The Royal College of Ophthalmologists' National Ophthalmology Database Study of cataract surgery. Report 5: Clinical outcome and risk factors for posterior capsule rupture and visual acuity loss following cataract surgery in patients aged 90 years and older

BACKGROUND

Older age is commonly associated with an increased risk of surgical complications and comparatively poor outcomes.

PURPOSE

To report cataract surgery outcomes and risk indicators for patients aged 90 years and older.

METHODS

Data collected as part of routine cataract care in 34 centres contributing to the United Kingdom Royal College of Ophthalmologists' National Ophthalmology Database (NOD) were analysed. Very elderly people undergoing cataract surgery were profiled in terms of demographics, pre- and postoperative best-measured visual acuity (VA), ocular co-morbidities, intraoperative posterior capsule rupture (PCR) or vitreous loss or both, and risk indicators for operative PCR and adverse VA outcome.

RESULTS

25,856 cataract operations in 19,166 people of 90 years or older between 2000 and 2014 are reported. Preoperative VA was available for 82.4% eyes, being 0.30 LogMAR or better in 21.5%. Postoperative VA was available for 61.8% eyes, being 0.30 LogMAR or better in 74.4%. For those without ocular co-morbidity, postoperative VA was 0.30 LogMAR or better in 84.7%. Various co-morbidities were present in 49% and contributed to an adverse VA outcome. PCR data were available for all operations and occurred in 2.7%. Significant risk indicators for PCR included pseudoexfoliation/phakodonesis, mature cataract, smaller pupil and worse preoperative VA.

CONCLUSIONS

Slightly poorer cataract surgery outcome results were noted in patients of 90 years or older, more so in patients with ocular co-morbidity which was highly prevalent. However, surgeons should not be deterred from offering cataract surgery to the very elderly as successful visual rehabilitation remains achievable.

Going paperless: improved cataract surgery outcome data quality in a new fully electronic unit

OBJECTIVES

To report outcome data on the first 5000 consecutive cataract cases at a new paperless eye unit and benchmark against the Royal College of Ophthalmologists' National Ophthalmology Database (RCOphth NOD).

METHODS

Using the in-built audit tool of the electronic medical records system, data from all cataract operations performed between 1 April 2014 and 13 January 2017 were compiled.

RESULTS

Five thousand and eight cases were recorded of which the overall intra-operative complication rate was 2.4%, the most common being posterior capsular rupture-1.14%. Follow-up data on post-operative complications were recorded in 98.6% of cases. Pre- and post-operative visual acuities was measured in 98.0% of cases. In all, 40.8% of eyes achieved a visual acuity of 6/6 or better and 90.7% achieved 6/12 or better.

CONCLUSIONS

A data set of >5000 consecutive cataract operations was obtained in this eye department. The recording of pre- and post-operative visual acuity in 98% of cases compare very favourably to the RCOphth NOD Audit Report 2017 where pre- and post-operative visual acuities were recorded in only 57.1% of operations. Despite this difference, the outcome measures from this unit and RCOphth NOD were very similar, validating the results of the RCOphth NOD audit reports. Significantly, when applying the RCOphth NOD audit criteria for measuring post-operative visual acuity, approximately 15% of cases were excluded from the data set, reducing the completeness of the data set. Paperless ophthalmology units are feasible in today's NHS and can produce near complete cataract data sets; this can ultimately lead to more comprehensive and reliable aggregate cataract outcome data.

Cat-PROM5: a brief psychometrically robust self-report questionnaire instrument for cataract surgery

Purpose

To develop a short, psychometrically robust and responsive cataract patient reported outcome measure suitable for use in high-volume surgical environments.

Methods

A prospective study in which participants completed development versions of questionnaires exploring the quality of their eyesight using items harvested from two existing United Kingdom developed parent questionnaires. Participants were 822 patients awaiting cataract surgery recruited from 4 cataract surgical centres based in the UK. Exclusion criteria were other visually significant comorbidities and age <50 years. An iterative multi-stage process of evaluation using Rasch and factor analyses with sequential item reduction was undertaken.

Results

A definitive item set of just five items delivered performance in accordance with the requirements of the Rasch model: no threshold disordering, no misfitting items, Rasch-based reliability 0.90, person separation 2.98, Cronbach’s α 0.89, good targeting of questions to patients with cataract with pre-operative item mean −0.41 logits and absence of significant floor or ceiling effects, minor deviations of item invariance, and confirmed unidimensionality. The test–re-test repeatability intra-class correlation coefficient was 0.89 with excellent responsiveness to surgery, Cohen’s d −1.45 SD. Rasch calibration values are provided for Cat-PROM5 users.

Conclusions

A psychometrically robust and highly responsive five-item cataract surgery patient reported outcome measure has been developed, which is suitable for use in high-volume cataract surgical services.

Cataract surgery patient-reported outcome measures: a head-to-head comparison of the psychometric performance and patient acceptability of the Cat-PROM5 and Catquest-9SF self-report questionnaires

Background Cataract surgery is the most frequently undertaken NHS surgical procedure. Visual acuity (VA) provides a poor indication of visual difficulty in a complex visual world. In the absence of a suitable outcome metric, recent efforts have been directed towards the development of a cataract patient-reported outcome measure (PROM) of sufficient brevity, precision, and responsiveness to be implementable in routine high volume clinical services.

Aim To compare and contrast the two most promising candidate PROMs for routine cataract surgery.

Method The psychometric performance and patient acceptability of the recently UK developed five-item Cat-PROM5 questionnaire was compared with the English translation of the Swedish nine-item Catquest-9SF using Rasch-based performance metrics and qualitative semistructured interviews.

Results Rasch-based performance was assessed in 822 typical NHS cataract surgery patients across four centres in England. Both questionnaires demonstrated good to excellent performance for all metrics assessed, including Person Reliability Indices of 0.90 (Cat-PROM5) and 0.88 (Catquest-9SF), responsiveness to surgery (Cohen’s standardized effect size) of 1.45 SD (Cat-PROM5) and 1.47 SD (Catquest-9SF) and they were highly correlated with each other (R=0.85). Qualitative assessments confirmed that both questionnaires were acceptable to patients, including in the presence of ocular comorbidities. Preferences were expressed for the shorter Cat-PROM5, which allowed patients to map their own issues to the questions as opposed to the more restrictive specific scenarios of Catquest-9SF.

Conclusion The recently UK developed Cat-PROM5 cataract surgery questionnaire is shorter, with performance and patient acceptability at least as good or better than the previous ‘best of class’ Catquest-9SF instrument.

The Royal College of Ophthalmologists' National Ophthalmology Database Study of cataract surgery: report 2, relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture

PURPOSE

To describe the relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture rates in patients undergoing cataract surgery.DesignThe Royal College of Ophthalmologists' National Ophthalmology Database (NOD) study.

METHODS

Anonymised data on 180 114 eyes from 127 685 patients undergoing cataract surgery between August 2006 and November 2010 were collected prospectively from 28 sites. Data parameters included: demographics, biometry, ocular copathology, visual acuity measurements, and surgical complications including posterior capsule rupture, or vitreous loss or both (PCR).

RESULTS

Consultant surgeons performed a higher proportion of operations on eyes whose axial length were at the extremes. Glaucoma and age related macular degeneration were more common in eyes with shorter axial lengths, whilst previous vitrectomy was associated with longer axial lengths. Eyes with brunescent or white cataracts or amblyopia were more common at both axial length extremes. Preoperative visual acuities were similar for eyes with axial length measurements up to approximately 28 mm and worse for eyes with longer axial length measurements. PCR rates showed little change with axial length (overall mean 1.95%, 95% CI: 1.89 to 2.01%), except for a borderline increase in eyes with axial length <20.0 mm where rates were 3.6% (95% CI: 2.0 to 6.3%). The likelihood of PCR in eyes with axial length <20.0 mm was 1.88 times higher than those of ≥20.0 mm (P=0.0373).

CONCLUSION

Rates of ocular comorbidities vary by axial length. PCR rates in eyes with very short or long axial lengths were lower than expected.

The prevalence and analysis of risk factors for age-related macular degeneration: 18-year follow-up data from the Speedwell eye study, United Kingdom

AIMS/PURPOSE

To determine the prevalence of age-related maculopathy (ARM) and age-related macular degeneration (AMD) in men aged 65-83 years living in the Speedwell region of Bristol, United Kingdom and identify modifiable risk factors.

METHODS

A total of 2348 men recruited to the Speedwell prospective cohort study in 1979 were followed up in 1997 with an eye questionnaire and had retinal photographs that were assessed using the International Classification System for ARM.

RESULTS

In all, 934 men (66.8% response rate) attended with a mean of 17.9 years (15.3-20.6 years) follow-up. Early ARM (grades 2-3) was found in 9.2% (95% confidence interval (CI) 7.4%, 11.4%) and late age-related maculopathy (grade 4, AMD) in 0.5% (95% CI 0.2%, 1.2%). The risk of ARM (grades 2-4) was increased with raised C-reactive protein and consumption of lard and solid fats, whereas triglyceride levels were associated with a lower risk. The latter were confirmed in multivariable analyses and in addition, haemodynamic measures also predicted risk (eg mean arterial pressure odds ratio (OR) per z-score 1.37, 95% CI 1.04, 1.79).

CONCLUSIONS

In a representative cohort of men aged 65-83 from Bristol, United Kingdom, many had macular changes that put them at higher risk of developing AMD. Various modifiable exposures were associated with an increased risk ARM/AMD. Opportunities for screening and undertaking secondary prevention interventions need to be explored to prevent progression of the disease and blindness.

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.

Reduced mortality compared with national averages following phacoemulsification cataract surgery: a retrospective observational study

BACKGROUND

Higher or equal rates of mortality are associated with cataract surgery compared with the general population. Cataract surgery has advanced, and the clinical characteristics of the patient undergoing cataract surgery have changed.

AIMS

To reinvestigate survival following cataract surgery.

METHOD

Survival data were gathered up to the end of 2006 on 933 consecutive patients who underwent cataract surgery between December 2000 and February 2001. These data were compared with national and regional mortality figures, and standardised mortality ratios (SMR) were calculated.

RESULTS

After adjusting for age and sex, there was a statistically significant reduced mortality compared with national (SMR = 0.88 (95% CI 0.79 to 0.99)) and regional figures (SMR = 0.87 (95% CI 0.78 to 0.98)).

CONCLUSION

All previous studies found decreased survival among cataract surgery cohorts. These data differ from data at earlier times, as cataract surgery seems to be associated with increased survival. This illustrates the need for continual re-evaluation of accepted medical knowledge in the light of changes in practice and population demographics.

Prevalence and risk factors for common vision problems in children: data from the ALSPAC study

OBJECTIVE

To estimate the distribution and predictors of some common visual problems (strabismus, amblyopia, hypermetropia) within a population-based cohort of children at the age of 7 years.

METHODS

Children participating in a birth cohort study were examined by orthoptists who carried out cover/uncover, alternate cover, visual acuity and non-cycloplegic refraction tests. Prospectively collected data on potential risk factors were available from the study.

RESULTS

Data were available for 7825 seven-year-old children. 2.3% (95% CI 2.0% to 2.7%) had manifest strabismus, 3.6% (95% CI 3.3% to 4.1%) had past/present amblyopia, and 4.8% (95% CI 4.4% to 5.3%) were hypermetropic. Children from the lowest occupational social class background were 1.82 (95% CI 1.03% to 3.23%) times more likely to be hypermetropic than children from the highest social class. Amblyopia (p = 0.089) and convergent strabismus (p = 0.066) also tended to increase as social class decreased.

CONCLUSIONS

Although strabismus has decreased in the UK, it and amblyopia remain common problems. Children from less advantaged backgrounds were more at risk of hypermetropia and to a lesser extent of amblyopia and convergent strabismus. Children's eye-care services may need to take account of this socio-economic gradient in prevalence to avoid inequity in access to care.

The Cataract National Dataset electronic multicentre audit of 55,567 operations: risk stratification for posterior capsule rupture and vitreous loss

AIMS

To identify and quantify risk factors for posterior capsule rupture or vitreous loss or both (PCR or VL or both) during cataract surgery and provide a method of composite risk assessment for individual operations.

METHODS

The Cataract National Dataset was extracted on 55,567 operations from 12 National Health Service (NHS) Trusts using an electronic patient record (EPR) system between November 2001 and July 2006. Risk indicators for variations in the rate of 'PCR or VL or both' were identified by univariate and multivariate analyses. Adjusted odds ratios (ORs) were used to formulate a composite 'bespoke' risk for individual cases.

RESULTS

Overall 'PCR or VL or both' rate was 1.92% (95% CI=1.81-2.04%). Risk indicators for this complication were increasing age, male gender, presence of glaucoma, diabetic retinopathy, brunescent/white cataract, no fundal view/vitreous opacities, pseudo-exfoliation/phacodonesis, reducing pupil size, axial length > or = 26.0 mm, the use of the alpha-blocker doxazosin, inability to lie flat and trainee surgeons performing operations. Adjusted ORs for these variables are used to estimate overall composite risk across multiple risk indicators in the form of a predicted probability of PCR or VL or both. Predicted probability for this complication ranged from less than 0.75% to more than 75%, depending on risk profile of individual operations.

CONCLUSIONS

Higher-risk cases can be predicted, thus better informing the consent process and allowing surgeons to take appropriate precautions. Case-mix is a major determinant of the probability of an intraoperative complication. A simple composite risk estimation system has been developed.

Evaluation of a new cataract surgery referral pathway

AIMS

To compare the quality of referrals and listing rates of direct optometric referrals vs traditional GP referrals for cataract surgery.

METHODS

A retrospective cohort of 124 patients referred for cataract surgery was identified (62 via optometric pathway and 62 via GP pathway). The quality of the referral was assessed by establishing if it contained adequate information relating to the College of Optometrists' referral framework document. Age, sex, drug history, listing rate, operative rate, and visual acuity (best corrected) at referral and at the postoperative visit were recorded and compared between the two referral pathways using the Fisher's exact test.

RESULTS

Optometric referrals, relative to GP referrals, were more likely to include information relating to objective visual loss (100 vs 87%, P=0.0061) and to counsel the patient (97 vs 18%, P=0.0001). GP referrals, relative to optometric referrals, were more likely to comment on personal circumstances (32 vs 3%, P=0.0001), past medical history (95 vs 68%, P=0.0001), and drug history (94 vs 69%, P=0.0009). Operative rates were higher for the optometric direct referrals relative to GP referrals (87 vs 69%, P=0.0284). There was no difference in the visual acuity before or after surgery between the pathways.

CONCLUSIONS

Optometric direct cataract referrals provide better information on objectively measured vision and better delivery of preoperative counselling. Traditional GP referrals contain better medical history, drug information, and details of personal circumstances. Rates of surgery were slightly higher with optometric referrals.

Performance of the 24-2-5 frequency doubling technology screening test: a prospective case study

AIM

To evaluate the performance of the frequency doubling technology (FDT) 24-2-5 screening test by comparison with the established N-30-5 FDT screening test for detection of glaucoma.

METHOD

A prospective random sample of individuals referred for possible glaucoma were tested with FDT screening tests 24-2-5 and N-30-5 using the Humphrey Matrix perimeter in addition to standard clinical examination relevant to glaucoma detection. Discriminatory power, reliability and test time of these tests were assessed and compared. The case definition for glaucoma was made by patient according to the established clinical diagnosis.

RESULTS

Of 63 referred eligible individuals, 53 (84%) were recruited. Sensitivity and specificity for the N-30-5 screening test was 78 and 85% respectively, compared with 83% and 75% for the 24-2-5 with areas under a receiver operator characteristic curve being 0.87 and 0.92. Differences between these indices were not statistically significant. For a specificity of 95%, sensitivity values were 76% and 56% for the 24-2-5 and N-30-5 respectively. Mean (standard deviation) test duration for the FDT 24-2-5 and N-30-5 screening tests were 111 (13) and 39 (10) seconds respectively (p<0.001). A total of 19 subjects (36%) produced unreliable test results in one or both eyes when tested with the 24-2-5 screening test compared with 5 subjects (9%) with the N-30-5 (p<0.0005).

CONCLUSION

Minimal discriminatory power differences existed between the two screening tests evaluated, with both screening tests exhibiting high discriminatory power for detection of individuals with glaucoma. More individuals produced unreliable results on the 24-2-5 screening, which also took longer to perform.

Monte–Carlo simulation of random clustering of endophthalmitis following cataract surgery

BACKGROUND

Endophthalmitis remains a serious and potentially blinding complication of cataract surgery with an overall incidence of approximately 0.14% or one in 700 operations. Despite this knowledge of overall frequency, healthcare providers find themselves confronted with clusters of cases where the appropriate level of response to the cluster is uncertain.

AIM

To illustrate, by means of Monte-Carlo simulation models, the likelihood of random clustering of cases arising in units within a healthcare setting resembling the NHS and separately within the practices of individual surgeons.

METHOD

Simulation models were constructed within a programming language in which individual cataract operations were simulated with a one in 700 likelihood of each operation resulting in a 'case of endophthalmitis'. Random clustering of 'cases of endophthalmitis' was observed in the models and 'outbreaks' were noted and tracked for various outbreak definitions.

RESULTS

The model outputs are presented graphically as the proportion of 'simulated units' affected by an 'outbreak' in a year and separately as the proportion of surgeons affected for a range of 'outbreak definitions'.

CONCLUSION

These data presentations are easy to use and should facilitate a better understanding of shifts from endemic to epidemic rates of endophthalmitis with appropriate investigation of situations where a remediable common cause may exist.

Risk factors for cataract subtypes waterclefts and retrodots: two case–control studies

Waterclefts and retrodots are independently associated with visual impairment, yet a review identified no data on risk factors.

PURPOSE

To investigate risk factors for these two human lens cataract subtypes.

METHOD

Two nested case-control studies: The host study comprised 1078 subjects (55 years) attending the Somerset and Avon Eye Study (SAES). In total, 197 watercleft cases (Oxford grade 0.2 in either eye) and 199 retrodot cases (Oxford grade 1.0 in either eye) were individually age/gender matched to controls. Detailed ophthalmic and potential risk factor data were collected, including body mass index (BMI), smoking, alcohol, diabetes, hypertension, analgesics, vitamin supplementation, nutrition, sunlight exposure, dehydration, hormonal (women), blood lipids, glucose, urea, creatinine, uric acid, and vitamin levels.

RESULTS

For waterclefts, univariable analysis identified BMI, alcohol intake, vitamin status, sunlight, urea, creatinine, and uric acid as possible risk factors. Multivariable analysis identified two independent associations. Total number of 'any' analgesics in the previous year: adjusted P<0.01 (U-shaped risk profile, unadjusted high vs medium use (=reference) OR 2.39, 95% CI 1.35-4.26 with medium use vs none (=reference) OR 0.43, 95% CI 0.26-0.72); total sunlight: adjusted P=0.03 (unadjusted highest exposure vs lowest (=reference) OR 3.25, 95% CI 1.11-9.50). For retrodots, univariable analysis identified alcohol, HRT, and lipids. Multivariable analysis identified two independent associations. Mean number of alcohol units consumed per month, adjusted P=0.02 and HDL cholesterol levels, adjusted P=0.02 (unadjusted ORs NS both).

CONCLUSION

This is the first available published information on risk factors for the human cataractous lens features waterclefts and retrodots.

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

INTRODUCTION

The aim of this study was to assess the vision-related quality of life (VR-QOL) in patients with good distance Snellen visual acuity (VA) who are listed for cataract surgery.

METHODS

An observational cross-sectional prospective study of patients listed for cataract surgery. VA and VR-QOL data using the VCMI questionnaire were collected on patients attending preoperative assessment during June 2002.

RESULTS

A total of 397 cataract patients were listed during this month. Following exclusions there were 378 eligible individuals, 210 (56%) of whom had a VA of 6/12 or better in the eye scheduled for surgery. Of these, 40% patients had only mild VR-QOL impairment. More than half of the patients with good VA (6/12 or better) in the surgery eye and mild VR-QOL impairment described their vision as poor in this eye. However, most of these patients were not dissatisfied with their overall level of vision.

CONCLUSION

A significant number of patients listed for cataract surgery with VA of 6/12 or better had only mild VR-QOL impairment and were not dissatisfied with their overall level of vision. The decision to list a patient for surgery may have been based on the patient's perception of monocular vision rather than their quality of life.

Clinical evaluation of frequency doubling technology perimetry using the Humphrey Matrix 24-2 threshold strategy

AIMS

To evaluate performance of frequency doubling technology (FDT) perimetry using the Humphrey Matrix 24-2 thresholding program in a hospital eye service (HES) glaucoma clinic.

METHODS

A random sample of individuals referred consecutively to the HES for suspected glaucoma were examined with 24-2 threshold FDT in addition to routine clinical tests. The discriminatory power of FDT and standard automated perimetry (SAP) were assessed using glaucomatous optic nerve head appearance as the reference gold standard.

RESULTS

48 of 62 eligible referred individuals were recruited. Glaucoma prevalence was 31%. Median test duration per eye was 5 minutes 16 seconds for FDT and 5 minutes 9 seconds for SAP. There was no significant difference (p = 0.184) between proportions of individuals with reliable test results (FDT 75%, SAP 63%). Using a clinically appropriate binary criterion for abnormal visual field, sensitivity and specificity levels were 100% and 26% respectively for FDT and 80% and 52% for SAP. Both tests had higher negative than positive predictive values with marginal differences between tests. Criterion free receiver operator characteristic analysis revealed minimal discriminatory power differences.

CONCLUSIONS

In a HES glaucoma clinic in which new referrals are evaluated, threshold 24-2 FDT testing with the Humphrey Matrix has performance characteristics similar to SAP. These findings suggest threshold testing using the FDT Matrix and SAP is comparable when the 24-2 test pattern is used.

Pilot National Electronic Cataract Surgery Survey: I. Method, descriptive, and process features

AIM

The primary aim of this large pilot survey was to demonstrate the use and benefits of electronic data collection with respect to rapidly monitoring the access, delivery, and outcome of cataract surgery in the NHS and to update benchmark standards for these parameters of care.

METHOD

Eight NHS departments that currently use specialty-specific electronic clinical systems or Electronic Patient Records (EPR) to collect a minimum preoperative, operative, and anaesthetic data set for cataract surgery agreed to pool their data.

RESULTS

A total of 162 surgeons from 50 consultant teams and eight NHS Trusts agreed to submit their data on a total of 16,541 operations for age-related cataract. This report describes the age, sex, and ethnic profiles of the patients, waiting time for surgery, ocular copathology causing a reason for a guarded visual prognosis, visual impairment on admission, visual acuity in the operated eye, and the characteristics of the anaesthetic and surgical procedures.

CONCLUSIONS

This survey has raised the benchmark standards established by the last National Survey in 1997. There has been a near universal switch to day case, phacosurgery under local anaesthesia (all used in > or =99.1% of cases compared with 70, 77, and 86%, respectively in 1997). The visual impairment in the operated eye is lower with 45% having 6 / 12 or better compared with 27% in 1997. Waiting times and visual impairment in the fellow eye have probably improved although data collection for these variables was incomplete. All departments require specialty-specific clinical systems to efficiently collect and analyse these data and this survey proves their potential to form the basis for national electronic surveys in the future.

Risk factors for progressive visual field loss in primary open angle glaucoma

PURPOSE

The aim of this study was to evaluate routine ophthalmic data to identify clinically useful risk factors for progressive visual field loss in patients with primary open-angle glaucoma (POAG) already receiving intraocular pressure-lowering treatments.

METHODS

A retrospective cohort study design was used. Routine ophthalmic data for all subjects were obtained from case records with the knowledge that baseline clinical data had been collected in a standardised manner. Progression was defined according to the AGIS visual field defect scoring system. Variables evaluated as candidate risk factors for progression were assessed by survival analysis. Factors exerting a significant effect on survival were subsequently tested in a Cox proportional hazards model.

RESULTS

A cohort of 108 eligible POAG patients was followed over an average of 3.6 years, with an average visual field intertest interval of 8 months. The incidence rate of progressive loss among the cohort was 5.4 cases per 100 person years. Increasing age was found to be independently associated with a small but significantly increased risk of glaucomatous visual field defect progression (hazard ratio 1.07, P=0.022), and a borderline association was also demonstrated with being male (hazard ratio 2.76, P=0.057).

CONCLUSIONS

This retrospective investigation has provided preliminary information on factors associated with increased risk of progressive glaucomatous visual field loss that may inform clinical care strategies. Lack of concordance with other studies suggests that further prospective investigations are needed if risk stratification strategies are to be employed in caring for patients with chronic open-angle glaucoma.

Amblyopia treatment outcomes after preschool screening v school entry screening: observational data from a prospective cohort study

BACKGROUND/AIMS

Preschool screening for amblyopia has controversially been abandoned in some localities within the United Kingdom, on the basis that there is no clear evidence of benefit to support its continuation. Data collected within a birth cohort study were used to examine visual outcomes at 7(1/2) years in children who did or did not receive preschool vision screening.

METHODS

Monocular logMAR visual acuity with and without a pinhole was assessed by orthoptists. Contemporary records were used to identify children who had been offered and/or received preschool screening.

RESULTS

Of 6081 children, 24.9% had been offered preschool screening and 16.7% had attended. The prevalence of amblyopia was approximately 45% lower in the children who received preschool screening than in those who did not (1.1% v 2.0%, p = 0.05). The mean acuity in the worse seeing eyes after patching treatment was better for amblyopic children who received preschool screening than for those who did not; 0.14 v 0.20 logMAR (p <0.001). These effects did not persist in an intention to screen analysis.

CONCLUSIONS

Preschool screening at 37 months was associated with an improved treatment outcome for individuals with amblyopia. However, the improvement was clinically small and disappeared when considering all children offered screening rather than only those who received it. Further research is needed into improving the effectiveness of vision screening for preschool children, while in the interim these data do not conflict with current recommendations for school entry screening by orthoptists.

The development and validation of a questionnaire to assess visual symptoms/dysfunction and impact on quality of life in cataract patients: the Visual Symptoms and Quality of life (VSQ) Questionnaire

The aim of the study was to develop a new questionnaire to assess visual symptoms/dysfunction and impact on vision-specific quality of life for those undergoing second eye cataract extraction. Items for the VSQ questionnaire were devised with reference to existing literature and following consultation with eye care experts (n = 18) and interviews with cataract patients (n = 40). Piloting work conducted with 53 patients indicated that the questionnaire was promising, with a high level of internal consistency, low levels of missing data and indications that it was responsive to surgery. A modified version of the questionnaire was completed by 105 patients having received 'early' surgery and 103 scheduled for routine surgery within a randomised controlled trial evaluating the effectiveness of second eye cataract surgery. Analyses showed that the internal consistency of both the visual symptoms/dysfunction and quality of life areas was high (Cronbach's alpha 0.82 and 0.83, respectively). Highly significant improvements were found for early surgery patients (p < 0.0001), with little change among routine surgery patients. Two final versions of the VSQ questionnaire have been produced for future use in assessing visual symptoms/dysfunction and impact on vision-specific quality of life: a scoreable short form and more detailed and sensitive long form.

Effect of a patient training video on visual field test reliability

AIMS

To evaluate the effect of a visual field test educational video on the reliability of the first automated visual field test of new patients.

METHODS

A prospective, randomised, controlled trial of an educational video on visual field test reliability of patients referred to the hospital eye service for suspected glaucoma was undertaken. Patients were randomised to either watch an educational video or a control group with no video. The video group was shown a 4.5 minute audiovisual presentation to familiarize them with the various aspects of visual field examination with particular emphasis on sources of unreliability. Reliability was determined using standard criteria of fixation loss rate less than 20%, false positive responses less than 33%, and false negative responses less than 33%.

RESULTS

244 patients were recruited; 112 in the video group and 132 in the control group with no significant between group difference in age, sex, and density of field defects. A significant improvement in reliability (p=0.015) was observed in the group exposed to the video with 85 (75.9%) patients having reliable results compared to 81 (61.4%) in the control group. The difference was not significant for the right (first tested) eye with 93 (83.0%) of the visual fields reliable in the video group compared to 106 (80.0%) in the control group (p = 0.583), but was significant for the left (second tested) eye with 97 (86.6 %) of the video group reliable versus 97 (73.5%) of the control group (p = 0.011).

CONCLUSIONS

The use of a brief, audiovisual patient information guide on taking the visual field test produced an improvement in patient reliability for individuals tested for the first time. In this trial the use of the video had most of its impact by reducing the number of unreliable fields from the second tested eye.

National audit of the outcome of primary surgery for rhegmatogenous retinal detachment. II. Clinical outcomes

PURPOSE

This national study was designed to audit anatomical outcome and complications relating to primary surgery for rhegmatogenous retinal detachments. This paper presents success and complication rates, and examines variations in outcome.

METHODS

Sampling and recruitment details of this nationwide cross-sectional survey of 768 patients of 167 consultant ophthalmologists having their first operation for rhegmatogenous retinal detachment have been described. The main clinical outcomes detailed here are anatomical reattachment at 3 months after surgery and complications related to surgery. Consultants with a declared special interest in retinal surgery and able to perform pars plana vitrectomy were designated specialists for the analyses.

RESULTS

Overall reattachment rate with a single procedure was 77% (95% CI 73.9-80.2). There were significant differences in reattachment rates between specialists and non-specialists. Without allowing for case-mix, specialists had a reattachment rate of 82% (95% CI 77.9-85.7) with a single procedure and non-specialists 71% (95% CI 65.9-76.0). Allowing for case-mix, there was a significant difference between specialists and non-specialists for grade 2 detachments of 87% and 70% respectively (P < 0.0001). Analysing detachments by break type, the largest difference between specialists and non-specialists was observed for retinal detachments secondary to horseshoe tears, 80% and 68% respectively (P < 0.003). Specialists met the standards set for primary reattachment rates, while non-specialists did not. Over a third of patients had at least one complication reported at some point during the audit period.

CONCLUSIONS

Significant differences were seen in reattachment rates between specialists and non-specialists, overall and for specific subgroups of patients. This study provides relevant, robust and valid standards to enable all surgeons to audit their own surgical outcomes for primary retinal detachment repair in rhegmatogenous retinal detachments, identify common categories of failure and aim to improve results.

National audit of the outcome of primary surgery for rhegmatogenous retinal detachment. I. Sample and methods

PURPOSE

This national study was designed to audit anatomical outcome and complications relating to primary surgery for rhegmatogenous retinal detachments. This paper presents survey methods, characteristics of participating consultants and the demographic and clinical characteristics of the patient sample.

METHODS

Two surveys were undertaken. The first identified consultants who at the time performed retinal detachment surgery in the National Health Service. These surgeons formed the sampling frame for a nationwide cross-sectional clinical study that audited the outcomes of primary surgery for rhegmatogenous retinal detachments. Consultants selected patients according to the study eligibility criteria and data were collected by self-administered postal questionnaires. A validation exercise was carried out to examine selection bias and reporting accuracy.

RESULTS

Only 256/671 (38%) of UK consultants, who responded to the first survey, indicated that they performed retinal detachment surgery on NHS patients. Annual activity varied between 0 and 400 primary procedures for rhegmatogenous retinal detachments. Seven hundred and sixty-eight eligible patients from 167 consultants were recruited for the clinical study. Twenty per cent of patients had a single retinal break with less than one quadrant of associated detachment and 45% had single or multiple breaks within the same quadrant and/or less than two quadrants of associated retinal detachment. Over 50% patients had single or multiple horseshoe tears. Validation studies suggested that there was no significant bias from the selection of patients or inaccuracy in reporting outcomes.

CONCLUSIONS

This large unselected group of primary rhegmatogenous retinal detachments provides a representative sample for considering variations in re-attachment rates.

Amblyopia treatment outcomes after screening before or at age 3 years: follow up from randomised trial

OBJECTIVE

To assess the effectiveness of early treatment for amblyopia in children.

DESIGN

Follow up of outcomes of treatment for amblyopia in a randomised controlled trial comparing intensive orthoptic screening at 8, 12, 18, 25, 31, and 37 months (intensive group) with orthoptic screening at 37 months only (control group).

SETTING

Avon, southwest England.

PARTICIPANTS

3490 children who were part of a birth cohort study.

MAIN OUTCOME MEASURES

Prevalence of amblyopia and visual acuity of the worse seeing eye at 7.5 years of age.

RESULTS

Amblyopia at 7.5 years was less prevalent in the intensive group than in the control group (0.6% v 1.8%; P=0.02). Mean visual acuities in the worse seeing eye were better for children who had been treated for amblyopia in the intensive group than for similar children in the control group (0.15 v 0.26 LogMAR units; P<0.001). A higher proportion of the children who were treated for amblyopia had been seen in a hospital eye clinic before 3 years of age in the intensive group than in the control group (48% v 13%; P=0.0002).

CONCLUSIONS

The intensive screening protocol was associated with better acuity in the amblyopic eye and a lower prevalence of amblyopia at 7.5 years of age, in comparison with screening at 37 months only. These data support the hypothesis that early treatment for amblyopia leads to a better outcome than later treatment and may act as a stimulus for research into feasible screening programmes.

Optic disc cup slope and visual field indices in normal, ocular hypertensive and early glaucomatous eyes

AIM

To evaluate the correlation between internal slope analysis of the optic nerve head and visual field changes in normal eyes and those with ocular hypertension (OHT) and early glaucoma (POAG).

METHODS

One eye of each of 22 normal subjects, 21 patients with ocular hypertension, and 50 patients with glaucoma were examined using the TopSS scanning laser ophthalmoscope. A series of topographic parameters measuring the internal features of the optic discs of these patients were obtained. These findings were compared with the Humphrey visual field analysis of these patients.

RESULTS

Global topographic average slope and cup to disc ratio could discriminate between groups of normal and OHT patients (p = 0.02). All global and sector analysis parameters could discriminate normal subjects from POAG patients. The average slope parameter provided the best separation with a receiver operating characteristic curve area of 0.88. Visual field mean deviation (MD) was most closely correlated with global average slope (r = -0.60, p<10(-7)) and cup to disc ratio (r = -0.40, p<0.001). Visual field MD was also well correlated (r = -0.50, p<0.0001) with slope parameters for sectors S8, S2, and S1.

CONCLUSION

Average slope, a parameter independent of reference planes and magnification effects, is capable of discriminating groups of OHT and POAG patients from a group of normal subjects. This topographic parameter is also well correlated with the visual field MD. Sector slope analysis suggests early glaucomatous damage may occur in the inferotemporal region of the optic disc.

Screening for amblyopia in preschool children: results of a population-based, randomised controlled trial. ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood

INTRODUCTION

The rationale for preschool vision screening programmes has recently been questioned. Evidence about the effects of early treatment is needed, but it is not known how early the target conditions can reliably be detected. In this study, an intensive programme comprising several different screening methods, used at different ages up to 37 months, was compared with the usual practice of visual surveillance and ad hoc referrals.

METHODS

Two groups were randomly selected from children in a population birth cohort study. The control group (n = 1461) received visual surveillance only. The intervention group (n = 2029) was offered in addition a programme of regular visual assessments by orthoptists testing visual acuity, ocular alignment, stereopsis and non-cycloplegic photorefraction.

RESULTS

The intervention group programme yielded more children with amblyopia (1.6% vs. 0.5%, p < 0.01), and was more specific (95% vs. 92%, p < 0.01), than the control programme. The individual components of the intervention programme were compared. The cover test and visual acuity tests were poorly sensitive until the children were 37 months, but were always >99% specific. Photorefraction was more sensitive than acuity testing at all ages below 37 months, with specificity >95% at 31 and 37 months.

CONCLUSIONS

Photorefraction would have detected more children less than 37 months of age with straight-eyed amblyopia than did visual acuity testing, but with more false positives. At 37 months, photorefraction plus a cover test would have been comparable in effectiveness to visual acuity testing plus a cover test.

Co-morbidity in patients with sight-threatening diabetic retinopathy

PURPOSE

To describe the level of co-morbidity in patients with sight-threatening diabetic retinopathy in the United Kingdom.

METHODS

Questionnaires were completed by patients undergoing first photocoagulation treatment for diabetic maculopathy or proliferative retinopathy during a 2 month period throughout the UK.

RESULTS

Overall 15% of patients described angina, 9% had suffered a myocardial infarction and 6% a stroke. Self-reported renal disease was present in 8.5%. Foot ulceration was described by 10% of patients, and 4% had undergone an amputation. 35.5% of patients were on treatment for hypertension. 17.5% of patients had been hospitalised in the previous 6 months, and 3% of patients had died within 9 months of the laser treatment.

CONCLUSIONS

There was significant co-morbidity in these patients, which may affect the management of their retinopathy.

Visual symptomatology in patients with sight-threatening diabetic retinopathy

AIMS

To assess the level of visual symptomatology in patients with sight-threatening diabetic retinopathy.

METHODS

Questionnaires were completed by patients undergoing first photocoagulation treatment for diabetic maculopathy or proliferative retinopathy during a 2-month period throughout the UK, and at 9 months' follow-up.

RESULTS

There were high levels of visual symptomatology prior to the first laser treatment and at follow-up for both patients with maculopathy or with proliferative retinopathy. Only 25.1% of patients with maculopathy and 17.2% of patients with proliferative retinopathy were asymptomatic in terms of reading, seeing the television screen, recognizing faces or with their night vision at baseline. For those with maculopathy 20.1% were aware of colour vision abnormality in the eye to be treated at baseline and 9.5% were aware of new central scotomata since the treatment. Of those with proliferative retinopathy, 13% said that they had given up driving due to poor eyesight and 19% were aware of new peripheral field defects since the treatment.

CONCLUSIONS

There are high levels of visual symptomatology for patients with sight-threatening diabetic retinopathy in the UK despite that fact that screening should aim to detect retinopathy prior to visual loss occurring. Patients should be aware that there may not be any significant improvement in their vision with laser treatment, and that the main aim of treatment is to reduce the likelihood of further visual deterioration.

The assessment of lens opacities in clinical practice: results of a national survey

AIM

To investigate the examination of lens opacities in routine ophthalmic clinical practice.

METHOD

A questionnaire survey was mailed to 703 consultant ophthalmologists in the UK. The surgeons were asked which lens feature(s) they assessed in their clinics when deciding whether to offer cataract surgery.

RESULTS

489 replies were received. A broad range of lens opacities was assessed, with differences between surgeons for some opacities with high prevalences in the population, particularly cortical opacities. Many (74% of 467) surgeons assessed one or more lens opacities (anterior subcapsular cataract, vacuoles, water clefts, coronary flakes, focal dots, retrodots, fibre folds) which may be visually important but which have received relatively little attention by researchers.

CONCLUSIONS

Some classes of lens opacity which are traditionally measured by researchers may be ignored in clinical practice and opacities which are traditionally ignored by some researchers are regarded as clinically important by a substantial number of surgeons.

Reliability of the VCM1 Questionnaire when administered by post and by telephone

PURPOSE

To assess the reliability of different methods of administration of the VCM1 vision-related quality-of-life questionnaire by: a) comparing responses obtained by post to responses obtained in a research clinic and b) comparing responses obtained by telephone to responses obtained in a research clinic.

METHOD

Questionnaire responses given in advance by post (96 subjects) or by telephone (92 subjects) were compared to those subsequently given at a visit to a research clinic. The questionnaire included the VCM1 and two other questions commonly used in surveys of visual impairment (reading small print and recognising a face across the street).

RESULTS

Similar levels of vision-related quality-of-life (VR-QOL) impairment were reported by post and in the research clinic. However, the participants in the telephone test group reported less VR-QOL impairment by telephone than they subsequently reported in the clinic (P = 0.0001). The mean score difference between telephone and clinic administration was 3.2% of the VCM1 questionnaire scale. Lower social class (P = 0.002) and increasing duration of interview (P = 0.003) were associated with a tendency to under-report VR-QOL impairment by telephone. Interference with reading small print (P = 0.0001) and recognising a face across the street (P = 0.0001) were also under-reported by telephone.

CONCLUSIONS

Telephone interviewing caused a general bias towards under-reporting of visual problems which was not confined to the VCM1. Care is required when planning outcome studies and questionnaire surveys to ensure that different methods of questionnaire administration produce comparable results.

Quantitative comparison of static perimetric strategies in early glaucoma: test-retest variability

PURPOSE

The aim of this study is to describe and compare test-retest variability of threshold-related suprathreshold and threshold examination strategies.

METHODS

Threshold-related suprathreshold and FASTPAC threshold central visual field examinations were performed twice (test and retest) within a 4-week period on 322 subjects with early to moderate primary open-angle glaucoma and glaucoma suspects. For both strategies, defects were quantified by a count, or score, of the number of defective locations within the field as a whole and by hemifield, thereby providing a simple measure of defect extent. This quantification was obtained for the suprathreshold strategy at three suprathreshold increments (5, 8, and 12 dB) and for the full threshold strategy at two levels of pattern deviation probability, although absolute full threshold defect depth was not considered. Mean test-retest score differences and spread of score differences were used to describe variability. An index of relative variability was used to compare the two visual field examination strategies.

RESULTS

Marked degrees of defect extent variability were found to exist in both suprathreshold and FASTPAC examination strategies. In general, the suprathreshold strategy exhibited lower test-retest variability of defect extent than the FASTPAC strategy. Suprathreshold test variability was dependent on the suprathreshold increment. FASTPAC examination variability was independent of defect depth when analyzed on the basis of pattern deviation probability values and was also found to be independent of the area of visual field loss.

CONCLUSIONS

Suprathreshold examination techniques may provide a reliable perimetric alternative to thresholding strategies for monitoring individuals with early and moderate glaucoma, although they may not be suitable for individuals with advanced glaucomatous visual field loss.

The Bristol shared care glaucoma study: outcome at follow up at 2 years

AIM

To examine the outcome of care for patients with glaucoma followed up by the hospital eye service compared with those followed up by community optometrists.

METHODS

A randomised study with patients allocated to follow up by the hospital eye service or community optometrists was carried out in the former county of Avon in south west England. 403 patients with established or suspected primary open angle glaucoma attending Bristol Eye Hospital and meeting defined inclusion and exclusion criteria were studied. The mean number of missed points on visual field testing in the better eye (using a "better/worse" eye analysis) in each group were measured. The visual field was measured using the Henson semiautomated central field analyser (CFA 3000). Measurements were made by the research team on all patients at baseline before randomisation and again 2 years after randomisation. The mean number of missed points on visual field testing in the worse eye, mean intraocular pressure (mm Hg), and cup disc ratio using a "better/worse" eye analysis in each group at 2 years were also measured. Measurements were made by the research team on all patients at baseline before randomisation and again 2 years after randomisation. An analysis of covariance comparing method of follow up taking into account baseline measurements of outcome variables was carried out. Additional control was considered for age, sex, diagnostic group (glaucoma suspect/established primary open angle glaucoma), and treatment (any/none).

RESULTS

From examination of patient notes, 2780 patients with established or suspected glaucoma were identified. Of these, 752 (27.1%) fulfilled the entry criteria. For hospital and community follow up group respectively, mean number of missed points on visual field testing at 2 year follow up for better eye was 7.9 points and 6.8 points; for the worse eye 20.2 points and 18.4 points. Similarly, intraocular pressure was 19.3 mm Hg and 19.3 mm Hg (better eye), and 19.1 mm Hg and 19.0 mm Hg (worse eye); cup disc ratio at 2 year follow up was 0.72 and 0.72 (better eye), and 0.74 and 0.74 for hospital and community follow up group respectively. No significant differences in any of the key visual variables were found between the two groups before or after adjusting for baseline values and age, sex, treatment, and type of glaucoma.

CONCLUSIONS

It is feasible to set and run shared care schemes for a proportion of patients with suspected and established glaucoma using community optometrists. After 2 years (a relatively short time in the life of a patient with glaucoma), there were no marked or statistically significant differences in outcome between patients followed up in the hospital eye service or by community optometrists. Decisions to implement such schemes need to be based on careful consideration of the costs of such schemes and local circumstances, including geographical access and the current organisation of glaucoma care within the hospital eye service.

Screening for refractive errors with the Topcon PR2000 Pediatric Refractometer

PURPOSE

The PR2000 (Topcon, Tokyo, Japan) is a photorefractor that has been used in a population study comparing different methods of screening preschool children. The present study was conducted to determine the accuracy of the device in a largely clinical population.

METHODS

Two hundred twenty-two children less than 8 years of age were included. All children were examined by an orthoptist using the PR2000 without inducing cycloplegia. All children then underwent retinoscopy with cycloplegia by an examiner who was unaware of the results from the PR2000 examination.

RESULTS

The PR2000 gave a numerical reading for 90% of the children's right eyes and the message "Out of range" for a further 5%. The readings underestimated the amount of hypermetropic or astigmatic refractive error found on retinoscopy by an amount proportional to the magnitude of the refractive error. Agreement with retinoscopy for the axis of astigmatism more than 0.75 D was moderately good (intraclass correlation coefficient [ICC] = 0.63). The PR2000 was more useful as a screener, especially for anisometropia for which it was 91% sensitive and 92% specific. The repeatability was good for sphere (ICC = 0.74), less so for astigmatism (ICC = 0.59), and better than the optometrist for anisometropia (ICC = 0.38). The presence of nonrefractive diagnoses and the age of the children examined made little difference in the screening results.

CONCLUSIONS

The PR2000 underestimated hypermetropic refractive errors when used without cycloplegia. However, it was at least as good a screening device as other similar instruments, especially when judged by its ability to detect anisometropia and the repeatability of the results.

Use of vision tests in clinical decision making about cataract surgery: results of a national survey

AIM

To provide information on the use of vision tests in clinical decision making about cataract surgery in the UK.

METHOD

A questionnaire survey was mailed to 703 consultant ophthalmologists.

RESULTS

A response rate of 70% was obtained. Monocular distance visual acuity was the only visual function that was tested routinely by all surgeons. Supplementary use of contrast sensitivity and glare testing was low. Many surgeons (35%) were willing to consider surgery at acuity levels better than 6/9 and a small but substantial number (12%) indicated that they did not use an acuity criterion. Being prepared to consider surgery at relatively good levels of acuity was not associated with more common use of other tests of vision.

CONCLUSION

Many UK surgeons are prepared to consider cataract extraction at relatively good levels of visual acuity and use other vision tests infrequently.

The Bristol Shared Care Glaucoma Study: reliability of community optometric and hospital eye service test measures

BACKGROUND/AIMS

Primary open angle glaucoma patients and glaucoma suspects make up a considerable proportion of outpatient ophthalmological attendances and require lifelong review. Community optometrists can be suitably trained for assessment of glaucoma. This randomised controlled trial aims to assess the ability of community optometrists in the monitoring of this group of patients.

METHODS

Measures of cup to disc ratio, visual field score, and intraocular pressure were taken by community optometrists, the hospital eye service and a research clinic reference "gold" standard in 405 stable glaucoma patients and ocular hypertensives. Agreement between and within the three centres was assessed using mean differences and intraclass correlation coefficients. Tolerance limits for a change in status at the level of individual pairs of measurements were also calculated.

RESULTS

Compared with a research clinic reference standard, measurements made by community optometrists and those made in the routine hospital eye service were similar. Mean measurement differences and variability were similar across all three groups compared for each of the test variables (IOP, cup to disc ratio, and visual field). Overall, the visual field was found to be the most reliable measurement and the cup to disc ratio the least.

CONCLUSIONS

Trained community optometrists are able to make reliable measurements of the factors important in the assessment of glaucoma patients and glaucoma suspects. This clinical ability should allow those optometrists with appropriate training to play a role in the monitoring of suitable patients.

The National Diabetic Retinopathy Laser Treatment Audit. III. Clinical outcomes

PURPOSE

To describe the short-term clinical outcomes for a cohort of patients undergoing first photocoagulation treatment for proliferative retinopathy or maculopathy in the United Kingdom.

METHOD

Nine-month follow-up of the Royal College of Ophthalmologists' national audit of laser treatment for diabetic retinopathy.

RESULTS

For eyes with maculopathy, 9.2% had had a deterioration in visual acuity equivalent to a doubling of the visual angle and 3.3% of eyes had a visual acuity of less than 6/60 at follow-up. There had been an improvement in the macular oedema or exudate in 64.6% and 77.3% respectively. Prognostic factors for a poorer visual acuity at follow-up were worse visual acuity at baseline, the presence of diffuse (vs focal) oedema and grid (vs focal) treatment. For eyes with proliferative retinopathy, the retinal neovascularisation had regressed fully in 50.8% of cases, whilst there had been no change or a deterioration in 10.3%. A visual acuity of less than 6/60 at follow-up was present in 8.6% of eyes. There was a poor morphological outcome at follow-up (as defined by rubeosis, new tractional detachment or having had a vitrectomy) in 7.2%. Risk factors for poor morphological outcome were the presence of 'high-risk characteristics', female sex and the presence of concurrent maculopathy at baseline. Regression of neovascularisation was associated with greater areas of retinal ablation at the initial treatment session. Although some eyes with proliferative retinopathy appeared to be undertreated initially compared with DRS and ETDRS protocols, some of these eyes did respond to lower amounts of treatment.

CONCLUSION

For maculopathy, poorer outcome was related to worse visual acuity at baseline, diffuse (vs focal) maculopathy, and grid treatment. For proliferative retinopathy, poorer outcome was related to 'high-risk characteristics' and coexistence of maculopathy at baseline, and improvement was related to larger areas of ablation. The relationship of poor outcome with worse initial disease argues for earlier detection of retinopathy.

Proposed classification for topographic patterns seen after penetrating keratoplasty

AIMS

To create a clinically useful classification for post-keratoplasty corneas based on corneal topography.

METHODS

A total of 360 topographic maps obtained with the TMS-1, from 95 eyes that had undergone penetrating keratoplasty (PKP), were reviewed independently by two examiners in a masked fashion, and were categorised according to a proposed classification scheme.

RESULTS

A high interobserver agreement (88% in the first categorisation) was achieved. At 12 months post-PKP, a regular astigmatic pattern was observed in 20/85 cases (24%). This was subclassified as oval in three cases (4%), oblate symmetric bow tie in six cases (7%), prolate asymmetric bow tie in six cases (7%), and oblate asymmetric bow tie in five cases (6%). An irregular astigmatic pattern was observed in 61/85 cases (72%), subclassified as prolate irregular in five cases (6%), oblate irregular in four cases (5%), mixed in seven cases (8%), steep/flat in 11 cases (13%), localised steepness in 16 cases (19%), and triple pattern in three cases (4%). Regular astigmatic patterns were associated with significantly higher astigmatism measurements. The surface asymmetry index was significantly lower in the regular astigmatic patterns.

CONCLUSIONS

In post-PKP corneas, the prevalence of irregular astigmatism is about double that of regular astigmatism, with a trend for increase of the irregular patterns over time.

Development of a questionnaire for measurement of vision-related quality of life

PURPOSE

To define vision-related quality of life, to outline the development of a vision-specific quality of life instrument and to present the characteristics of a 10-item 'core' questionnaire.

METHOD

A standard method included: 1. Generation of relevant issues by individual interviews with 38 visually impaired adults, consultation with 37 professionals and support workers and literature review. 2. Operationalisation, involving 58 ophthalmic patients. 3. Pre-testing, to maximise face validity and content validity, involving 184 individuals with a variety of different visual problems and social backgrounds. 4. Adoption of a modular approach to item selection. 5. Formal piloting in 92 individuals to establish reliability and construct validity.

RESULTS

More than 232 items were tested of which 139 were considered suitable for a final question pool or 'parent' questionnaire (the VQOL). From this parent questionnaire individual items or groups of items can be selected. Ten broadly applicable items referring to physical, social and psychological issues were selected for the core questionnaire (the VCM1). The VCM1 has high reliability (alpha = 0.93) and validity.

CONCLUSIONS

Any self-reported problem relating to vision may constitute a quality of life issue. A modular approach to item selection may provide the flexibility to investigate vision-related quality of life in a wide range of clinical settings, allowing detailed assessment of specific problems and also cross-study comparisons where appropriate.