Magnetic hyperthermia adjunctive therapy for fungi: in vitro studies against Candida albicans.

The poor penetration of anti-fungal agents into the cornea through the intact epithelium layer makes it difficult to treat acute fungal corneal infections. Herein, we developed Amphotret (amphotericin B) antifungal drug contained polycaprolactone-Fe3O4 (PCL-FO) magnetic nanofibers (MNFs) using the electrospinning technique. These MNFs generate heat in the presence of AC magnetic field (AMF) and release drug upon heating. MNFs were compatible with human mesenchymal stem cells (hMSCs) and HeLa cells, which exhibited unaltered proliferation, ruling out any toxicity from the systems. Hyperthermia induced via MNFs from 42 °C to 50 °C compromised the viability of Candida albicans cells. Further, the efficacy of the systems was increased in the presence of both heat and drug simultaneously in vitro, leading to near 100% loss in viability of C. albicans cells at 50 °C with simultaneous drug release from MNFs. Thus, we propose magnetic hyperthermia as adjunctive therapy for fungal keratitis.

Anterior segment optical coherence tomography for evaluation of cornea and ocular surface.

Current corneal assessment technologies make the process of corneal evaluation extremely fast and simple. Several devices and technologies allow to explore and manage patients better. Optical coherence tomography (OCT) technology has evolved over the years, and hence a detailed evaluation of anterior segment (AS) structures such as cornea, conjunctiva, tear meniscus, anterior chamber, iris, and crystalline lens has been possible in a noncontact and safe procedure. The purpose of this special issue is to present and update in the evaluation of cornea and ocular surface, and this paper reviews a description of the AS-OCT, presenting the technology and common clinical uses of OCT in the management of diseases involving cornea and ocular surface to provide an updated information of the clinical recommendations of this technique in eye care practice.

Anatomy of cornea and ocular surface.

Important functions of cornea in the eye include protecting the structures inside the eye, contributing to the refractive power of the eye, and focusing light rays on the retina with minimum scatter and optical degradation. Considerable advances have taken place in understanding the organization of collagen in the corneal stroma and its clinical significance. In this review, the structure and function of various components of cornea and ocular surface are presented.

Clinical signs in cornea and ocular surface.

A careful examination of cornea and ocular surface eliciting the basic signs will help a clinician toward an accurate diagnosis. Flipping the upper lid or pulling the lower lid to look at the inferior fornix may help to pick up any subtle clinical sign. Meticulous documentation by diffuse and slit view will help in following up the disease. Eyelids and ocular surface are evaluated externally and by slit lamp. Slit-lamp examination with the use of the stains such as fluorescein, rose bengal, or lissamine green provides extensive knowledge about the ocular surface. Tests of tear production are also detailed herein. This review is intended to help the eye practitioners in eliciting common clinical signs seen in cornea and ocular surface diseases.

Evaluation of Kayser-Fleischer ring in Wilson disease by anterior segment optical coherence tomography.

PURPOSE: The purpose of the study is to present anterior segment optical coherence tomography (AS-OCT) as an alternative method of evaluating Kayser-Fleischer (KF) ring in Wilson disease (WD) not only by ophthalmologists but also by other clinicians dealing with WD. MATERIALS AND METHODS: This was a retrospective case series of six WD patients with KF ring. Evaluation of KF ring was done by naked eye examination using torch light, slit lamp biomicroscopy (SL), and AS-OCT. SL examination was done using a narrow slit of the superior cornea. AS-OCT was done using the Optovue RTvue PremierTM device (Fremont, CA, USA). RESULTS: AS-OCT revealed KF ring as an intense hyperreflective band at the level of Descemet membrane (DM). Color scale of AS-OCT showed KF ring as greenish/greenish yellow/orange yellow/yellowish/red band. Validation of AS-OCT findings was done by second ophthalmologist, medical gastroenterologist, surgical gastroenterologist, and neurophysician. After seeing the first observation, they could identify the AS-OCT features in all pictures with ease. CONCLUSIONS: This is the first observation of KF ring in WD on AS-OCT. On AS-OCT, KF ring is visualized as intense hyperreflectivity at the level of DM in the peripheral cornea. Further, studies are needed to evaluate the usefulness of AS-OCT in WD management.

Anterior segment optical coherence tomography to look for Kayser-Fleischer rings.

Ophthalmologists usually use slit lamp biomicroscopy to look for Kayser-Fleischer rings in Wilson's disease; anterior segment optical coherence tomography is a new alternative to identify the characteristic hyper-reflective layer in the deep corneal periphery at the level of Descemet's membrane. This method allows non-ophthalmologists to look for and to quantify Kayser-Fleischer rings.

Advantages of Anterior Segment Optical Coherence Tomography Evaluation of the Kayser-Fleischer Ring in Wilson Disease.

PURPOSE: To present anterior segment optical coherence tomography (AS-OCT) findings of the Kayser-Fleischer (KF) ring in Wilson disease (WD) and to discuss the potential advantages of evaluating the KF ring by AS-OCT. METHODS: This is a retrospective case series of 7 patients with WD with KF rings seen in our institute during the study period (August 2015 to June 2016). All patients underwent slit-lamp examination of the cornea and AS-OCT (Optovue RTVue Premier). In 2 patients, the length of the KF ring was measured using the gray scale of AS-OCT. RESULTS: The KF ring on the gray scale of AS-OCT was visualized as a hyperreflective deep corneal layer at the level of Descemet membrane in all eyes. The OCT color scale revealed the KF ring as a greenish, greenish-yellow, yellow, or yellow-orange band. The gray scale of AS-OCT could easily measure the length of the KF ring in patients 6 and 7. CONCLUSIONS: AS-OCT is an alternative method of evaluating the KF ring in WD, which can be used in combination with slit-lamp examination. The KF ring can be easily measured using the gray scale of AS-OCT. Further studies are required to study the potential advantages of AS-OCT including assessing the density of the KF ring, as a tool to assess response to treatment in WD, in differentiating the KF ring of WD disease from copper deposits in other situations and pigmented corneal rings in non-Wilsonian liver disease.

Clinical and microbiological profile of microsporidial keratoconjunctivitis in southern India.

PURPOSE: To report the clinical and microbiological profile of microsporidial keratoconjunctivitis in immunocompetent individuals in southern India. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Nineteen cases of microsporidial keratoconjunctivitis diagnosed between January 2002 and December 2004 were studied. METHODS: All medical and laboratory records of patients with infectious keratitis during the study period were reviewed. In all cases, after relevant history recording and slit-lamp examination, corneal/conjunctival scrapings were collected. Multiple scrapings were taken from the lesions and examined by fluorescence or light microscopy after staining with potassium hydroxide and calcofluor white (KOH + CFW), Gram's stain, Kinyoun's, and Giemsa stain. In some cases, the serum was tested for human immunodeficiency virus antibody by enzyme-linked immunosorbent assay. MAIN OUTCOME MEASURES: Clinical course, demographic features, predisposing factors, microbiological profile, treatment, and final outcome. RESULTS: Of 4822 cases of suspected microbial keratitis seen during the period, 19 (0.4%) were identified as microbiologically proven microsporidial keratitis. All patients were apparently healthy; 8 had a history of ocular trauma, and 3 mentioned bathing in unclean river water. All but 2 had unilateral involvement. The mean age of the patients was 38.4+/-13.7 years (range, 23-73). The duration of symptoms ranged from 1 day to 2 years, with 11 of 19 (58%) presenting within a week of onset of symptoms. Slit-lamp examination revealed multifocal, coarse, punctate, raised epithelial lesions in all patients. A mild to moderate nonpurulent conjunctivitis was present in all cases, with papillary and/or follicular reaction in 14. Corneal/conjunctival scrapings demonstrated microsporidial spores by KOH + CFW in 16 of 17 cases tested, whereas the diagnosis was made by Giemsa stain in 2 cases and by Gram's stain in one. Kinyoun's (1% acid fast) stain was confirmatory in all cases. In all patients, treatment was started after debridement and included oral and/or topical antimicrobial agents. At last follow-up, 15 of 19 achieved a visual acuity of 20/20. CONCLUSIONS: Microsporidial keratoconjunctivitis should be considered in the differential diagnosis of atypical punctate epithelial keratitis associated with conjunctivitis and can be diagnosed by routine microbiological methods. The disease can occur in healthy individuals, and the outcome of treatment is often satisfactory.

Genotype-phenotype correlation in 2 Indian families with severe granular corneal dystrophy.

OBJECTIVES: To determine genotypes in 2 Indian families with severe granular corneal dystrophy, to document clinical and histopathologic features, and to attempt a genotype-phenotype correlation. METHODS: Mutation analysis of exon 12 of the TGFBI gene was carried out in 9 individuals from 2 families. RESULTS: A C-->T mutation at residue 1710 of TGFBI complementary DNA, corresponding to an Arg555Trp mutation in keratoepithelin, was found in affected members of both families. In 5 patients, this mutation was homozygous, and it was heterozygous in the other 4. Clinical examination revealed a severe form of granular corneal dystrophy with early onset and superficial lesions in the homozygous individuals and a milder phenotype in the heterozygous individuals. Histopathologic evaluation of corneal specimens from 2 homozygous patients confirmed the presence of superficial granular deposits. CONCLUSIONS: To our knowledge, this is the first molecular and clinical characterization of severe granular corneal dystrophy in India. Genotype-phenotype correlation and comparison with earlier reports on this entity highlight the uniform expressivity of the Arg555Trp allele in homozygous individuals. CLINICAL RELEVANCE: Homozygous granular corneal dystrophy has a severe phenotype and can be recognized based on clinical and histopathologic features, especially in association with consanguinity or inbreeding.

Amniotic membrane transplantation for ocular surface reconstruction.

The amniotic membrane, composed of 3 layers, the epithelium, basement membrane, and the stroma, was first used along with the chorion as a biologic membrane to promote healing of skin burns in 1910. In ophthalmology, it was used in 1940 in the management of conjunctival defects. Its revival in the 1990s was due to its ability to reduce ocular surface inflammation and scarring, promote rapid epithelialization due to the presence of growth factors, and antimicrobial properties. This has resulted in its application in several ocular disorders. A review of the literature shows that amniotic membrane is definitely beneficial in some but not all pathology. The future of amniotic membrane transplantation is very exciting, especially in the field of limbal stem cell research. However, further work is needed to elucidate whether it functions merely as a biologic contact lens or whether it has additional benefits.

TGFBI gene mutations causing lattice and granular corneal dystrophies in Indian patients.

PURPOSE: To identify mutations in the TGFBI gene in Indian patients with lattice corneal dystrophy (LCD) or granular corneal dystrophy (GCD) and to look for genotype-phenotype correlations. METHODS: Thirty-seven unrelated patients were studied, 18 with LCD and 19 with GCD. The diagnosis of LCD or GCD was made on the basis of clinical and/or histopathological evaluation. Exons and flanking intron sequences of the TGFBI gene were amplified by PCR with specific primers. PCR products were screened by the method of single-strand conformation polymorphism followed by sequencing. Mutations were confirmed by screening at least 100 unrelated normal control subjects. RESULTS: Mutations were identified in 14 of 18 patients with LCD and in all 19 patients with GCD. In LCD, three novel heterozygous mutations found were glycine-594-valine (Gly594Val) in 2 of 18 patients, valine-539-aspartic acid (Val539Asp) in 1 patient, and deletion of valine 624, valine 625 (Val624-Val625del) in 1 patient. In addition, mutation of arginine 124-to-cysteine (Arg124Cys) was found in 8 of 18 patients and histidine 626-to-arginine (His626Arg) in 2 of 18 patients. Atypical clinical features for LCD were noted in patients with the Gly594Val and Val624-Val625del mutations. In GCD, 18 patients with GCD type I had a mutation of arginine 555-to-tryptophan (Arg555Trp) and 1 patient with GCD type III (Reis-Bucklers dystrophy), had the Arg124Leu mutation. Seven novel single-nucleotide polymorphisms (SNPs) were also found, of which a change of leucine 269 to phenylalanine (Leu269Phe) was found in 12 of 18 patients with the Arg555Trp mutation. CONCLUSIONS: Arg124Cys and Arg555Trp appear to be the predominant mutations causing LCD and GCD, respectively, in the population studied. The novel mutations identified in this study are associated with distinct phenotypes.

Lattice corneal dystrophy type III with corneal fistula. A case report.

Lattice corneal dystrophy is a distinct clinical entity characterised by amyloid deposits in the corneal stroma. We report a patient who presented with a corneal fistula in the right eye and thick lattice lines involving the peripheral cornea in both eyes suggestive of type III lattice dystrophy. The association of corneal fistula with lattice corneal dystrophy type III makes this a unique case.

Limbal stem cell transplantation.

The past two decades have witnessed remarkable progress in limbal stem cell transplantation. In addition to harvesting stem cells from a cadaver or a live related donor, it is now possible to cultivate limbal stem cells in vitro and then transplant them onto the recipient bed. A clear understanding of the basic disease pathology and a correct assessment of the extent of stem cell deficiency are essential. A holistic approach towards management of limbal stem cell deficiency is needed. This also includes management of the underlying systemic disease, ocular adnexal pathology and dry eye. Conjunctival limbal autografts from the healthy contralateral eye are performed for unilateral cases. In bilateral cases, tissue may be harvested from a cadaver or a living related donor; prolonged immunosuppression is needed to avoid allograft rejection in such cases. This review describes the surgical techniques, postoperative treatment regimes (including immunosuppression for allografts), the complications and their management. The short and long-term outcomes of the various modalities reported in the literature are also described.

Novel mutations of the carbohydrate sulfotransferase-6 (CHST6) gene causing macular corneal dystrophy in India.

PURPOSE: Macular corneal dystrophy (MCD) is an autosomal recessive disorder characterized by progressive central haze, confluent punctate opacities and abnormal deposits in the cornea. It is caused by mutations in the carbohydrate sulfotransferase-6 (CHST6) gene, encoding corneal N-acetyl glucosamine-6-O-sulfotransferase (C-GlcNAc-6-ST). We screened the CHST6 gene for mutations in Indian families with MCD, in order to determine the range of pathogenic mutations. METHODS: Genomic DNA was isolated from peripheral blood leukocytes of patients with MCD and normal controls. The coding regions of the CHST6 gene were amplified using three pairs of primers and amplified products were directly sequenced. RESULTS: We identified 22 (5 nonsense, 5 frameshift, 2 insertion, and 10 missense) mutations in 36 patients from 31 families with MCD, supporting the conclusion that loss of function of this gene is responsible for this corneal disease. Seventeen of these mutations are novel. CONCLUSIONS: These data highlight the allelic heterogeneity of macular corneal dystrophy in Indian patients.

Subepithelial amyloid deposits in congenital hereditary endothelial dystrophy: a histopathologic study of five cases.

PURPOSE: To report the clinical, histologic, ultrastructural, and immunohistochemical features of congenital hereditary endothelial dystrophy (CHED) associated with subepithelial amyloid deposits. METHODS: The clinical features of seven patients and histologic characteristics of eight corneal buttons were evaluated. The corneal specimens included five cases with histologic features of CHED associated with subepithelial amyloid. The remaining three corneal buttons of CHED without amyloid were obtained from the fellow eye of an affected patient and from siblings of two affected patients. Light microscopic studies were performed on sections stained with hematoxylin and eosin, periodic acid Schiff stain, and Congo red stain with and without permanganate bleach. Immunohistochemistry with an antibody to the amyloid AA protein and lambda and kappa light chains was done on all specimens. Electron microscopy was performed on three corneal specimens. The cases were followed for 1-9 years. RESULTS: The notable clinical findings included decreased vision, history of parental consanguinity (4/7 cases), and affected siblings (5/7 cases). Examination revealed nystagmus (5/7 cases) and bilateral ground-glass corneas in all patients. In addition, central subepithelial whitish opacities were noted in patients with CHED and amyloid. Three patients had associated congenital glaucoma. The patients underwent penetrating keratoplasty at a mean age of 10 years. Histologically, five corneal buttons of CHED revealed varying degrees of subepithelial amyloid deposits associated with a subepithelial fibrous pannus. Immunohistochemically, the deposits were nonreactive to anti-amyloid A antibody but were immunoreactive with an antibody to lambda light chains in two cases. Electron microscopy confirmed the presence of subepithelial amyloid. Thickening of Descemet's membrane and attenuation of corneal endothelial cells, noted in all cases, was consistent with features of CHED. The corneal buttons from the fellow eye and the siblings showed histologic features of CHED, with a subepithelial fibrous pannus without amyloid deposits. Spheroidal degeneration was noted in two corneal specimens. To date, no recurrence of the amyloid deposits has been seen in the grafts. CONCLUSIONS: This study demonstrates that subepithelial amyloidosis may be rarely associated with a recessive form of congenital hereditary endothelial dystrophy. The clinical, histologic, and immunohistochemical features suggest a secondary form of amyloidosis.

Open-sky pupilloplasty during phakic penetrating keratoplasty to treat a fixed, dilated pupil.

We report a technique in which penetrating keratoplasty is performed in conjunction with open-sky pupilloplasty in a phakic patient. The technique was used in a 27-year-old man with poor vision and severe light sensitivity in the left eye dating back to an episode of presumed herpes simplex keratouveitis 13 years previously. Examination showed a best corrected visual acuity of 20/40, a paracentral midstromal corneal scar, a fixed dilated pupil, and a clear lens. Postoperatively, the pupil was relatively round with a diameter of approximately 4.0 mm, the cosmetic result was favorable, the photophobia had resolved, and the lens and corneal transplant were clear.

Complications of laser-in-situ-keratomileusis.

Laser-in-situ-keratomileusis (LASIK) has become a popular technique of refractive surgery because of lower postoperative discomfort, early visual rehabilitation and decreased postoperative haze. Compared to photorefractive keratectomy (PRK), LASIK involves an additional procedure of creating a corneal flap. This may result in complications related to the flap, interface and underlying stromal bed. The common flap-related complications include thin flap, button holing, free caps, flap dislocation and flap striae. The interface complications of diffuse lamellar keratitis, epithelial ingrowth and microbial keratitis are potentially sight threatening. Compared to PRK, there is less inflammation and faster healing after LASIK, but there is a longer period of sensory denervation leading to the complication of dry eyes. The refractive complications include undercorrection, regression, irregular astigmatism, decentration and visual aberrations. Honest and unbiased reporting is important to understand the aetiology and redefine the management.