The Bristol cataract listing survey: profile of listed patients with visual acuity 6/12 or better

Cataract extraction and patient vision-related quality of life: a cohort study

AIMS

Cataract surgery is one of the most common surgeries performed, but its overuse has been reported. The threshold for cataract surgery has become increasingly lenient; therefore, the selection process and surgical need has been questioned. The aim of this study was to evaluate the changes associated with cataract surgery in patient-reported vision-related quality of life (VR-QoL).

METHODS

A prospective cohort study was conducted. Consecutive patients referred to cataract clinics in an NHS unit in Scotland were identified. Those listed for surgery were invited to complete a validated questionnaire (TyPE) to measure VR-QoL pre- and post-operatively. TyPE has five different domains (near vision, distance vision, daytime driving, night-time driving, and glare) and a global score of vision. The influence of pre-operative visual acuity (VA) levels, vision, and lens status of the fellow eye on changes in VR-QoL were explored.

RESULTS

A total of 320 listed patients were approached, of whom 36 were excluded. Among the 284 enrolled patients, 229 (81%) returned the questionnaire after surgery. Results revealed that the mean overall vision improved, as reported by patients. Improvements were also seen in all sub-domains of the questionnaire.

CONCLUSION

The majority of patients appear to have improvement in patient-reported VR-QoL, including those with good pre-operative VA and previous surgery to the fellow eye. VA thresholds may not capture the effects of the quality of life on patients. This information can assist clinicians to make more informed decisions when debating over the benefits of listing a patient for cataract extraction.

[Clinical practice variation in cataract surgery]

PURPOSE

Cataract surgery rates have dramatically increased in the last two decades. However, clinical practice variation in cataract surgery has not been thoroughly studied. The aim of this review is to analyze clinical practice variation, including the causes and consequences of this phenomenon. Then, its role in health care planning and health care quality is focused, emphasizing the importance of reducing it and providing several practical strategies to accomplish it.

RECENT FINDINGS

The latest researches are presented in this article. They identify the development and implementation of clinical practice guidelines as the best tool to standardize care processes.

CONCLUSION

Managing unwarranted or unwanted variation would improve quality of care and may lead to a significant saving in health care spending.

The British Asian community eye study: outline of results on the prevalence of eye disease in British Asians with origins from the Indian subcontinent

Background:

Asians from the Indian Subcontinent form the largest ethnic minority in the United Kingdom. Data on the prevalence of visually-impairing eye conditions in this population are vital for planning eye health care services.

Materials and Methods:

This survey was based in the two London boroughs with the largest Asian populations. Subjects originating from the Indian Subcontinent were identified from GP practice records. All subjects were asked about demographic details and were given a full ophthalmological examination. The severity of cataract, glaucoma, diabetic retinopathy, and age-related maculopathy was recorded. Blindness was defined as logMAR visual acuity of 0.99 (Snellen equivalence 20/200 in the better eye) or worse, ‘low vision’ was defined as Snellen equivalence of 20/63 or worse (logMAR 0.5 or higher), and visual impairment was defined as visual acuity worse than 20/40.

Results:

The median age was 56 years. Two hundred and eighty four subjects did not attend for eye examination. Of the 922 examined, 128 subjects (13.9%) were ‘visually impaired,’ 39 (4.2%) had ‘low vision,’ and 6 (0.7%) were bilaterally blind. The overall prevalence of cataract, open-angle glaucoma, age-related macular degeneration, and diabetic retinopathy were 77%, 1.0%, 8.7%, and 8.8%, respectively.

Conclusion:

Visual impairment rates amongst Asians seem to be similar to Caucasian populations in the UK. The prevalence of cataract and diabetic retinopathy is higher, while the risk of ARMD and OAG are comparable. In view of the high cataract prevalence, a more detailed assessment of the visual profile and factors limiting healthcare accessibility in this community are needed.

Relationship between socioeconomic deprivation or urban/rural residence and visual acuity before cataract surgery in Northern Scotland

PURPOSE

To evaluate the influence of socioeconomic factors on visual acuity before cataract surgery. 


METHODS

The medical case notes of 240 consecutive patients listed for cataract surgery from January 1, 2010, at Grampian University Hospital, Aberdeen, were reviewed retrospectively. Patients with ocular comorbidity were excluded. Demographics, postal codes, and visual acuity were recorded. Scottish Index of Multiple Deprivation was used to determine the deprivation rank. Home location was classified as urban or rural. The effect of these parameters on preoperative visual acuity was investigated using chi-square tests or Fisher exact test as appropriate. 


RESULTS

A total of 184 patients (mean 75 years) were included. A total of 127 (69%) patients had visual acuity of 6/12 or better. An association was found between affluence and preoperative visual acuity of 6/12 or better (χ2trend = 4.97, p = 0.03), with a significant rising trend across quintile of deprivation. There was no evidence to suggest association between geographical region and preoperative visual acuity (p = 0.63). 


CONCLUSION

Affluence was associated with good visual acuity (6/12 or better) before cataract surgery. There was no difference in preoperative visual acuity between rural and urban populations.

An evaluation of the 10-item vision core measure 1 (VCM1) scale (the Core Module of the Vision-Related Quality of Life scale) using Rasch analysis

PURPOSE

To assess and re-engineer the Vision Core Measure 1 (VCM1) questionnaire in low vision (LV) and cataract participants using Rasch analysis.

METHODS

295 participants drawn from a low vision clinic and 181 from a cataract surgery waiting list completed the 10-item VCM1. Unidimensionality, item fit to the model, response category performance, differential item functioning (DIF) and targeting of items to patients were assessed. Category collapsing and item removal were considered to improve the questionnaire.

RESULTS

The initial fit of the VCM1 (combined populations) to the Rasch model showed lack of fit (chi2 = 83.3, df = 50, p = 0.002). There was evidence of DIF between the two populations which could not be resolved. Consequently, each population was assessed separately. Irrespective of the population, disordering of response category thresholds was evident. However, collapsing categories produced ordered thresholds and resulted in fit to the Rasch model for the LV (Total chi2 = 41.6, df = 30; p = 0.08) and cataract population (Total chi2 = 17.9, df = 20, p = 0.59). Overall, the VCM1 behaved as a unidimensional scale for each population and no item showed evidence of DIF. Item targeting to patients was however sub-optimal particularly for the cataract population.

CONCLUSION

The VCM1 questionnaire could be improved by shortening the response scale, although different response categories are required for cataract and LV populations. Calibration of items also differed across populations. While the VCM1 performs well within the Rasch model, in line with its initial purpose, it requires the addition of items to satisfactorily target low vision and cataract populations.