Home arrow World News  
Translator
Main Menu
Home
Keratoconus
About Us
FAQs
Search
Education
Medical Library
Global Network
World News
Research
Discovery
Links
Glossary
References
Contact Us
Terms of Use
Login Form





Lost Password?
No account yet? Register
Advertisement
World News
The Cornea
This feed was created by mixing existing feeds from various sources.

  • Effect of Donor and Recipient Diabetes Status on Descemet Membrane Endothelial Keratoplasty Adherence and Survival
    imagePurpose: To evaluate whether donor and/or recipient diabetes status affects the outcomes of Descemet membrane endothelial keratoplasty (DMEK). Methods: A consecutive, single-center DMEK case series was reviewed. The outcome measures were success of surgeon tissue preparation, air reinjection rate, Kaplan?Meier 4-year graft replacement/failure rate for any reason, and endothelial cell loss. Results: The donor had a history of diabetes in 504 of 1791 cases (28%) and the recipient in 14%. For donors without and with diabetes, the preparation success rate was 99% versus 95% (P < 0.0001), the air reinjection rate was 16% versus 18% (P = 0.19), and the 4-year graft replacement/failure rate was 7% versus 9%, respectively (P = 0.15). Endothelial cell loss was not associated with donor diabetes (P = 0.76). For recipients without and with diabetes, the 4-year graft replacement/failure rate was 7% versus 9% (P = 0.68), and median endothelial cell loss increased from 27% versus 29% at 1 month to 42% versus 48% at 4 years, respectively (P = 0.02). Recipient use of insulin therapy was associated with poorer graft attachment and a higher air reinjection rate (P = 0.0023). Conclusions: Although donor diabetes was associated with a 5-fold increased risk of tissue preparation failure, it was not significantly associated with air reinjection, graft survival, or endothelial cell loss. This provides reassurance that tissue prepared successfully from donors with diabetes is safe to use for DMEK. Recipient diabetes was associated with increased endothelial cell loss; the potential effect on longer-term graft survival merits further study.

  • Technician Consistency in Specular Microscopy Measurements: A ?Real-World? Retrospective Analysis of a United States Eye Bank
    imagePurpose: To quantify consistency of endothelial cell density (ECD) measurements among technicians in a single US eye bank operating under typical operating conditions. Methods: In this retrospective analysis of 51 microscopy technicians using a semiautomated counting method on 35,067 eyes from July 2007 to May 2015, technician- and date-related marginal ECD effects were calculated using linear regression models. ECD variance was correlated with the number of specular microscopy technicians. Results: Technician mean ECDs ranged from 2386 431 to 3005 560 cells/mm2. Nine technicians had statistically and clinically significant marginal effects. Annual mean ECDs adjusted for changes in technicians ranged from 2422 433 to 2644 430 cells/mm2. The period of 2007 to 2009 had statistically and clinically significant marginal effects. There was a nonstatistically significant association between the number of technicians and ECD standard deviation. Conclusions: There was significant ECD variability associated with specular microscopy technicians and with the date of measurement. We recommend that eye banks collect data related to laboratory factors that have been shown to influence ECD variability.

  • Comparison of 5% Sulfur Hexafluoride Versus 100% Air Tamponade in Descemet Membrane Endothelial Keratoplasty
    imagePurpose: To compare the rebubbling rate and clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) with 5% sulfur hexafluoride (SF6) gas versus 100% air as a tamponade for graft attachment. Methods: Retrospective, comparative, interventional case series including 368 consecutive pseudophakic eyes with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy that underwent DMEK in a tertiary referral center between October 2010 and August 2015 using either air (group 1, 191 eyes) or 5% SF6 (group 2, 177 eyes) as a tamponade. The rebubbling rate, complications, best-corrected distance visual acuity (BCVA), manifest refraction, and endothelial cell density were analyzed before and at 1 week, 1, 3, 6, 12, 24, and 36 months after surgery. Results: The rebubbling rate was 20.4% (39/191, group 1) versus 6.8% (12/177, group 2; P < 0.001). Complications included cystoid macular edema (n = 5, group 1, and n = 10, group 2; P = 0.14) and 1 case of presumed allograft rejection (n = 1, group 2). The follow-up period was 12 8 months for group 1 and 6 4 months for group 2. BCVA (logarithm of the minimum angle of resolution) had improved after 12 months from 1.43 0.63 to 0.18 0.26 (group 1, P < 0.001) and from 1.8 0.63 to 0.18 0.17 (group 2, P < 0.001). The percentage of eyes with BCVA ?0.2 logarithm of the minimum angle of resolution at 12 months was 70.9% (90/127, group 1) and 78.4% (40/51, group 2; P = 0.3). Endothelial cell loss at 12 months after DMEK was 44 18% (group 1) versus 33 15% (group 2, P = 0.07). Conclusions: The use of a tamponade with 5% SF6 yielded a significantly lower incidence of graft detachment requiring surgical reintervention with no detrimental effect on graft endothelial cells. Thus, routine use of 5% SF6 for a graft tamponade in DMEK is recommended.

  • Tacrolimus Eye Drops as Adjunct Therapy in Severe Corneal Endothelial Rejection Refractory to Corticosteroids
    imagePurpose: To evaluate the safety and efficacy of tacrolimus eye drops as adjunctive therapy in the treatment of severe corneal endothelial rejection after penetrating keratoplasty refractory to corticosteroids. Methods: In this prospective interventional case series, 11 eyes of 11 patients assessed for severe corneal endothelial rejection, with an inadequate response to topical, local, and systemic corticosteroids, were treated with either 0.01% or 0.05% tacrolimus eye drops 4 times daily. Improvement in signs of rejection, visual function, and development of complications were monitored. Results: The duration of steroid treatment before intervention was 8.1 1.4 days (range = 7?11). Patients were subsequently administered topical tacrolimus 0.01% or 0.05% qid. The time to clinical improvement was 10.3 3.4 days (range = 3?17). The time to rejection reversal was 27.8 16.3 days (range = 7?52). After 3 months, 10 patients (90.8%) demonstrated clinical improvement, and complete restoration of graft clarity was achieved in 5 patients (45.4%). In responsive cases, steroid therapy was successfully tapered off after 60.2 19.7 days (range = 36?93). The best spectacle-corrected visual acuity improved from 1.7 0.9 to 0.8 0.5 logMAR (P = 0.0016). Reported side effects included stinging on drop instillation and punctate epithelial keratopathy. Conclusions: Tacrolimus eye drops may be able to play an adjunctive therapeutic role in patients with severe corneal endothelial rejection refractory to conventional steroid treatment. Controlled studies are needed to further investigate the role of tacrolimus in this setting.

  • Codeine Plus Acetaminophen for Pain After Photorefractive Keratectomy: A Randomized, Double-Blind, Placebo-Controlled Add-On Trial
    imageBackground: Pain after photorefractive keratectomy (PRK) is significant, and the analgesic efficacy and safety of oral opioids in combination with acetaminophen has not been fully investigated in PRK trials. Purpose: To assess the efficacy and safety of the combination of codeine plus acetaminophen (paracetamol) versus placebo as an add-on therapy for pain control after PRK. Study design: Randomized, double-blind, placebo-controlled trial. Setting: Single tertiary center. Methods: One eye was randomly allocated to the intervention, whereas the fellow eye was treated with a placebo. Eyes were operated 2 weeks apart. The participants were adults older than 20 years with refractive stability for ?1 year, who underwent PRK for correction of myopia or myopic astigmatism. Codeine (30 mg) plus acetaminophen (500 mg) was given orally 4 times per day for 4 days after PRK. The follow-up duration was 4 months. The study outcomes included pain scores at 1 to 72 hours, as measured by the visual analog scale, McGill Pain Questionnaire, and Brief Pain Inventory, as well as adverse events and corneal wound healing. Results: Of the initial 82 eyes, 80 completed the trial (40 intervention, 40 placebo). Median (interquartile range) pain scores as measured by the visual analog scale were statistically and clinically lower during treatment with codeine/acetaminophen compared with the placebo: 1 hour: 4 (2?4) versus 6 (3?6), P < 0.001; 24 hours: 4 (3?6) versus 7 (6?9), P < 0.001; 48 hours: 1 (0?2) versus 3 (2?5), P < 0.001; and 72 hours: 0 (0?0) versus 0 (0?2), P = 0.001. Virtually identical results were obtained by the McGill Pain Questionnaire and Brief Pain Inventory scales. The most common adverse events with codeine/acetaminophen were drowsiness (42%), nausea (18%), and constipation (5%). No case of delayed epithelial healing was observed in both treatment arms. Conclusions: When added to the usual care therapy, the oral combination of codeine/acetaminophen was safe and significantly superior to the placebo for pain control after PRK. Clinical Trial Registration: URL: http://www.clinicaltrials.gov . Unique identifier: NCT02625753.

  • Comparison of Outcomes Between Combined Transepithelial Photorefractive Keratectomy With and Without Accelerated Corneal Collagen Cross-Linking: A 1-Year Study
    imagePurpose: To investigate the effects of combined transepithelial photorefractive keratectomy (tPRK) and accelerated corneal collagen cross-linking (CXL) on visual acuity and refractive outcomes. Methods: The medical records of 89 eyes (89 patients) undergoing combined tPRK and CXL (tPRK-CXL group) or tPRK alone (tPRK group) were retrospectively analyzed. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity, and manifest refraction spherical equivalent (MRSE) were evaluated preoperatively and 2 weeks, 1, 3, 6, and 12 months after surgery. Results: At 2 weeks after surgery, the tPRK-CXL group had better UDVA than the tPRK group (0.97 0.22 vs. 0.85 0.22, P = 0.015). At 2 weeks and 1 month after surgery, the tPRK-CXL group had a significantly lower spherical error than the tPRK group (0.24 vs. 0.63 D, P = 0.017, for 2 weeks and 0.43 vs. 0.57 D, P = 0.019, for 1 month). At 12 months after surgery, the tPRK-CXL group had a lower spherical error and MRSE than the tPRK group (0.30 vs. 0.44 D, P < 0.001, for the spherical error and 0.17 vs. 0.31 D, P < 0.001, for the MRSE). Both groups had comparable predictability, efficacy, and safety indices at 12 months after surgery. Conclusions: Combined tPRK and accelerated CXL demonstrated comparable predictability, efficacy, and safety compared with tPRK alone. Combined tPRK and CXL provides better UDVA in the early postoperative period and better refractive outcomes at 12 months postoperatively in terms of spherical error and MRSE.

  • Refractive Surgery: Malpractice Litigation Outcomes
    imagePurpose: To review data on malpractice claims related to refractive surgery to identify common allegations and injuries and financial outcomes. Methods: The WestlawNext database was reviewed for all malpractice lawsuits/settlements related to refractive eye surgery. Data evaluated included patient demographics, type of operation performed, plaintiff allegation, nature of injury, and litigation outcomes. Results: A total of 167 cases met the inclusion criteria, of which 108 cases (64.7%) were found to be favorable and 59 cases (35.3%) unfavorable to the defendant. A total of 141 cases were tried by a jury with 108 cases (76.4%) favorable and 33 cases (23.6%) unfavorable to the defendant. Laser in situ keratomileusis was performed in 127 cases (76%). The most common allegations were negligence in treatment or surgery in 127 cases (76%) and lack of informed consent in 83 cases (49.7%). For all cases, the need for future surgery (P = 0.0001) and surgery resulting in keratoconus (P = 0.05) were more likely to favor the plaintiff. In jury verdict decisions, cases in which failure to diagnose a preoperative condition was alleged favored the defendant (P = 0.03), whereas machine malfunction (P = 0.05) favored the plaintiff. After adjustment for inflation, the overall mean award was $1,287,872. Jury verdicts and settlements led to mean awards of $1,604,801 and $826,883, respectively. Conclusions: Malpractice litigation in refractive surgery tends to favor the defendant. However, large awards and settlements were given in cases that were favorable to the plaintiff. The need for future surgery and surgery leading to keratoconus increased the chance of an unfavorable outcome.

  • Scleral Pneumatonometry in Penetrating Keratoplasty: A Clinical Study
    imagePurpose: To evaluate the reliability between pneumatonometry intraocular pressure (IOP) measurement in different scleral locations and corneal IOP in a penetrating keratoplasty (PK) setting. Our aim is to validate a method that can potentially be used for patients with keratoprostheses. Methods: This is a prospective observational study of 40 patients who underwent monocular PK by a single surgeon and had no significant anterior segment condition in the contralateral eye. Participants were recruited during routine visits to the Cornea Clinic at the Stein Eye Institute, between November 2016 and February 2017. Goldmann applanation tonometry, central corneal pachymetry, and inferior, inferotemporal, and temporal scleral pneumatonometry of both eyes were collected. Results: The correlation coefficient between corneal Goldmann applanation tonometry IOP and inferior, inferotemporal, and temporal scleral pneumatonometry IOP in the transplanted eye found that all locations were significantly and strongly correlated (r = 0.76, r = 0.80, and r = 0.75, respectively; P < 0.001). The correlation coefficient was higher for inferior and inferotemporal scleral measurements when the contralateral eye was used to predict the PK corneal IOP (r = 0.85 and r = 0.79, respectively; P < 0.001) and weaker for temporal measurement (r = 0.72; P < 0.001). Central corneal thickness correction formulas did not improve the correlation between scleral and corneal IOPs. All linear regression analyses were statistically significant (P < 0.001). Conclusions: The inferotemporal sclera was the optimal location for pneumatonometry IOP measurement. The contralateral eye could be used to more accurately predict the IOP in the eye of interest. Scleral pneumatonometry is an intuitive and reliable method to monitor IOP when corneal measurement is not available.

  • Simple Single-Pass Technique for Ultrathin Descemet Stripping Automated Endothelial Keratoplasty: A Pilot Study
    imagePurpose: To assess intraoperative and postoperative graft thickness (GT) after donor deturgescence for ultrathin Descemet stripping automated endothelial keratoplasty and to evaluate visual outcomes, endothelial cell density, and patient satisfaction at 1 year. Methods: Prospective interventional case series of patients with Fuchs endothelial dystrophy, Fuchs endothelial dystrophy and cataract, and pseudophakic bullous keratopathy (n = 12 grafts). The donor cornea was allowed to thin out by simple evaporation on an artificial anterior chamber, to the required precut thickness, before a single microkeratome pass. GT after microkeratome cut, at 1 week, 1, 3, 6, and 12, months was measured. Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity, Pelli?Robson contrast sensitivity, endothelial cell density, and score on the visual function questionnaire (VFQ-25) were assessed. Results: Mean intraoperative postmicrokeratome cut GT was 78.9 33.3 ?m. Mean GT at 1 week, 1, 3, 6, and 12 months was 70.7, 70.9, 62.8, 66.5, and 58.9 ?m, respectively. Mean initial donor corneal thickness was 647 67 ?m, and mean precut thickness was 526 4.5 ?m (mean thinning time: 17 min). Best-corrected visual acuity at 1 week, 1, 3, 6, and 12 months was 68.8, 76.9, 76.3, 76.9, and 78.6 letters with 9-letter gain at 12 months (P = 0.02). Mean endothelial cell loss at 3, 6, and 12 months was 36.8% 6.75%, 37.2% 8%, and 37.9% 9.75% loss, respectively. At 1 year, 83.3% of patients achieved ?20/40 (6/12) and 66.7% of patients achieved ?20/32 (6/9.5). VFQ-25 testing showed an improvement in the visual function. Conclusions: This pilot study demonstrates a simple graft deturgescence technique that reproducibly creates ultrathin grafts without donor wastage.

  • Teleophthalmic Approach for Detection of Corneal Diseases: Accuracy and Reliability
    imagePurpose: Corneal and anterior segment diseases cause most of the urgent visits to eye care professionals. We evaluated the diagnostic accuracy of detecting corneal diseases using external photographs from 2 portable cameras for telemedicine purposes. Methods: This is a prospective study of adults with a clinical diagnosis of corneal pathology including corneal abrasions, ulcers, scars, and pterygia. A cornea specialist provided the gold standard diagnosis by slit-lamp examination. Images of both eyes were obtained using iTouch 5S and Nidek VersaCam cameras in multiple gazes and interpreted by 3 cornea specialists for the presence of pathology. Accuracy to detect disease was compared with gold standard diagnosis, stratified by the camera and grader. Reliability was evaluated with weighted kappa statistics. Graders assessed image quality on a Likert scale from 1 (poor) to 9 (optimal). Results: A total of 198 eyes (110 subjects) were photographed. By gold standard diagnosis, 59 eyes (30%) had corneal scars, 34 (17%) had ulcers, 13 (7%) had abrasions, 10 (5%) had pterygia, and 82 (41%) were normal. Sensitivity to detect AS pathology ranged from 54% to 71% for the iTouch and 66% to 75% for the Nidek, across graders; specificity ranged from 82% to 96% for the iTouch and 91% to 98% for the Nidek. The intergrader reliability was moderate to strong (kappa ranges: 0.54?0.71 for the iTouch; 0.75?0.76 for the Nidek). Quality ratings were variable between graders. Conclusions: External photographs taken by standard, nonenhanced portable cameras and interpreted remotely by ophthalmologist graders yielded sensitivity values that are not yet suitable for telemedicine applications. Additional work is needed to improve the ability to detect AS pathology remotely.

  • Recurrence of Granular Corneal Dystrophy Type 1 After Phototherapeutic Keratectomy, Lamellar Keratoplasty, and Penetrating Keratoplasty in a Single Population
    imagePurpose: To describe the recurrence of granular corneal dystrophy type 1 (GCD1) after penetrating keratoplasty (PKP), anterior lamellar keratoplasty (ALK), deep anterior lamellar keratoplasty (DALK), and phototherapeutic keratectomy (PTK) in a single population. The time required to achieve best-corrected visual acuity (BCVA) after each intervention was also analyzed. Methods: Retrospective review of all patients with GCD1 from a single center between 1989 and 2016. Surgical interventions were performed 50 times on 28 eyes of 15 patients. Data were primarily analyzed through Cox regression modeling with clustering and robust log-rank testing. Results: Significant recurrence occurred most rapidly after PTK (median time 2.7 years) and was most delayed after PKP (13.7 years). Significant recurrence occurred at a similar interval after ALK and DALK (3.7 and 3.2 years, respectively). Significant recurrence-free survival was longer for PKP than for ALK, DALK, or PTK (P = 0.04). The time required to obtain BCVA was shorter in the PTK group (median 1.8 months) than in the PKP and DALK groups (median 5.3 and 8.4 months, respectively; P = 0.03 and P = 0.02). All groups achieved a similar median BCVA (20/25?20/30). Conclusions: This series indicates that GCD1 recurrence-free survival is longest after PKP with an associated delay in attaining BCVA. Conversely, PTK provided the fastest visual recovery with shorter recurrence-free survival.

  • CYP1B1 Cytopathy: Uncommon Phenotype of a Homozygous CYP1B1 Deletion as Internal Corneal Ulcer of Von Hippel
    imagePurpose: To report a mutation of CYP1B1 in a newborn with a rare phenotype without the classic features of anterior segment dysgenesis or congenital glaucoma. Methods: The newborn presented with diffuse corneal edema and bilaterally elevated intraocular pressure (IOP). Ophthalmological examination, ultrasound, and ultrasound biomicroscopy were performed; congenital infections were ruled out. Genetic analysis was performed. The patient underwent penetrating keratoplasty and goniotomy in a single surgical time. The button was subjected to histopathological examination. Results: The patient is the first child of young, healthy, consanguineous parents. Ophthalmological examination revealed visual acuity of light perception and increased IOP in both eyes. CYP1B1 gene analysis demonstrated homozygosity for a 1-bp deletion in exon 2 (c.830delT). IOP was normalized, and the corneal button was clear after surgical treatment. Histopathological analysis revealed loss of the Bowman membrane in the central cornea, fibrosis of the stroma, absence of endothelial cells, and loss of Descemet membrane centrally. Conclusions: We present an uncommon mutation and clinical description of CYP1B1. This report and further studies could provide us better understanding of the mutational spectrum of CYP1B1.

  • Correlation of Corneal Biomechanical Stiffness With Refractive Error and Ocular Biometry in a Pediatric Population
    imagePurpose: To assess the correlation between corneal biomechanical stiffness and refractive error (RE) in the pediatric population. Methods: A total of 733 pediatric eyes were included in the study retrospectively. All eyes underwent corneal tomography (Pentacam), RE assessment, and air-puff deformation (Corvis-ST). Waveform analyses of deformation provided corneal stiffness (CS) and extraocular tissue stiffness (EOS). Eyes were subgrouped into emmetropia [manifest refraction spherical equivalent (MRSE) ? 0 D], hyperopia (MRSE > 0 D), myopia I (MRSE between 0 D and ?3 D), myopia II (MRSE between ?3 D and ?6 D), and myopia III (MRSE greater than ?6 D) for multivariate analyses. Ocular biometry variables [age, intraocular pressure (IOP), central corneal thickness (CCT), corneal astigmatism, anterior chamber depth, and RE] were used as covariates. The apparent elastic modulus (E) was defined as the ratio of CS and CCT. Results: All groups had similar age, CCT, and IOP (P > 0.05). CS was the only parameter to differ between all the grades of myopia (P < 0.0001). CS was lower by 3.72%, 6.84%, and 10.68% in myopia I, II, and III eyes, respectively, relative to emmetropic eyes. EOS increased by 11.15%, 22.60%, and 28.5%, respectively. Multivariate regression revealed age, IOP, CCT, corneal astigmatism, anterior chamber depth, and RE as significant predictors of CS, with a high coefficient of regression (R2 = 0.66). Corneal E negatively correlated with the grade of myopia. Conclusions: CS and EOS correlated negatively and positively with the grade of myopia, respectively. Ocular biometry variables were significant predictors of both CS and EOS. The decrease in CS was attributed to that in elastic modulus.

  • Mechanical Modeling of a Keratoconic Cornea
    imagePurpose: We created a laboratory model of a cornea that was subjected to various pressures and thermal and mechanical factors to better understand the genesis of keratoconus deformation. Methods: A steel base allowed for fixation of circular multilaminated patches of araldite (10 cm in diameter, 5 mm thick) in which the corneal anatomy was modeled. The model was plunged into a steam room (374F/3 bars of pressure for 1 h) to ensure thermal homogeneity and was subjected to pressure using compressed air. Three models were assessed: a fault-free model with no lesion (model 1), and 2 models with a defect. The first of the defective models (model 2) had an external crack-type lesion (1 cm long; 1 mm deep). The second defective model (model 3) had one quarter thinned down using abrasive sandpaper (thickness reduced by 30%?40%). Results: For model 1, which represented a healthy cornea, homogeneous modification was noted when examined under polarized light. In model 2, no excessive deformation was noticed, but there were stress lines at the edge of the lesion. Model 3 had a deformity, similar to keratoconic deformation. Conclusions: Our findings suggest that the disease progresses under environmental stresses, but only when there is an initial defect, and especially when there is a thinning down defect. This thinning down defect may be induced by continual eye rubbing.

  • Teleophthalmic Approach for Detection of Corneal Diseases: Accuracy and Reliability
    imagePurpose: Corneal and anterior segment diseases cause most of the urgent visits to eye care professionals. We evaluated the diagnostic accuracy of detecting corneal diseases using external photographs from 2 portable cameras for telemedicine purposes. Methods: This is a prospective study of adults with a clinical diagnosis of corneal pathology including corneal abrasions, ulcers, scars, and pterygia. A cornea specialist provided the gold standard diagnosis by slit-lamp examination. Images of both eyes were obtained using iTouch 5S and Nidek VersaCam cameras in multiple gazes and interpreted by 3 cornea specialists for the presence of pathology. Accuracy to detect disease was compared with gold standard diagnosis, stratified by the camera and grader. Reliability was evaluated with weighted kappa statistics. Graders assessed image quality on a Likert scale from 1 (poor) to 9 (optimal). Results: A total of 198 eyes (110 subjects) were photographed. By gold standard diagnosis, 59 eyes (30%) had corneal scars, 34 (17%) had ulcers, 13 (7%) had abrasions, 10 (5%) had pterygia, and 82 (41%) were normal. Sensitivity to detect AS pathology ranged from 54% to 71% for the iTouch and 66% to 75% for the Nidek, across graders; specificity ranged from 82% to 96% for the iTouch and 91% to 98% for the Nidek. The intergrader reliability was moderate to strong (kappa ranges: 0.54?0.71 for the iTouch; 0.75?0.76 for the Nidek). Quality ratings were variable between graders. Conclusions: External photographs taken by standard, nonenhanced portable cameras and interpreted remotely by ophthalmologist graders yielded sensitivity values that are not yet suitable for telemedicine applications. Additional work is needed to improve the ability to detect AS pathology remotely.

  • Peripheral Endothelial Cell Count Is a Predictor of Disease Severity in Advanced Fuchs Endothelial Corneal Dystrophy
    imagePurpose: In advanced Fuchs endothelial corneal dystrophy (FECD), central endothelial changes do not correlate with disease severity. The peripheral endothelial cell count (ECC) has not been studied as a marker of FECD severity. The goal of this study was to determine the relationship between the peripheral ECC and known clinical markers of FECD in advanced cases. Methods: Patients with FECD examined between January 1, 2013, and September 1, 2016, by 1 cornea specialist were identified. Medical records from all previous visits were reviewed to include eyes with high-quality central and peripheral in vivo confocal microscopy images performed on the same day as a clinical evaluation. Endothelial photographs were used to perform manual cell counts centrally and peripherally. Clinical grading of FECD from 1 to 4 was performed at the slit-lamp. Results: We identified 154 eyes of 126 patients that met criteria for inclusion. With higher disease grades, central ECC and peripheral ECC decreased, visual acuity worsened, and central corneal thickness (CCT) increased (all P < 0.05). In patients with advanced disease (defined as either grade 3 or 4, CCT >700, or central ECC <350), the peripheral ECC was the best predictor of disease severity and had the highest number of statistically significant correlations with other clinical markers compared with competing variables. Conclusions: In advanced FECD, severity is best determined by the peripheral ECC compared with the central ECC, visual acuity, clinical disease grade, and CCT. The peripheral ECC should be added to the clinical parameters used to evaluate FECD severity.

  • Technician Consistency in Specular Microscopy Measurements: A ?Real-World? Retrospective Analysis of a United States Eye Bank
    imagePurpose: To quantify consistency of endothelial cell density (ECD) measurements among technicians in a single US eye bank operating under typical operating conditions. Methods: In this retrospective analysis of 51 microscopy technicians using a semiautomated counting method on 35,067 eyes from July 2007 to May 2015, technician- and date-related marginal ECD effects were calculated using linear regression models. ECD variance was correlated with the number of specular microscopy technicians. Results: Technician mean ECDs ranged from 2386 431 to 3005 560 cells/mm2. Nine technicians had statistically and clinically significant marginal effects. Annual mean ECDs adjusted for changes in technicians ranged from 2422 433 to 2644 430 cells/mm2. The period of 2007 to 2009 had statistically and clinically significant marginal effects. There was a nonstatistically significant association between the number of technicians and ECD standard deviation. Conclusions: There was significant ECD variability associated with specular microscopy technicians and with the date of measurement. We recommend that eye banks collect data related to laboratory factors that have been shown to influence ECD variability.

  • Simple Single-Pass Technique for Ultrathin Descemet Stripping Automated Endothelial Keratoplasty: A Pilot Study
    imagePurpose: To assess intraoperative and postoperative graft thickness (GT) after donor deturgescence for ultrathin Descemet stripping automated endothelial keratoplasty and to evaluate visual outcomes, endothelial cell density, and patient satisfaction at 1 year. Methods: Prospective interventional case series of patients with Fuchs endothelial dystrophy, Fuchs endothelial dystrophy and cataract, and pseudophakic bullous keratopathy (n = 12 grafts). The donor cornea was allowed to thin out by simple evaporation on an artificial anterior chamber, to the required precut thickness, before a single microkeratome pass. GT after microkeratome cut, at 1 week, 1, 3, 6, and 12, months was measured. Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity, Pelli?Robson contrast sensitivity, endothelial cell density, and score on the visual function questionnaire (VFQ-25) were assessed. Results: Mean intraoperative postmicrokeratome cut GT was 78.9 33.3 ?m. Mean GT at 1 week, 1, 3, 6, and 12 months was 70.7, 70.9, 62.8, 66.5, and 58.9 ?m, respectively. Mean initial donor corneal thickness was 647 67 ?m, and mean precut thickness was 526 4.5 ?m (mean thinning time: 17 min). Best-corrected visual acuity at 1 week, 1, 3, 6, and 12 months was 68.8, 76.9, 76.3, 76.9, and 78.6 letters with 9-letter gain at 12 months (P = 0.02). Mean endothelial cell loss at 3, 6, and 12 months was 36.8% 6.75%, 37.2% 8%, and 37.9% 9.75% loss, respectively. At 1 year, 83.3% of patients achieved ?20/40 (6/12) and 66.7% of patients achieved ?20/32 (6/9.5). VFQ-25 testing showed an improvement in the visual function. Conclusions: This pilot study demonstrates a simple graft deturgescence technique that reproducibly creates ultrathin grafts without donor wastage.

  • Effect of Donor and Recipient Diabetes Status on Descemet Membrane Endothelial Keratoplasty Adherence and Survival
    imagePurpose: To evaluate whether donor and/or recipient diabetes status affects the outcomes of Descemet membrane endothelial keratoplasty (DMEK). Methods: A consecutive, single-center DMEK case series was reviewed. The outcome measures were success of surgeon tissue preparation, air reinjection rate, Kaplan?Meier 4-year graft replacement/failure rate for any reason, and endothelial cell loss. Results: The donor had a history of diabetes in 504 of 1791 cases (28%) and the recipient in 14%. For donors without and with diabetes, the preparation success rate was 99% versus 95% (P < 0.0001), the air reinjection rate was 16% versus 18% (P = 0.19), and the 4-year graft replacement/failure rate was 7% versus 9%, respectively (P = 0.15). Endothelial cell loss was not associated with donor diabetes (P = 0.76). For recipients without and with diabetes, the 4-year graft replacement/failure rate was 7% versus 9% (P = 0.68), and median endothelial cell loss increased from 27% versus 29% at 1 month to 42% versus 48% at 4 years, respectively (P = 0.02). Recipient use of insulin therapy was associated with poorer graft attachment and a higher air reinjection rate (P = 0.0023). Conclusions: Although donor diabetes was associated with a 5-fold increased risk of tissue preparation failure, it was not significantly associated with air reinjection, graft survival, or endothelial cell loss. This provides reassurance that tissue prepared successfully from donors with diabetes is safe to use for DMEK. Recipient diabetes was associated with increased endothelial cell loss; the potential effect on longer-term graft survival merits further study.

  • Comparison of 5% Sulfur Hexafluoride Versus 100% Air Tamponade in Descemet Membrane Endothelial Keratoplasty
    imagePurpose: To compare the rebubbling rate and clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) with 5% sulfur hexafluoride (SF6) gas versus 100% air as a tamponade for graft attachment. Methods: Retrospective, comparative, interventional case series including 368 consecutive pseudophakic eyes with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy that underwent DMEK in a tertiary referral center between October 2010 and August 2015 using either air (group 1, 191 eyes) or 5% SF6 (group 2, 177 eyes) as a tamponade. The rebubbling rate, complications, best-corrected distance visual acuity (BCVA), manifest refraction, and endothelial cell density were analyzed before and at 1 week, 1, 3, 6, 12, 24, and 36 months after surgery. Results: The rebubbling rate was 20.4% (39/191, group 1) versus 6.8% (12/177, group 2; P < 0.001). Complications included cystoid macular edema (n = 5, group 1, and n = 10, group 2; P = 0.14) and 1 case of presumed allograft rejection (n = 1, group 2). The follow-up period was 12 8 months for group 1 and 6 4 months for group 2. BCVA (logarithm of the minimum angle of resolution) had improved after 12 months from 1.43 0.63 to 0.18 0.26 (group 1, P < 0.001) and from 1.8 0.63 to 0.18 0.17 (group 2, P < 0.001). The percentage of eyes with BCVA ?0.2 logarithm of the minimum angle of resolution at 12 months was 70.9% (90/127, group 1) and 78.4% (40/51, group 2; P = 0.3). Endothelial cell loss at 12 months after DMEK was 44 18% (group 1) versus 33 15% (group 2, P = 0.07). Conclusions: The use of a tamponade with 5% SF6 yielded a significantly lower incidence of graft detachment requiring surgical reintervention with no detrimental effect on graft endothelial cells. Thus, routine use of 5% SF6 for a graft tamponade in DMEK is recommended.



Global Keratoconus Foundation - 2017 © All rights reserved