The Neuropeptide α-Melanocyte-Stimulating Hormone Prevents Persistent Corneal Edema following Injury.

Corneal endothelial cells (CEnCs) regulate corneal hydration and maintain tissue transparency through their barrier and pump function. However, these cells exhibit limited regenerative capacity following injury. Currently, corneal transplantation is the only established therapy for restoring endothelial function, and there are no pharmacologic interventions available for restoring endothelial function. This study investigated the efficacy of the neuropeptide α-melanocyte-stimulating hormone (α-MSH) in promoting endothelial regeneration during the critical window between ocular injury and the onset of endothelial decompensation using an established murine model of injury using transcorneal freezing. Local administration of α-MSH following injury prevented corneal edema and opacity, reduced leukocyte infiltration, and limited CEnC apoptosis while promoting their proliferation. These results suggest that α-MSH has a proregenerative and cytoprotective function on CEnCs and shows promise as a therapy for the prevention and management of corneal endothelial dysfunction.

New Endothelial Corneal Dystrophy in a Chinese Family.

PURPOSE: The aim of this study was to characterize the clinical presentation of atypical endothelial corneal dystrophy (ECD) and to identify possible associated genetic variants in a Chinese family. METHODS: Six affected members, 4 unaffected first-degree relatives, and 3 spouses who were enrolled in this study underwent ophthalmic examinations. Genetic linkage analysis was performed for 4 affected and 2 unaffected members, and whole-exome sequencing (WES) was performed for 2 patients to identify disease-causing variants. Candidate causal variants were verified using Sanger sequencing in family members and 200 healthy controls. RESULTS: The mean age at disease onset was 16.5 years. The early phenotype of this atypical ECD was characterized by multiple small white translucent spots located in Descemet membrane of the peripheral cornea. These spots coalesced to form opacities with variable shapes, and eventually merged along the limbus. Subsequently, translucent spots appeared in central Descemet membrane and accumulated, causing diffuse polymorphous opacities over time. Finally, significant endothelial decompensation led to diffuse corneal edema. A heterozygous missense variant in the KIAA1522 gene (c.1331G>A; p.R444Q) was identified by WES, which was present in all 6 patients but was absent in the unaffected members and healthy controls. CONCLUSIONS: The clinical features of atypical ECD are unique compared with those of known corneal dystrophies. Moreover, genetic analysis identified the c.1331G>A variant in KIAA1522 , which may be responsible for the pathogenesis of this atypical ECD. Thus, we propose this is a new form of ECD based on our clinical findings.

Unilateral buphthalmos, corneal staphyloma and corneal fistula caused by pathogenic variant in the PITX3 gene: a case report.

INTRODUCTION: PITX3 has been reported to be associated with congenital cataracts, anterior segment mesenchymal dysgenesis, Peters' anomaly, and microphthalmia. In this case, an infant with unilateral buphthalmos, corneal staphyloma and corneal fistula carrying a variant in PITX3 was reported. CASE DESCRIPTION: We describe a 4-month-old female infant who was referred to our Eye Clinic because of gradual enlargement of the eyeball in the right eye and whitish opacity in both eyes. Buphthalmos with long axial length (22.04 mm), macrocornea with diffuse corneal oedema and opacity (14.50 mm*14.50 mm) and high intraocular pressure (23.78 mmHg) were detected in the right eye. Microphthalmia with short axial length (16.23 mm), microcornea with diffuse corneal oedema and opacity (7.50 mm*6.50 mm) were detected in the left eye. A 360° trabeculotomy was performed for the right eye. However, corneal staphyloma and corneal fistula in the right eye were detected 6 months after the surgery. A variant in exon 4 of PITX3 (c.640_656dup (p. Gly220Profs*95)) was identified in the proband but was not detected in her healthy parents. CONCLUSION: A novel phenotype characterized by unilateral buphthalmos, corneal staphyloma and corneal fistula in an infant were reported to be associated with PITX3 in our study. Our study expands the scope of the clinical heterogeneity of PITX3 variants. It also improves our understanding and increases the attention given to patients with PITX3 variants.

Keratopathy in Noonan Syndrome.

PURPOSE: Anterior segment abnormalities associated with Noonan syndrome are rare. We report our experience with 2 patients who developed keratopathy with significant visual sequelae. METHODS: case series. RESULTS: The first patient is a 9-year-old boy with genetically confirmed Noonan syndrome. At presentation, he was noted to have diffuse inferior epitheliopathy with vascularization and bilateral mild ptosis. Over 1 year, he developed focal areas of scarring with deterioration of vision and underwent superficial keratectomy in the left eye. However, over the following 2 years, he experienced recurrent corneal scarring and vascularization. The second patient is a 7-year-old boy with phenotypic Noonan syndrome. At presentation, he had an anterior subepithelial corneal scar inferiorly with epithelial defects in both eyes. He also had bilateral moderate ptosis and lagophthalmos. Despite lubrication, he developed recurrent bilateral corneal erosions with focal areas of scarring associated with vascularization and underwent superficial keratectomy for both eyes. Despite this, there was worsening corneal scarring and vascularization over time, eventually requiring deep anterior lamellar keratoplasty in the left eye. The host cornea showed a disturbed Bowman layer and an acellular mass of fibrous collagenous tissue between epithelium and stroma. CONCLUSIONS: Noonan syndrome may be associated with visually significant keratopathy, manifesting as focal corneal scarring with vascularization. These changes may due to an excessive fibrotic response in Noonan syndrome. Early recognition and treatment can help to delay the progression of keratopathy and need for surgical intervention.

[Morphological features of the cornea in eyes with pseudophakic bullous keratopathy and Fuchs endothelial corneal dystrophy]. / Morfologicheskie osobennosti rogovitsy pri psevdofakichnoi bulleznoi keratopatii i endotelial'noi distrofii Fuksa.

PURPOSE: To evaluate the morphological features of posterior corneal layers in pseudophakic bullous keratopathy (PBK) and Fuchs endothelial corneal dystrophy (FECD). MATERIAL AND METHOD: The study included 20 patients (20 eyes) aged 73.8±7.8 with PBK and 24 patients (25 eyes) aged 72.5±10.6 with FECD. Central corneal thickness was measured in all eyes before the surgery by anterior segment optical coherence tomography (AS-OCT, RTVue-100, Optovue, USA). All patients underwent corneal transplantation (DSAEK or DMEK). Postoperative donor graft status was assessed as attached or detached by AS-OCT (RTVue-100, Optovue, USA). Specimens of Descemet's membranes (DMs) were obtained intraoperatively and investigated histologically (hematoxylin and eosin staining). Morphometric analysis was performed using optical microscope Leica DM-2500 (Digital Color Camera Leica DFC295) and ImageScope M software. RESULTS: There was no difference in thickness of DMs' prenatal anterior banded layer (2.58±0.49 µm) and postnatal posterior non-banded layer (11.30±2.64 µm) between PBK and normal cornea. In FECD eyes, DM was significantly thickened by additional collagen layer and guttate excrescences (postnatal layer thickness - 16.62±4.34 µm). Morphological study of the DMs of patients with graft detachment in the early postoperative period revealed residual stromal collagen fibrils that were fixed to the area with dense extracellular matrix. CONCLUSION: The study shows that chronic corneal edema is associated with pathological morphological changes in the posterior corneal layers in PBK and FECD. Individual features of the dense extracellular matrix in the DMs may play a key role in the attachment of donor graft to the corneal stroma and affect the postoperative outcome.

Implementation of the Corneal Sweep Test in the Diagnosis of Recurrent Corneal Erosion: A 2-Year Retrospective Study.

PURPOSE: The purpose of this study was to evaluate the incidence and epidemiology of recurrent corneal erosion within a clinical population using standard diagnostic techniques and a new technique called the corneal sweep test (CST). METHODS: A retrospective chart review was conducted on 58 eyes of 51 patients with the diagnosis of recurrent corneal erosion from July 2018 to June 2020. All underwent a thorough history and physical examination. The CST was performed as a confirmatory test and on any patient who lacked visible corneal pathology. RESULTS: The CST was necessary on 49 of the 58 eyes to help confirm the diagnosis of a corneal erosion. Among them, 34 had an occult corneal erosion, which is defined as having a normal-appearing cornea on slitlamp examination but found to have loose corneal epithelium with the CST. Clear corneal cataract surgery (28 eyes, 48.2%) was the most common presumed mechanism of injury, with 20 (71.4%) developing symptoms only after cataract surgery. All 20 eyes had an erosion located directly over a clear corneal cataract incision. CONCLUSIONS: The CST is a new and effective technique to help diagnose corneal erosions in the absence of visible corneal findings. Clear corneal cataract surgery is an under-recognized but important risk factor to consider because the incision can be the source for an erosion. Using the CST could lead to a paradigm shift in the way clinicians approach RCEs and patients with a persistent ocular pain syndrome.

Unnoticed metallic foreign body in the camerular angle inducing chronic uveitis / Corpo estranho metálico não notado em ângulo camerular induzindo uveíte crônica

ABSTRACT We report the case of an eight-year-old male patient with a four-month history of unilateral anterior chronic uveitis, associated with a pigmented lesion surrounded by fibrinoid material in the inferior camerular angle and with a fibrotic lesion in the extreme periphery of the inferior retina. The patient had no history of trauma or any other clinical symptoms. Although the patient was suspected of having toxocariasis, serological tests were negative. Partial symptomatic improvement was achieved using both orally and topically administered corticosteroids. In addition, a decrease in fibrinoid material around the pigmented camerular lesion revealed it to be regular and cylindric. Computed tomography of the orbits revealed a metallic foreign body in the topography of the inferior camerular angle. The patient underwent removal of the foreign body through a corneal incision and photocoagulation around the inferior retinal traction. Excellent visual and anatomical results were obtained.(AU)

RESUMO Os autores relatam o caso de paciente do sexo masculino, 8 anos de idade, com história de uveíte crônica anterior unilateral há quatro meses, associada a lesão pigmentada envolvida por material fibrinóide em ângulo camerular inferior e a lesão fibrótica em extrema periferia de retina inferior. Não havia histórico de trauma ou outros sintomas clínicos. A hipótese de toxocaríase foi afastada diante de testes sorológicos negativos. Melhoria sintomática parcial foi alcançada com administração de corticosteróide vias oral e tópica. Ademais, redução na quantidade de material fibrinóide ao redor da lesão camerular a revelou regular e cilíndrica. Foi realizada tomografia computadorizada de órbitas, permitindo a detecção de corpo estranho metálico na topografia de ângulo camerular inferior. O paciente foi submetido a remoção do corpo estranho através de incisão corneana e a fotocoagulação ao redor da tração retiniana inferior. Excelentes resultados visual e anatômico foram obtidos.(AU)

Treatment of cytomegalovirus anterior segment infection with intravitreal injection of ganciclovir in adjunction with or without oral valganciclovir: a long-term results.

We evaluated the therapeutic outcome of intravitreal injection (IVI) of ganciclovir with/without oral valganciclovir for cytomegalovirus (CMV) anterior segment infection. We enrolled 61 patients (61 eyes) with PCR-proven CMV anterior segment infection. IVI of ganciclovir (2 mg/0.05 mL) was given as a loading dose; subsequent use of oral valganciclovir (900 mg twice daily) was determined according to the severity of anterior chamber inflammation after injection. All eyes had IVI of ganciclovir, and 53 patients received oral valganciclovir as adjunctive therapy with a mean duration of 1.9 months to achieve disease remission. Repeated diagnostic aqueous taps were performed in 37 eyes with suspected recurrence, and CMV DNA was positive in 24 eyes. This therapeutic strategy afforded a median 50% recurrence-free survival time of 47.0 ± 8.12 months. The patients' mean best corrected visual acuity, intraocular pressure and corneal endothelial cell counts stabilized or improved. Corneal transplantation before CMV infection diagnosis was identified as an independent risk factor for recurrence (hazard ratio 6.81, 95% confidence interval 1.21-38.23, P = 0.029). In patients with CMV anterior segment infection, the relative short-term therapeutic strategy, IVI of ganciclovir in adjunction with/without oral valganciclovir, effectively achieved a median recurrence-free survival time of nearly 4 years.

Transient Reticular Cystic Corneal Epithelial Edema With Topical Netarsudil: A Case Series and Review.

PURPOSE: To describe cases in which netarsudil ophthalmic solution 0.02% precipitated reversible, reticular cystic epithelial edema. METHODS: A retrospective case review at the Brooklyn Veteran's Association Hospital of patients with corneal stromal edema that were treated with netarsudil and subsequently developed cystic epithelial edema. RESULTS: Four male patients with a mean age of 72 ± 8.0 years developed a reticular, honeycomb-like pattern of epithelial edema located in the interpalpebral and inferior cornea. In 3 of 4 patients, epithelial edema arose within 1 month compared with 2 months in 1 patient. New epithelial cysts did not correlate with worsening central corneal thickness and best spectacle-corrected visual acuity in every patient, which was likely due to the location of the cysts. Two of 4 patients developed increased central corneal thickness with worsening best spectacle-corrected visual acuity. In comparison, 1 patient had improvement in both parameters, whereas 1 patient had no significant change. In all cases, there was resolution of the epithelial cysts after discontinuation of netarsudil. CONCLUSIONS: Although rho-kinase inhibitors have been suggested to improve endothelial function, we have documented worsening epithelial cysts in a subset of patients with pre-existing corneal edema. These effects of netarsudil were transient and resolved after discontinuing treatment within 2 weeks in most patients. We hypothesize that the incidence of this adverse finding is more common than previously believed. Nevertheless, large-scale studies are needed to accurately report on the incidence and clinical significance of this novel finding.

Safety of intracameral moxifloxacin in the pediatric population: an equivalence study.

PURPOSE: To investigate whether the safety of intracameral moxifloxacin (IC-Mox) was equivalent to subconjunctival antibiotics (SC-Abs) in pediatric lens surgery. SETTING: The Hospital for Sick Children, Toronto, Canada. DESIGN: Retrospective consecutive cohort study. METHODS: This equivalence study compared 95% CI in the difference between the preoperative and postoperative safety variables of best corrected visual acuity (BCVA), intraocular pressure (IOP), central corneal thickness (CCT), endothelial cell density (ECD), corneal edema, and anterior chamber (AC) inflammation in IC-Mox with SC-Abs. The zone of clinical equivalence for BCVA was set at ±0.2 logarithm of the minimum angle of resolution, IOP at ±3 mm Hg, CCT at ±30 µm, and ECD at ±400 cells/mm. RESULTS: The charts of 358 patients undergoing lens-related surgeries were reviewed. Of 317 eyes (215 patients) included, 170 eyes received IC-Mox and 147 eyes had SC-Abs. The mean age was 4.9 and 5.1 years with a mean follow-up of 19 and 34.4 months (P < .001) in IC-Mox and SC-Ab groups, respectively. The 95% CIs for the change from preoperative to postoperative safety parameters between IC-Mox and SC-Abs were all in the zones of clinical equivalence (BCVA, P = 0.75; highest IOP in the first 6 weeks postoperatively, P = 0.27; IOP at the last visit, P = 0.74; CCT, P = 0.89; and ECD, P = 0.76). During the first 6 weeks postoperatively, there was no difference in corneal edema (P = .69) and AC flare (P = .4) between IC-Mox and SC-Ab groups, whereas AC cellular activity was significantly higher in the SC-Ab group (P = .028). CONCLUSIONS: IC-Mox prophylaxis in pediatric patients showed equivalent postoperative safety outcomes when compared with SC-Abs. The use of IC-Mox (250 µg) for endophthalmitis prophylaxis appears to be safe in the pediatric population.

Clinical, ultrasonographic, and histopathologic findings in seven horses with Descemet's membrane detachment: A case series.

OBJECTIVE: To describe ultrasonography as a diagnostic method of in vivo Descemet's membrane detachment (DMD) in horses. ANIMALS STUDIED: Seven horses (three Icelandic horses, two Dutch Warmblood horses, one Appaloosa, and one Welsh Pony), presenting with moderate-to-severe focal or diffuse corneal edema, in whom DMD was suspected on ultrasonographic examination and confirmed with histopathology, were studied. PROCEDURE: A retrospective analysis of case records of horses with suspected DMD was performed. RESULTS: Median age at presentation was 14 years (range 11-24). Clinical signs in eyes with DMD were unilateral in all horses and included blepharospasm and epiphora (6/7), buphthalmos (5/7), moderate-to-severe focal or diffuse corneal edema (7/7), corneal epithelial bullae (4/7), corneal neovascularization (4/7), Haab's striae (2/7), corneal endothelial precipitates (1/7), fibrin in the anterior chamber (1/7), focal cataract (2/7), and pigment deposits on the anterior lens capsule (1/7). During transpalpebral ultrasonography, a distinct linear echogenic structure was noted in the anterior chamber, initially diverging from, and later running parallel to, the posterior lining of the cornea in all eyes studied. In all cases, the cornea was severely thickened and echogenic, consistent with edema, and DMD was suspected. In all horses, the clinical signs progressed and the affected eye was eventually enucleated. Histopathology revealed DMD (7/7), spindle cell proliferation (4/7), Descemet's membrane reformation (3/7), and inflammation of the anterior uvea (5/7). Overall incidence was 1.04%. CONCLUSIONS: Ultrasonography is an adequate tool in diagnosing DMD in horses. Descemet's membrane detachment should be included in the differential diagnosis in horses with dense focal or diffuse corneal edema.

Decreased epithelial to corneal thickness ratio in healthy fellow eyes of patients with unilateral bullous keratopathy.

PURPOSE: To study the relationship between epithelial thickness (ET) and corneal thickness (CT) in healthy fellow eyes of patients with unilateral bullous keratopathy (BKP) and healthy subjects. METHODS: Seventeen BKP patients (nine males, eight females, 73.2±10.4 years) and 40 healthy individuals (20 males, 20 females, 69.5±9.8 years) were included. All participants received anterior segment optical coherence tomography and specular microscopy with calculation of endothelial cell density. ET, CT, stromal thickness and ET-to-CT ratio were defined automatically (within 2 mm central area). Central epithelial thickness (CET) and central corneal thickness (CCT) were measured manually at the corneal centre and stromal thickness and CET-to-CCT ratio were calculated. RESULTS: In healthy fellow eyes of BKP patients compared with eyes of healthy individuals ET was statistically significantly lower (p<0.001) while CT was statistically significantly higher (by 28.9 and 30.9 µm in 2 mm zone and corneal centre, respectively). Both 2 mm ET-to-CT ratio (0.091±0.01 and 0.10±0.004, respectively [p<0.001]) and CET-to-CCT ratio (0.083±0.006 and 0.97±0.005, respectively [p<0.0001]) were statistically significantly lower in healthy fellow eyes of BKP patients compared with eyes of healthy individuals. To identify healthy fellow eyes of BKP patients, area under curve for CET-to-CCT ratio and CET was 0.94 and 0.80, respectively (p=0.01), and for 2 mm ET-to-CT ratio and 2 mm ET was 0.91 and 0.80, respectively (p=0.03). CONCLUSION: Decreased СET-to-СCT ratio resulting from simultaneous epithelial thinning and stromal thickening without significant corneal thickening indicates subclinical dysfunction of corneal endothelium in healthy fellow eyes in unilateral BKP patients.

Corneal hydrops secondary to undiagnosed keratoconus.

A 21-year old female presented to the emergency department with an abnormal appearance of her left eye after trivial trauma the previous day. A protruding, opaque appearing area was noted on the left cornea. The patient underwent visual acuity testing, fluorescein staining with slit lamp examination revealing a conical corneal protrusion with corneal stromal edema suggestive of corneal hydrops. Corneal hydrops is a rare complication of keratoconus and various corneal ectasias where aqueous humor can leak into the corneal stroma causing edema and protruding pockets of fluid. Treatment is based on treating the underlying keratoconus or corneal ectasia in addition to cycloplegics, topical corticosteroids, topical antibiotics, and topical hypertonic saline.

Efficacy of Anterior Stromal Puncture Surgery with Corneal Bandage Lens for Bullous Keratopathy.

Objective: To investigate the safety and efficacy of the combination therapy of anterior stromal puncture (ASP) with bandage contact lens for bullous keratopathy (BK). Methods: Twelve cases (12 eyes) with vision acuity no better than light perception were treated with ASP surgery and bandage contact lens. 200 points punctures were made through the corneal epithelium and Bowman's layer vertically, using fine needles. A soft bandage contact lens was applied immediately and removed 2 weeks later. The severity of irrigating symptoms including pain, photophobia and tearing was graded and calculated before treatment and 1, 2, 4, 12 weeks after the surgery, slit-lamp microscope examination was used to quantify the time for corneal epithelial blisters disappearing, optical coherence tomography (OCT) was used to monitor the central corneal thickness. Results: No cornea infection was observed during the following up period. The average grade scores of the irrigating symptoms was 8.3 ± 2.1 before surgery, while it was reduced to 4.8 ±1.9 two weeks after the surgery (p=0.0003). Slit-lamp microscope examination showed that corneal edema relieved obviously after the operation, the average time for epithelial blisters disappearing was 15.6 ± 4.0 days. The average central corneal thickness of the eyes was 999.3 ±278.0 µm before the treatment, while it was 805.1 ± 145.0 µm four weeks after the treatment, with a statistically significant difference (p=0.043). Conclusions: ASP with bandage contact lens is an effective and safe treatment for patients with BK and low vision that not suitable for corneal transplantation.

Recalcitrant Paecilomyces keratitis.

A 54-year-old Caucasian woman presented with corneal ulcer of the right eye of 4 weeks duration after scratching her cornea while removing her contact lens and artificial eye lashes. Her visual acuity was 20/32 (left eye) and finger counting (right eye). She had a 3x3 mm epithelial defect with underlying corneal oedema and hypopyon. Right eye cultures grew Paecilomyces species. Topical and systemic antifungal agents were initiated. Due to the sight-threatening disease, the patient underwent surgical intervention with intrastromal injection of amphotericin B and a large conjunctival flap covering 75% of the right eye corneal ulcer. After 3 months of therapy, she had near-complete resolution of the corneal ulcer. Unfortunately, recurrence of the corneal ulcer occurred within 3 weeks of cessation of therapy, prompting reinitiation of ophthalmic and systemic antifungal agents. The patient was advised to continue therapy for 6 months with regular follow-up.

Functional Evaluation of Two Corneal Endothelial Cell-Based Therapies: Tissue-Engineered Construct and Cell Injection.

Restoration of vision due to corneal blindness from corneal endothelial dysfunction can be achieved via a corneal transplantation. However, global shortage of donor tissues has driven the development cell-based therapeutics. With the capacity to propagate regulatory compliant human corneal endothelial cells (CEnCs), this study evaluated the functionality of propagated CEnCs delivered via tissue-engineered endothelial keratoplasty (TE-EK) or corneal endothelial cell injection (CE-CI) within a rabbit model of bullous keratopathy. For animals with TE-EK grafts, central corneal thickness (CCT) increased to >1000 µm post-operatively. Gradual thinning with improvements in corneal clarity was observed from week 1. CCT at week 3 was 484.3 ± 73.7 µm. In rabbits with CE-CI, corneal clarity was maintained throughout, and CCT at week 3 was 582.5 ± 171.5 µm. Control corneas remained significantly edematous throughout the study period compared to their respective experimental groups (p < 0.05). Characterization of excised corneas showed a monolayer with heterogeneously shaped CEnCs in both TE-EK and CE-CI groups. Immunohistochemistry demonstrated reactivity to anti-human specific nuclei antibody attributing corneal recovery to the functional human CEnCs. This study showed that regulatory compliant cell-based therapy for corneal endothelial dysfunction can be delivered by both TE-EK and CE-CI, and holds great promise as an alternative to traditional corneal transplantation.

Optical Coherence Tomography Assessment of the Cornea During Corneal Swelling: Should the Term "Descemet Membrane Folds" Be Reconsidered?

PURPOSE: Previous work has suggested that Descemet membrane (DM) folds arise in response to corneal swelling. However, their origin has not been closely explored. In this study, we used optical coherence tomography to evaluate whether DM folds arise secondary to folds in the middle stroma. METHODS: Serial optical coherence tomography images of donor cornea pairs in deionized water were taken for each of the following corneal manipulations: 1) untreated, 2) DM and the endothelium removed, 3) excised in the region of the deep middle/posterior stroma, and 4) excised in the middle stroma. RESULTS: For intact corneas, increasing duration in deionized water was marked by a progressive increase in corneal thickness and number of folds along the posterior surface. With DM and the endothelium removed, a similar phenomenon was observed. In the third set of corneas, the plane of resection created a structural separation in the region of the deep middle/posterior stroma. Folds were seen originating anterior to the resection plane. For corneas with the posterior and part of the middle stroma removed, the typical folds on the posterior surface as seen in the previous conditions were not observed. Instead, less numerous and smaller irregularities of the posterior surface of the resection plane were present. CONCLUSIONS: Folds in DM associated with corneal edema originate in the middle and posterior stroma and are secondarily transmitted into DM. On the basis of the stromal origin of these anatomic changes, "stromal folds" should be considered a more accurate term to replace "Descemet membrane folds."

Keratometric, Pachymetric, and Surface Elevation Characterization of Corneas With Fuchs Endothelial Corneal Dystrophy Treated With DMEK.

PURPOSE: To characterize pachymetric, keratometric, and surface elevation parameters in pseudophakic eyes with Fuchs dystrophy that underwent Descemet membrane endothelial keratoplasty (DMEK) and to compare these characteristics with those in normal pseudophakic eyes. METHODS: Postoperative corneal tomography with a median follow-up of 20 months was evaluated using the Pentacam tomographer on 46 DMEK eyes. Results were compared with data from an age-matched cohort of 46 normal eyes. Parameters included curvature analysis, keratometry values, corneal thickness (CT), pachymetric progression index, Ambrósio relational thickness, posterior elevation, and D-index values. Bonferroni correction was used for multiple comparisons. RESULTS: CT at the apex (mean difference 41 µm; 95% confidence interval 28-54) and CT at the thinnest point (46 µm; 33-60) were statistically significantly lower in the DMEK group (P < 0.001), whereas pachymetric progression index average (0.47; 0.32-0.62), Ambrósio relational thickness maximum (172; 126-228), IHD (0.096; 0.005-0.014), and the global D-index (1.03; 0.51-1.56) were significantly higher in eyes with DMEK (P < 0.001). The mean CT along the vertical and horizontal meridians was significantly lower in the DMEK group within the central 5 mm. A quarter and one half of the DMEK eyes had a CT of less than 500 µm at the apex or at the thinnest point, respectively. CONCLUSIONS: Resolution of corneal edema after DMEK was associated with a thinner-than-normal central cornea, steeper pachymetric progression from the thinnest point to the periphery, and some high-end outliers for posterior elevation values. Caution should be exerted in planning corneal refractive surgery for residual refractive errors.

Accuracy of Tonopen Versus iCare in Human Cadaveric Eyes With Edematous Corneas Over a Wide Range of Intraocular Pressures.

PURPOSE: The purpose of this study was to compare the accuracy of 2 portable tonometers, Tonopen and iCare, in extreme corneal edema, while also accounting for the location of pressure measurement over a wide range of intraocular pressure (IOP). METHODS: Utilizing an experimental laboratory investigation, IOP measurements were obtained with iCare and Tonopen against an internal digital manometer in 2 enucleated human cadaveric eyes with edematous corneas. Pachymetry was used to measure central corneal thickness in each eye. Each eye was then mounted on an upright-positioned mannequin, and a 30-G needle connected to a digital manometer was introduced into the anterior chamber at the limbus. Pressures were maintained at 0, 10, 20, 30, 40, and 50 mmHg using the digital manometer. Three measurements were taken with the tonometers at the central cornea, limbal cornea, and sclera, for a total of 9 measurements per device per eye at each manometric pressure reading. RESULTS: Comparing the mean absolute error of Tonopen versus iCare measurements at the central cornea for each manometric pressure reading, both devices underestimated the control at pressures >10 mmHg, with mean error increasing as IOP increased [mean absolute error (MAE) ranged from 1.67 to 13.33 with Tonopen and 3.67 to 21.00 with iCare]. Tonopen more accurately estimated pressure with an average MAE of 5.72 at the central cornea, compared with MAE of 10.83 at the central cornea for iCare (P<0.03). Comparing MAE between the devices at the limbus, there was no significant difference between the 2 (P=0.91), with average MAE for the Tonopen 5.47 and average MAE for the iCare 5.22. There was no significant difference between average MAE for Tonopen measurements at the central cornea versus the limbus (P=0.89), while the iCare was more accurate at the limbus with average MAE of 5.22 than the central cornea with average MAE of 10.83 (P<0.03). When measuring at the sclera, there was no statistically significant difference between average MAE for Tonopen (18.03) versus iCare (10.39) (P=0.24). DISCUSSION: Tonopen was more accurate than iCare when measuring at the central cornea, but consistently underestimated the control. MAE for both devices increased linearly with increasing true IOP. With limbus measurements in an edematous cornea, Tonopen and iCare performed similarly. The iCare performed better at the limbus than at the central cornea. Scleral measurements for both Tonopen and iCare were poor. In this experimental model, Tonopen performed superiorly to iCare with central cornea measurements in a grossly edematous cornea. Both devices underestimated true IOP.