects of visual disability on other aspects of corneal transplant patients' health status, including their emotional and social functioning.

Adenovirus-mediated transfer of human factor IX gene in immunodeficient and normal mice: evidence for prolonged stability and activity of the transgene in liver.

Recombinant adenovirus has recently become a promising gene delivery vehicle that may be used therapeutically for various medical disorders. However, in vivo expression of transgenes delivered by E1 region-deleted adenoviral vectors is transient in immunocompetent animals. It has been proposed that destruction of adenovirally transduced cells by the host immune mechanisms, particularly cytotoxic T-lymphocytes, may play a major role in limiting the duration of transgene expression in vivo. In the present study, Southern blot analysis of genomic DNA prepared from transduced liver tissues showed the persistent presence of the viral genome in both immunocompetent and immunodeficient animals, indicating the survival of the adenovirally transduced liver cells. Furthermore, active expression of the surviving factor IX transgenes was shown by the presence of recombinant human factor IX as well as specific human factor IX mRNA and protein in the transduced liver tissues. The transient appearance of human factor IX in the circulation of normal as well as partially immunodeficient mice is primarily due to the generation of mouse antihuman factor IX antibodies in these mice rather than host immune destruction of transduced cells. These results suggest that liver cells transduced with recombinant adenoviral vectors can escape from being destroyed by the host immune mechanism in normal animals. The present study thus provides a new rationale for further engineering of adenoviral vectors into a durable expression system for gene therapy of various diseases including congenital disorders such as hemophilia B.