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Biomedical subjects

K Ramaesh

Publications and source records attributed to K Ramaesh.

At least 19 recordsLinked to original sources
PubMed2006

Traumatic wound dehiscence after penetrating keratoplasty-a cause for concern.

AIM: We report the incidence, causes, characteristics, and the outcome of traumatic corneal graft ruptures in a tertiary referral centre in the UK. METHOD: A retrospective analysis of all graft ruptures secondary to trauma that were treated at our centre between 1999 and 2005 was undertaken. Statistical analysis of possible prognostic factors was undertaken using the Fisher's test. RESULTS: Nineteen eyes in 18 patients sustained eye trauma resulting in graft rupture (median age of 53 years; range 27-82; 15 men and four women). Seventeen cases were accidental and two were from violence. The median time interval between grafting and rupture was 8.3 months (range 3 days to 15 years). The 6-year incidence was 3.8%. All graft ruptures occurred at the host-graft junction and ranged from 45 to 270 degrees . Iris prolapse/loss was noticed in 89% and lens loss in 53%. The most common posterior segment complication was vitreous loss (74%), followed by vitreous haemorrhage (32%) and retinal detachment (21%). Grafts with 180 degrees or more of dehiscence were more likely to fail (P<0.001), had more extensive posterior segment damage, and a poorer visual outcome. Grafts without sutures had a more extensive dehiscence (P<0.01). Final visual acuity was worse than 6/60 in 58%. CONCLUSIONS: The risk of traumatic corneal graft rupture is significant and is associated with a poor visual outcome. This fact needs to be clearly emphasised during preoperative counselling and protective measures encouraged.

Adolescent↗
PubMed2006

Therapeutic deep lamellar keratoplasty for corneal perforations.

OBJECTIVES/AIMS: Corneal perforation can be potentially blinding unless the integrity of the globe is restored quickly. Although penetrating keratoplasty (PK) may achieve this, it carries a high risk of endothelial rejection in inflamed eyes. Deep lamellar keratoplasty (DLK) may be an alternative option to PK in such eyes owing to its potential for a lower incidence of rejection. We report the efficacy of DLK in patients with corneal perforations. PATIENTS AND METHODS: Four patients underwent layer-by-layer DLK for noninfective corneal perforation, after measures such as the use of a bandage contact lens, tissue adhesive, and conjunctival pedicle flap had failed. The preoperative visual acuity was hand movements in one patient, 1/60 in two, and 6/60 in one. All four had iris incarcerated within the corneal perforations. SF6 gas (three patients) and air (one patient) were injected into the anterior chamber at the end of surgery. RESULTS: The integrity of the globe was restored in all four patients with an improvement in visual acuity (6/60 in one and 6/36 or better in three). The mean follow-up time was 7 months. All four patients had clear corneas 3 months postoperatively, apart from the area of the original perforation. There was no recurrence of ulceration or perforation. CONCLUSION: DLK is a safe and effective therapeutic measure in the management of patients with corneal perforations acting to preserve the integrity of the globe and restore vision.

Adolescent↗
PubMed2006

Superior forniceal conjunctival advancement pedicles (SFCAP) in the management of acute and impending corneal perforations.

OBJECTIVE/AIM: Corneal perforations can result from a wide variety of disorders and can lead to devastating visual sequelae. Various surgical procedures have been described to manage nontraumatic corneal perforation. Conjunctival flaps offer an important technique in dealing with such corneal emergencies. We report a modified conjunctival flap procedure referred to as superior forniceal conjunctival advancement pedicle (SFCAP) in the successful management of corneal perforation and impending corneal perforation. PATIENTS AND METHODS: Out of 20 patients who underwent SFCAP for non-traumatic corneal perforation and impending perforation, 16 had corneal perforations. Perforations were secondary to acne rosacea (2), advanced bacterial keratitis (6), corneal anaesthesia(2), multiple retinal procedures (2), previous corneal grafts with a compromised ocular surface (3), and advanced Mooren's ulcer (1). RESULTS: The globe was preserved in all patients. In 14 of the 16 eyes with perforated corneas the pedicle stabilised. One patient, who was a chronic alcoholic, rubbed the eye during sleep detaching the pedicle a week after surgery. However, the ulcer healed and the integrity of the globe was restored. None of these patients developed secondary glaucoma or ptosis. CONCLUSION: SFCAP is an appropriate procedure to manage corneal perforations and impending corneal perforations where donor material is not available and transplantation of such tissue is not suitable.

Acute Disease↗
PubMed2006

Microbial contamination of preservative free eye drops in multiple application containers.

BACKGROUND/AIMS: The majority of eye drops used in the United Kingdom contain preservatives and are bottled in plastic containers. Preservative free drops are used to avoid ocular irritation and allergies in certain individuals. The aim of this study was to investigate the incidence of microbial contamination of preservative free drops dispensed from multiusage containers. METHODS: Eye drop bottles were collected from patients attending the Tennent Institute of Ophthalmology outpatient and inpatient departments. The bottles were collected on day 3 (for inpatients) and day 7 (for outpatients) of use. The drops were inoculated onto different culture plates (chocolate agar, blood agar, fungal culture media, and enriched media) and the resulting microbial growth was identified using standard microbial identification techniques. RESULTS: 95 eye drop bottles were collected, containing a variety of 10 different eye drops. Significant bacterial growth was found in eight bottles. In total, seven different types of organism were identified from the eye drops. The organisms identified were Staphylococcus aureus, coagulase negative staphylococcus, Bacillus spp, Serattia spp, Klebsiella oxytoca, Enterobacter cloacae, and alpha streptococcus. Staph aureus was the commonest microbial organism. CONCLUSION: Preservative free eye drops in multiple application containers are at risk of contamination by potentially pathogenic micro-organisms.

Anti-Bacterial Agents↗
PubMed2005

Pathogenesis, clinical features and management of recurrent corneal erosions.

Recurrent corneal erosions (RCE) are common. They are characterised by repeated episodes of pain, difficulty in opening the eyes, watering, and photophobia resulting from poor epithelial adhesion. In the majority of patients with RCE, trauma is the initiating factor. Epithelial, stromal, and endothelial corneal dystrophies have all been described in association with RCE. Other causes that may lead to RCE include chemical and thermal injuries, previous herpetic keratitis, meibomian gland dysfunction, ocular rosacea, diabetes mellitus, Salzmann's nodular degeneration, band keratopathy, previous bacterial ulceration, kerato-conjunctivitis sicca, and epidermolysis bullosa. The conditions that are associated with RCE can be either primary or secondary depending on whether the basement membrane complex abnormality is intrinsic or acquired. Primary types tend to be bilateral, symmetrical and develop in multiple corneal locations. The pathogenetic mechanism of this disorder is related to poor adhesion of the corneal epithelium to the underlying stroma. Excessive matrix metalloproteinase (MMP) activity may play a role in the pathogenesis. Although the majority of patients will respond to simple measures such as padding and antibiotic ointment, RCE resistant to simple measures require approaches that are more elaborate. The common goal of these approaches is to encourage proper formation of adhesion complexes between the epithelium and the stroma. The use of long-term contact lenses, autologous serum eye drops, botulinum toxin, induced ptosis, oral MMP inhibitors, diamond burr polishing of Bowman's membrane have been reported with varying degree of success in treating RCE. Anterior stromal puncture with insulin needles or Neodymium : aluminium-yttrium-garnet may enhance the epithelial adhesion to the basement membrane by scar formation and success rates of up to 80% have been reported in the treatment of recalcitrant RCE. Excimer laser photo-therapeutic keratectomy (PTK) is now a well-established treatment modality for RCE and is being used both safely and effectively. Partial ablation of Bowman's layer with PTK gives a smooth surface for the newly generating epithelium to migrate and form adhesion complexes. The pathogenesis, clinical features, and management options of this common disorder are discussed in this review article.

Corneal Diseases↗
PubMed2005

Evolving concepts on the pathogenic mechanisms of aniridia related keratopathy.

Heterozygosity for PAX6 deficiency (PAX6+/-) results in aniridia. Corneal changes in aniridia-related keratopathy (ARK) include corneal vascular pannus formation, conjunctival invasion of the corneal surface, corneal epithelial erosions and epithelial abnormalities, which eventually result in corneal opacity and contribute to visual loss. Corneal changes in aniridia have been attributed to congenital deficiency of corneal limbal stem cells. The aim of this paper is to review the potential mechanisms that may underlie the pathogenesis of aniridia related keratopathy. Current evidence, based on clinical observations and an animal model of aniridia suggest that the proliferative potential of the corneal limbal stem cells may not primarily be impaired. The corneal changes in aniridia may be related to an abnormality within the limbal stem cell niche. The mechanisms underlying progressive corneal pathology in aniridia appear multi-factorial and include: (1) abnormal corneal healing responses secondary to anomalous extracellular matrix metabolism; (2) abnormal corneal epithelial differentiation leading to fragility of epithelial cells; (3) reduction in cell adhesion molecules in the PAX6 heterozygous state, rendering the cells susceptible to natural shearing forces; and (4) conjunctival and corneal changes leading to the presence of cells derived from conjunctiva on the corneal surface.

Animals↗
PubMed2004

Immunolocalisation of leukaemia inhibitory factor in the cornea.

AIM: Leukaemia inhibitory factor (LIF) is a pleotrophic cytokine expressed in a variety of cell types, and have shown to regulate stem cell proliferation, vascular genesis, inflammation, and immunity in various locations. Expression of LIF and its role in the cornea have not been studied previously. In this study, we examined the expression of LIF in the cornea. MATERIALS AND METHOD: Immunohistochemistry was performed using polyclonal LIF antibodies, and Avidin-Biotin ABC complex on cultured human corneal epithelium corneal fibroblasts and wild-type murine corneal epithelium. RESULTS: LIF was detected in the cytoplasm of murine corneal epithelium, cultured human corneal epithelium, and fibroblasts. The expression of LIF was mainly cytoplasmic. CONCLUSION: LIF is expressed in the corneal epithelium and fibroblasts. It may have an important role in the maintenance of homeostasis of the corneal epithelium and cornea stroma. Further studies are necessary to elucidate the role of LIF in the cornea.

Animals↗
PubMed2003

Trans-orbital intra-cranial air gun injury.

PURPOSE: To describe a case of trans-orbital intra-cranial air gun injury with a discussion on air gun related morbidity and mortality. METHODS: Case report and literature review. RESULTS: The air gun pellet travelled through the orbit without penetrating the globe. It passed into the middle cranial fossa through the superior orbital fissure and lodged in the temporal lobe. The patient was managed conservatively with antibiotics and antiepilectis. CONCLUSIONS: Air gun design has changed in recent years resulting in an increased morbidity and mortality. Stricter legislation on the sale and use of these weapons needs to be implemented.

Adolescent↗
PubMed2003

Ex vivo expansion of corneal limbal epithelial/stem cells for corneal surface reconstruction.

PURPOSE: The management of severe ocular surface disease due to limbal stem cell deficiency has changed dramatically. The concept of limbal stem cells, as the source of corneal epithelium revolutionised the therapeutic approach of ocular surface reconstruction. Deficiency of limbal stem cells results in blinding ocular surface diseases. Grafting viable limbal tissue, from either fellow healthy eye or a donor eye, with the resident stem cell population may replenish limbal stem cells and can restore the corneal surface to normality. Transplanting the limbal tissue can be achieved through a variety of procedures that include cadaveric keratolimbal allograft (KLAL), live or living related conjunctival limbal allograft (Ir-CLAL) and limbal autograft. Advances in tissue engineering techniques have offered a viable alternative to overcome the limitation of limbal tissue available for transplantation. Epithelial stem cells harvested from a small limbal biopsy can be expanded in vitro on a suitable carrier and then transplanted to the diseased cornea to successfully restore the corneal surface. This article is a chronological review of the important steps that brought ex vivo expanded stem cell transplantation in ocular, particularly corneal surface reconstruction. METHODS: The MEDLINE data base was searched for the years 1966-2002, using key words cornea, cell culture, ex-vivo expansion, limbus, stem cell, ocular surface and transplantation. Several articles that were not found by MEDLINE search were taken from references from other articles. Inclusion or exclusion of article was based on the relevance to the subject. CONCLUSIONS: Corneal epithelial reconstruction with ex vivo expanded limbal cells is a potential tool in ocular surface reconstruction, although the technique is currently investigational. Strategies to achieve conjunctival epithelial restoration and tear film replenishment will allow ophthalmic surgeons to truly reconstruct the ocular surface.

Amnion↗
PubMed2001

Conjunctival myxoma, Zollinger-Ellison syndrome and abnormal thickening of the inter-atrial septum: a case report and review of the literature.

PURPOSE: To report a 36-year-old man with a slowly growing painless bulbar conjunctival mass. RESULTS: Following excision of the lesion, histological examination was performed and a diagnosis of myxoma was made. A cardiac echogram showed thickening of the interatrial septum. Seventeen years previously he had had Zollinger Ellison syndrome due to gastrinoma of the pancreas which was treated by surgical removal. A review of the literature shows ocular myxomas may be associated with endocrine abnormalities such as Cushing's syndrome, acromegaly, sexual precocity and cardiac myxoma. CONCLUSION: In this case we report a novel association of conjunctival myxoma with Zollinger-Ellison syndrome and inter-atrial septal thickening.

Adult↗