Rohit Ramesh Modi

Factors influencing polymerase chain reaction outcomes in patients with clinically suspected ocular tuberculosis.

BackgroundPolymerase chain reaction (PCR) assay can be a useful method for definitive diagnosis in paucibacillary infections such as ocular tuberculosis (TB). In this study, we have evaluated factors affecting PCR outcomes in patients with clinically suspected ocular TB. Patients with clinically suspected ocular TB were investigated by PCR of aqueous or vitreous samples. Three control groups were also tested: group 1 included culture-proven non-tuberculous endophthalmitis, group 2 culture-negative non-tuberculous endophthalmitis, and group 3 patients undergoing surgery for uncomplicated cataract. PCR targeted one or more of following targets: IS6110, MPB64, and protein b genes of Mycobacterium tuberculosis complex. Multiple regression analysis (5% level of significance) was done to evaluate the associations between positive PCR outcome and laterality of disease, tuberculin skin test (TST)/interferon-gamma release assay (IGRA), chest radiography, and type of sample (aqueous or vitreous). The main outcome measures were positive PCR by one or more gene targets, and factors influencing positive PCR outcomes.ResultsAll 114 samples were tested for MPB64, 110 for protein b, and 88 for IS6110. MPB64 was positive in 70.2% (n = 80) of tested samples, protein b in 40.0% (n = 44), and IS6110 in only 9.1% (n = 8). DNA sequencing of amplicons from four randomly chosen PCR reactions showed homology for M. tuberculosis complex. Of the 80 PCR-positive patients, 71 completed a full course of antitubercular therapy, of which 65 patients (91.5%) had complete resolution of inflammation at final follow-up. Among controls, 12.5% (3 out of 24) in group 1 and 18.7% (6 out of 32) in group 2 also tested positive by PCR. No PCR-positive outcome was observed in control group 3 (n = 25). Multiple regression analysis revealed significant association of positive PCR outcome with bilateral presentation, but not with a positive TST/IGRA, chest radiography, or type of sample (aqueous/vitreous) used.ConclusionsCareful selection of gene targets can yield high PCR positivity in clinically suspected ocular TB. Bilateral disease presentation but not any evidence of latent systemic TB influences PCR outcomes. False-positive results may be seen in ocular inflammation unrelated to ocular TB.

Normalised quantitative polymerase chain reaction for diagnosis of tuberculosis-associated uveitis

Polymerase chain reaction (PCR)-based diagnosis of tuberculosis-associated uveitis (TBU) in TB-endemic countries is challenging due to likelihood of latent mycobacterial infection in both immune and non-immune cells. In this study, we investigated normalised quantitative PCR (nqPCR) in ocular fluids (aqueous/vitreous) for diagnosis of TBU in a TB-endemic population. Mycobacterial copy numbers (mpb64 gene) were normalised to host genome copy numbers (RNAse P RNA component H1 [RPPH1] gene) in TBU (n = 16) and control (n = 13) samples (discovery cohort). The mpb64:RPPH1 ratios (normalised value) from each TBU and control sample were tested against the current reference standard i.e. clinically-diagnosed TBU, to generate Receiver Operating Characteristic (ROC) curves. The optimum cut-off value of mpb64:RPPH1 ratio (0.011) for diagnosing TBU was identified from the highest Youden index. This cut-off value was then tested in a different cohort of TBU and controls (validation cohort, 20 cases and 18 controls), where it yielded specificity, sensitivity and diagnostic accuracy of 94.4%, 85.0%, and 89.4% respectively. The above values for conventional quantitative PCR (≥1 copy of mpb64 per reaction) were 61.1%, 90.0%, and 74.3% respectively. Normalisation markedly improved the specificity and diagnostic accuracy of quantitative PCR for diagnosis of TBU.

Subconjunctival hemorrhage and vision loss after regional ocular anesthesia

PurposeTo report two cases of retinal vascular occlusion and associated subconjunctival hemorrhage in needle optic nerve injury during local bulbar anesthesia.MethodsSurgical records of these two subjects who presented with acute vision loss after cataract extraction were studied, and systemic workup and ocular imaging were carried out to establish the cause.ResultsComputerized tomography showed evidence of optic nerve injury.ConclusionSubconjunctival hemorrhage could be an associated clinical finding in hypodermic needle injury-related retinal vascular occlusion during ocular anesthesia.

Bilateral macular infarction after gemcitabine and carboplatin chemotherapy

PurposeTo report a case of macular infarction after doublet chemotherapy with gemcitabine and carboplatin.MethodsA middle-aged lady presenting with bilateral macular infarction post-chemotherapy for metastatic cervical malignancy was investigated for thromboembolic risks and treated.ResultsThe macular perfusion and edema improved with control of hypertension and treatment with pentoxifylline. Visual improvement was satisfactory, and the possible associated risk such as hypertension was noted.ConclusionThis case underscores the need for active screening of patients on chemotherapy with gemcitabine and carboplatin for retinal vascular occlusive changes when hypertension is associated.

Choroidal neovascular membrane in paediatric patients: clinical characteristics and outcomes

Purpose To analyse the clinical characteristics and treatment outcomes of choroidal neovascular membranes (CNVM) in paediatric subjects at three paediatric retina referral centres. Methods Medical charts of patients aged 18 years or less with a diagnosis of CNVM were retrospectively reviewed. The demographic profile, laterality, presenting complaint, corrected vision, underlying pathology, fundus, fundus fluorescein angiogram and optical coherence tomogram (OCT) were analysed. CNVM type, frequency, treatment indications, recurrences and final visual acuity were noted. Results There were a total of 35 subjects (43 eyes) with a mean age of 11.2 years. The CNVMs were mostly type 2 (90.0%), classic (90.9%), subfoveal (59.09%) and active (84.1%). Best vitelliform macular dystrophy was found to be the most common association (32.5%). Intravitreal injection of an anti-vascular endothelial growth factor (VEGF) agent was the initial therapy of choice in all. Eyes with CNVMs responsive to anti-VEGF alone required a mean of 2.11 injections. Patients with recurrent disease (21.21%) had an average of 1.14 episodes per eye. While 50% of recurrent CNVMs stabilised with repeat anti-VEGF treatment, the remaining patients required photodynamic therapy, laser or surgery. Conclusion Paediatric CNVMs in this series differed from those in the adult population with regard to aetiology, OCT and angiographic characteristics, treatment response and rate of recurrence.

Choriovitreal ingrowth of a large choroidal vessel after scatter retinal photocoagulation

Choriovitreal ingrowth of a large choroidal vessel is a known complication of intense focal retinal laser photocoagulation. With a standard grey-white burn in panretinal photocoagulation where the power density used is low, such an invasion is rarely reported. We came across the complication in a clinical scenario where a patient with proliferative diabetic retinopathy and associated ocular ischemic syndrome developed the neovascular ingrowth after scatter retinal photocoagulation.

Posterior scleritis with retinal pigment epithelium rip: an unusual presentation

Posterior scleritis is a great mimicker and can cause irreversible visual loss because of late or misdiagnosis. We report a case of retinal pigment epithelial rip in the event of nodular posterior scleritis that is hardly reported in the literature. The authors hypothesize the rip to be a result of inflammation, exudation and continuing pressure by the fluid or granuloma on the pigment epithelium.

Three-muscle surgery for very large-angle constant exotropia

our experiment that employed well-controlled and repeatable conditions. Our study was by no means intended to refute the clinical efficacy of Holt and colleagues’s superior obliqueZ-tenotomyprocedure; their clinical results demonstrate that the operation is beneficial. We simply propose that the procedure may not be biomechanically different from complete, unguarded superior oblique tenotomy, which would seem technically easier to perform. A randomized trial comparing the two approaches would be required to resolve the clinical question conclusively. We thank Holt and colleagues for drawing attention to biomechanical considerations in strabismus surgery.

Increased risk of coronary heart disease in male patients with central serous chorioretinopathy: results of a population-based cohort study.

In the recent article published in British Journal of Ophthalmology , Chen et al 1 concluded that central serous chorioretinopathy (CSCR) was a risk factor for coronary heart disease (CHD). The abstract mentioned that 835 subjects were in the CSCR group and 4175 subjects were in the non-CSCR group. However, the materials and methods figured 815 in the CSCR group and 4075 in the non-CSCR …