12 research outputs found
Diagnostic Utility of Ocular Symptoms and Vision for Cytomegalovirus Retinitis
Purpose: CMV retinitis remains a leading cause of blindness in countries with a high burden of AIDS. Although dilated fundus examinations are recommended for those with CD4 counts below 100 cells/µL, in practice only those with poor vision and/or symptoms are routinely referred for screening. Therefore, the predictive value of this common practice should be assessed.
Methods: This is a prospective cross-sectional study. Patients with known HIV and a CD4 count of less than 100 cells/µL attending an HIV clinic in Chiang Mai, Thailand completed a standardized questionnaire about visual symptoms and underwent visual acuity testing and dilated fundus examination. Participants without CMV retinitis were invited for repeated examinations every 3 months until their CD4 count exceeded 100 cells/µL. Patient-level statistical analyses were conducted to calculate diagnostic test characteristics, with bootstrapping to account for correlated data.
Results: HIV patients with CMV retinitis were more likely to complain of visual symptoms (p = 0.01) compared to those without CMV retinitis, including scotoma (p = 0.0002), itchy or watery eyes (p < 0.0001), and eye pain (p = 0.003); they were also more likely to have visual acuity worse than CF (p = 0.0003). However, the absence of eye symptoms and the absence of poor vision did not strongly affect the probability that a patient did not have disease (negative likelihood ratio 0.56 and 0.76, respectively).
Conclusions: Ocular symptoms and poor visual acuity were poor diagnostic indicators for the presence of CMV retinitis. Systemic screening for HIV patients with CD4 count below 100 cells/µl should be carried out to catch the disease at its early stage to avoid blindnes
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Diagnostic Utility of Ocular Symptoms and Vision for Cytomegalovirus Retinitis.
PurposeCytomegalovirus (CMV) retinitis remains a leading cause of blindness in countries with a high burden of AIDS. Although dilated fundus examinations are recommended for those with CD4 counts below 100 cells/μL, in practice only those with poor vision and/or symptoms are routinely referred for screening. Therefore, the predictive value of this common practice should be assessed.MethodsThis is a prospective cross-sectional study. Patients with known HIV and a CD4 count of less than 100 cells/μL attending an HIV clinic in Chiang Mai, Thailand completed a standardized questionnaire about visual symptoms and underwent visual acuity testing and dilated fundus examination. Participants without CMV retinitis were invited for repeated examinations every 3 months until their CD4 count exceeded 100 cells/μL. Patient-level statistical analyses were conducted to calculate diagnostic test characteristics, with bootstrapping to account for correlated data.ResultsOf 103 study participants, 16 had CMV retinitis diagnosed at some point during the study. Participants with CMV retinitis were more likely to complain of visual symptoms compared to those without CMV retinitis (p = 0.01), including scotoma (p = 0.0002), itchy or watery eyes (p < 0.0001), and eye pain (p = 0.003); they were also more likely to have visual acuity worse than Counting Fingers (p = 0.0003). However, the absence of eye symptoms and the absence of poor vision did not strongly affect the probability that a patient did not have disease (negative likelihood ratio 0.56 and 0.76, respectively).ConclusionsOcular symptoms and poor visual acuity were poor diagnostic indicators for the presence of CMV retinitis. Systematic screening of HIV patients with CD4 counts below 100 cells/μl should be carried out to detect disease at an early stage, when blindness can still be prevented
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Access to Ophthalmologic Care in Thailand: A Regional Analysis
PurposeThe World Health Organization (WHO) recommends that Southeast Asian countries have ≥ 1 ophthalmologist per 100,000 persons, equally distributed in urban and rural areas. However, regional patterns of eye care have been poorly characterized. This study investigates the distribution of ophthalmologists in Thailand and provides regional estimates of access to ophthalmologists.MethodsWe geocoded the work address of ophthalmologists listed in the 2008 directory of the Royal College of Ophthalmologists of Thailand. We determined the number of ophthalmologists per 100,000 persons at the national, provincial, and district levels using data from the 2000 Thai Population Census, and assessed demographic factors associated with meeting the WHO recommendation of ≥ 1 ophthalmologist per 100,000 persons.ResultsIn 2008, Thailand had 1.52 ophthalmologists per 100,000 persons; however, only 20 of 76 provinces (26%) and 134 of 926 districts (14%) met the WHO recommendation of ≥ 1 ophthalmologist per 100,000 persons. District factors associated with not meeting the WHO recommendation included a high proportion of children, a high proportion of elderly, and a high proportion of rural residents.ConclusionThailand meets the WHO's goal for access to ophthalmologic care, but the distribution of ophthalmologists is uneven, with less access to ophthalmologic care in rural areas
Telemedicine Diagnosis of Cytomegalovirus Retinitis by Nonophthalmologists
ImportanceCytomegalovirus (CMV) retinitis continues to be a leading cause of blindness in many developing countries. Telemedicine holds the potential to increase the number of people screened for CMV retinitis, but it is unclear whether nonophthalmologists could be responsible for interpreting fundus photographs captured in a telemedicine program.ObjectiveTo determine the accuracy of nonophthalmologist photographic graders in diagnosing CMV retinitis from digital fundus photographs.Design, setting, and participantsFifteen nonexpert graders each evaluated 182 mosaic retinal images taken from the eyes of patients with AIDS who were evaluated at the Ocular Infectious Diseases Clinic at Chiang Mai University in Chiang Mai, Thailand.Main outcomes and measuresGraders diagnosed each image as CMV retinitis present, CMV retinitis absent, or unknown. The results from each grader were compared with those of an indirect ophthalmoscopic examination from an experienced on-site ophthalmologist as well as with the consensus grade given by a panel of CMV retinitis experts.ResultsRelative to the on-site ophthalmologist, the sensitivity of remote CMV retinitis diagnosis by nonexpert graders ranged from 64.0% to 95.5% (mean, 84.1%; 95% CI, 78.6%-89.6%)), and the specificity ranged from 65.6% to 92.5% (mean, 82.3%; 95% CI, 76.6%-88.0%)). Agreement between nonexpert and expert graders was high: the mean sensitivity and specificity values of nonexpert diagnosis using expert consensus as the reference standard were 93.2% (95% CI, 90.6%-95.8%) and 88.4% (95% CI, 85.4%-91.1%), respectively. Mean intrarater reliability also was high (mean Cohen κ, 0.83; 95% CI, 0.78-0.87).Conclusions and relevanceThe sensitivity and specificity of remote diagnosis of CMV retinitis by nonexpert graders was variable, although several nonexperts achieved a level of accuracy comparable to that of CMV retinitis experts. More intensive training and periodic evaluations would be required if nonexperts are to be used in clinical practice
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Telemedicine Screening for Cytomegalovirus Retinitis at the Point of Care for Human Immunodeficiency Virus Infection
ImportanceCytomegalovirus (CMV) retinitis is a leading cause of blindness in many developing countries, likely the result of inadequate screening. Telemedicine screening for CMV retinitis instituted at the point of care for human immunodeficiency virus (HIV) infection may allow for earlier detection.ObjectivesTo determine the diagnostic accuracy of retinal photography in detecting CMV retinitis at the point of HIV care and to characterize the clinical manifestations of CMV retinitis detected through the screening program.Design, setting, and participantsWe enrolled 103 participants from a population of 258 patients with HIV and a CD4 level of less than 100/μL treated at an HIV clinic in Thailand from June 2010 through June 2012. We captured mosaic fundus photographs through a dilated pupil using a digital fundus camera. An experienced on-site ophthalmologist masked to the results of the fundus images subsequently examined each eye with indirect ophthalmoscopy and recorded the clinical findings on a standardized form. Three remote graders evaluated each image for CMV retinitis.InterventionFundus photography and indirect ophthalmoscopy.Main outcomes and measuresSensitivity and specificity of telemedicine relative to indirect ophthalmoscopy for diagnosis of CMV retinitis and clinical features of CMV retinitis lesions.ResultsSixteen patients (15.5%) were diagnosed as having CMV retinitis, of whom 5 (31%) had bilateral disease. Of the 21 eyes (10.2%) with CMV retinitis, 7 (33%) had visual symptoms. Retinitis lesions occupied less than 10% of the total retinal surface area in 13 of 21 eyes (62%) and did not involve the posterior pole (ie, zone 1) in 15 of 21 eyes (71%). Mean logMAR visual acuity in affected eyes was 0.41 (95% CI, 0.11-0.71; Snellen equivalent, 20/50 [95% CI, 20/25-20/100]). The mean sensitivity for the 3 remote graders in detecting CMV retinitis on fundus photography was 30.2% (95% CI, 10.5%-52.4%), and mean specificity was 99.1% (95% CI, 97.8%-100.0%). The CMV retinitis lesions missed by the remote graders (false-negative findings) were more likely to be small (P = .001) and located in the peripheral retina (P = .04).Conclusions and relevancePatients undergoing screening at a clinic for HIV treatment had less extensive retinitis than patients in recent reports from an ophthalmology clinic. Retinal photography with the camera used in this study was not highly sensitive in detecting CMV retinitis but may identify disease with an immediate threat to vision. Improved accuracy will require a camera that can more easily image the peripheral retina
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Retinal Detachment Associated With AIDS-Related Cytomegalovirus Retinitis: Risk Factors in a Resource-Limited Setting
PurposeTo determine risk factors predictive of retinal detachment in patients with cytomegalovirus (CMV) retinitis in a setting with limited access to ophthalmic care.DesignCase-control study.MethodsSixty-four patients with CMV retinitis and retinal detachment were identified from the Ocular Infectious Diseases and Retina Clinics at Chiang Mai University. Three control patients with CMV retinitis but no retinal detachment were selected for each case, matched by calendar date. The medical records of each patient were reviewed, with patient-level and eye-level features recorded for the clinic visit used to match cases and controls, and also for the initial clinic visit at which CMV retinitis was diagnosed. Risk factors for retinal detachment were assessed separately for each of these time points using multivariate conditional logistic regression models that included 1 eye from each patient.ResultsPatients with a retinal detachment were more likely than controls to have low visual acuity (odds ratio [OR], 1.24 per line of worse vision on the logMAR scale; 95% confidence interval [CI], 1.16-1.33) and bilateral disease (OR, 2.12; 95% CI, 0.92-4.90). Features present at the time of the initial diagnosis of CMV retinitis that predicted subsequent retinal detachment included bilateral disease (OR, 2.68; 95% CI, 1.18-6.08) and lesion size (OR, 2.64 per 10% increase in lesion size; 95% CI, 1.41-4.94).ConclusionBilateral CMV retinitis and larger lesion sizes, each of which is a marker of advanced disease, were associated with subsequent retinal detachment. Earlier detection and treatment may reduce the likelihood that patients with CMV retinitis develop a retinal detachment
Diagnostic test characteristics of ocular symptoms and visual acuity for the prediction of cytomegalovirus retinitis.
<p>Diagnostic test characteristics of ocular symptoms and visual acuity for the prediction of cytomegalovirus retinitis.</p
Risk factors for CMV retinitis among individuals with HIV and low CD4 count in northern Thailand: importance of access to healthcare
AimTo determine if poor access to healthcare is associated with increased cytomegalovirus (CMV) retinitis risk among patients with HIV with CD4 counts of <100 cells/μL screened in a resource-limited setting.MethodsThis is a prospective cross-sectional study. Patients with known HIV and a CD4 count of <100 cells/μL attending an HIV clinic in Chiang Mai, Thailand, completed a standardised questionnaire and underwent dilated fundus examination. Participants without CMV retinitis were invited for repeated examinations every 3 months until their CD4 count exceeded 100 cells/μL. The relationship between various potential risk factors and CMV retinitis was assessed with logistic regression.Results103 study participants were enrolled. At enrolment, the mean age was 37.5 (95% CI 35.7 to 39.2) years, 61.2% (95% CI 51.6% to 70.7%) were male and the mean CD4 count was 29.5 (95% CI 25.9 to 33.1) cells/μL. 21 eyes from 16 (15.5%) participants were diagnosed with CMV retinitis. In multivariate analyses, CMV retinitis was significantly associated with lower CD4 count (OR 1.42 per 10-cell decrement, 95%CI 1.05 to 1.93), longer travel time to clinic (OR 3.85 for those with >30-min travel time, 95% CI 1.08 to 13.8) and lower income (OR 1.22 per US$50 less income, 95% CI 1.02 to 1.47).ConclusionsCD4 count, low income and longer travel time to clinic were significant risk factors for CMV retinitis among patients with HIV in a resource-limited setting. These results suggest that reducing blindness from CMV retinitis should focus on increasing accessibility of screening examinations to poor and hard-to-reach patients