Cost-effectiveness and cost utility of community screening for glaucoma in urban India.

OBJECTIVES: Population-based screening for glaucoma has been demonstrated to be cost-effective if targeted at high-risk groups such as older adults and those with a family history of glaucoma, and through use of a technician for conducting initial assessment rather than a medical specialist. This study attempts to investigate the cost-effectiveness of a hypothetical community screening and subsequent treatment programme for glaucoma in comparison with current practice (i.e. with no screening programme but with some opportunistic case finding) in the urban areas of India. STUDY DESIGN: A hypothetical screening programme for both primary open-angle glaucoma and angle-closure disease was built for a population aged between 40 and 69 years in the urban areas of India. METHODS: Screening and treatment costs were obtained from an administrator of a tertiary eye hospital in India. The probabilities for the screening pathway were derived from published literature and expert opinion. The glaucoma prevalence rates for urban areas were adapted from the Chennai Glaucoma Study findings. A decision-analytical model using TreeAge Pro 2015 was built to model events, costs and treatment pathways. One-way sensitivity analyses were conducted. RESULTS: The introduction of a community screening programme for glaucoma is likely to be cost-effective, the estimated incremental cost-effectiveness ratio (ICER) values being 10,668.68 when compared with no screening programme and would treat an additional 4443 cases and prevent 1790 person-years of blindness over a 10-year period in the urban areas of India. Sensitivity analyses revealed that glaucoma prevalence rates across various age groups, screening uptake rate, follow-up compliance after screening, treatment costs and utility values of health states associated with medical and surgical treatment of glaucoma had an impact on the ICER values of the screening programme. CONCLUSIONS: In comparison with current practice (i.e. without a screening programme but with some opportunistic case finding), the introduction of a community screening programme for glaucoma for the 40-69 years age group is likely to be relatively cost-effective if implemented in the urban areas of India.

Non-fluent Primary Progressive Aphasia and Its Association to Motor Neuron Disease.

Frontotemporal dementia (FTD) is among the most common forms of dementia, with an average symptom onset in the fifth decade of life. Neuropathologic changes in FTD demonstrate degeneration in the frontal and/or temporal lobes, which is defined as frontotemporal lobar degeneration (FTLD). FTD is categorized into a subset of variants by symptomatic presentation and corresponding clinical workup. Primary progressive aphasia (PPA) is among these variants of FTD and is distinguished by its primary clinical presentation of language impairment with correlating neuropathology in the aforementioned areas of the brain. More specifically, the classification of PPA is further subdivided into three clinical variants, which has allowed for appropriate diagnostic and prognostic considerations within this patient population. Among these variants in PPA are the semantic (svPPA), non-fluent (navPPA), and logopenic (lvPPA) forms. Motor neuron disease (MND) is a progressive and irreversible process of neuronal degeneration that can lead to an upper motor neuron, a lower motor neuron, or a combination of these two symptomologies. FTD and its association with MND is a well-established spectrum, although more rarely among the PPA variant of FTD. Comparatively, there is a significant body of clinical knowledge on the association between the behavioral variant of FTD (bvFTD) and MND. This is the case of a 69-year-old female with navPPA who later presented with clinical symptoms of MND. Although the two clinical diagnoses, PPA and MND, are irreversible and progressive, this case serves to elucidate diagnostic and prognostic considerations in this rare patient population.

Cerebral Venous Thromboses in a Patient With No Reported Risk Factors: A Case Report.

Stroke is a neurologic condition caused either by brain ischemia or brain hemorrhage, where most cases are a result of ischemic brain injury. Stroke more commonly affects the arterial blood supply of the brain, but in rare cases, it is evoked by the occlusion of the venous sinuses that drain blood from the brain. This phenomenon is known as cerebral venous sinus thrombosis (CVST), also referred to as cerebral sinovenous thrombosis. The pathogenesis of CVST is not completely understood, although common risk factors associated with the condition include obesity, hypercoagulable states, oral contraceptive use, intracranial infections, trauma, and, more recently, coronavirus disease 2019 (COVID-19). Immediate medical intervention is required because CVST can result in increased intracranial pressure and diffuse cerebral edema, which can bring about fatal complications that can lead to early death. However, CVST is challenging to diagnose, as its clinical presentation is highly variable. It can range from headaches to signs of elevated intracranial pressure, including nausea, vomiting, and vision problems. In this case report, the patient is a 25-year-old previously healthy African American female who presented with a weeklong headache and acute onset of delirium an hour prior to arrival at the hospital. The patient had prior emergency department (ED) visits from different facilities where head imaging was performed and showed negative results allowing her to return home. The patient was then brought by a friend to our ED due to altered mental status and agitation. Initial computed tomography of the head did not reveal acute abnormalities; however, magnetic resonance angiography and magnetic resonance venography revealed evidence of venous sinus thrombosis and lack of flow requiring urgent attention. The patient was then referred to endovascular neurology, but despite medical intervention, the patient's medical status deteriorated, and she was declared brain dead. Although rare, this case report emphasizes the atypical presentation and the severity of CVST where a young individual with no significant past medical history presented with neurological symptoms that rapidly progressed to complications that caused her early death.

A polymorphism in the CYP1B1 promoter is functionally associated with primary congenital glaucoma.

Primary congenital glaucoma (PCG) is a childhood autosomal-recessive disorder caused by developmental defects in the trabecular meshwork and anterior chamber angle. These defects cause raised intraocular pressure (IOP) that damages the optic nerve and if left untreated, results in irreversible blindness. Mutations in CYP1B1 gene at the GLC3A locus (2p21) are associated with PCG. However, there has been very limited exploration of its promoter region. We resequenced the CYP1B1 promoter in a large cohort (n = 835) that included patients with PCG (n = 301), other primary glaucomas (primary open-angle glaucoma: n = 115 and primary angle closure glaucoma: n = 100) and unaffected controls (n = 319). We functionally characterized one associated variant by luciferase reporter assay using the trabecular meshwork (TM3) cell line. We found evidence of strong (P = 6.01 × 10(-4)) association of rs2567206 (T2805C) SNP in PCG and not in other primary glaucomas. Luciferase assay indicated a ∼90% reduction in CYP1B1 promoter activity in the risk-allele (C) compared to the other allele (T). The association of the risk allele was stronger in cases harboring homozygous CYP1B1 mutations (P = 3.42 × 10(-12)). The risk haplotype 'C-C-G' in the promoter had a strong non-random association to the previously characterized risk haplotype 'C-G-G-T-A' in the coding region. The independent effect of genotype at the promoter T2805C locus (P = 0.001), and the interaction effect of genotypes at the promoter and coding region mutations loci (P = 0.001) were significant for the presenting IOP of the worst affected eye. This is the first study that unequivocally shows the functional involvement of a CYP1B1 promoter variant in PCG.

There is insufficient evidence to recommend lens extraction as a treatment for primary open-angle glaucoma: an evidence-based perspective.

Cataract extraction in primary open-angle glaucoma has not been thought to provide a clinically useful or predictable decrease in IOP. This concept has now been challenged, with the opposite belief being promulgated: namely, that lens exchange should be considered as treatment for glaucoma. This revelation could bring a significant change in the glaucoma treatment paradigm. There are no randomised controlled trials to guide the role of lens extraction in primary open-angle glaucoma. The available evidence suggests at most a modest reduction in IOP from cataract extraction - greater in the presence of pseudoexfoliation - which is likely to be of marginal benefit, and only in milder forms of open-angle glaucoma. There is currently no evidence of any quality to suggest that lens extraction routinely represents a clinically useful treatment for primary open-angle glaucoma.

Clinical implication of recent randomized control trial in primary angle-closure disease management.

Blindness due to primary angle-closure glaucoma (PACG) can be reduced significantly if the ongoing angle-closure process is arrested at an early stage. Various treatments such as laser peripheral iridotomy (LPI), iridoplasty, and clear lens extraction (CLE) have been advocated as first-line therapy for primary angle-closure (PAC), PACG, and high-risk cases of primary angle-closure suspect (PACS). EAGLE study, propagated the effectiveness of CLE over LPI for the management of primary angle closure and have sparked controversy regarding the role of LPI as a first line procedure. Randomized controlled trials (RCT), systematic reviews, and meta-analyses of RCTs done on the same question provide us with a solid base for creating guidelines/modules for our day-to-day clinical practice. A systematic review was conducted, searching several databases, including PubMed, Cochrane Library, EMBASE, and ClinicalTrials.gov, for the last 16 years (January 2005-December 2021) for RCTs with data published related to primary angle-closure disease (PACD). The search strategy included the following terms: "Primary Angle Closure disease," "Primary Angle Closure Glaucoma," "Primary Angle Closure," "Primary Angle Closure Suspect," "clear lens extraction," "laser iridotomy," "laser peripheral iridotomy," "argon laser peripheral iridoplasty," "selective laser trabeculoplasty," "trabeculectomy," "randomized control trial," and "meta-analysis of randomized control trial." In this review, we will discuss recently published RCTs (within the last 16 years) for the management of PACD and their clinical implications in day-to-day practice.

Retinal nerve fiber layer thickness in amblyopia.

Purpose: To report retinal nerve fiber layer thickness (RNFLT) in eyes with amblyopia compared with contralateral healthy eyes. Methods: In this cross-sectional study, we included patients with anisometropic amblyopia, strabismic amblyopia, and mixed amblyopia. All subjects underwent complete ophthalmic examination, including RNFLT measurement with time-domain OCT (Stratus OCT) and scanning laser polarimeter (GDX VCC). A paired "t" test was used to compare average and quadrant-wise RNFL thickness between the amblyopic and contralateral normal eyes. In addition, an analysis of variance test was used to compare various RNFL thickness parameters between the three groups. Results: A total of 33 eyes of 33 subjects with anisometropic amblyopia, 20 eyes of 20 subjects with strabismic amblyopia, and 38 eyes of 38 subjects with mixed amblyopia were included. In the anisometropic amblyopia group, the average RNFLT in the amblyopic eye was 98.2 µm and 99.8 µm in the fellow normal eye (P = 0.5), the total foveal thickness was 152.82 µm (26.78) in the anisometropic eye and 150.42 µm (23.84) in the fellow eye (P = 0.38). The difference between amblyopic and contralateral normal eye for RNFL and macular parameters was statistically insignificant in all three groups. The RNFL thickness in four quadrants was similar in the amblyopic and non-amblyopic eye between all three groups and statistically non-significant. Conclusion: Our study showed that RNFL thickness was similar in amblyopic and non-amblyopic eyes between all three amblyopia groups.

A deep dive into the latest European Glaucoma Society and Asia-Pacific Glaucoma Society guidelines and their relevance to India.

Glaucoma is the second leading cause of blindness in India. Despite advances in diagnosing and managing glaucoma, there is a lack of India-specific clinical guidelines on glaucoma. Ophthalmologists often refer to the European Glaucoma Society (EGS) and Asia-Pacific Glaucoma Society (APGS) guidelines. A group of glaucoma experts was convened to review the recently released EGS guideline (fifth edition) and the APGS guideline and explore their relevance to the Indian context. This review provides the salient features of EGS and APGS guidelines and their utility in Indian scenario. Glaucoma diagnosis should be based on visual acuity and refractive errors, slit-lamp examination, gonioscopy, tonometry, visual field (VF) testing, and clinical assessment of optic nerve head, retinal nerve fiber layer (RNFL), and macula. The intraocular pressure target must be individualized to the eye and revised at every visit. Prostaglandin analogues are the most effective medications and are recommended as the first choice in open-angle glaucoma (OAG). In patients with cataract and primary angle-closure glaucoma (PACG), phacoemulsification alone or combined phacoemulsification and glaucoma surgery are recommended. Trabeculectomy augmented with antifibrotic agents is recommended as the initial surgical treatment for OAG. Laser peripheral iridotomy and surgery in combination with medical treatment should be considered in high-risk individuals aged <50 years. In patients with phakic and PACG, phacoemulsification alone or combined phacoemulsification and glaucoma surgery are recommended. Visual acuity, VF testing, clinical assessment of the optic disc and RNFL, and tonometry are strongly recommended for monitoring glaucoma progression.

Clear lens extraction in angle closure glaucoma.

PURPOSE OF REVIEW: Clear lens extraction is being advocated for primary angle closure disease (PACD). It is important that this advocacy should be based on a sound, peer-reviewed evidence base. This review attempts to establish the extent of that evidence and provide some management guidelines. RECENT FINDINGS: There are only three reports that incorporate clear lens extraction (CLE) for angle closure: numbers are sparse and none compare modern phacoemulsification to alternative treatments for primary angle closure glaucoma or provide enough detail to guide clinical decisions. A Cochrane review in 2006 found that there was no evidence to support lens extraction as treatment for primary angle closure glaucoma (PACG). More recent randomized controlled trials have provided support for cataract extraction--although not specifically for CLE--as treatment for part of the spectrum of PACD. A recent review has attempted to provide guidelines for application of CLE in PACG by extrapolating from this evidence. SUMMARY: There are currently no randomized controlled trials supporting the use of CLE as treatment for PACG. A benefit from the procedure is biologically plausible and extrapolation from existing randomized trials to a few specific situations may be possible. Any potential benefit must be carefully weighed against the risks of intervention.

Enter the reverend: introduction to and application of Bayes' theorem in clinical ophthalmology.

BACKGROUND: Ophthalmic practice utilizes numerous diagnostic tests, some of which are used to screen for disease. Interpretation of test results and many clinical management issues are actually problems in inverse probability that can be solved using Bayes' theorem. DESIGN: Use two-by-two tables to understand Bayes' theorem and apply it to clinical examples. SAMPLES: Specific examples of the utility of Bayes' theorem in diagnosis and management. METHODS: Two-by-two tables are used to introduce concepts and understand the theorem. The application in interpretation of diagnostic tests is explained. Clinical examples demonstrate its potential use in making management decisions. MAIN OUTCOME MEASURE: Positive predictive value and conditional probability. RESULTS: The theorem demonstrates the futility of testing when prior probability of disease is low. Application to untreated ocular hypertension demonstrates that the estimate of glaucomatous optic neuropathy is similar to that obtained from the Ocular Hypertension Treatment Study. Similar calculations are used to predict the risk of acute angle closure in a primary angle closure suspect, the risk of pupillary block in a diabetic undergoing cataract surgery, and the probability that an observed decrease in intraocular pressure is due to the medication that has been started. The examples demonstrate how data required for management can at times be easily obtained from available information. CONCLUSIONS: Knowledge of Bayes' theorem helps in interpreting test results and supports the clinical teaching that testing for conditions with a low prevalence has a poor predictive value. In some clinical situations Bayes' theorem can be used to calculate vital data required for patient management.

Chemical disinfectants in ophthalmic practice.

The instrumentation used in ophthalmic clinics can be a source of epidemics in health care set up. Contact tonometry with Schiotz or Applanation tonometer is associated with nosocomial epidemic keratoconjunctivitis outbreaks. Recently identified SARS-CoV-2 (COVID -19) spreads mainly via the respiratory route and fomites and can transmit through other body fluids, including tear film. Various ophthalmic instruments can become a common source of spreading cross infections. Chemical disinfection is one of the most common methods employed to decontaminate instruments and environmental surfaces and prevent transmission of infectious pathogens to patients through medical and surgical instruments. Various chemical disinfectants are available with a varied spectrum to work on a different group of organisms. In this article, we briefly cover commonly used chemical disinfectants in ophthalmic practice like Alcohol (Ethyl Alcohol, Isopropyl Alcohol), Chlorine-based solution (mainly Sodium Hypochlorite), Glutaraldehyde, Hydrogen Peroxide, Formaldehyde, Iodophors, and Quaternary Ammonium Compounds.

Optic disc morphology in primary open-angle glaucoma versus primary angle-closure glaucoma in South India.

Purpose: The aim of this study was to investigate the optic disc morphology in primary angle-closure glaucoma (PACG) versus primary open-angle glaucoma (POAG) in South Indians. Methods: A total of 60 patients (60 eyes) with PACG and 52 patients (52 eyes) with POAG were included in a cross-sectional observational study. The glaucoma diagnosis was based on a glaucomatous appearance of the optic disc correlating with visual field defects. The glaucoma was graded as early, moderate, or severe, depending upon perimetric loss. All patients underwent an ophthalmic evaluation, including visual field examination and planimetric analysis of 30° stereoscopic color optic disc photographs. Results: The POAG and PACG groups did not differ significantly in a disc or rim area, rim width, and frequencies of disc hemorrhages or rim notches. However, early POAG group (n = 15) had a significantly deeper cup depth (P = 0.01), larger beta zone (P = 0.01), and a higher frequency of localized retinal nerve fiber layer (RNFL) defects (P = 0.02) than early PACG (n = 20). Conclusion: In the early stage of the disease, POAG compared to PACG may be characterized by deeper disc cupping, a larger beta zone of peripapillary atrophy, and a higher frequency of localized RNFL defects. Such differences in early glaucoma may suggest differences in pathophysiology in POAG and PACG.

Ocular manifestation in treated multibacillary Hansen's disease.

PURPOSE: To report the prevalence of ocular morbidity in patients with treated multibacillary Hansen's disease (HD) using modern ophthalmic diagnostic techniques in a rural community endemic for HD. DESIGN: Cross-sectional, observation study. PARTICIPANTS: All patients with multibacillary HD who had completed their multidrug therapy and who resided in 4 defined geographical areas in Vellore, Tamil Nadu, India. METHODS: All participants underwent a complete eye examination that included slit-lamp examination, esthesiometry, gonioscopy, applanation tonometry, and dilated fundus examination, including a stereobiomicroscopic examination of the fundus at an ophthalmic center set up for that purpose. Glaucoma suspects underwent automated perimetry using a Humphrey Field Analyzer (Humphrey Instruments, San Leandro, CA). MAIN OUTCOME MEASURES: The prevalence of various ocular disease parameters were reported as mean value with 95% confidence interval. The difference of disease prevalence between various leprosy groups was compared using an unpaired t test. The association between eye symptoms and potentially sight-threatening complications was analyzed using the chi-square test. RESULTS: Three hundred eighty-six of the 446 patients with multibacillary HD residing in the defined areas were evaluated. Four patients (1.04%; 95% confidence interval [CI], 0.0%-2.0%) were bilaterally blind; 33 (8.55%; 95% CI, 5.8%-11.3%) had unilateral blindness. Mean intraocular pressure was 12 mmHg (standard deviation, 4.1 mmHg), and prevalence of glaucoma was 3.6% (95% CI, 1.8%-5.5%). Potentially sight-threatening (PST) pathologic features (corneal anesthesia, lagophthalmos, uveitis, scleritis, and advanced glaucoma) were present in 10.4% (95% CI, 7.4%-13.4%) of patients. Significant cataracts occurred 3 times more frequently in those with polar lepromatous leprosy. The odds ratio for PST pathology in the presence of patient-reported symptoms (pain, redness, inability to close eye, burning, and irritation) was 2.9 (95% CI, 1.34-6.26). CONCLUSIONS: Patients who have completed treatment for multibacillary HD continue to have significant ocular morbidity. A history of specific eye symptoms can be the basis for referral by field staff.

Likelihood ratios: clinical application in day-to-day practice.

In this article we provide an introduction to the use of likelihood ratios in clinical ophthalmology. Likelihood ratios permit the best use of clinical test results to establish diagnoses for the individual patient. Examples and step-by-step calculations demonstrate the estimation of pretest probability, pretest odds, and calculation of posttest odds and posttest probability using likelihood ratios. The benefits and limitations of this approach are discussed.

Clinical measurement and categorization of optic disc in glaucoma patients.

BACKGROUND: Assessment of optic disc size is an important component of optic nerve head examination. Agreement between different methods of disc size measurements is not very good. PURPOSE: To assess the agreement between the disc size assessed by Heidelberg retina tomograph (HRT) and stereobiomicroscopy with a 90 diopter (D) lens. To report the clinical (measured by biomicroscopy) disc diameters of small, average and large optic discs categorized by HRT disc areas. SETTING AND DESIGN: Observational study of subjects examined in the glaucoma clinic of a tertiary eye institute. MATERIALS AND METHODS: Seventy-five eyes of 75 glaucoma subjects were studied. Disc diameter was measured using stereobiomicroscopy and HRT. The agreement between the two sets of measurements was assessed by intraclass correlation coefficient (ICC). Discs were classified into small (<1.6 mm(2)), average (1.6-2.6 mm(2)) and large (>2.6 mm(2)) depending on cutoffs provided by the manufacturers of HRT. The means (95% CI) of the corresponding vertical disc diameter in these groups were assessed. STATISTICAL ANALYSIS: ICC, Bland and Altman plots. RESULTS: ICC for measurements of clinical and HRT horizontal disc diameter was 0.518 and for vertical disc diameter measurement was 0.487. The mean difference between the clinical and HRT measurements as analyzed by the Bland and Altman plot was 0.17 (95% CI, 0.13- 0.47) for horizontal and 0.22 (95% CI, 0.11- 0.54) for vertical disc diameter. Of the 75 eyes, 3 eyes had small discs, 54 average and 18 large discs. The mean clinical vertical disc diameter for small discs was 1.55 mm (95% CI, 1.2-1.7), for average discs was 1.91 mm (95% CI, 1.87-1.96) and for large discs was 2.15 mm (95% CI, 2.03-2.27). CONCLUSION: The agreement between clinical and HRT disc diameter measurements is moderate. Disc diameter measurement on stereobiomicroscopy can be used to categorize discs into small, average and large discs.

The LOXL1 gene variations are not associated with primary open-angle and primary angle-closure glaucomas.

PURPOSE: Glaucoma is a complex disease involving multiple genetic factors. Recently, single nucleotide polymorphisms (SNPs) in the LOXL1 gene have been implicated in exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) but not in the primary glaucomas. This study was conducted to determine the possible involvement of these SNPs in cases of primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). METHODS: The three associated SNPs of LOXL1 (rs1048661, rs3825942, and rs2165241) were screened in 208 unrelated and clinically well-characterized glaucoma cases comprising patients with POAG (n = 112) or PACG (n = 96) along with 105 ethnically matched normal control subjects from Indian populations. Subjects with exfoliative material on the lens and radial pigmentation in the periphery of the lens that could be earlier signs of XFS were excluded. These SNPs were screened by resequencing and further confirmed by PCR-based restriction digestions. Haplotypes were generated with the three SNPs in cases and control subjects, and linkage disequilibrium (LD) and haplotype analysis were performed with the Haploview software, which uses the EM (expectation-maximization) algorithm. RESULTS: The SNPs of LOXL1 did not exhibit any significant association with POAG or PACG, unlike previous studies from Icelandic, Swedish, U.S., and Australian populations with XFS/XFG. Haplotypes generated with these intragenic SNPs did not indicate any significant risk with POAG or PACG phenotypes. The risk haplotype G-G in XFS/XFG in other populations was present in 46% of the normal control subjects in the present cohort. CONCLUSIONS: The results from the present study do not indicate the involvement of the LOXL1 SNPs in POAG and PACG.

Diagnostic capability of scanning laser polarimetry with variable cornea compensator in Indian patients with early primary open-angle glaucoma.

PURPOSE: To evaluate the diagnostic ability of scanning laser polarimetry (GDx variable corneal compensator [VCC]) for early glaucoma in Asian Indian eyes. DESIGN: Cross-sectional observational study. PARTICIPANTS: Two groups of patients (early glaucoma and normal) who satisfied the inclusion and exclusion criteria were included. Early glaucoma was diagnosed in presence of open angles, characteristic glaucomatous optic disc changes correlating with the visual field (VF) on automated perimetry (VF defect fulfilling at least 2 of 3 Anderson and Patella's criteria with mean deviation >or= -6 decibels). Normal subjects had visual acuity >or= 20/30 and intraocular pressure < 22 mmHg, with a normal optic disc and fields and no ocular abnormality. METHODS: All patients underwent complete ophthalmic evaluation, including VF examination (24-2/30-2 Swedish interactive threshold algorithm standard program) and imaging with GDx VCC. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value and negative predictive value, area under the receiving operating characteristic curve, and likelihood ratios (LRs) were calculated for various GDx VCC parameters. RESULTS: Seventy-four eyes (74 patients) with early glaucoma and 104 eyes (104 normal subjects) were enrolled. TSNIT Std Dev (temporal-superior-nasal-inferior-temporal standard deviation) had the best combination of sensitivity and specificity-61.3 and 95.2, respectively-followed by nerve fiber index score > 50 (sensitivity, 52.7%; specificity, 99%). Nerve fiber index score > 50 had positive and negative predictive values of 74.3% and 97.6%, respectively, for an assumed glaucoma prevalence of 5%. Nerve fiber index score > 50 had a positive LR (+LR) of 54.8 for early glaucoma. CONCLUSIONS: GDx VCC has moderate sensitivity, with high specificity, in the diagnosis of early glaucoma. The high +LR for the nerve fiber index score can provide valuable diagnostic information for individual patients.

Learning micro incision surgery without the learning curve.

We describe a method of learning micro incision cataract surgery painlessly with the minimum of learning curves. A large-bore or standard anterior chamber maintainer (ACM) facilitates learning without change of machine or preferred surgical technique. Experience with the use of an ACM during phacoemulsification is desirable.

Practical approach to medical management of glaucoma.

Primary open angle glaucoma (POAG) is usually a chronic, slowly progressive disease. At present, all resources are directed towards reduction of intraocular pressure (IOP), the only known causal and treatable risk factor for glaucoma, and medical management is frequently the first choice in most cases. With the introduction of innovative tools for early diagnosis and newer medications for treatment, decision-making in diagnosis and treatment of glaucoma has become more complex. The philosophy of glaucoma management is to preserve the visual function and quality of life (QOL) of the individual with minimum effects on QOL in terms of cost, side effects, treatment regime, follow-up schedules as well as socioeconomic burden. Our aim should be not to treat just the IOP, optic disc or visual field, but to treat the patient as a whole so as to provide maximum benefit with minimal side effects. In this article, we describe the scientific approach to medical management, mainly of POAG.

Understanding and using sensitivity, specificity and predictive values.

In this article, we have discussed the basic knowledge to calculate sensitivity, specificity, positive predictive value and negative predictive value. We have discussed the advantage and limitations of these measures and have provided how we should use these measures in our day-to-day clinical practice. We also have illustrated how to calculate sensitivity and specificity while combining two tests and how to use these results for our patients in day-to-day practice.