Lily Therese

Use of polymerase chain reaction in detection of Mycobacterium tuberculosis complex DNA from vitreous sample of Eales' disease

Editor,—Eales’ disease, first described by Henry Eales in 1880 is a primary retinal perivasculitis that predominantly affects the peripheral retina of young and otherwise healthy adults in the age group 15–40 years. Of the several aetiologies proposed, most favoured are tuberculosis and hypersensitivity to tuberculoprotein.1 Since polymerase chain reaction (PCR) using primers for the insertion sequence of IS6110 consisting of upstream primer: 5′ CCTGCGAGCGTAGGCGT CGG3′ and downstream primer: 5′CTC GTCCAGCGCCGCTTCGG 3′ …

Detection of mycobacterium Tuberculosis by Nested Polymerase Chain Reaction in a Case of Subconjunctival Tuberculosis

Purpose. To highlight the importance of nested polymerase chain reaction (PCR) in the detection of Mycobacterium tuberculosis in a case of subconjunctival tuberculosis. Methods. We report a case of a 60-year-old man with subconjunctival nodule in the right eye for duration of 6 weeks. Biopsy of the nodule showed a granuloma with extensive caseation necrosis. Ziehl Neelsen staining for acid-fast bacilli (AFB) was negative. However, because of a strong suspicion of Mycobacterium infection, PCR for M. tuberculosis genome was done, using the nested PCR technique. Results. Polymerase chain reaction for M. tuberculosis showed amplification of Mycobacterium tuberculosis genome with the nested PCR technique. Conclusion. Our case indicates that PCR can be a valuable tool in the diagnosis of conjunctival tuberculosis from paraffin sections.

Anterior chamber exudative mass due to Scedosporium apiospermum in an immunocompetent individual

Endogenous intraocular infection of fungal etiology is extremely rare in an immunocompetent individual. Usually, an antecedent history of trauma, surgery, intravenous drug abuse or an immunocompromized state can be elicited. Scedosporium apiospermum is a known cause of keratomycosis after traumatic implantation and can cause fatal disseminated infection in immunocompromized patients. However, cases of S. apiospermum intraocular infection in immunocompetent individuals have been very rarely reported in literature. We report here a case of an anterior chamber exudative mass due to S. apiospermum in an immunocompetent individual which was managed successfully with anterior chamber wash and intravitreal injection of voriconazole.

Polymerase Chain Reaction in Intraocular Inflammation

Polymerase chain reaction (PCR) is a technique involving enzymatic amplification of nucleic acid sequences in repeated cycles of denaturation, oligonucleotide annealing and DNA polymerase extension. It is a powerful molecular biologic tool that allows the rapid production of analytic quantities of DNA from small amounts of starting material. PCR can be performed on nearly any ocular specimen or biopsy. For diagnosis of uveitis, the obtained sample is usually an anterior chamber paracentesis or vitreous tap. PCR potentially is more sensitive than culture for detection of many organisms. By utilizing a secondary detection system in concert with the initial PCR reaction, perfect specificity can be assured. The initial application of PCR diagnostics to ophthalmic disease was in the detection of viral uveitis. PCR has also been implicated in studies of noninfectious uveitis. The most common application is HLA typing. A universal bacterial PCR can be very helpful for the diagnosis of bacterial endophthalmitis at an early stage of the disease.

Endophthalmitis in Eyes Following Vitrectomy

The authors describe two patients who underwent pars plana vitrectomy for nonclearing vitreous hemorrhage. Both patients had severe pain, increased intraocular pressure, and orbital swelling. The anterior chamber became flat in a phakic eye. The infection progressed rapidly, and ultimately evisceration was required in both cases. The presence of a flat anterior chamber in gas-filled, phakic eyes and a severe orbital inflammatory reaction in the early postoperative period should alert the physician to the possibility of endophthalmitis.

Diagnosis of Aspergillus fumigatus endophthalmitis from formalin fixed paraffin-embedded tissue by polymerase chain reaction-based restriction fragment length polymorphism.

New molecular biological technique of Polymerase Chain Reaction (PCR) based Restriction Fragment Length Polymorphism (RFLP) can identify the species from paraffin-embedded tissue section. We demonstrated Aspergillus fumigatus fungus by PCR-based RFLP technique from paraffin section of an eyeball of an eight- month-old child removed for endogenous endophthalmitis.

Enterococcus faecalis Endophthalmitis in Children – A 21 Year Study

ABSTRACT Purpose: To report Enterococcus faecalis endophthalmitis (EFE) in children and its comparison with adults. Methods: Retrospective study of 19 children up to 18 years age, undergoing vitrectomy for EFE at a referral eye center from January 1995 to December 2015. The results were compared to 18 adults with EFE. Results: The mean age was 7.4 ± 3.06 years. Post-traumatic EFE was seen in 17 (89.4%) children (p < 0.05) versus postoperative EFE seen in 12 (66%) adults. Broomstick 9 (52.9%) and hypodermic needle injury 6 (35.2%) were common associations. “Optimum functional outcome” was achieved in 12 (63.1%) eyes of children and 5 (27.7%) eyes of adults (p = 0.03). Sealed and Zone II wounds, lens, and needle injuries had good outcome whereas intervention after 3 days and retinal detachment had poor outcomes (p < 0.05). The was no correlation with the Ocular Trauma Score. Conclusion: EFE in children is rare; seen with broom stick and needle injuries, if managed early recovers optimum vision.

Clinical profile of pythium keratitis: perioperative measures to reduce risk of recurrence

Purpose To report the clinical profile and role of perioperative adjunctive measures to reduce the risk of recurrence in Pythium insidiosum keratitis. Methods Retrospective analysis of 10 eyes of 10 patients with P. insidiosum keratitis. Diagnosis was confirmed by PCR DNA sequencing. Results 7out of 10 patients were from urban locales, and none had any obvious history of injury with vegetative matter and were being treated for fungal keratitis. 6 eyes presented with central full thickness infiltrates with subepithelial and superficial stromal infiltrates radiating in a reticular pattern. Corneal scraping in all eyes revealed sparsely septate fungal-like filaments on potassium hydroxide/Calcofluor. All eyes underwent the first therapeutic penetrating keratoplasty (TPK) based on worsening or non-responsiveness of clinical features to the antifungal regimen. Recurrence was noted in 7 out of 10 eyes of which 2 eyes underwent evisceration. Of the six eyes that underwent cryotherapy following confirmation of microbiological diagnosis of Pythium (along with primary TPK-1, with re-TPK-5), only one eye had a recurrence and had to be eviscerated. Of the two eyes that did not undergo cryotherapy during re-TPK, following microbiological diagnosis, one eye had a recurrence and had to be eviscerated. In two eyes with adjoining scleritis, the host bed was swabbed using absolute alcohol of which one eye was salvaged. Conclusion This series highlights the need to be aware of this entity in the management of refractory fungal keratitis. It also brings to fore the adjunctive measures that could have a beneficial role in the management of pythium keratitis.

Diagnostic Challenge with Nocardia Subretinal Abscess: A Case Report from Tuberculosis-Endemic Region

ABSTRACT Purpose: To describe a case of Nocardia subretinal abscess, which posed a diagnostic challenge due to the presence of mycobacterial genome in sample obtained from fine needle aspiration biopsy (FNAB). Methods: A retrospective chart review. Results: A 25-year-old male presented with sudden, painless onset diminution of vision of left eye and found to have placoid patch of choroiditis just temporal to the macula in right eye and showed vitritis, subretinal abscess with exudative retinal detachment and vitreous hemorrhage in left eye. Both aqueous and vitreous samples were negative microbiologically and polymerase chain reaction for various genomes. Sample obtained from FNAB was positive for mycobacterial genome and yielded Nocardia arthritidis on culture. She was treated with antitubercular therapy and intravenous and intravitreal antimicrobials. Conclusions: Nocardia subretinal abscess can be a diagnostic challenge in tuberculosis-endemic region, especially in conditions when there is co-infection with Mycobacterium tuberculosis.

Isolated Unilateral Infiltrative Cryptococcal Optic Neuropathy in an Immunocompetent Individual

A 46-year-old male developed painful decrease in vision in the left eye which progressed to only perception of light over a period of 2 days. A fundus examination revealed optic disc oedema and multiple white-centred haemorrhages in the left eye. The patient had no fever nor any abnormal neurological signs. Magnetic resonance imaging showed thickening of the left intraorbital and intracanalicular optic nerve with extensive perioptic enhancement. Microscopic examination of cerebrospinal fluid showed the presence of Cryptococcus neoformans. An enzyme-linked immunosorbent assay for human immunodeficiency virus was negative and the patient had no history of immunosuppression. A course of amphotericin B and fluconazole resolved the lesion, which was noted after imaging on subsequent visits. The authors report a hitherto undocumented entity of isolated infiltrative cryptococcal optic neuropathy in an immunocompetent individual. A fungal aetiology may be the cause of drastic loss of vision due to infiltrative optic neuropathy even in immunocompetent patients.