Peripheral ulcerative keratitis: A review of aetiology and management

Background: Peripheral ulcerative keratitis (PUK) is a severe inflammatory disease of the peripheral cornea that can be caused by local factors or systemic inflammatory disease.Aim: The purpose of this review is to give an overview of the pathophysiology, aetiology, clinical features, diagnosis, and management of PUK.Method: A PubMed search was conducted using the keywords, ‘peripheral ulcerative keratitis’ and ‘Mooren’s ulcer’.Results: The peripheral cornea has unique characteristics the predispose to the development of PUK. These include fine capillary arcades that allow for deposition of immune complexes and subsequent activation of an inflammatory cascade with corneal melt. Several conditions have been implicated in the aetiology of PUK. The most commonly cited causes are rheumatoid arthritis (RA), granulomatosis with polyangiitis (GPA) and various dermatoses. In patients with RA, PUK usually presents in established disease, whereas in GPA, PUK may be the presenting feature in up to 60% of cases. In RA it heralds the onset of a systemic vasculitis with significant associated morbidity and mortality. The management of PUK follows an individualised stepwise approach. All patients require supportive measures to encourage healing and halt the process of keratolysis. Systemic autoimmune conditions need a systemic corticosteroid as a fast-acting agent to halt the inflammatory process while cytotoxic therapy maintains long term disease control. Failure to achieve disease control with CTT, necessitates the use of a biologic agent.Conclusion: Peripheral ulcerative keratitis is a severe inflammatory disease of the peripheral cornea that needs a thorough diagnostic workup and stepwise management approach.

A Clinical Case of Fitting Scleral Lens for Correction of Pellucid Marginal Degeneration

Background. Pellucid Marginal Degeneration (PMD) is a rare bilateral degenerative corneal disease. It causes corneal ectasia with bilateral, clear, inferior (typically 4 o’clock to 8 o’clock), peripheral corneal thinning. It usually affects about 80% of corneal stroma, which leads to the corneal ectasia above the thinning area as well as provokes the irregular astigmatism and visual impairment that are difficult to correct. Purpose. To study the possibilities of correction and social rehabilitation in a patient with PMD wearing scleral lenses. Materials and methods. The study included a patient with PMD, signs of corneal dysfunction and narrow-angle subcompensated glaucoma in the right eye, and PMD of the cornea resulted in a corneal leukoma – terminal glaucoma in the left eye. In addition to standard ophthalmic methods, we performed corneal topography and optical coherence tomography (OCT). For intraocular pressure measurement, ICARE IOP tonometer was used in several areas of the intact peripheral cornea. Results. Prior to lens fitting, UCVA in the right eye amounted to 0.06. Scleral lens helped achieve a high visual acuity of 0.9–1.0. The lens was well-tolerated by the patient. Conclusion. Scleral lenses may be a good choice for patients with irregular cornea caused by corneal dystrophy. Not only they are easy to use and have a good visual effect, but they also help patients with social rehabilitation.

The Senescence Difference Between the Central and Peripheral Cornea Induced by Sutures

Introduction: Cell senescence plays a regulatory role in tissue fibrosis, and corneal scarring is usually more severe in the central cornea based on clinical observation. We attempted to explore the senescence difference between the central and peripheral cornea in an in vivo mouse model of suture-induced senescence and an in vitro model of senescence with hydrogen peroxide (H2O2)-induced rabbit corneal fibroblasts. Methods: Male Balb/c mice (6-8 weeks) received sutures in the central, superior, inferior, nasal, and temporal cornea, and the sutures were removed on day 14. Corneal neovascularization (CNV) was observed under a slit lamp microscope with a digital camera. Fibroblasts isolated from central and peripheral rabbit corneas were induced with H2O2 to establish an in vitro model of senescence. The senescence was evaluated with SA-β-gal staining and gene expression analysis of p21, p27, and p53. Results: Senescent cells accumulated in the corneal stroma from day 3 to day 14 after the operation and peaked on day 14, later than CNV. More senescent keratocytes were observed in the peripheral cornea in the mouse model. The peripheral corneal fibroblasts were more likely to become senescent related to H2O2 in vitro. The PCR results revealed that the senescence-related genes, p21, p27, and p53, were all highly expressed in the peripheral corneal fibroblasts. Conclusions: As senescent fibroblasts can limit tissue fibrosis, the senescence difference between the central and peripheral cornea may contribute to the difference in scarring.

Case Report of Brown McLean Syndrome

Purpose: To report two rare cases of Brown McLean syndrome after cataract surgery in a patient with aphakia.Case summary: (Case 1) A 54-year-old woman with Marfan’s syndrome who had aphakia and peripheral corneal edema after left eye cataract surgery 4 years ago. The patient had an elevated lesion in the peripheral cornea without involving the central cornea, and had symptoms of pain, irritation and tearing. Specular microscopy showed normal endothelial cell density and morphology in the edematous cornea. The peripheral corneal edema improved after use of antibiotics, autoserum eyedrops and 5% NaCl eyedrops. (Case 2) A 61-year-old woman with aphakia in her left eye after bilateral cataract surgery 11 years ago, underwent surgery for a macular hole in both eyes. The patient developed peripheral corneal erosions and edema in the left eye 2 months after the surgery. Specular microscopy showed normal endothelial cell density and morphology. The peripheral corneal edema was static over the years while using 5% NaCl eyedrops and artificial tears, and did not progress to involve the central cornea.Conclusions: Brown McLean syndrome is a rare disease but the possibility should be considered if a patient with aphakia after cataract surgery has peripheral corneal edema for several years.

Corneal Densitometry in Bilateral Keratoconus Patients with Unilateral Corneal Vogt's Striae: A Contralateral Eye Study

BackgroundWe aimed to investigate corneal densitometry and correlations with corneal morphological parameters in bilateral keratoconus (KCN) patients with unilateral Vogt's striae.MethodsOne hundred and-twelve patients (224 eyes) with bilateral KCN and unilateral Vogt's striae were enrolled in this cross-sectional contralateral eye study. Corneal densitometry and morphological parameters were measured using Pentacam HR.ResultsOur study revealed that corneal densitometry values of the anterior 0–2 mm and 2–6 mm, intermediate 0–2 mm and 2–6 mm, posterior 2–6 mm, and total cornea 2–6 mm in eyes with Vogt’s striae were significantly higher than those in eyes without Vogt's striae (P < 0.05). The corneal densitometry values of the anterior 6–10 mm, posterior 0–2 mm, and total cornea 6–10 mm were significantly lower in eyes with Vogt's striae (P < 0.05). The corneal densitometry values in the anterior 0–2 mm and total cornea 2–6 mm were positively correlated with K1, K2, Km, Kmax, ACE, and PCE (P < 0.05) and negatively correlated with CCT and TCT in eyes with Vogt's striae (P < 0.05). K2, Km, and Kmax were significantly correlated with densitometry values of the anterior 0–2 mm and the intermediate 0–2 mm in eyes without Vogt’s striae (P < 0.05). Corneal densitometry values of the anterior and intermediate layers in the central cornea were higher in KCN eyes with Vogt's striae than in eyes without Vogt's striae, and the densitometry values of the anterior corneal stroma in the central region of the cornea were higher than those of the peripheral cornea in KCN eyes with and without Vogt's striae.ConclusionsIn conclusion, these results indicate that Vogt's striae mainly occur on the anterior and intermediate layers during the progression of KCN.

Effect of spherical rigid gas permeable lens on correction of corneal astigmatism

Background: Objectives were to study an effect of spherical RGP (rigid gas permeable) contact lens in correcting high corneal astigmatism more than 3 diopter.Methods: Total 48 eyes with corneal astigmatism greater than 3.00 diopter were included in study. At the first visit, routine preliminary examination, parameter assessment and subjective refraction has been carried out followed by patient counselling for RGP lens wear. Based on the corneal parameters considering keratometry as well as corneal topography, RGP lens trial was done. Post adaptation period, lens fitting analysis was done by understanding Fluorescein pattern with slit lamp and over refraction was done. Final lens has been ordered on this basis with understanding of tear lens formed, lens performance on cornea and edge width minimal of 0.80 mm to 1.00 mm. Patients were assessed at an interval of every two months from a date of lens dispensing.Results: The spherical RGP lens did correct the corneal astigmatism of more than 3D by formation of tear lens between cornea and lens. Vision improved by 2 to 3 lines compared to the spectacle correction without compromising corneal integrity at the central or peripheral cornea. Keratoconic eye showed significant vision improvement without the use of toric lens.Conclusions: Astigmatic eyes showed significant improvement in acuity with spherical RGP lens without compromising corneal integrity.

Effect of herpes simplex keratitis scar location on bilateral corneal nerve alterations: an in vivo confocal microscopy study

AimsTo evaluate the impact of herpes simplex virus (HSV)-induced scar location on bilateral corneal nerve alterations using laser in vivo confocal microscopy (IVCM).MethodsCentral and peripheral corneal subbasal nerve density (CSND) were assessed bilaterally in 39 patients with unilateral HSV-induced corneal scars (21 central scars (CS), 18 peripheral scars (PS)) using IVCM. Results were compared between patients and 24 age-matched controls. CSND was correlated to corneal sensation for all locations.ResultsOverall patients revealed significant decrease of CSND in the central and peripheral cornea (9.13±0.98 and 6.26±0.53 mm/mm2, p<0.001), compared with controls (22.60±0.77 and 9.88±0.49 mm/mm2). CS group showed a decrease in central (8.09±1.30 mm/mm2) and total peripheral nerves (5.15±0.62 mm/mm2) of the affected eyes, whereas PS group demonstrated a decrease in central (10.34±1.48 mm/mm2) and localised peripheral nerves only in the scar area (4.22±0.77 mm/mm2) (all p<0.001). In contralateral eyes, CSND decreased in the central cornea of the CS group (16.88±1.27, p=0.004), and in the peripheral area, mirroring the scar area in the affected eyes of the PS group (7.20±0.87, p=0.032). Corneal sensation significantly decreased in the whole cornea of the affected, but not in contralateral eyes (p<0.001). A positive correlation between CSND and corneal sensation was found in all locations (p<0.001).ConclusionsPatients with HSV scar demonstrate bilateral CSND decrease as shown by IVCM. CSND and corneal sensation decrease in both central and peripheral cornea in affected eyes, although only in the scar area in PS group. Interestingly, diminishment of CSND was found locally in the contralateral eyes, corresponding and mirroring the scar location in the affected eyes.

Effect of Corneal Cross-linking on Endothelial Cell Density and Morphology in the Peripheral Cornea.

BACKGROUND: To compare the endothelial cell density and morphology in the peripheral cornea before and after corneal cross-linking (CXL).METHODS: This study evaluated thirty-one eyes of 31 patients who were treated with standard CXL for progressive keratoconus. Preoperatively and 6 months postoperatively, we compared the corneal endothelial cell density (ECD), the coefficient of variation in cell size (CV), and the percentage of hexagonal cells (HEX), in the peripheral regions of the cornea, using a non-contact specular microscope (EM-3000, Tomey).RESULTS: All keratoconic eyes in this series were measurable in the peripheral regions. No significant differences were found in the peripheral ECD preoperatively and 6 months postoperatively at each point (Wilcoxon signed-rank test, superior, p=0.16, nasal superior, p=0.12, temporal superior, p= 0.17, inferior, p=0.37, nasal inferior, p=0.28, temporal inferior, p=0.17). The mean percentage of the ECD loss was 1.3%, 1.3%, 1.0%, 1.4%, 0.7%, and 1.4%, respectively. No significant differences in the peripheral CV or HEX were found preoperatively and 6 months postoperatively at each point.CONCLUSIONS: Standard CXL does not cause significant changes in endothelial cell density, polymegethism, or polymorphism, in the peripheral regions of the cornea. It is suggested that CXL is a minimally invasive surgical approach for progressive keratoconus, even in terms of peripheral endothelial cells.