Biomedical subjects

Paisan Ruamviboonsuk

Publications and source records attributed to Paisan Ruamviboonsuk.

6 recordsLinked to original sources

PubMed2006

Interobserver agreement in the interpretation of single-field digital fundus images for diabetic retinopathy screening.

PURPOSE: To assess agreement among a group of ophthalmic care providers, including ophthalmologists and trained nonphysician personnel, in the interpretation of single-field digital fundus images for diabetic retinopathy screening. DESIGN: Interobserver reliability study. PARTICIPANTS: Twelve ophthalmic care personnel, including 3 retina specialists, 3 general ophthalmologists, 3 ophthalmic nurses, and 3 ophthalmic photographers. METHODS: All participants were to read 400 good single-field digital fundus images of diabetic patients from a community hospital. The nonphysician personnel group read the images 1 month after attending a 2-day intensive instruction course regarding diabetic retinopathy screening. The ophthalmologists read the images without additional training. The 3 retina specialists read the images again together 2 months later to form a consensus regarding retinopathy severity and macular edema for each case. All readers used the Early Treatment Diabetic Retinopathy Study standard photographs as guidelines. MAIN OUTCOME MEASURES: The kappa statistic was used for the reliability assessment of the diabetic retinopathy severity and macular edema, and for the identification of cases that needed referral to ophthalmologists. RESULTS: There is only fair agreement among all readers. The multirater kappa coefficient for retinopathy severity is 0.34; for macular edema, 0.27; and for referral cases, 0.28. Retina specialists have the best agreement among all groups (kappa = 0.58 for retinopathy severity or macular edema, kappa = 0.63 for referrals). There is also fair agreement when all readers are compared with the consensus of retina specialists (kappas = 0.35, 0.28, and 0.29 for retinopathy severity, macular edema, and referrals, respectively), and the retina specialist group also has the best agreement (kappas = 0.63, 0.65, and 0.67 for retinopathy severity, macular edema, and referrals). CONCLUSIONS: Without additional training, retina specialists may be the most reliable personnel to interpret single-field digital fundus images for diabetic retinopathy screening. For other ophthalmic care personnel to achieve comparable reliability, a comprehensive instruction course with specific continuing education is essential. Authorized nonphysician interpreters should be experts, and new standard photographs for single-field digital fundus image interpretation may also be required to improve interobserver reliability.

Adult↗

PubMed2005

Screening for diabetic retinopathy in rural area using single-field, digital fundus images.

OBJECTIVE: To evaluate the practicability of using single-field, 2.3 million-pixel, digital fundus images for screening of diabetic retinopathy in rural areas. MATERIAL AND METHOD: All diabetic patients who regularly attended the diabetic clinic at Kabcheang Community Hospital, located at 15 kilometers from the Thailand-Cambodia border, were appointed to the hospital for a 3-day diabetic retinopathy screening programme. The fundi of all patients were captured in single-field, 45 degrees, 2.3 million-pixel images using nonmydriatic digital fundus camera and then sent to a reading center in Bangkok. The fundi were also examined through dilated pupils by a retinal specialist at this hospital. The grading of diabetic retinopathy from two methods was compared for an exact agreement. RESULTS: The average duration of single digital fundus image capture was 2 minutes. The average file size of each image was 750 kilobytes. The average duration of single image transmission to a reading center in Bangkok via satellite was 3 minutes; via a conventional telephone line was 8 minutes. Of all 150 patients, 130 were assessed for an agreement between dilated fundus examination and digital fundus images in diagnosis of diabetic retinopathy. The exact agreement was 0.87, the weighted kappa statistics was 0.74. The sensitivity of digital fundus images in detecting diabetic retinopathy was 80%, the specificity was 96%. For diabetic macular edema the exact agreement was 0.97, the weighted kappa was 0.43, the sensitivity was 43%, and the specificity was 100%. CONCLUSION: The image capture of the nonmydriatic digital fundus camera is suitable for screening of diabetic retinopathy and single-field digital fundus images are potentially acceptable tools for the screening. The real-time image transmission via telephone lines to remote reading center, however, may not be practical for routine diabetic retinopathy screening in rural areas.

Adult↗

PubMed2005

The fundoscopic features for differentiation between polypoidal choroidal vasculopathy and choroidal neovascularization from age-related macular degeneration.

OBJECTIVES: To evaluate the fundus features that can differentiate polypoidal choroidal vasculopathy (PCV) from choroidal neovascularization (CNV) due to age-related macular degeneration (AMD). DESIGN: Retrospective, case-control study. MATERIAL AND METHOD: The fundoscopic features of AMD-related CNV and PCV were compared for evaluation of relative risks for PCV. The odds ratio, sensitivity and specificity of each feature were also calculated. RESULTS: A total of 30 patients, 15 PCV and 15 age-matched non-PCV cases, approved by indocyanine green angiography (ICG), were enrolled. The odds ratio is highest for subretinal polyp-like structure and lowest in scar formation (28 and 0, respectively) and these ratios are statistically significant differences (p = 0.001 and 0.032 respectively). The ratio for either circinate exudates, or larger than 4-disc area of subretinal fluid, or retinal pigment epithelial detachment is 1.75. The ratio for peripapillary location is 1.63. Subretinal membrane has a ratio of 1 while subretinal hemorrhage and subretinal fibrin have less than 1; they are 0.31 and 0.23 respectively. All these ratios are not statistically significant differences (p > 0.05). CONCLUSION: The orange polyp-like structures beneath retina are hallmarks for diagnosis of PCV. The "serosanguineous retinopathy", described as serous retinal deatchment or retinal pigment epithelial detachment with circinate exudates with or without subretinal hemorrhage at the posterior pole or peripapillary region, may also suggest the condition.

Adult↗

PubMed2005

The high-dose, alternate-week intravitreal ganciclovir injections for cytomegalovirus retinitis in acquired immune deficiency syndrome patients on highly active antiretroviral therapy.

OBJECTIVES: To evaluate the efficacy, and complications of the high-dose, alternate-week, intravitreal ganciclovir injection for cytomegaloviral retinitis (CMVR) in acquired immune deficiency syndrome (AIDS) patients on highly active antiretroviral therapy (HAART). DESIGN: Retrospective case series. PARTICIPANTS: AIDS patients with CMVR and on HAART MATERIAL AND METHOD: The high-dose, 4 mg/0.1 ml, ganciclovir was injected intravitreally to the enrolled patients on an alternate-week basis. The patients were monitored clinically until the retinitis was inactive, then the injections were withdrawn. The injections were re-initiated if relapse occurred. MAIN OUTCOME MEASURES: The number of eyes achieved inactive retinitis and corresponded to the number of injections, number of relapses and corresponded duration, visual acuity during the injection, and complications of the injection. RESULTS: Inactive lesions were found in 42/51 eyes (82.40%), the corresponding mean number of injections was 5.4 (1-18) per eye. There was no relapse and the corresponded duration of follow-up was 5.1 months (1-16). The final visual outcomes were improved or stable in 26 eyes (50.9%). These visual outcomes were statistically related to initial visual acuity (p = 0.022) but not statistically related to the number of injections (p = 0.929). Complications were found in 7/51 eyes (13.7%). They were vitreous haze, immune recovery uveitis, rhegmatogenous retinal detachment, and infectious endophthalmitis. CONCLUSION: The high-dose, alternate-week, intravitreal injection of ganciclovir may be an alternative for the treatment of CMVR in AIDS patients who are on HAART However, the induction course is longer than the weekly regimen and close monitoring of patients is essential.

AIDS-Related Opportunistic Infections↗

PubMed2003

Repeatability of an automated Landolt C test, compared with the early treatment of diabetic retinopathy study (ETDRS) chart testing.

PURPOSE: To evaluate the repeatability of visual acuity scores from the automated test and compare them with the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart. DESIGN: Instrument validation study based on a model of repeatability study in two observations. SMETHODS: a prospective, clinic-based, comparative study. A total of 206 participants without ocular diseases and refractive errors in their right eyes were randomly enrolled in the automated group in which 107 participants performed the automated test and the ETDRS group in which 99 participants read the ETDRS chart. All participants were tested with only their right eyes without corrections at 4 meters and came back to have the same tests 1 week later. The automated test used the Landolt rings as optotypes and was conducted by a low-ended personal computer with a 15-inch monitor and a wireless keyboard. The "letter" score calculated by counting every correct response to optotypes, and the "threshold curve" score interpreted from the optotype size at the midpoint of a visual acuity threshold curve. RESULTS: The 95% confidence interval of test-retest of visual acuity scores from the automated test are comparable to the ETDRS chart (.143 compared with.125 for letter scores,.145 compared with.122 for threshold curve scores). The score repeatabilities, calculated from the standard deviations of test-retest, from the automated test are also comparable to the ETDRS chart (.201 compared with.177 for letter scores,.206 compared with.172 for threshold curve scores). All comparisons demonstrated no statistical difference (P >.05). CONCLUSIONS: The automated testing system in this study enables practical measuring visual acuity by the Landolt rings. The system's repeatability, which is comparable to the ETDRS chart, supports its role as an alternative tool for measuring outcome in new clinical research. Its ability to practically generate visual acuity threshold curves may also be useful in future clinical research studies.

Adolescent↗

PubMed2002

The Thai logarithmic visual acuity chart.

OBJECTIVE: To evaluate visual acuity scores from the Thai and the standard logarithmic visual acuity chart. DESIGN: Comparative non-randomized clinical study. PARTICIPANTS AND METHOD: 153 subjects, calculated from sample size estimation, without any ocular disease and aged between 18 and 80 years old who could read English and at least 3 out of 5 letters of the largest line of both charts were enrolled to use only their right eyes to read the Thai and the standard logarithmic visual acuity chart without any refractive correction. 27 subjects came back for second measurements of visual acuity in the same manner as the first a week later. MAIN OUTCOME MEASUREMENT: The visual acuity scores were divided into the Snellen or the whole line score and the ETDRS or the letter-by-letter score. The former was compared by weighted Kappa and the latter was compared by the paired t-test. RESULTS: There was high agreement in weighted Kappa between the Snellen scores from the Thai and standard chart (k = 0.7375). There was also high agreement in weighted Kappa between the Snellen scores from the first and second reading of the Thai chart (k = 0.7304) and the standard chart (k = 0.7282). A high correlation was observed between the ETDRS scores from the Thai and standard charts (r = 0.947). Also there was a high correlation between the ETDRS scores of the first and second reading of both the Thai chart (r = 0.962) and the standard chart (r = 0.952). There was a significant difference between the ETDRS scores from the Thai and standard chart (p<0.0001). There was no significant difference between the ETDRS scores from the first and second reading of either the Thai chart (p = 0.794) or the standard chart (p = 0.62). CONCLUSION: The Snellen visual acuity score from the Thai chart is comparable to the standard chart. Although the ETDRS score from the Thai chart is different statistically from the standard chart, its test-retest variability tends to be low. This suggests the possibility of using the Thai chart for monitoring of the ETDRS score in research studies.

Adolescent↗