Validity of EuroQOL-5D, time trade-off, and standard gamble for age-related macular degeneration in the Singapore population.

BACKGROUND/AIMS: Utility values of age-related macular degeneration (AMD) in Asian patients are unknown. This study aims to assess utility values and construct validity of the EuroQOL-5D (EQ-5D), time trade-off (TTO), and standard gamble (SG) instruments in the Singapore multi-ethnic AMD population. METHODS: Cross-sectional, two-centre, institution-based study. Visual acuity (VA), clinical AMD severity, and utility scores on the EQ-5D, TTO, and SG were obtained from 338 AMD patients. VA was analysed in terms of the better-seeing eye (BEVA), worse-seeing eye (WEVA), and weighted average of both eyes (WVA). We evaluated SG on the perfect health-death (SG(death)) and binocular perfect vision-binocular blindness (SG(blindness)) scales. Construct validity was determined by testing a priorihypotheses relating the EQ-5D, TTO, and SG utility scores to VA and clinical AMD severity. RESULTS: The mean utilities on the EQ-5D, TTO, SG(death), and SG(blindness) were 0.89, 0.81, 0.86, and 0.90, respectively. EQ-5D scores correlated weakly with BEVA, WEVA, and WVA (Pearson's correlation coefficients -0.291, -0.247, and -0.305 respectively, P<0.001 for all). SG(death) and SG(blindness) demonstrated no correlation with BEVA, WEVA, or WVA (Pearson's correlation coefficients, range -0.06 to -0.125). TTO showed weak association only with WEVA and WVA (correlation coefficients -0.237, -0.228, P<0.0001), but not with BEVA (correlation coefficient -0.161). Clinical AMD severity correlated with EQ-5D and SG(death), but not with TTO and SG(blindness) (P=0.004, 0.002, 0.235, and 0.069, respectively). CONCLUSIONS: AMD has a negative impact on utilities, although utility scores were high compared with Western cohorts. EQ-5D, TTO, and SG showed suboptimal construct validity, suggesting that health status utilities may not be sufficiently robust for cost-utility analyses in this population.

Awareness of blindness and other smoking-related diseases and its impact on motivation for smoking cessation in eye patients.

PURPOSE: Cigarette smoking is a major cause of morbidity and mortality. The association between smoking and eye diseases is less widely recognised relative to other better-known smoking-related conditions. This study aims to assess the awareness and fear of known smoking-related diseases among current smokers attending an ophthalmology outpatient clinic and to evaluate their relative impact on the likelihood of smoking cessation. PATIENTS AND METHODS: A cross-sectional survey using a structured interview of randomly selected current smokers attending an eye clinic was conducted. The knowledge of six smoking-related diseases (lung cancer, heart attack, stroke, blindness, other cancers, and other lung diseases) was assessed. The fear of smoking-related conditions and the relative impact of each smoking-related condition on the smoker's motivation to quit smoking were evaluated. RESULTS: Out of 200 current smokers aged from 14 to 83 years, only 42.5% (85 patients) were aware that smoking causes blindness. Smokers' perception of harm caused by smoking was 6.53±3.21 (mean±SD) on a visual analogue scale of 0 to 10. Patients placed blindness as the second most important motivating factor to quit smoking immediately, within 1 year and 5 years, after lung cancer. CONCLUSION: The awareness of the risk of blindness from smoking was lowest compared with five other smoking-related diseases among eye patients who smoke. However, blindness remains a key motivational factor in smoking cessation and hence should be emphasised as an important negative health consequence of smoking in public health education and anti-smoking campaigns.

Optimising the management of choroidal neovascularisation in Asian patients: consensus on treatment recommendations for anti-VEGF therapy.

In Asian countries, age-related macular degeneration (AMD), specifically wet AMD or choroidal neovascularisation (CNV), is an important cause of blindness and visual handicap. Vascular endothelial growth factors (VEGF) play an integral role in the development of CNV and thus provide an important therapeutic target. Current treatment paradigms for neovascular AMD recognise the place of photodynamic therapy (PDT) in the management of this condition. However, combination therapy targeting different pathways to produce a synergistic effect may result in improved visual outcomes and reduced duration of treatment. Anti-VEGF therapy has greatly improved treatment outcomes in patients with CNV, and a growing body of evidence supports the role of these agents as monotherapy or in combination with PDT. In particular, anti-VEGF may be a first-line treatment option in certain types of subfoveal myopic CNV as well as for classic and occult juxtafoveal and subfoveal CNV. The implementation of evidence-based medicine into current clinical practice is paramount to improving patient care. The authors, who are also members of the Singapore Medical Retina Advisory Board, outline the consensus points and recommended treatment algorithms based on currently available knowledge to provide a structured management approach to the treatment of Asian patients with CNV.

Health Promotion Board-Ministry of Health clinical practice guidelines: functional screening for older adults in the community.

The Health Promotion Board (HPB) and the Ministry of Health (MOH) publish clinical practice guidelines to provide doctors and patients in Singapore with evidence-based guidance on managing important medical conditions. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the HPB-MOH clinical practice guidelines on Functional Screening for Older Adults in the Community, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Health Promotion Board website (http://www.hpb.gov.sg/uploadedFiles/HPB_Online/Publications/CPGFunctionalscreening.pdf). The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Awareness of smoking risks and attitudes towards graphic health warning labels on cigarette packs: a cross-cultural study of two populations in Singapore and Scotland.

BACKGROUND: Little is known about the level of awareness of blindness as a smoking-related condition, although the relationship has been well established. AIM: To compare the awareness of smoking risks and the impact of graphic health warning labels on cigarette packs in discouraging smoking among adults in Singapore and Scotland. METHODS: A cross-sectional survey using a structured interview of adults in ophthalmic, general medical, and general surgical outpatient clinics in Singapore and Scotland. RESULTS: One hundred and fifteen out of 163 (70.6%) outpatients in Singapore and 105 out of 112 (93.8%) outpatients in Scotland responded to the study. In both samples, awareness levels for smoking-related diseases such as lung cancer, mouth and throat cancer, heart disease, and stroke were all greater than 85%. These were found to be significantly higher than the level of awareness of blindness as a smoking-related condition (chi (2)-test, P<0.001). Although the awareness of blindness as a smoking-related condition was greater in Singapore (36.5%) than in Scotland (30.5%), this difference was not statistically significant. More than half of the respondents indicated that graphic health warning labels would be effective in discouraging them from smoking. CONCLUSION: Graphic health warning labels reading 'Smoking causes blindness' printed on cigarette packs may be useful in raising public awareness of blindness as a smoking-related condition and discouraging the habit of smoking in Singapore and Scotland.

Cycloplegic refraction in preschool children: comparisons between the hand-held autorefractor, table-mounted autorefractor and retinoscopy.

AIMS: It is common for refraction to be measured using different testing methods in children, with much debate still ongoing on the preferred method. Therefore, we compared cycloplegic refraction measurements using three objective methods in a large cohort of children. METHODS: We present the findings from a total of 51 children who were recruited and examined as part of the Strabismus, Amblyopia and Refractive error in Singapore preschool children (STARS) study. Each child underwent a comprehensive eye examination, which included cycloplegic refraction using a hand-held autorefractor (Retinomax), a table mounted autorefractor (Canon FK-1) and streak retinoscopy. Spherical equivalent (SE) was calculated as (sphere + half of minus cylinder) and astigmatism was determined using the negative cylindrical component. RESULTS: The current study sample consisted of 29 boys and 22 girls aged between 24 and 72 months (mean age 52.3 months). The mean spherical equivalent (SE) using the table-mounted autorefractor (1.03 +/- 1.64 D) was not significantly different from the streak retinoscopy (1.09 +/- 1.58 D, p = 0.66). However, the mean SE using the hand-held Retinomax (0.80 +/- 1.43 D) was significantly different (more 'minus'p = 0.0004) to streak retinoscopy. The astigmatism measured using the hand held (-0.89 +/- 0.51 D) and table-mounted autorefractor (-0.83 +/- 0.61 D) were significantly greater than that obtained with streak retinoscopy (-0.58 +/- 0.56, p = 0.0003). CONCLUSIONS: The table-mounted autorefractor provided a reading more similar to that of streak retinoscopy than to that of the hand-held autorefractor. However, there were only small differences in mean SE (<0.32 D) between the hand-held Retinomax and the other methods, which will have implications in research investigations of refractive error.

Knowledge of visual experience during cataract surgery under local anaesthesia: a nationwide survey of UK ophthalmologists.

AIM: To evaluate the knowledge and practices of UK ophthalmologists regarding patients' subjective visual experience during cataract surgery under local anaesthesia. METHODS: A nationwide postal survey was conducted on UK ophthalmologists using a standardised questionnaire. RESULTS: The proportion of surgeons who operated under regional anaesthesia who thought that patients could experience the following visual sensations were: no light perception (54%); light perception (95%); one or more colours (93%); flashes of light (81%); movement (87%); instruments (61%); surgeon's hands or fingers (53%); surgeon (43%); and changes in light brightness (88%). Fifty-eight per cent of them thought that patients might be frightened by this, and 77% thought that preoperative counselling could help alleviate this fear. The proportion of surgeons who operated under topical anaesthesia who thought that patients could experience the following visual sensations were: no light perception (10%); light perception (94%); one or more colours (97%); flashes of light (86%); movement (96%); instruments (81%); surgeon's hands or fingers (65%); surgeon (51%); changes in light brightness (95%). Fifty-nine per cent of them thought that patients might be frightened by this, and 80% thought that preoperative counselling could help alleviate this fear. CONCLUSION: Most UK surgeons believed that during cataract surgery under local anaesthesia, patients might experience various visual sensations which could cause fear and that such fear could be alleviated by preoperative counselling.

Conscious sedation during ophthalmic surgery under local anesthesia.

Sedation during ophthalmic local anesthesia helps to ensure comfort and cooperation during eye surgery. Sedation requirements of ophthalmic patients have changed with the popularization of newer surgical and anesthetic techniques. Many sedative agents are available to anesthesiologists including benzodiazepines, intravenous anesthetic induction agents, narcotic analgesics and a-adrenoreceptor agonists. However, there is no single ideal sedative agent, regime or protocol that can completely cater to the wide spectrum of ophthalmic procedures performed in a heterogeneous patient population. Moreover, the clinical practice of sedation during ophthalmic surgery under local anesthesia is varied and not without risk of complications and adverse events. Hence, balanced sedative techniques should only be used after careful consideration of patient profile, the type of eye surgery, and patient and surgeon preferences. Good knowledge of the pharmacology of sedative agents is fundamental to their useful clinical application.

Optic neuropathy associated with dengue fever.

PURPOSE: To report a case series of three patients of optic neuropathy associated with dengue fever. METHODS: Observational case series. RESULTS: Three patients aged of 19, 31, and 40 years (cases 1, 2, and 3) complained of unilateral blurring of vision within a week of being diagnosed with dengue fever. Their presenting visual acuities were counting fingers in cases 1 and 2, and 6/6 in case 3, with features suggestive of optic neuropathy. Two of the three patients (cases 2 and 3) had bilateral ocular signs. The visual acuity recovered to 6/9 in case 1, worsened to no light perception in case 2, and remained unchanged in case 3. CONCLUSIONS: Although spontaneous visual recovery is possible, optic neuropathy associated with dengue fever may result in severe and permanent visual loss.

Practice preferences of ophthalmic anaesthesia for cataract surgery in Singapore.

INTRODUCTION: This study aims to describe the preferences of ophthalmic anaesthesia for cataract extraction among ophthalmologists in Singapore. METHODS: A nationwide questionnaire survey of all cataract surgeons in institutional and private practice in Singapore was conducted in August 2004. RESULTS: The response rate was 61.1 percent (88 out of 144 eligible ophthalmologists surveyed). Phacoemulsification was the preferred surgical technique for 92 percent of the respondents while extra-capsular cataract extraction was preferred by eight percent. For all surgeons performing phacoemulsification, the anaesthesia technique of choice was peribulbar anaesthesia for 43 percent, topical anaesthesia for 42 percent, retrobulbar anaesthesia for 13 percent, and sub-tenons and general anaesthesia for one percent each of the respondents. For all the surgeons performing extra-capsular cataract extraction, the preferred anaesthetic technique was peribulbar anaesthesia for 69 percent, retrobulbar anaesthesia for 30 percent and sub-tenons anaesthesia for one percent of the respondents. The surgeons' main reasons for choosing a specific anaesthesia modality for their surgery were patient comfort and surgeon's choice. The majority of surgeons used mild sedation and monitored anaesthesia care for their cataract surgeries. CONCLUSION: Peribulbar anaesthesia is currently the preferred anaesthesia technique for both phacoemulsification and extra-capsular cataract extraction in Singapore. Topical anaesthesia closely follows peribulbar anaesthesia as a preferred choice for phacoemulsification.

Patients' expectation and experience of visual sensations during phacoemulsification under topical anaesthesia.

PURPOSE: To describe what patients expect to see and the visual sensations they actually experience during phacoemulsification under topical anaesthesia. We also sought to determine if patients find their intraoperative visual experience frightening and the factors associated with this. MATERIALS AND METHODS: Ninety-eight patients who underwent phacoemulsification and intraocular lens implantation under topical anaesthesia were interviewed preoperatively on what they expected to see with their operated eye during surgery and again postoperatively on what they actually saw. No patient received counselling about possible intraoperative visual sensations. A logistic (multivariate) regression model was used for statistical analysis. RESULTS: Preoperatively, 36 patients (36.7%) expected at least light perception, 38 (38.8%) expected no light perception, and 24 (24.5%) were unsure what to expect. Some patients also expected a variety of different visual sensations. Postoperatively, all patients (100%) reported seeing light intraoperatively and many experienced various other visual sensations. Nineteen patients (19.4%) found their visual experience frightening. The following factors were statistically associated with a frightening visual experience: preoperative anxiety, previous cataract surgery in the fellow eye, experiencing an intraoperative increase in clarity, not seeing movement intraoperatively, and not knowing what to expect. CONCLUSIONS: The majority of patients in this study either expected that they would see nothing at all during the surgery or were unsure of what to expect. All patients subsequently saw at least some light, and many perceived various other visual sensations that were frightening to nearly one in five patients. Preoperative counselling should inform about possible intraoperative visual experience.

A survey on the knowledge and attitudes of anaesthesia providers in the United States of America, United Kingdom and Singapore on visual experiences during cataract surgery.

BACKGROUND AND OBJECTIVE: To assess the knowledge, beliefs and attitudes of anaesthesia providers on the patients' possible intraoperative visual experiences during cataract surgery under local anaesthesia. METHODS: Anaesthesia providers from the Ophthalmic Anaesthesia Society (USA); British Ophthalmic Anaesthesia Society (UK); Alexandra Hospital, National University Hospital, Tan Tock Seng Hospital, Singapore General Hospital and Changi General Hospital (Singapore) were surveyed using a structured questionnaire. RESULTS: A total of 146 anaesthesiologists (81.6%), 10 ophthalmologists (5.6%) and 23 nurse anaesthetists (12.8%) responded to the survey. Most respondents believed that patients would experience light perception and many also felt that patients might encounter other visual sensations such as movements, flashes, colours, surgical instruments, hands/fingers and the surgeon during the surgery. A significantly higher proportion of anaesthesia providers with previous experience of monitoring patients under topical anaesthesia believed that patients might experience the various visual sensations compared to those who have not previously monitored. For both topical and regional anaesthesia, anaesthesia providers who routinely counsel their patients are (1) more likely to believe that preoperative counselling helps or (2) were previously told by patients that they could see intraoperatively and/or that they were frightened by their visual sensations. These findings were statistically significant. CONCLUSIONS: The majority of anaesthesia providers in the USA, UK and Singapore are aware that patients may experience a variety of visual sensations during cataract surgery under regional or topical anaesthesia. Those who have previously managed patients undergoing cataract surgery under topical anaesthesia are more likely to believe this compared to those who have not.