Orbital ophthalmomyiasis caused by Chrysomya bezziana in Thailand

Orbital ophthalmomyiasis occurs infrequently in Thailand. Herein, we report a case in Chiang Mai, Thailand, of orbital ophthalmomyiasis due to larvae of the blow fly Chrysomya bezziana (Diptera: Calliphoridae). A 94-year-old woman was admitted to Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand, with a swollen and ulcerated right upper eyelid. The lesion in the eyelid had multiple holes around the ulcer site; bleeding was accompanied by pus and necrotic tissue - the site was filled with dipteran larvae. Eleven larvae were removed from the patient, of which five were killed for microscopic examination and six were reared in the laboratory under ambient temperature and natural relative humidity until they metamorphose into adult. Five third instars and one adult were morphologically identified as C. bezziana. The predisposing factors were probably chronic immobility, inability of the patient to perform daily activities, and presumably neglected and/or poor personal hygiene. To our knowledge, this case represents the first reported case of orbital ophthalmomyiasis caused by C. bezziana in Thailand.

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.

Relationship between vitamin A deficiency, malnutrition, and conjunctival impression cytology

One hundred seventy-eight children from three villages were studied in a cross-sectional fashion to evaluate the efficacy of conjunctival impression cytology (CIC) to characterize vitamin A status of individual children and populations of children and to examine the relationship of vitamin A status to nutritional status. Although children with abnormal CIC results had lower retinol concentrations than those with normal CIC results (P < 0.02), CIC exhibited poor sensitivity and specificity. Results of a CIC prevalence criterion were concordant with plasma retinol criteria in characterizing the vitamin A status of each community. Plasma retinol measurements, but not CIC, were associated with height (P < 0.003) and severe stunting (P < 0.001). We conclude that although CIC was a poor indicator of an individual child's vitamin A status, it accurately characterized the risk of vitamin A deficiency of communities. Furthermore, vitamin A deficiency defined by circulating retinol measurements but not CIC is associated with poor linear growth.