Diabetic retinopathy progression and visual outcome after phacoemulsification in South-Asian and Afro-Caribbean patients with diabetes.

PURPOSE: To determine diabetic retinopathy or maculopathy progression and visual outcome following phacoemulsification in South-Asian and Afro-Caribbean patients with diabetes. METHODS: Review of notes of patients with type II diabetes undergoing phacoemulsification by one surgeon. The inclusion criteria were: (a) South-Asian or Afro-Caribbean ethnicity, (b) monocular cases with a minimum postoperative follow-up of 6 months, and (c) binocular cases with an interval of at least 6 months between the operation in the two eyes. The nonoperated eye was used as control. The development or progression of diabetic retinopathy or maculopathy and final visual acuity were recorded. RESULTS: In all, 30 diabetic patients were included. There were 19 South-Asians (Pakistani, Indian, and Bangladeshi) and 11 Afro-Caribbeans. The mean (+/-SD) age was 68.9 (+/-10) years. Retinopathy or maculopathy progression was noted in seven patients (23.4%), two South-Asians, and five Afro-Caribbeans. There was no significant difference in the number of operated and fellow eyes whose retinopathy or maculopathy progressed postoperatively. Progression of retinopathy or maculopathy occurred more often in Afro-Caribbeans compared to South-Asians (P=0.02, logistic regression analysis). The mean (+/-SD) postoperative follow-up was 12.4 (+/-6.5) months. Visual acuity improved by at least two or more Snellen lines in 19 eyes (63.3%); 26 eyes (86.7%) achieved a final visual acuity of at least 6/12. CONCLUSIONS: Afro-Caribbeans may be at a higher risk of progression of retinopathy or maculopathy after phacoemulsification.

Mass photokeratitis following exposure to unprotected ultraviolet light.

We report a cluster of patients developing photokeratitis as a result of exposure to unprotected UV-B light source. The incident occurred at a cattle livestock market auction where the light source protective covers of mercury vapour lamps were damaged because of vandalism. The incident was investigated by the District Council as a public health and safety issue. This report stresses the hazards of ultraviolet lamps routinely used in public places and the need for proper maintenance of these light sources.

A rapid and highly selective method for the estimation of pyro-, tri- and orthophosphates.

A rapid, highly selective and simple method has been developed for the quantitative determination of pyro-, tri- and orthophosphates. The method is based on the formation of a solid complex of bis(ethylenediamine)cobalt(III) species with pyrophosphate at pH 4.2-4.3, with triphosphate at pH 2.0-2.1 and with orthophosphate at pH 8.2-8.6. The proposed method for pyro- and triphosphates differs from the available method, which is based on the formation of an adduct with tris(ethylenediamine)cobalt(III) species. The complexes have the composition [Co(en)(2)HP(2)O(7)]4H(2)O and [Co(en)(2)H(2)P(3)O(10)]2H(2)O, respectively. The precipitation is instantaneous and quantitative under the recommended optimum conditions giving 99.5% gravimetric yield in both cases. There is no interferences from orthophosphate, trimetaphosphate and pyrophosphate species in the triphosphate estimation up to 5% of each component. The efficacy of the method has been established by determining pyrophosphate and triphosphate contents in various matrices. In the case of orthophosphate, the proposed method differs from the available methods such as ammonium phosphomolybdate, vanadophosphomolybdate and quinoline phosphomolybdate, which are based on the formation of a precipitate, followed by either titrimetry or gravimetry. The precipitation is instantaneous and the method is simple. Under the recommended pH and other reaction conditions, gravimetric yields of 99.6-100% are obtainable. The method is applicable to orthophosphoric acid and a variety of phosphate salts.