Resolution of adefovir-related nephrotoxicity by adefovir dose-reduction in patients with chronic hepatitis B.

BACKGROUND: Chronic hepatitis B patients (CHB) treated with adefovir were followed up to evaluate nephrotoxicity and its outcome. AIM: To assess the incidence of renal dysfunction during adefovir therapy in Asian patients and factors associated with it, and evaluate strategies to improve adefovir-related renal dysfunction and their impact on viral suppression. METHODS: Chronic hepatitis B clinic patients from a tertiary hospital on adefovir treatment, with their clinical and laboratory parameters were extracted from the hospital electronic clinical database in an observational study design. Patients were excluded if they had liver/renal transplant, baseline renal impairment or were on dialysis. Adefovir-related renal dysfunction was defined as adefovir-related abnormal serum creatinine (ARASC) > 125 µmol/L (males), >90 µmol/L (females); adefovir-related abnormal GFR <60 mL/min; and adefovir-related increased serum creatinine >0.5 mg/dL, without other known causes of nephrotoxicity. RESULTS: A total of 271/383 adefovir-treated patients were suitable for analysis and 33(12%) patients developed abnormal serum creatinine. Cumulative increase in proportion of patients with ARASC was 33.8% and GFR ≤60 mL/min was 38.3% by 6 years, while serum creatinine increase ≥0.5 mg/dL was 21.48% by 5 years. Using multivariate analysis, the only independent baseline predictor of ARASC was GFR ≤76.1 mL/min. Patients who had ARASC had similar levels of viral suppression to those who did not have ARASC. Those who had ARASC either continued adefovir (24%), switched therapy (24%) or had adefovir dose reduction (52%). ARASC resolved and GFR normalised in almost all patients after either switching therapy or reducing adefovir dose, with no difference between the two strategies (P = 0.737). Those with adefovir dose reduction had no significant increase in HBV DNA (P = 0.170). CONCLUSIONS: Adefovir-related renal dysfunction occurred in a significant number of adefovir-treated patients, but reduction of the dose led to renal improvement without compromising treatment efficacy.

The lacrimal lens as an assessment factor in hard contact lens fitting.

The fitting of hard contact lenses relies primarily on the evaluation of the findings of 'K' readings, the fluorescein pattern of the tear configuration and the interpretation of the lens movement upon blinking and the lens position after blinking. All of these methods have some disadvantages in the evaluation procedure: (a) keratometer readings measure cornical radius in a small and restricted area of the central cornea not in the larger area to eventually be covered by the lens (Bennett and Rabbetts, Clinical Visual Optics. Butterworths, London, UK, pp. 420-421, 1984); (b) the fluorescein pattern is sometimes unreliable especially in the presence of excessive tear flow; (c) lens movement, arguably the most reliable of evaluation methods, nonetheless requires some alternative back-up technique. This presentation outlines the possibility of utilising the lacrimal lens as a useful additional procedure to the above when prescribing a lens curvature of choice. It should be pointed out that the technique discussed refers to spherical or near spherical corneas.