ISSN:0277-3740    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeRecent new reports of possible iatrogenic transmission of Creutzfeldt-Jakob disease (CJD) in Europe have prompted renewed scrutiny of current Eye Bank Association of America criteria for evaluation of potential corneal donors in this country. A prior study evaluated the risk of CJD occurring in U.S. corneal donors by using data to 1994. This report updates these data, analyses the risk by using data to 1997, and predicts potential risk into the next decade.MethodsEBAA data inclusive through 1997 were reviewed and correlated with incidence figures for CJD in the United States as provided by the Communicable Disease Center in Atlanta.ResultsThe annual incidence of CJD has remained stable at 1 case per million population. Thus 270 new cases of CJD would be expected to occur each year in the United States. From this, the calculated risk of a prion-infected corneal donor appearing in the donor pool is 0.045 cases per year. If the data are corrected for age (90% of CJD patients are older than 60 years) and for possible infected but asymptomatic CJD patients (prevalence, 70 cases per million), at worst, 2.12 cases per year would appear for potential corneal donation (0.005% of all donors). Whereas donors completely without any neurologic symptoms cannot be screened by using any currently available laboratory method, those with a characteristic quadrate clinical prodrome including cognitive changes, speech abnormalities, cerebellar findings, and myoclonus could all be potentially excluded by using tightened medical record and historical screening criteria. Although no cases of bovine spongiform encephalopathy (madcow disease) or new variant CJD have been reported in the United States, if such should occur, only 4.2 cases of CJD would be expected in potential donors each year (0.009% of all donors). Tightening of exclusionary queries would significantly reduce the risk of even this number of patients appearing for corneal donation.ConclusionsHistorical queries of potential corneal donors should be tightened to assure exclusion of donors with early neurologic alterations. Any patient undergoing autopsy for evaluation of possible central nervous system (CNS) disease should be absolutely excluded. With this approach, the risk of inclusion of CJD-infected transplant tissues derived from ocular sources is very small, and all previously reported cases would have been prospectively excluded from surgical use. Clearly, the benefits of corneal transplantation in the overall population continue significantly to outweigh the risks of transmission of prion disease.

ISSN:0277-3740    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeWe reviewed the clinical data on 10 obese patients to define the role of obesity as a factor for consideration in planning penetrating keratoplasty.MethodsWe performed a retrospective case series review of penetrating keratoplasty in obese patients.ResultsIn our series of 10 patients, spontaneous extrusion of lens and vitreous (three patients) and choroidal hemorrhage (one patient) were intraoperative complications. Wound leakage, wound dehiscence (two patients), iridocorneal synechia formation, and graft rejection (one patient) were post-operative complications. Despite these complications, seven of the 10 patients achieved a final postoperative visual acuity of ≥20/30.ConclusionCornea surgeons must consider obesity as a potential risk factor that may be mitigated partially by careful preoperative patient evaluation, anesthesia planning, and meticulous attention to patient positioning and comfort during surgery.

ISSN:0277-3740    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeTo evaluate the long-term effect of single continuous corneal suture adjustment on reducing penetrating keratoplasty astigmatism after suture removal.MethodsPatients were identified from the original study of single continuous penetrating keratoplasty suture adjustment to reduce corneal astigmatism who were followed for more than a year after suture removal. A matching unadjusted control group was selected in the same way from those patients in the original study undergoing penetrating keratoplasty during the 2 years before the development of suture adjustment. The corneal astigmatism was compared before adjustment (study group) or <3 months after surgery (control group), >4 months after suture adjustment, and >12 months after suture removal in both groups.ResultsA study group of 54 patients with suture adjustment and a control group of 45 patients without suture adjustment were identified. Before suture adjustment, the study group had an average keratometric astigmatism of 6.44 diopters (standard deviation [SD] = 2.51, range = 0.38–12.25), and the control group had 6.38 diopters (SD = 3.29, range = 2.75–16.00,p= 0.536). Compared to that in the unadjusted control group, the average penetrating keratoplasty astigmatism in the suture-adjusted group was reduced by 44.6% (2.36 diopters) 4.5 months after surgery and before suture removal (p= 0.0002) and by 25.4% (1.19 diopters) at least 12 months after suture removal (p= 0.011).ConclusionPostoperative adjustment of a single continuous corneal suture significantly reduces penetrating keratoplasty astigmatism after suture removal.

ISSN:0277-3740    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeThis study compared the duration of corneal reepithelialization between photorefractive (PRK) and photoastigmatic (PARK) keratectomy and evaluated the possible correlation of the epithelial healing rate with clinical parameters as well as the refractive outcome.MethodsThe duration until complete reepithelialization was examined in 33 eyes of 33 patients (14 men), not suffering from any known disease, who underwent PRK or PARK surgery. In all cases, a +0.5 diopters (D) therapeutic contact lens (Acuvue Vistakon) was used post-operatively. Clinical parameters such as age, sex, preoperative spherical equivalent, attempted correction, corneal curvature, and surgical plan were recorded in the patient file. All patients received standard medication and were followed up for 12 months postoperatively. Results were statistically analyzed by using the package SPSS 6.0.ResultsThe duration of recepithelialization was significantly correlated to age and was longer in PARK than in PRK cases and in eyes with an average K reading >43.5D. A shorter reepithelialization period correlated to myopic regression, 1 month postoperatively, but the correlation was annulled thereafter.ConclusionThe longer reepithelialization period in older patients and in PARK surgery could be attributed to the age-related decrease in the healing response and to differences in the profile of the ablation area, respectively. Epithelial healing was shorter in eyes with steeper K readings, perhaps because of better contact lens mobility, Understanding the role of factors involved in epithelial healing could allow better postoperative surveillance and treatment.

ISSN:0277-3740    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeTo record morphologic changes that occur in corneal endothelial cells during daily wear of rigid, gas-permeable fluorocarbon contact lenses during 3 years.MethodsNineteen new wearers and 32 previous wearers were fitted with daily-wear fluorocarbon contact lenses. Photographic images of the central corneal endothelium and central corneal thickness measurements were recorded at baseline, 2 months, and 1, 2, and 3 years after fitting.ResultsIn the new wearers, an increase in the coefficient of variation of cell area was present by 2 months after lens fitting and increased further over the subsequent 3 years. The increase in coefficient of variation of cell area was correlated with the oxygen transmissibility of the lens. Endothelial cell density was decreased at 2 and 3 years. Corneal thickness did not change. In the previous lens wearers after 3 years, there were no significant changes from baseline in any morphologic value. Corneal thickness was decreased significantly.ConclusionsAlthough oxygen transmissibility in fluorocarbon contact lenses is improved over previous hard and soft lenses, polymegethism still was induced within 2 months by these lenses, and morphologic changes present from past lens wear did not improve during 3 years of daily wear.

ISSN:0277-3740    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeThe multicenter Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study is a prospective, observational study of 1,209 keratoconus patients. We report on the prevalence of corneal scarring in these patients. We also report on the test-retest repeatability of corneal scar documentation at the slit-lamp biomicroscope by trained clinicians and by masked photograph readers and on the scarring-status agreement at baseline between clinicians and photograph readers.MethodsClinicians and masked photograph readers graded each cornea as to scarring status. Patients were examined by clinicians, and their corneas were photographed at baseline (2,297 nongrafted eyes of 1,209 patients) and at a repeated visit (258 nongrafted eyes of 138 patients). These photographs were evaluated by the masked readers at the CLEK Photography Reading Center (CPRC). Clinicians reported corneal scars in right eyes at baseline as “definitely not present‘’ in 53.9%, “probably not present‘’ in 8.4%, “probably present‘’ in 8.2%, and “definitely present‘’ in 29.4% of patients. A weighted kappa statistic of 0.83 (95% confidence interval from 0.78 to 0.88) indicates that agreement is excellent between baseline and repeated assessments for the presence of a corneal scar by clinicians.ResultsAgreement is very good between baseline and repeated photograph-reader assessments for the presence of a scar, with a weighted kappa of 0.77 (95% confidence interval, 0.72–0.82). The kappa statistic comparing photograph-reader scarring assessments with clinician results was 0.69 (95% confidence interval, 0.66–0.71).ConclusionThe data also suggest better agreement between clinicians and readers when Vogt's striae and corneal nerves were observed. The data also suggest better agreement when corneal staining was not observed by the photograph readers. The CLEK Study protocol for determining the presence of scars is highly repeatable.

ISSN:0277-3740    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeTo evaluate the efficacy of an antiherpetic vaccine in recurrent herpetic ocular infections.MethodsTwenty patients with herpes simplex virus 1-related recurrent keratitis/keratouveitis were prospectively enrolled and randomly assigned to receive either a specific vaccination with heat shock-inactivated herpes simplex virus type 1 (10 patients) or to be observed as controls (10 patients). The number, duration, and anatomic localization of relapses were recorded in all the patients for 12 months before inclusion in the study and for a similar period after the assignment of each subject to vaccine or control group.ResultsIn the vaccine group, we observed a reduction both in the number (p= 0.016) and average duration (p= 0.050) of recurrences, whereas in the control group, no significant change was found comparing a 12-month period before and after inclusion in the study. The comparison between the two groups highlighted a significant reduction in the number (p= 0.013) and average duration (p= 0.051) of relapses in treated subjects, who did not show any significant vaccine-induced side effects.ConclusionThe use of a vaccination with heat shock-inactivated herpes simplex virus 1 seems to be able to reduce the number and duration of relapses in herpes simplex virus 1-related keratitis/keratouveitis.

ISSN:0277-3740    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeTo facilitate increased use of keratolimbal allograft transplantation (KLAL) for severe ocular surface disease (OSD) by informing clinicians and eye banks of differences in tissue requirements and preparation for the procedure and to describe the surgical technique of KLAL transplantation.MethodsThe protocol of the Minnesota Lions Eye Bank is described for procuring and preparing tissue for KLAL transplantation. The surgical technique is described in detail.ResultsOver the last several years, we have modified our eye-banking procedures as well as our surgical technique to improve the success of KLAL transplantation.ConclusionKLAL transplantation for patients with severe ocular-surface disease is an important management option. Success is influenced by the ability to obtain appropriate tissue; this requires clinicians and eye banks to expand current procurement guidelines.

ISSN:0277-3740    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

PurposeTo report the efficacy of topical mitomycin C in preventing local recurrences after incomplete surgical excision of conjunctival squamous cell neoplasia.MethodsFour patients presented with unilateral conjunctival tumors. Excisional biopsy results revealed conjunctival intraepithelial neoplasia with an intact basement membrane. Neoplastic cells were present in at least one of the surgical borders of the excised conjunctiva in all four cases. Patients were treated with topical mitomycin C 0.02% three times daily for 2 weeks to prevent recurrences.ResultsAll four patients were free of clinically detectable tumors after a mean follow-up period of 20 months (range, 16–23 months). Side effects included mild discomfort, redness, photophobia, and punctate epithelial keratopathy that subsided on discontinuation of the medication.ConclusionPostoperative topical mitomycin C application may be a useful adjunct to prevent recurrences in patients with incompletely excised conjunctival squamous cell neoplasia.

ISSN:0277-3740    

出版商:OVID    

年代:1999

数据来源: OVID