The effect on visual function of Hydroview intraocular lens opacification: a cross-sectional study.

PURPOSE: Hydroview intraocular lenses (IOLs) have been associated with symptomatic opacification of the optic necessitating IOL exchange. Glare and misty vision have been noted as common presenting symptoms. This study's purpose was to investigate the impact of IOL opacification on objective measurements of visual function, including glare, and on vision-related quality of life. METHODS: All patients who underwent Hydroview IOL implantation at Bristol Eye Hospital between December 2000 and the end of February 2001 were invited for assessment along with patients found to have Hydroview IOL opacification in routine ophthalmic clinics. Glare, visual acuity, contrast sensitivity, visual field, and colour vision were assessed. Vision-related quality of life and subject's symptoms were determined by questionnaire. IOL opacification was assessed by slit lamp bio-microscopy and anterior segment photography. RESULTS: Data from 129 patients were analysed. Fifty subjects had opacified IOLs and 79 clear IOLs. Subjects with opacified IOLs showed dramatically higher levels of glare (adjusted mean difference of 0.63 log units 95% CI, 0.45-0.82; P<0.001) with only mildly reduced visual acuity (adjusted mean difference of 0.09 logMAR units 95% CI, 0.03-0.15; P=0.002). Opacification was associated with poorer contrast sensitivity (P<0.001), visual field (P<0.001), and with lower vision-related quality of life (P<0.001). CONCLUSIONS: This study highlights the significant impact IOL opacification has on visual performance and experience, in particular glare and consequent impact on quality of life. The study shows that to quantify accurately the effect of IOL opacification on vision glare must be assessed.

The Cataract National Dataset electronic multicentre audit of 55,567 operations: when should IOLMaster biometric measurements be rechecked?

PURPOSE: Calculation of intraocular lens (IOL) power for implantation during cataract surgery depends on ocular biometric measurements. The aim of this study was to characterise the normal range of intra- and interindividual variation in axial length (AL) and corneal power (K) when IOLMaster measurements were possible and to derive recommendations as to which outlying measurements merit verification before acceptance. METHODS: The Medisoft electronic patient database contains prospectively collected data conforming to the United Kingdom (UK) Cataract National Dataset on 55,567 cataract operations. From this AL and K information on the 32,556 eyes (14,016 paired) of patients older than 25 years, without corneal pathology, history of intraocular surgery and who had all biometric measurements taken with the Zeiss IOLMaster (Carl Zeiss Meditec) were extracted. R 2.8.1 (R Foundation for Statistical Computing) was used for statistical analysis. RESULTS: Mean age was 76.4 years and 62.0% were female. Mean (95% confidence interval) values for AL, mean K and corneal astigmatism were 23.40 (21.27-26.59) mm, 43.90 (40.94-47.01) D and 1.04 (<2.50) D. Nearly all astigmatism was either with or against the rule. Differences between paired eyes were not statistically significant. 95% individuals had asymmetry of AL and mean K<0.70 mm and 0.92 D, respectively. CONCLUSIONS: On the basis of approximation of the 95% CI above, it is suggested that AL, mean K and keratometric astigmatism measurements outside the ranges 21.30-26.60 mm, 41.00-47.00 D and >2.50 D, respectively, and intraindividual asymmetry of AL >0.70 mm or mean K>0.90 D should be verified before acceptance.