Contact Lenses in the Management of Corneal Dystrophies.

Among the group of diseases comprising corneal dystrophies, there are a number for which contact lenses may be considered. For example, soft contact lenses may be beneficial in the management of recurrent corneal erosions and advanced bullous keratopathy and may lead to disease attenuation in some conditions. They also may be used in conjunction with surgical procedures to promote tissue healing and patient comfort in the postoperative period. Rigid contact lenses may be beneficial in the setting of irregular astigmatism. The present review of the literature will discuss the use of contact lenses in the management of corneal dystrophies.

Fuchs Endothelial Corneal Dystrophy: Update on Pathogenesis and Future Directions.

Fuchs endothelial corneal dystrophy (FECD) is the most common indication for corneal transplantation in the United States, accounting 36% of the almost 47,000 transplants performed in 2016. Although the surgical management of FECD has undergone a revolution over the past 20 years, its pathogenesis remains elusive, with multiple putative disease pathways and an ever increasing number of candidate genes thought to play a role. This review will summarize the recent advancements in our understanding of the biology of FECD, including potential parallels with neurodegenerative disease like amyotrophic lateral sclerosis and will highlight prospects for future treatment advances.

Clinical Outcomes Using Oversized Back Plates in Type I Boston Keratoprosthesis.

OBJECTIVES: To examine clinical outcomes of oversized titanium back plates in type I Boston keratoprosthesis (KPro) implantation. METHODS: Retrospective study of 22 sequential eyes (20 patients) undergoing type I KPro implantation with an oversized titanium back plate (larger than trephined wound diameter by 1.0 mm or more), performed by a single surgeon (K.A.C.) from June 2010 to November 2014. Data were collected regarding preoperative eye characteristics, surgical details, and postoperative clinical outcomes. RESULTS: Mean follow-up time per eye was 24.1±14.9 months. All eyes had improved vision after surgery; 13 eyes (59.1%) maintained visual acuity improvement at last follow-up. Initial KPro's were retained in 19 eyes (86.4%); one eye required KPro replacement. Primary retroprosthetic membrane (RPM) developed in three eyes (13.6%), with similar occurrence in aniridic (14.3%) and nonaniridic eyes (13.3%). Secondary RPM's developed in two eyes (9.1%) after vitritis (one eye) and retinal and choroidal detachment (one eye). Glaucoma was a common comorbidity: 2 of 14 eyes (14.3%) with preoperative glaucoma had glaucoma progression, and 4 of 8 eyes (50.0%) without preoperative glaucoma developed glaucoma postoperatively. Other postoperative complications included retinal detachment (5 eyes, 22.7%) and idiopathic vitritis (3 eyes, 13.6%). CONCLUSIONS: Oversized titanium KPro back plates are associated with a low rate of primary RPM formation and may have particular utility in reducing primary RPM formation in aniridic eyes. Glaucoma remains a challenge in postoperative KPro management. Complex eyes, at increased risk of postoperative complications, require careful management.

Histopathology of Failed Descemet Membrane Endothelial Transfer.

OBJECTIVES: To describe the postmortem histologic features after an unsuccessful Descemet membrane endothelial transfer (DMET) and assess any potential clinical implications. METHODS: Postmortem, an eye from a patient who previously underwent unsuccessful DMET for pseudophakic bullous keratopathy (PPBK) was harvested and processed for morphologic evaluation. RESULTS: Clinically and histologically, the host cornea showed evidence of diffuse stromal edema. Although the edges of the surgical descemetorhexis were well visualized, there was no evidence of endothelial migration or repopulation of the posterior stroma from any direction. A multilayered, retrocorneal membrane was present that appeared to originate from the trabecular meshwork. CONCLUSIONS: Descemet membrane endothelial transfer and "descemetorhexis alone" may be insufficient treatment for eyes operated on for PPBK, that is, eyes with a significantly depleted or dysfunctional endothelium.

Pigmented Caruncular Apocrine Hidrocystoma With Oncocytic Features.

An unprecedented pigmented caruncular apocrine hidrocystoma with the additional feature of an oncocytic transformation of the cyst's lining cells is reported. Over a year, a 79-year-old woman developed a centrally pigmented lesion of her right caruncle with translucent borders. Because of concern about a melanoma, a carunculectomy with adjunctive cryotherapy and placement of an amniotic membrane graft were performed, and the excised specimen was evaluated microscopically. A large cyst dominated the caruncle and was lined by an inner layer of columnar eosinophilic and granular cells with an outer, interrupted layer of flattened myoepithelial cells. Phosphotungstic acid hematoxylin staining disclosed myriad cytoplasmic, dot-like mitochondria signifying an oncocytic change. Immunohistochemistry revealed gross cystic fluid disease protein-15 and cytokeratin 7-positivity indicative of apocrine differentiation. Oncocytic change is characteristically encountered in lacrimal ductal cysts and tumors.

Design and Biocompatibility of a Novel, Flexible Artificial Cornea.

Purpose: We sought to introduce the materials, design, and biocompatibility of a flexible and suturable artificial corneal device. Methods: Single-piece, fully synthetic, optic-skirt design devices were made from compact perfluoroalkoxy alkane. The skirt and the optic wall surfaces were lined with a porous tissue ingrowth material using expanded polytetrafluoroethylene. Full-thickness macroapertures around the skirt perimeter were placed to facilitate nutrition of the recipient cornea. Material properties including the skirt's modulus of elasticity and bending stiffness, optic light transmission, wetting behavior, topical drug penetrance, and degradation profile were evaluated. Results: The final prototype suitable for human use has a transparent optic with a diameter of 4.60 mm anteriorly, 4.28 mm posteriorly, and a skirt outer diameter of 6.8 mm. The biomechanical and optical properties of the device closely align with the native human cornea with an average normalized device skirt-bending stiffness of 4.7 kPa·mm4 and light transmission in the visible spectrum ranging between 92% and 96%. No optical damage was seen in the 36 devices tested in fouling experiments. No significant difference was observed in topical drug penetrance into the anterior chamber of the device implanted eye compared with the naïve rabbit eye. Conclusions: The flexibility and biocompatibility of our artificial cornea device may offer enhanced tissue integration and decreased inflammation, leading to improved retention compared with rigid keratoprosthesis designs. Translational Relevance: We have developed a fully synthetic, flexible, suturable, optic-skirt design prototype artificial cornea that is ready to be tested in early human feasibility studies.

Variations in Management of Zone 1 Open Globe Injuries Across Corneal Specialists.

PURPOSE: The aim of this study was to describe variations in practice patterns for the management of zone 1 open globe injuries among corneal specialists worldwide. METHODS: This cross-sectional study was performed using an online survey distributed to members of The Cornea Society. Responses were collected between September 9, 2021, and September 30, 2021. RESULTS: Of 94 responses included in analysis, respondents averaged 18.2 ± 14.5 years of postfellowship experience. Among respondents, 53 (56.4%) were affiliated with an academic institution and 41 (43.6%) with private practice. Ophthalmologists practicing in the United States were significantly more likely to use an eye shield preoperatively (98.5% vs. 85.7%, P = 0.03) and less likely to perform primary lensectomy in cases of lens involvement (40.9% vs. 75.0%, P = 0.002) compared with those practicing outside the United States. Ophthalmologists in practice fewer than 10 years were more likely to administer preoperative systemic antibiotics (91.4% vs. 66.1%, P = 0.006) and tetanus prophylaxis (88.6% vs. 67.8%, P = 0.03), and to obtain preoperative computed tomography scans (85.7% vs. 54.2%, P = 0.002) compared with more senior physicians. Ophthalmologists at academic institutions were more likely to perform preoperative B-scan (30.2% vs. 9.8%, P = 0.02), use general anesthesia (90.6% vs. 70.7%, P = 0.03), and admit for postoperative antibiotics (28.3% vs. 9.8%, P = 0.04), and were less likely to perform surgery overnight (45.3% vs. 70.7%, P = 0.02) compared with private practice physicians. CONCLUSIONS: There is significant variation in the practice patterns for the management of zone 1 open globe injuries among corneal specialists, which presents an opportunity to investigate whether certain treatment options lead to better outcomes in these injuries.

Twelve-Month Clinical and Histopathological Performance of a Novel Synthetic Cornea Device in Rabbit Model.

Purpose: To report the biological stability and postoperative outcomes of a second-generation, single-piece, flexible synthetic cornea in a rabbit model. Methods: Device materials and design were amended to enhance biointegration. Optic skirt design devices were made from compact perfluoroalkoxy alkane with porous expanded polytetrafluoroethylene ingrowth surface overlying the skirt and optic wall. Sixteen devices were implanted into intrastromal pocket in rabbit eyes. Rabbits were randomly assigned to 6- and 12-month follow-up cohorts (n = 8 in each) postoperatively. Monthly examinations and optical coherence tomography assessed cornea-device integration, iridocorneal angle, optic nerve, and retina. Results: There were no intraoperative complications. All devices were in situ at exit, with clear optics. No retroprosthetic membrane, glaucoma, cataract formation, or retinal detachment was observed. Two rabbits in the 6-month group had mild, focal anterior lamella thinning without retraction adjacent to the optic near tight sutures. Three postoperative complications occurred in the 12-month group. One rabbit diagnosed with endophthalmitis was euthanized on day 228. Mild sterile focal retraction of anterior lamella occurred in two rabbits, which were terminated on days 225 and 315. Light microscopic examination of enucleated globes demonstrated fibroplasia with new collagen deposition into the porous scaffold without significant inflammation, encapsulation, or granuloma formation. Conclusions: Clinical evaluations, imaging, and histopathological findings indicate favorable outcomes of this synthetic corneal device in a rabbit model. Early feasibility studies in humans are being planned. Translational Relevance: Favorable 12-month results of the device in rabbits demonstrate vision-restoring potential in corneally blind individuals at high risk of failure with donor keratoplasty.

Follow-up Rates After Teleretinal Screening for Diabetic Retinopathy: Assessing Patient Barriers to Care.

Purpose: To study patient follow-up after they engage in a teleretinal screening program and to understand potential barriers to care. Methods: This was a retrospective analysis and a prospective study of telephone-based patient interviews of outpatients screened for diabetic retinopathy (DR) through a teleretinal referral system. Results: Of 2761 patients screened through a teleretinal referral program, 123 (4.5%) had moderate nonproliferative DR (NPDR), 83 (3.0%) had severe NPDR, and 31 (1.1%) had proliferative DR. Of the 114 patients with severe NPDR or worse, 67 (58.8%) saw an ophthalmologist within 3 months of referral. Eighty percent of interviewed patients reported they were not aware of the need for follow-up eye appointments. Conclusions: Of patients with severe retinopathy or worse, 58.8% presented for in-person evaluation and treatment within 3 months of screening. Although this result was negatively affected by factors related to the COVID-19 pandemic, key elements of patient education and improved referral strategies to facilitate in-person treatment are essential to improving follow-up after patients engage in telescreening.

Pediatric herpes simplex of the anterior segment: characteristics, treatment, and outcomes.

PURPOSE: To describe the clinical characteristics, treatment, and outcomes of herpes simplex virus (HSV) infections of the cornea and adnexae to raise awareness and to improve management of this important eye disease in children. DESIGN: Retrospective case series. PARTICIPANTS: Fifty-three patients (57 eyes) 16 years of age or younger with HSV keratitis (HSK), HSV blepharoconjunctivitis (HBC), or both in an academic cornea practice. METHODS: The following data were collected: age at disease onset, putative trigger factors, coexisting systemic diseases, duration of symptoms and diagnoses given before presentation, visual acuity, slit-lamp examination findings, corneal sensation, dose and duration of medications used, drug side effects, and disease recurrence. MAIN OUTCOME MEASURES: Presence of residual corneal scarring, visual acuity at the last visit, changes in corneal sensation, recurrence rate, and manifestations of HSK were assessed in patients receiving long-term prophylactic systemic acyclovir. RESULTS: The median age at onset was 5 years. Mean follow-up was 3.6 years. Eighteen eyes had HBC only; 4 patients in this group had bilateral disease. Of 39 eyes with keratitis, 74% had stromal disease. Thirty percent of HSK cases were misdiagnosed before presentation. Seventy-nine percent of patients with keratitis had corneal scarring and 26% had vision of 20/40 or worse at the last visit. Eighty percent of patients had recurrent disease. Six of 16 patients (37%) receiving long-term oral acyclovir had recurrent HSV, at least one case of which followed a growth spurt that caused the baseline dosage of acyclovir to become subtherapeutic. CONCLUSIONS: In a large series, pediatric HSK had a high rate of misdiagnosis, stromal involvement, recurrence, and vision loss. Oral acyclovir is effective, but the dosage must be adjusted as the child grows.

Descemet Stripping Only for Fuchs Endothelial Corneal Dystrophy: Will It Become the Gold Standard?

ABSTRACT: Descemet stripping only (DSO) has become a viable treatment option for certain cases of Fuchs Endothelial Corneal Dystrophy (FECD). This article describes the history of the development of DSO, its current status, and what successful DSO tells us about the pathophysiology of FECD. Remaining questions and future directions are also highlighted.

MALT Lymphoma Presenting with Peripheral Ulcerative Keratitis.

Objective: To report a case of ocular mucosa-associated lymphoid tissue (MALT) lymphoma presenting with peripheral ulcerative keratitis. Methods: A 58-year-old man with a history of vitreous syneresis in both eyes and glaucoma presented with an abnormal, painful sensation of the left eye and mild hyperemia. Physical examination revealed peripheral ulcerative keratitis superiorly and a salmon-colored lesion in the superior conjunctiva. Results: The differential diagnosis of superior corneal thinning includes collagen vascular disease, Terrien's marginal degeneration, infectious keratitis, and other forms of peripheral keratitis. Our patient was diagnosed with conjunctival MALT lymphoma by surgical excision of the mass, and the peripheral ulcerative keratitis may be related to this diagnosis. Conclusion: Although rare, this case demonstrates a peripheral keratitis possibly related to the underlying disease of MALT lymphoma. The patient is being treated with local radiation treatment.

Zoster Eye Disease Study: Rationale and Design.

PURPOSE: The purpose of this study was to describe the rationale and design of the Zoster Eye Disease Study (ZEDS). METHODS: ZEDS is a National Eye Institute-supported randomized clinical trial designed to determine whether 1 year of suppressive valacyclovir in patients with herpes zoster ophthalmicus (HZO) reduces complications because there is currently no high-quality evidence to support its use. Eligible patients are 18 years and older, immunocompetent, have a history of a typical rash at disease onset, and have had a record of active epithelial or stromal keratitis or iritis within 1 year before enrollment. Exclusion criteria include estimated glomerular filtration rate less than 45 or pregnancy. The primary endpoint is the time to first occurrence of new or worsening dendriform epithelial keratitis, stromal keratitis without or with ulceration, endothelial keratitis, or iritis due to HZO during 12 months of study treatment requiring prespecified treatment changes. The study has 80% power to detect a 30% difference between treatment groups, with a 30% rate of endpoints by 1 year assumed among controls. Secondary and exploratory questions include whether there is a persistent treatment benefit during the 6 months after treatment, whether development of postherpetic neuralgia varies by treatment group, and whether vaccinations against herpes zoster affect study outcomes and coronavirus disease 19 status. RESULTS: Over approximately 4 years, over 400 study participants have been enrolled. CONCLUSIONS: ZEDS aims to provide scientific evidence on whether suppressive valacyclovir treatment improves outcomes in HZO and should become the standard of care.

Clinical and microbiological characteristics of fungal keratitis in the United States, 2001-2007: a multicenter study.

OBJECTIVE: To study the epidemiology, clinical observations, and microbiologic characteristics of fungal keratitis at tertiary eye care centers in the United States. DESIGN: Retrospective multicenter case series. PARTICIPANTS: Fungal keratitis cases presenting to participating tertiary eye care centers. METHODS: Charts were reviewed for all fungal keratitis cases confirmed by culture, histology, or confocal microscopy between January 1, 2001, and December 31, 2007, at 11 tertiary clinical sites in the United States. MAIN OUTCOME MEASURES: Frequency of potential predisposing factors and associations between these factors and fungal species. RESULTS: A total of 733 cases of fungal keratitis were identified. Most cases were confirmed by culture from corneal scraping (n = 693) or biopsies (n = 19); 16 cases were diagnosed by microscopic examination of corneal scraping alone; and 5 cases were diagnosed by confocal microscopy alone. Some 268 of 733 cases (37%) were associated with refractive contact lens wear, 180 of 733 cases (25%) were associated with ocular trauma, and 209 of 733 cases (29%) were associated with ocular surface disease. No predisposing factor was identified in 76 cases (10%). Filamentous fungi were identified in 141 of 180 ocular trauma cases (78%) and in 231 of 268 refractive contact lens-associated cases (86%). Yeast was the causative organism in 111 of 209 cases (53%) associated with ocular surface disease. Yeast accounted for few cases of fungal keratitis associated with refractive contact-lens wear (20 cases), therapeutic contact-lens wear (11 cases), or ocular trauma (21 cases). Surgical intervention was undertaken in 26% of cases and was most frequently performed for fungal keratitis associated with ocular surface disease (44%). Surgical intervention was more likely in cases associated with filamentous fungi (P = 0.03). Among contact lens wearers, delay in diagnosis of 2 or more weeks increased the likelihood of surgery (age-adjusted odds ratio = 2.2; 95% confidence interval, 1.2-4.2). CONCLUSIONS: Trauma, contact lens wear, and ocular surface disease predispose patients to developing fungal keratitis. Filamentous fungi are most frequently the causative organism for fungal keratitis associated with trauma or contact lens wear, whereas yeast is most frequently the causative organism in patients with ocular surface disease. Delay in diagnosis increases the likelihood of surgical intervention for contact lens-associated fungal keratitis.

Expanding indications for the Boston keratoprosthesis.

PURPOSE OF REVIEW: To review emerging indications for the Boston keratoprosthesis (KPro) and to discuss current research underway to improve clinical outcomes. RECENT FINDINGS: In addition to multiple failed corneal grafts, other ocular conditions for which the Boston KPro has been used include herpetic keratitis, aniridia, autoimmune ocular disorders, and pediatric corneal opacities. In the recent years, the KPro has been implanted for various other conditions and has also been explored as a cost-effective treatment for severe corneal diseases internationally. Cicatricial and inflammatory ocular conditions remain the most difficult cases for KPro use but studies investigating various immunomodulators and biologic materials for improved retention are ongoing. Postoperative management of glaucoma is critical for preserving the visual gains achieved with the Boston KPro. Current studies are evaluating novel devices for intraocular pressure measurement. SUMMARY: Accrued experience with the Boston KPro has demonstrated its versatility but also the difficulties that remain in postoperative management. With many studies underway to improve cost-effectiveness, intra-operative and postoperative management, keratoprostheses will be made increasingly available to those countries most in need.

Electronic energy migration in solid versus liquid host matrices for concentrated perylenediimide dye solutions.

In this paper, we continue our evaluation of Forster-type theories of exciton diffusion in disordered environments. The perylenediimide dye Lumogen Red is used as a donor molecule in two different liquids, CHCl(3) and dimethylformamide, and the energy transfer to the acceptor molecule Rhodamine 700 is measured using time-resolved fluorescence decays. The exciton motion is measured over Lumogen Red concentrations ranging from 1 × 10(-4) to 5 × 10(-2) M, and the results are compared to previous results for exciton diffusion in a solid polymer. Depending on the theoretical approach used to analyze the data, we find that the energy migration in the liquids is a factor of 2-3 faster than in the solid polymer, even after taking molecular translation into account. Measurements for a Lumogen Red concentration of 10 mM in the different host environments yield diffusion constants ranging from 2.2 to 3.1 nm(2)/ns in the liquids, as compared to 1.1-1.2 nm(2)/ns in solid poly(methyl methacrylate) (PMMA). The results in the liquids are in good agreement with theoretical predictions and numerical simulations of previous workers, while the results in solid PMMA are 2-3 times slower. This discrepancy is discussed in the context of the rapid energetic averaging present in the liquid environments but absent in the solid matrix, where unfavorable configurations and low energy trapping sites are frozen in by the static disorder.