Sopa Wattananikorn

Normative database of retinal nerve fiber layer and macular retinal thickness in a Thai population

PurposeTo investigate the distribution of retinal nerve fiber layer (RNFL) and macular retinal thickness measured by optical coherence tomography (OCT) in a Thai population.MethodsWe studied one eye each of 250 healthy subjects [age ≥ 18 years; spherical refractive error within ±6 diopters (D); astigmatism ≤3 D; no ocular pathology]. A complete eye examination, standard automated perimetry, and fast RNFL and macular thickness measurement by OCT were performed, and a disc photograph was taken. The distributions of both thicknesses, including their relationship with demographic data, were analyzed.ResultsThe mean ± SD age of the study population was 44.7 ± 12.2 years. The mean ± SD RNFL thickness was 109.3 ± 10.5 m, which was 10% thicker than that in the OCT normative database. RNFL decreased 2.3 m per decade (P < 0.001). Sex and spherical equivalent were not associated with RNFL thinning. The mean ± SD central foveal thickness was 183.2 ± 1.3 m. The macular thickness in the outer area was significantly thinner than that in the inner area (P < 0.001). The temporal regions were the thinnest among the four quadrants (P < 0.001). Thinning of all macular areas, except the center, was found to be associated with advancing age (P < 0.05).ConclusionsRNFL thickness in the measured Thai population was about 10% thicker than that in the original normative database. Macular thickness and RNFL thickness in the superior and inferior quadrants decreased with advancing age.

Blindness and low vision in a tertiary ophthalmologic center in Thailand: The importance of cytomegalovirus retinitis

Purpose: To determine the causes of blindness and low vision in patients consulting a tertiary ophthalmologic center in northern Thailand. Methods: The study population included 2,951 new consecutive patients from the Department of Ophthalmology at University Hospital in Chiang-Mai, Thailand. Main outcome measures were blindness and low vision, which were defined according to World Health Organization criteria. Results: Of 2,951 patients, 369 (12.5%) had blindness and/or low vision (bilateral blindness in 73, unilateral blindness in 129, bilateral low vision in 77, and unilateral low vision in 90). Of the etiological causes of visual loss, age-related ocular disease was the most frequent (128 patients [35%]) followed by infections (66 patients [18%]) and trauma (43 patients [12%]). Although infections and trauma were the predominant causes of blindness, age-related disorders were frequently found in patients with low vision. Of anatomical sites, the lens (134 patients [36%]) was the main location of visual loss, closely followed by disorders of the retina and/or uvea (126 patients [34%]). Blindness and low vision were considered avoidable in 70% of cases. Of 73 patients with bilateral blindness, 14 had active cytomegalovirus retinitis, accounting for 19% of all patients with bilateral blindness. Conclusion: The most common causes of blindness and low vision in a tertiary center in northern Thailand were age-related ocular disorders and infections, which were predominantly cases of cytomegalovirus retinitis in human immunodeficiency virus–infected patients.

HLA-B27-associated acute anterior uveitis in the University Referral Centre in North Thailand: clinical presentation and visual prognosis

Background: Acute anterior uveitis (AAU) is the most frequent type of uveitis encountered in the west. Although human leucocyte antigen (HLA)-B27-associated ankylosing spondylitis was reported in South East Asia, it is not known whether HLA-B27-associated ocular disease is prevalent in Thailand. Methods: A prospective study of 100 unrelated blood donors and 121 consecutive patients with AAU was carried out. All people underwent HLA-B27 typing and full ocular examination. Radiological examination of the sacroiliac joints was conducted in patients with low back pain or arthralgias. Results: The prevalence of HLA-B27 was 10% among the blood donors in contrast with 44% in the AAU group (p<0.001). The clinical characteristics of HLA-B27-associated AAU were similar to those published throughout the world (unilaterality in 74%, hypopyon in 31%, recurrent AAU in 64%). However, the increased intraocular pressure (IOP) was more common in the HLA-B-27-negative group (p = 0.03) than in their HLA-B27-positive counterparts. At least 15% of the HLA B27-positive group had radiological signs of ankylosing spondylitis. Conclusion: The prevalence of HLA-B27 in the population without uveitis in Thailand is about 10% and clinical characteristics of HLA-B27-positive AAU are similar to those reported in the west. In contrast with earlier reports, HLA-B27-negative AAU in Thailand was associated with increased IOP and should be further studied.

Endogenous endophthalmitis due to Salmonella choleraesuis in an HIV-positive patient.

Purpose: To report a case of endogenous endophthalmitis caused by the gram-negative bacterium Salmonella choleraesuis as a first sign of HIV infection in a patient from Thailand. Method: Case description and literature review. Results: A 54-year-old male without systemic complaints developed non-painful panuveitis in his left eye accompanied by high intraocular pressure. On investigation, HIV serology was found positive, and aqueous and blood cultures revealed the bacterium Salmonella choleraesuis. Despite aggressive treatment with antibiotics, the affected eye did not improve, and his visual acuity decreased to no light perception. Conclusions: Endogenous endophthalmitis with the non-typhoidal Salmonellae can occur in the absence of systemic symptoms in an immunocompromised host.