K G Au Eong

Local intra-arterial fibrinolysis for acute occlusion of the central retinal artery: a meta-analysis of the published data

BACKGROUND/AIM Central retinal artery occlusion (CRAO) is typically associated with a poor visual outcome. Several favourable reports of local intra-arterial fibrinolysis (LIF), which involves the superselective administration of a thrombolytic agent directly into the ophthalmic artery, have appeared in the recent literature. The aim of this study was to critically appraise these studies in a collective fashion. METHODS A meta-analysis was performed of all the published literature germane to LIF in cases of CRAO. RESULTS Of the 16 studies identified, all were retrospective and non-randomised. After correction for data duplication, the results of LIF in 100 patients can be reported. A final acuity of 6/6 or better was seen in 14% of patients following LIF, and a visual result of 6/12 or better was seen in 27% of subjects. A poor final acuity of 3/60 or worse was seen in 60.6% of eyes treated with local intra-arterial fibrinolysis. These results compare favourably with conventional forms of therapy. Potentially serious complications were seen in four patients, but no patient suffered a permanent neurological deficit. CONCLUSION The results of this study suggest that there may be a marginal visual benefit associated with LIF compared with conventional management of CRAO. However, the methodology of the cited studies was often unsatisfactory, and a randomised controlled trial of LIF in cases of CRAO is justified. Outside of a randomised clinical trial, the use of superselective fibrinolytic therapy for CRAO cannot be recommended on the basis of current evidence.

Epidemiology of pterygium on a tropical island in the Riau Archipelago

ObjectivesTo describe the epidemiology of pterygium among residents of an island in Indonesia and to examine the roles of age and gender as determinants of bilaterality and severity of the disease.MethodsVoluntary eye screening on Pulau Jaloh, Riau Archipelago, Indonesia. Gender difference was tested using the χ2 test. The difference in age between subjects with and without disease was tested using unpaired Students t-test. Odds ratio (relative risk) for gender was calculated using logistic regression model with adjustment for age.ResultsOf the 550 inhabitants, 477 (86.7%) responded to the eye screening. The overall prevalence rate of pterygium was 17.0%. Out of 211, 48 male (22.7%) and 33 out of 266 female subjects (12.4%) had the disorder, with the gender difference being statistically significant. Adjusted for age, the risk of disease was 3.1-fold higher among the males. In all, 71.6% of subjects with pterygium had bilateral disease. Subjects with pterygium were significantly older, their mean age being 42.9 years compared to 18.7 years among those without disease. The prevalence rates in male subjects increased from age 20 to reach a plateau of 63.6% at age 35 and remained stable thereafter. In the female subjects, the rates also increased with age, albeit at a slower rate, from age 20 to reach a plateau of 46.7% at age 55 and remained stable thereafter.ConclusionsThere is a high prevalence rate of pterygium among the study subjects, with the rates increasing rapidly with age.

Charles Bonnet syndrome in Asian patients in a tertiary ophthalmic centre

Aims: To describe the epidemiology of Charles Bonnet syndrome (CBS) among patients in an Asian tertiary ophthalmic centre and to describe the characteristics of the hallucinations experienced. Methods: 1077 consecutive patients aged 50 years and above were asked a standardised question to determine if they had ever experienced formed visual hallucinations. All patients who experienced these symptoms were further interviewed using a detailed, standardised questionnaire to ascertain if they met the diagnostic criteria established for CBS. Results: There were 491 men (45.6%) and 586 women (54.4%). The best corrected visual acuity ranged from 20/20 to light perception in the better seeing eye and from 20/20 to no light perception in the worse seeing eye. Four patients (0.4%) were diagnosed with CBS; two men and two women. There were two Chinese and two Indians. The average age of the CBS patients was 76.3 years (range 65–90 years). Two patients had cataracts, one had glaucoma, and one had both cataracts and glaucoma. A wide variety of visual hallucinations were reported. Three out of four patients experienced a negative reaction to their hallucinations. Only one patient had discussed his symptoms with a doctor. Conclusions: This is the first report on the epidemiology of CBS in Asian patients. The prevalence rate of CBS (0.4%) is slightly lower than in comparable studies in non-Asian populations. The nature of the hallucinations experienced were similar to those previously reported.

Subjective visual experience during extracapsular cataract extraction and intraocular lens implantation under retrobulbar anaesthesia

Purpose To investigate the subjective visual experience of patients during cataract surgery under retrobulbar anaesthesia.Methods One hundred cataract patients who underwent routine extracapsular cataract extraction and intraocular lens implantation under retrobulbar anaesthesia were interviewed by the authors on the same day after their operation regarding their visual experience in the operated eye during surgery.Results Forty-three men and 57 women were included in the study. Their mean age was 68.4 years (range 40-87 years). Their pre-operative best corrected visual acuity ranged from 6/12 to perception of light. Eighty-four eyes had no other ocular pathology apart from cataract. Twenty patients reported no light perception during the surgery. The rest reported that they could see light (80 patients), one or more colours (56 patients), movements (39 patients), flashes (36 patients), instruments (16 patients) and/or the surgeons fingers or hands (10 patients). The colours seen included red (29 patients), yellow (29 patients), green (12 patients), blue (11 patients) and orange (2 patients). Fifteen patients saw a spectrum of colours similar to that of the rainbow. Forty-four patients reported that the brightness of light changed during the operation. Five patients found their visual experience frightening. There was no correlation between those who found the experience frightening and the sex or age of patient, presence of coexisting ocular pathology, duration of operation, whether the operation was the first or second cataract operation in the patient, or the type of visual sensation experienced.Conclusion Many patients undergoing cataract surgery under retrobulbar anaesthesia experience a variety of visual sensations that may be frightening in a small proportion of cases.

Optic neuropathy associated with dengue fever

PurposeTo report a case series of three patients of optic neuropathy associated with dengue fever.MethodsObservational case series.ResultsThree 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.ConclusionsAlthough spontaneous visual recovery is possible, optic neuropathy associated with dengue fever may result in severe and permanent visual loss.

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.

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

PurposeTo 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 methodsNinety-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.ResultsPreoperatively, 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.ConclusionsThe 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.

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

Background/aimsUtility 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.MethodsCross-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.ResultsThe 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 (Pearsons 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 (Pearsons 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).ConclusionsAMD 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 smoking risks and attitudes towards graphic health warning labels on cigarette packs: a cross-cultural study of two populations in Singapore and Scotland

BackgroundLittle is known about the level of awareness of blindness as a smoking-related condition, although the relationship has been well established.AimTo 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.MethodsA cross-sectional survey using a structured interview of adults in ophthalmic, general medical, and general surgical outpatient clinics in Singapore and Scotland.ResultsOne 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 (χ 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.ConclusionGraphic 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.

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

PurposeCigarette 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 methodsA 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 smokers motivation to quit smoking were evaluated.ResultsOut 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.ConclusionThe 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.