1.Paradigm shifts in corneal transplantation.
Donald T H TAN ; Arundhati ANSHU ; Jodhbir S MEHTA
Annals of the Academy of Medicine, Singapore 2009;38(4):332-338
Conventional corneal transplantation, in the form of penetrating keratoplasty (PK), involves full-thickness replacement of the cornea, and is a highly successful procedure. However, the cornea is anatomically a multi-layered structure. Pathology may only affect individual layers of the cornea, hence selective lamellar surgical replacement of only the diseased corneal layers whilst retaining unaffected layers represents a new paradigm shift in the field. Recent advancements in surgical techniques and instrumentation have resulted in several forms of manual, microkeratome and femto-second laser-assisted lamellar transplantation procedures. Anterior lamellar keratoplasty (ALK) aims at replacing only diseased or scarred corneal stroma, whilst retaining the unaffected corneal endothelial layer, thus obviating the risk of endothelial allograft rejection. Posterior lamellar keratoplasty/endothelial keratoplasty (PLK/EK) involves the replacement of the dysfunctional endothelial cell layer only. Whilst significant technical and surgical challenges are involved in performing lamellar micro-dissection of a tissue which is only 0.5 mm thick, the benefits of a more controlled surgical procedure and improved graft survival rates have resulted in a shift away from conventional PK. This review details the current advances in emerging lamellar corneal surgical procedures and highlights the main advantages and disadvantages of these new lamellar corneal procedures.
Contraindications
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Corneal Transplantation
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methods
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trends
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Humans
2.Recombinant tissue plasminogen activator (r-TPA) in fibrin dissolution due to postoperative endophthalmitis.
Yasmin RIAZ ; Jodhbir S MEHTA ; Arosho FERNANDO ; Veronica FERGUSON
Annals of the Academy of Medicine, Singapore 2006;35(10):723-725
INTRODUCTIONThe aim of this paper was to describe the use of r-TPA for fibrin clot dissolution following endophthalmitis.
CLINICAL PICTUREA 74-year-old man presented with painful loss of vision following routine uncomplicated cataract surgery.
TREATMENTHe underwent standard treatment for postoperative endophthalmitis but despite this, developed a dense fibrin clot. He underwent further intracameral injection of r-TPA.
OUTCOMEFollowing the injection, he had complete clot dissolution within 2 hours without any complications.
CONCLUSIONR-TPA may be used effectively in the treatment of fibrin clots secondary to endophthalmitis following cataract surgery.
Aged ; Cataract Extraction ; adverse effects ; Endophthalmitis ; drug therapy ; etiology ; Fibrin ; drug effects ; Fibrinolytic Agents ; therapeutic use ; Humans ; Male ; Postoperative Period ; Recombinant Proteins ; therapeutic use ; Tissue Plasminogen Activator ; therapeutic use
3.Demographics and behaviour of patients with contact lens-related infectious keratitis in singapore.
Janice S H LAM ; Grace TAN ; Donald T H TAN ; Jodhbir S MEHTA
Annals of the Academy of Medicine, Singapore 2013;42(10):499-506
INTRODUCTIONThis study aims to identify the demographics and hygiene behaviours associated with contact lens (CL)-related microbial keratitis in Singapore.
MATERIALS AND METHODSThe hygiene and social behaviours of lens wearers presenting with infectious keratitis in Singapore were examined using an externally validated questionnaire. Fifty-eight consecutive lens wearers who presented with infectious keratitis at Singapore National Eye Centre were surveyed using a self-administered questionnaire. Patients' demographics, CL-related behaviour, attitude to aftercare visits and microbial study results were collected and analysed.
RESULTSMore than half (55%) of the patients surveyed were female, and the average age of the participants was 25.7 ± 6.4 years. Ninety-six percent of participants used soft CL, with the majority wearing monthly disposable lenses (74.1%). Myopia was the commonest reason for use of CL. CL overwear (81%), sleeping (50.9%) and swimming (33%) with their CL were the major non-compliant behaviours discovered. When encountered with eye discomfort as a result of lens-related infective keratitis, 83% of patients sought the advice of general medical practitioners prior to presentation at the hospital. Many (59%) patients have encountered media coverage but only 24% had any behavioural change as a result. Many patients relied on the recommendations of eyecare practitioners when purchasing disinfecting solutions (26%) and other hygiene practices. Pseudomonas Aeruginosa was the most common organism grown in 22.4% of patients while 47% of patients were culture-negative.
CONCLUSIONInadequate lens cleaning, poor aftercare, sleeping and swimming with CL were the major non-compliant behaviours among participants, and these are significant factors when assessing risks in acquiring CL-related infectious keratitis. General eyecare practitioners are the first-line of contact in patients presenting with keratitis symptoms and play an important role in emphasising the need for regular aftercare and good hygiene practices to CL wearers.
Contact Lenses, Hydrophilic ; Demography ; Humans ; Hygiene ; Keratitis ; Singapore