Sakarin Ausayakhun

Accuracy and Reliability of Telemedicine for Diagnosis of Cytomegalovirus Retinitis

PURPOSE To determine the feasibility of remote diagnostic screening for cytomegalovirus (CMV) retinitis among HIV patients in northern Thailand. DESIGN Prospective, observational cross-sectional study. METHODS One hundred eighty-two eyes from 94 consecutive patients with HIV seen in 2008 and 2009 at a tertiary university-based medical center were photographed using a digital retinal camera. Individual and composite images were uploaded to a secure web site. Three expert graders accessed the electronic images and graded each image for signs of CMV retinitis. Results of remote expert grading were compared with on-site patient examination by local expert ophthalmologists. RESULTS On-site ophthalmologists diagnosed CMV retinitis in 89 (48.9%) of 182 eyes. Trained ophthalmic photographers obtained digital retinal images for all 182 eyes. As compared with the on-site examinations, the sensitivity for detecting CMV retinitis by remote readers using composite retinal images ranged from 89% to 91%. The specificity for detecting CMV retinitis by remote readers ranged from 85% to 88%. Intrarater reliability was high, with each grader achieving a κ value of 0.93. Interrater reliability among the 3 graders also was high, with a κ value of 0.86. CONCLUSIONS Remote diagnostic screening for CMV retinitis among HIV-positive patients may prove to be a valuable tool in countries where the burden of HIV exceeds the capacity of the local eye care providers to screen for ocular opportunistic infections.

Clinical features of newly diagnosed cytomegalovirus retinitis in northern Thailand.

PURPOSE To characterize the clinical manifestations of cytomegalovirus (CMV) retinitis in northern Thailand. DESIGN Prospective, observational, cross-sectional study. METHODS We recorded characteristics of 52 consecutive patients newly diagnosed with CMV retinitis at a tertiary university-based medical center in northern Thailand. Indirect ophthalmoscopy by experienced ophthalmologists was supplemented with fundus photography to determine the proportion of eyes with various clinical features of CMV retinitis. RESULTS Of the 52 patients with CMV retinitis, 55.8% were female. All were HIV-positive. The vast majority (90.4%) had started antiretroviral therapy. CMV retinitis was bilateral in 46.2% of patients. Bilateral visual acuity worse than 20/60 was observed in 23.1% of patients. Of 76 eyes with CMV retinitis, 61.8% had zone I disease and 21.6% had lesions involving the fovea. Lesions larger than 25% of the retinal area were observed in 57.5% of affected eyes. CMV retinitis lesions commonly had marked or severe border opacity (47.4% of eyes). Vitreous haze often was present (46.1% of eyes). Visual impairment was more common in eyes with larger retinitis lesions. Retinitis lesion size, used as a proxy for duration of disease, was associated with fulminant appearance (odds ratio, 1.24; 95% confidence interval, 1.01 to 1.51) and marked or severe border opacity (odds ratio, 1.36; 95% confidence interval, 1.11 to 1.67). Based on lesion size, retinitis preceded antiretroviral treatment in each patient. CONCLUSIONS Patients seeking treatment at a tertiary medical center in northern Thailand had advanced CMV retinitis, possibly because of delayed diagnosis. Earlier screening and treatment of CMV retinitis may limit progression of disease and may prevent visual impairment in this population.

Telemedicine Diagnosis of Cytomegalovirus Retinitis by Nonophthalmologists

IMPORTANCE Cytomegalovirus (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. OBJECTIVE To determine the accuracy of nonophthalmologist photographic graders in diagnosing CMV retinitis from digital fundus photographs. DESIGN, SETTING, AND PARTICIPANTS Fifteen 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 MEASURES Graders 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. RESULTS Relative 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 RELEVANCE The 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.

Retinal Detachment Associated With AIDS-Related Cytomegalovirus Retinitis: Risk Factors in a Resource-Limited Setting

PURPOSE To determine risk factors predictive of retinal detachment in patients with cytomegalovirus (CMV) retinitis in a setting with limited access to ophthalmic care. DESIGN Case-control study. METHODS Sixty-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. RESULTS Patients 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). CONCLUSION Bilateral 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.

Access to ophthalmologic care in Thailand: a regional analysis.

Abstract Purpose: The 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. Methods: We 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. Results: In 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. Conclusion: Thailand 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.

Comparison of autophotomontage software programs in eyes with CMV retinitis.

PURPOSE Automated mosaic software programs are used to stitch together overlapping retinal fundus photographs. The performance of these programs in eyes with retinal diseases has not been independently evaluated. This study compares the quality of the mosaic products of three autophotomontage software programs, using digital fundus photographs of eyes with cytomegalovirus (CMV) retinitis. METHODS Photographs of 99 eyes with CMV retinitis of 94 patients with HIV were taken at Maharaj Nakorn Chiang Mai Hospital in Chiang Mai, Thailand. Automated mosaic images were created for each of the 99 eyes by three different commercially available programs: IMAGEnet (Topcon, Oakland, NJ), i2k Retina (DualAlign LLC, Clifton Park, NY), and AutoMontage (OIS, Sacramento, CA). Three masked graders ranked each set of mosaics for each eye. The graders also assessed the overall image quality and documented mosaic artifacts in each image. RESULTS i2k Retina was ranked as the best program (70%-88%) more often than AutoMontage (10%-33%, P < 0.001) or IMAGEnet (0%-4%, P < 0.001) for creating automontages from digital fundus photographs of eyes with CMV retinitis. Acceptable quality mosaic images were reported most commonly for i2k Retina (93%-94%) and AutoMontage (91%-95%), followed by IMAGEnet (27%-56%, P < 0.001). IMAGEnet had a significantly higher percentage of mosaic errors than did either i2k Retina or AutoMontage (P < 0.001). CONCLUSIONS In eyes with CMV retinitis, both the i2k Retina and AutoMontage software packages appear to create higher quality mosaics than does IMAGEnet. Automated retinal mosaic imaging may be valuable in diagnosing CMV retinitis and observing disease progression.

Visual acuity outcomes in cytomegalovirus retinitis: early versus late diagnosis

Aims To determine if early dilated fundus examination for cytomegalovirus (CMV) retinitis leads to better visual outcomes in areas with limited HIV care, where patients may have long-standing retinitis before they are diagnosed with HIV. Methods Twenty-four eyes of 17 patients with CMV retinitis who were seen at an urban HIV clinic in Chiang Mai, Thailand, were included in this retrospective cohort study. Participants were divided into two groups based on the amount of time from the first documented CD4 count below 100 cells/mm3 to the first eye examination for CMV retinitis. Average visual acuity in each group was calculated at the time CMV retinitis was first detected, and then at 3, 6 and 12 months after diagnosis. Results The group of patients who received an eye examination within approximately 4 months of the initial low CD4 count measurement had better baseline visual acuity (median 20/30,IQR 20/20 to 20/60) compared with patients who presented later (median 20/80, 20/60 to hand motion); p=0.03). Visual acuity did not change significantly during the 12-month study period in either the early group (p=0.69) or late group (p=0.17). Conclusion In this study, patients who were examined sooner after a low CD4 count had better vision than patients who were examined later. Routine early screening of patients with CD4 counts under below 100 cells/mm3 may detect earlier disease and prevent vision loss.