Optical Coherence Tomography: Clinical Applications in Medical Practice

Optical Coherence Tomography (OCT) is a success story of scientific and technological co-operation between a physicist and a clinician. The concept of cross-sectional imaging revolutionalized the applicability of OCT in the medical profession. OCT is a non-contact, topographic, biomicroscopic device that provides high resolution, cross-sectional digital images of live biological tissues in vivo and in real time. OCT is based on the property of tissues to reflect and backscatter light involving low-coherence interferometry. The spatial resolution of as little as 3 microns or even less has allowed us to study tissues almost at a cellular level. Overall, OCT is an invaluable adjunct in the diagnosis and follow up of many diseases of both anterior and posterior segments of the eye, primarily or secondary to systemic diseases. The digitalization and advanced software has made it possible to store and retrieve huge patient data for patient services, clinical applications and academic research. OCT has revolutionized the sensitivity and specificity of diagnosis, follow up and response to treatment in almost all fields of clinical practice involving primary ocular pathologies and secondary ocular manifestations in systemic diseases like diabetes mellitus, hypertension, vascular and neurological diseases, thus benefitting non-ophthalmologists as well. Systemically, OCT is proving to be a helpful tool in substantiating early diagnosis in diseases like multiple sclerosis and drug induced retinopathies by detecting early changes in morphology of the retinal nerve fiber layer

Sebaceous gland carcinoma of the eyelid

Sebaceous gland carcinoma, commonly arises in the periocular area, is an uncommon condition. It represents 1-5.5% of eyelid malignancies and is considered to be the third most common eyelid malignancy after basal cell and squamous cell carcinomas, although few reports placed this tumor as second most common after basal cell carcinoma. It usually affects elderly women and characterized by high rate of local recurrence, regional, and distant metastases. A delay in diagnosis, which can be attributed primarily to ability of this tumor to masquerade as more benign conditions, often leads to inappropriate management with increased morbidity and mortality rates. In this study, the authors discuss key elements of the primary disease and therapeutic options available to treat such devastating problem

Culture Negative Confoscan Positive Acanthamoeba Keratitis: A relentless course

Acanthamoeba keratitis is a protozoal infection of the eye, mainly due to the use of non-sterile solutions, like saline for disinfecting contact lenses. We report a case where delay in the diagnosis of acanthamoeba keratitis due to inadequate laboratory investigations and clinical management led to an excruciatingly painful course of the disease. The importance of non-invasive imaging techniques of confocal microscopy in the diagnosis of acanthamoeba keratitis, in the absence of positive culture reports, is highlighted in this case

Bacterial Keratitis: Perspective on Epidemiology, Clinico-Pathogenesis, Diagnosis and Treatment

Bacterial keratitis is an acute or chronic, transient or recurrent infection of the cornea with varying predilection for anatomical and topographical parts of the cornea like marginal or central. It is a potentially sight-threatening corneal infection in humans that is generally found in eyes with predisposing elements, the most common of which is contact lens wear. The epidemiological data reveals the universal occurrence of this disease. With advances in the understanding of its pathogenesis, laboratory investigations like immunohistochemistry, fluorescent microscopy, enzyme immunoassays and molecular biology, and the availability of fourth generation antibiotics, the overall visual outcome in bacterial keratitis has improved with time. Particular attention should be given to this condition as it can progress very rapidly with complete corneal destruction occurring within 24–48 hours. Early diagnosis, which is primarily clinical and substantiated largely by microbiological data, and prompt treatment are needed to minimise the possibility of permanent visual loss and reduce structural damage to the cornea

Quantitative and Qualitative Corneal Endothelial Morphology of Omani Patients with Pseudoexfoliation Syndrome

Objective: Pseudoexfoliation (PEX) syndrome is one of the leading causes of secondary open angle glaucoma and blindness. This study explored whether in PEX eyes, preoperative changes in corneal endothelial cell morphology might be a risk factor for postoperative corneal decompensation. Methods: One hundred twenty six eyes of 69 preoperative cataract patients (43 males, 26 females) were enrolled in this cross-sectional study from the Ophthalmology Department at Sultan Qaboos University Hospital between 2003-2005. All patients were subjected to confocal biomicroscopy. Results: The mean age of patients with PEX eyes was 63.2 years. One hundred and eight (85.7%) eyes with PEX had endothelial cell counts within the normal range (1650-3500/mm²). The qualitative morphology of the endothelium of PEX corneas was highly abnormal in term of polymegathism and pleomorphism. Twelve eyes had endothelial cell counts higher than normal for that age group. Only 6 eyes had endothelial cell counts lower than normal. The mean value for the pleomorphism was found to be significantly lower than normal and for polymegathism significantly more than normal. The relationship between pleomorphism and polymegathism was stronger for males than for females and stronger for patients under 60 years than patients over 60 years. The same relationship between pleomorphism and polymegathism showed a stronger relationship for the glaucoma group as compared to the non-glaucoma group. Conclusion: This study revealed that corneal decompensation in PEX eyes can occur in presence of abnormalities in polymegathism and pleomorphism, even when the endothelial cell counts may be normal