23 research outputs found
Corneal Microlayer Optical Tomography Review
Anterior segment ultra-high resolution OCT (UHR-OCT) uses a resolution of 1–4 μm to provide non-invasive imaging of the tear film and cornea. This new high definition imaging technology increases our understanding of normal structure and pathological changes in the cornea, and resolution has continued to improve over time. UHR-OCT is useful in the treatment of disease such as dry eye, subclinical keratoconus, keratoconus, and ocular surface pathology. It also aids clinicians in fitting contact lenses and screening tissue for corneal transplantation. In this review, we summarize applications of imaging the normal and pathologic ocular surface and cornea. Novel developments, such as the new-generation micro-OCT, Anterior segment OCT angiography and artificial intelligence have the potential to continue to increase our knowledge
Peripheral Ulcerative Keratitis: A Review
Peripheral ulcerative keratitis (PUK) is a rare but serious ocular condition that is an important clinical entity due to its ophthalmological and systemic implications. It is characterized by progressive peripheral corneal stromal thinning with an associated epithelial defect and can be associated with an underlying local or systemic pro-inflammatory condition, or present in an idiopathic form (Mooren ulcer). Associated conditions include autoimmune diseases, systemic and ocular infections, dermatologic diseases, and ocular surgery. Cell-mediated and autoantibody- mediated immune responses have been implicated in the pathogenesis of PUK, destroying peripheral corneal tissue via matrix metalloproteinases. Clinically, patients with PUK present with painful vision loss, a peripheral corneal ulcer, and often adjacent scleritis, episcleritis, iritis, or conjunctivitis. Diagnostic evaluation should be focused on identifying the underlying etiology and ruling out conditions that may mimic PUK, including marginal keratitis and Terrien marginal degeneration. Treatment should be focused on reducing local disease burden with topical lubrication, while simultaneously addressing the underlying cause with antimicrobials or anti-inflammatory when appropriate. Existing and emerging biologic immunomodulatory therapies have proven useful in PUK due to autoimmune conditions. Surgical treatment is generally reserved for cases of severe thinning or corneal perforation
Anchored absorbable versus conventional nonabsorbable sutures in hang-back medial rectus muscle recession for large-angle esotropia
Purpose The aim of this study was to compare the clinical safety and efficacy of the anchored hang-back technique (HBT) to the HBT using nonabsorbable sutures in bilateral medial rectus recession (BMR) for large-angle esotropia (ET).
Design This is a prospective comparative interventional study.
Patients and methods The study included 81 patients with concomitant ET who were indicated for BMR of at least 6 mm. The patients were randomly assigned to have either (a) anchored HBT-BMR using absorbable 6–0 polyglactin 910 suture or (b) conventional HBT-BMR using nonabsorbable 6–0 polyester suture. Postoperatively, angles of deviation were measured for both near and far at 1 week and at 2 and 6 months. Success was defined as alignment within 10 prism diopters (PD) of orthotropia by the end of 2 months.
Results Nonabsorbable HBT was used in 42 patients, whereas the anchored HBT was used in 39 patients. The mean preoperative angles of deviation for near and far were 60.9 and 58.7 PD, respectively, in the nonabsorbable group, compared with 61.7 and 58.8 PD, respectively, in the anchored group (P>0.05). By the sixth postoperative month, the mean angles for near and far in the nonabsorbable group were 8.1±0.6 PD of exotropia (XT) and 8.3±1.2 PD of XT, compared with 9.9±0.03 and 9.5±1.2 PD of XT in the anchored group, respectively. Repeated measures analysis of variance showed insignificant differences in the near and far angles between both groups. The success rate was 92.8% (39/42) in the nonabsorbable group compared with 89.7% (35/39) in the anchored group (P=0.32).
Conclusion Anchored HBT was as safe and effective as nonabsorbable HBT in BMR for large-angle ET
Topical insulin in neurotrophic keratopathy after diabetic vitrectomy
Abstract To assess the efficacy and safety of topical insulin (TI) for treating neurotrophic keratopathy (NK) within one-month post-diabetic vitrectomy (DV) compared to conventional non-invasive measures, we conducted this retrospective case-control study including all eyes that developed acute NK (stages 2 and 3) following DV between October 2020 and June 2023. The control group included NK cases managed with preservative-free lubricant eye drops and prophylactic topical antibiotics. In contrast, the study group included NK cases treated with TI [1 unit per drop] four times daily, in addition to the previously mentioned treatment. The primary outcome measure was time to epithelial healing. Secondary outcome measures included any adverse effect of TI or the need for amniotic membrane transplantation (AMT). During the study period, 19 patients with a mean age of 49.3 ± 8.6 years received TI versus 18 controls with a mean age of 52.5 ± 10.7 years. Corneal epithelial healing was significantly faster in the TI-treated group compared to controls, with a mean difference of 12.16 days (95% CI 6.1–18.3, P = 0.001). Survival analysis indicated that the insulin-treated group had 0% and 20% of NK stages 2 and 3, respectively, that failed to achieve corneal epithelial healing, compared to 20% and 66.7% for the control group (P < 0.001). In the control group, two eyes required AMT due to progressive thinning. Additionally, three patients in the control group, progressing to stage 3 NK, were switched to TI, achieving healing after a mean of 14 days. No adverse effects were reported in the TI-treated group. Our study suggests that TI can effectively and safely promote the healing of NK after DV
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Automated diagnosis and staging of Fuchs' endothelial cell corneal dystrophy using deep learning
Background To describe the diagnostic performance of a deep learning algorithm in discriminating early-stage Fuchs' endothelial corneal dystrophy (FECD) without clinically evident corneal edema from healthy and late-stage FECD eyes using high-definition optical coherence tomography (HD-OCT). Methods In this observational case-control study, 104 eyes (53 FECD eyes and 51 healthy controls) received HD-OCT imaging (Envisu R2210, Bioptigen, Buffalo Grove, IL, USA) using a 6 mm radial scan pattern centered on the corneal vertex. FECD was clinically categorized into early (without corneal edema) and late-stage (with corneal edema). A total of 18,720 anterior segment optical coherence tomography (AS-OCT) images (9180 healthy; 5400 early-stage FECD; 4140 late-stage FECD) of 104 eyes (81 patients) were used to develop and validate a deep learning classification network to differentiate early-stage FECD eyes from healthy eyes and those with clinical edema. Using 5-fold cross-validation on the dataset containing 11,340 OCT images (63 eyes), the network was trained with 80% of these images (3420 healthy; 3060 early-stage FECD; 2700 late-stage FECD), then tested with 20% (720 healthy; 720 early-stage FECD; 720 late-stage FECD). Thereafter, a final model was trained with the entire dataset consisting the 11,340 images and validated with a remaining 7380 images of unseen AS-OCT scans of 41 eyes (5040 healthy; 1620 early-stage FECD 720 late-stage FECD). Visualization of learned features was done, and area under curve (AUC), specificity, and sensitivity of the prediction outputs for healthy, early and late-stage FECD were computed. Results The final model achieved an AUC of 0.997 +/- 0.005 with 91% sensitivity and 97% specificity in detecting early-FECD; an AUC of 0.974 +/- 0.005 with a specificity of 92% and a sensitivity up to 100% in detecting late-stage FECD; and an AUC of 0.998 +/- 0.001 with a specificity 98% and a sensitivity of 99% in discriminating healthy corneas from all FECD. Conclusion Deep learning algorithm is an accurate autonomous novel diagnostic tool of FECD with very high sensitivity and specificity that can be used to grade FECD severity with high accuracy
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Pathological-Corneas Layer Segmentation and Thickness Measurement in OCT Images
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Comparison of Autonomous AS-OCT Deep Learning Algorithm and Clinical Dry Eye Tests in Diagnosis of Dry Eye Disease
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Diagnostic Performance of 3-Dimensional Thickness of the Endothelium-Descemet Complex in Fuchs' Endothelial Cell Corneal Dystrophy
To describe the diagnostic accuracy of 3-dimensional (3D) endothelium-Descemet's membrane complex thickness (En-DMT) in Fuchs' endothelial corneal dystrophy (FECD) and determine its potential role as an objective index of disease severity.
Observational case-control study.
One hundred four eyes of 79 participants (64 eyes of 41 FECD patients and 40 eyes of 38 healthy controls).
All participants received high-definition OCT imaging (Envisu R2210; Bioptigen, Buffalo Grove, IL). Fuchs' endothelial corneal dystrophy was classified clinically into early-stage (without edema) and late-stage (with edema) disease. Automatic and manual segmentation of corneal layers was performed using a custom-built segmental tomography algorithm to generate 3D maps of total corneal thickness (TCT) and En-DMT of the central 6-mm cornea. Regional En-DMT, regional TCT, and central-to-peripheral total corneal thickness ratio (CPTR) were evaluated and correlated to the clinical severity of FECD. Intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to assess the reliability of the repeated measurements in all eyes.
Central-to-peripheral total corneal thickness ratio and average En-DMT and TCT of central, paracentral, and peripheral regions.
In FECD, a significant increase in En-DMT, CPTR
and TCT was found compared to controls (P < 0.001). For identifying FECD, average En-DMT of paracentral and peripheral regions achieved 94% sensitivity and 100% specificity (cutoffs, 19 μm and 20 μm, respectively), whereas CPTR showed 94% sensitivity with a 73% specificity (cutoff, 0.97). Regarding early-stage FECD, average En-DMT of central zones achieved 92% sensitivity and 97% specificity (cutoff, 18 μm), whereas CPTR showed 90% sensitivity and 88% specificity (cutoff, 0.97). The average En-DMT of central, paracentral, and peripheral regions was correlated highly with FECD clinical stage (Spearman's ρ = 0.813, 0.793, and 0.721, respectively; all P < 0.001), compared with CPTR and mean TCT of paracentral zones (0.672 and 0.481, respectively; P < 0.001). The ICC values ranged from 0.98 (En-DMT) to 0.99 (TCT) with a good agreement between the automatic and manual measurements.
Regional 3D En-DMT is a novel diagnostic tool of FECD that can be used to quantify the disease severity with excellent reliability
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Case Series of Brittle Cornea Syndrome
Purpose. This case series demonstrate diagnostic features, treatment options, and challenges for Brittle Cornea Syndrome. Observations. Three cases presented with bluish sclera and extremely thin cornea. Genetic workup was performed and confirmed the diagnosis of Brittle Cornea Syndrome, a rare autosomal recessive disorder characterized by corneal thinning and blue sclera. Case 1 was a 4-year-old boy who developed cataract and glaucoma after undergoing right tectonic penetrating keratoplasty (PK) secondary to a spontaneous corneal rupture. Glaucoma was controlled medically. Later, the kid underwent right transcorneal lensectomy and vitrectomy with synechiolysis. After 6 weeks, he sustained graft dehiscence that was repaired using onlay patch graft. Case 2 was a 7-year-old boy who underwent PK in the right eye, then a pericardial patch graft in the left eye following spontaneous corneal rupture. Glaucoma in both eyes was controlled medically. Case 3 was the 2-year-old sister of the 2nd case. She had a pachymetry of 238 μm OD and 254 μm OS. In the 3 cases, parents were instructed to take protective measures for both eyes and to continue with follow-up visits. Also, they were instructed to have regular screenings for late-onset hearing loss, dental abnormalities, and bone deformities. Conclusions. Long-term follow-up of children diagnosed with Brittle Cornea Syndrome is paramount to minimize the morbidity of corneal rupture and late-onset extraocular conditions