Kepatuhan temujanji oleh pesakit di Klinik Optometri UKM

Kepatuhan temujanji pesakit merujuk kepada kebersediaan dan kebolehan pesakit untuk menghadiri temujanji yang telah ditetapkan. Kegagalan pesakit untuk berbuat demikian memberi pelbagai kesan terutamanya di klinik pengajaran seperti Klinik Optometri Universiti Kebangsaan Malaysia (UKM). Peratus kepatuhan temujanji oleh pesakit di Klinik Optometri UKM dianalisa dari September sehingga Disember 2015 dan dibahagikan mengikut jenis dan sesi klinik serta jantina dan etnik pesakit. Peratus kepatuhan temujanji adalah sekitar 60% untuk Klinik Optometri Primer. Kepatuhan meningkat ke sekitar 70% bagi klinik khas untuk pesakit bermasalah penglihatan seperti Klinik Penglihatan Terhad dan Klinik Penglihatan Pediatrik. Hari dan masa klinik tidak mempengaruhi kehadiran pesakit secara signifikan (p > 0.05). Jantina dan etnik pesakit tidak mempengaruhi kepatuhan temujanji secara signifikan tetapi pesakit berbangsa India secara konsisten menunjukkan peratus kehadiran temujanji terendah. Suatu protokol perlu dibangunkan untuk meningkatan kadar kepatuhan temujanji pesakit. Ini seterusnya dapat menambah produktiviti di kalangan kakitangan dan pelajar dan mengoptimumkan penggunaan sumber. Penerangan juga boleh diberikan kepada pesakit mengenai kos yang ditanggung oleh pihak pengurusan untuk setiap temujanji walaupun tiada sebarang caj dikenakan kepada pesakit

Effects of monocular blur on clinical measurements of stereopsis and binocular contrast sensitivity

Visual conditions such as anisometropia, monovision and monocular undercorrection affect the combination of visual input from both eyes. This study investigated the effects of monocular blur, in binocularly normal participants, on stereoacuity and binocular contrast sensitivity. Fifteen young adults (age range between 19 and 23 years old) with normal visual acuity and binocular vision participated in this study. Stereopsis was measured using the TNO test with a series of positive spherical lenses placed before the dominant eye. The procedure was repeated using the Titmus Stereotest on five participants as a control experiment. Monocular and binocular contrast sensitivities were also measured using the Pelli-Robson Contrast Sensitivity Chart. Blur was induced monocularly with a series of positive spherical lenses placed before the dominant eye and binocular contrast sensitivity was re-measured. Stereopsis scores decreased significantly when monocular blur was imposed. Across blur levels, absolute stereopsis scores measured with TNO test were worse than those measured with Titmus stereotest (all p < 0.05). However, the ratio of scores obtained without blur and under monocular blur appeared to be similar for both tests. Stereopsis without blur was between 6.82× to 8× better than that obtained with the highest level of imposed monocular blur. Binocular contrast sensitivity score decreased significantly with increasing level of monocular blur (p < 0.01). Binocular contrast sensitivity score without blur was 1.62× better than that obtained under binocular viewing with highest level of imposed blur. Stereopsis tests are more sensitive than measurements of binocular contrast sensitivity as an indicator of interocular acuity discrepancies which could occur in anisometropic or monovision patients. However, the choice of stereopsis test is crucial, as the TNO test appears to be more sensitive to monocular blur than the Titmus stereostest

Comparison of habitual visual acuity and stereoacuity between children attending KEMAS and urban private preschools

The assessment of a preschooler’s visual status is important as it forms part of the measure to assess the child’s school readiness. However, not all children attending preschools have equal opportunity to undergo vision screening programmes. In this study, we measured presenting habitual near and distance visual acuity and stereoacuity in 6-year-old children (n=385). These parameters were measured in and compared between preschoolers attending urban, privately-run kindergartens and those attending KEMAS preschools, which were typically from suburban and rural areas with families of very low income. Seven percent of KEMAS preschoolers failed the distance visual acuity test while the failure rate for private preschoolers was 6.0%. For near visual acuity, a higher percentage of private preschoolers failed the test (8.7%) than KEMAS preschoolers (4.9%). A slightly higher percentage of private preschoolers had weak stereopsis (3.3%) compared to KEMAS preschoolers (2.5%). However, the differences found between the two preschooler groups were not statistically significant (all p>0.05). The proportion of children who failed each of the screening criteria for distance vision, near vision, and stereopsis was similar between KEMAS and private preschools. Therefore, an universally inclusive vision screening programme should be conducted for all preschool types to detect, diagnose, treat, and potentially prevent any visual impairment

Foveal visual acuity is worse and shows stronger contour interaction effects for contrast-modulated than luminance-modulated Cs

Contrast-modulated (CM) stimuli are processed by spatial mechanisms that operate at larger spatial scales than those processing luminance-modulated (LM) stimuli and may be more prone to deficits in developing, amblyopic, and aging visual systems. Understanding neural mechanisms of contour interaction or crowding will help in detecting disorders of spatial vision. In this study, contour interaction effects on visual acuity for LM and CM C and bar stimuli are assessed in normal foveal vision. In Experiment 1, visual acuity is measured for all-LM and all-CM stimuli, at ~3.5× above their respective modulation thresholds. In Experiment 2, visual acuity is measured for Cs and bars of different type (LM C with CM bars and vice versa). Visual acuity is degraded for CM compared with LM Cs (0.46 ± 0.04 logMAR vs. 0.18 ± 0.04 logMAR). With nearby bars, CM acuity is degraded further (0.23 ± 0.01 logMAR or ~2 lines on an acuity chart), significantly more than LM acuity (0.11 ± 0.01 logMAR, ~1 line). Contour interaction for CM stimuli extends over greater distances (arcmin) than it does for LM stimuli, but extents are similar with respect to acuities (~3.5× the C gap width). Contour interaction is evident when the Cs and bars are defined differently: it is stronger when an LM C is flanked by CM bars (0.17 ± 0.03 logMAR) than when a CM C is flanked by LM bars (0.08 ± 0.02 logMAR). Our results suggest that contour interaction for foveally viewed acuity stimuli involves feature integration, such that the outputs of receptive fields representing Cs and bars are combined. Contour interaction operates at LM and CM representational stages, it can occur across stage, and it is enhanced at the CM stage. Greater contour interaction for CM Cs and bars could hold value for visual acuity testing and earlier diagnosis of conditions for which crowding is important, such as in amblyopia

Perbandingan zon interaksi ruang dua dimensi subjek normal dan ambliopia anisometropik

Akuiti visual subjek ambliopia anisometropik sering disimulasi pada individu normal dengan mengkaburkan penglihatan fovea mereka. Walau bagaimanapun, prestasi akuiti visual periferi subjek ini tidak diketahui dan kaedah pengkaburan ini tidak semestinya dapat mensimulasi penglihatan periferi mereka. Untuk mendalami ketepatan kaedah ini, kami mengkaji akuiti dan bentuk zon interaksi ruang di fovea dan periferi retina subjek normal dan ambliopia anisometropik serta kesan pengkaburan pada akuiti subjek normal pada esentrisiti retina yang berbeza untuk dibandingkan dengan periferi subjek ambliopia. Akuiti diukur menggunakan Kaedah Rangsangan Malar untuk huruf Sheridan-Gardiner pada 6 orang subjek normal dan 6 orang subjek ambliopia anisometropik. Kesan kesesakan diukur dengan membandingkan respons pengesanan huruf sasaran yang diapit oleh huruf lain yang diletakkan pada orientasi mendatar, menegak dan pepenjuru. Rangsangan dipaparkan pada fovea dan 2.5, 5 dan 10 darjah di medan penglihatan inferior. Selain itu, akuiti fovea 4 orang subjek normal dikaburkan supaya sepadan dengan akuiti fovea subjek ambliopia menggunakan kaedah pengkaburan optik dan penuras digital Gaussian. Subjek normal menunjukkan kemerosotan akuiti yang lebih besar dengan peningkatan esentrisiti retina (E2: 2.25±0.21) berbanding subjek ambliopia anisometropik (E2: 6.02±1.45). Kesemua subjek menunjukkan zon interaksi ruang yang tidak simetri di kesemua esentrisiti retina yang diuji. Interaksi antara jenis kabur dan esentrisiti retina adalah signifikan F(2.13,6.38)=4.93, p=0.049) tetapi akuiti subjek normal yang dikaburkan dengan kedua-dua kaedah pengkaburan tidak berbeza secara signifikan dengan akuiti subjek ambliopia. Zon interaksi ruang subjek ambliopia anisometropik adalah sama dengan subjek normal. Akuiti fovea subjek ambliopia anisometropik lebih teruk berbanding subjek normal kerana peningkatan pengkaburan intrinsik. Walau bagaimanapun, periferi subjek ambliopia adalah normal secara fungsian

Perubahan tahap pencahayaan dalam bilik darjah di sebuah sekolah pendidikan khas cacat penglihatan dan perbandingan tahap pencahayaan di bawah keadaan pencahayaan yang berbeza

Illumination is one of the important physical aspects that influences comfortability during learning session particularly among visually impaired students. The purpose of this study was to determine changes in illumination level in classrooms during learning session at Sekolah Menengah Pendidikan Khas (SMPK), Setapak. The second objective was to compare the illumination level in the classrooms under three different lighting conditions: daylight only, with additional artificial light and with removal of obstructions to daylight. Illumination levels in 17 classrooms was measured at one hour interval, between 8 am to 1 pm for the first stage and 19 classrooms under three different lighting conditions from 11 am to 12 noon for the second stage, using ILM1335 (ISO-TECH, Taiwan) digital luxmeter. Illumination level increased significantly from 8 am to 11 am (One-Way Repeated Measures ANOVA: F(2.14, 34.26)=76.49, p<0 .001) and was maximum at 1 pm. The illumination level was highest for the condition of daylight with additional artificial light (One-Way Repeated Measures ANOVA: F(2,34)=110.51, p<0.001) compared to other conditions. Illumination levels for daylight without obstruction was significantly higher than daylight only (pairwise comparison: p=0.001). Classroom illumination level was lowest in the early morning. However, classroom illumination can be increased either by removing the obstructions to daylight or with additional artificial lighting

Behavioural and emotional issues among primary school pupils with congenital colour vision deficiency in the Federal Territory of Kuala Lumpur, Malaysia: A case-control study [version 1; referees: 2 approved, 1 approved with reservations]

Background: Congenital colour vision deficiency (CCVD) is an untreatable disorder which has lifelong consequences. Increasing use of colours in schools has raised concern for pupils with CCVD. This case-control study was conducted to compare behavioural and emotional issues among age, gender and class-matched pupils with CCVD and normal colour vision (NCV). Methods: A total of 1732 pupils from 10 primary schools in the Federal Territory of Kuala Lumpur were screened, of which 46 pupils (45 males and 1 female) had CCVD. Mothers of male pupils with CCVD (n=44) and NCV (n=44) who gave consent were recruited to complete a self-administered parent report form, Child Behaviour Checklist for Ages 4-18 (CBCL/ 4-18) used to access behavioural and emotional problems. The CBCL/ 4-18 has three broad groupings: Internalising, Externalising and Total Behaviour Problems. Internalising Problems combines the Withdrawn, Somatic Complaints and Anxiety/ Depression sub constructs, while Externalising Problems combines the Delinquent and Aggressive Behaviour sub constructs. Results: Results from CBCL/ 4-18 showed that all pupils from both groups had scores within the normal range for all constructs. However, results from the statistical analysis for comparison, Mann-Whitney U test, showed that pupils with CCVD scored significantly higher for Externalising Problems (U=697.50, p=0.02) and Total Behaviour Problems (U=647.00, p= 0.01). Significantly higher scores were observed in Withdrawn (U=714.00, p=0.02), Thought Problems (U=438.50, p<0.001) and Aggressive Behaviour (U=738.00, p=0.04). Odds ratios, 95% CI, showed significant relative risk for high Total Behaviour Problem (OR:2.39 ,CI:1.0-5.7), Externalising Problems (OR:2.32, CI:1.0-5.5), Withdrawn (OR:2.67, CI:1.1-6.5), Thought Problems (OR:9.64, CI:3.6-26.1) and Aggressive Behaviour (OR:10.26, CI:3.4-31.0) scores among pupils with CCVD. Conclusion: Higher scores among CCVD pupils indicates that they present more behavioural and emotional problems compared to NCV pupils. Therefore, school vision screenings in Malaysia should also include colour vision to assist in the early clinical management of CCVD children

Evaluation of the relationships between corneal parameters, ocular biometry, and myopia magnitude

Axial length of the eye correlates with the magnitude of myopia. However, there are conflicting reports on the relationship between certain corneal parameters with myopia magnitude. The objective of this study was to compare ocular biometry and corneal parameters between emmetropic and myopic groups. Participants (n=127) were categorized as emmetropia (spherical equivalent, SE, ±0.50D), low myopia (-0.75D≤SE0.05). Corneal curvature correlated significantly with axial length (p=0.001) but not with myopia magnitude (p=0.91). Rather than myopia magnitude, axial length appears to be more sensitive to detect changes in corneal curvature in myopes. In conclusion, myopic patients’ axial length should be carefully considered for interventions that involve the cornea, such as orthokeratology and refractive surgery

Participants’ sociodemographics and cumulative grade point average (CGPA).

Participants’ sociodemographics and cumulative grade point average (CGPA).</p

Binocular and monocular resolution thresholds throughout adulthood for luminance-modulated and contrast-modulated noise letters

Contrast-modulated (CM) noise stimuli are thought to be processed in higher, more binocular visual areas compared to luminance-modulated (LM) stimuli, and the ability to perceive them may be more susceptible to ageing. The aim of this study was to determine monocular and binocular resolution thresholds for LM and CM noise letters throughout adulthood. Resolution thresholds for LM and CM noise letters were measured in 25 participants (age 21-70 years old) under monocular and binocular viewing. Stimuli were H, O, T and V letters created by adding or multiplying a luminance modulation function to a binary white noise carrier to create LM and CM noise letters, respectively. Resolution thresholds, determined using a 2-down-1-up staircase procedure, were lower for LM, than for CM, stimuli in both monocular and binocular viewing conditions (p<0.05). Binocular summation ratio for CM noise letters was significantly higher than that for LM noise letters (p<0.05) but declined rapidly with increasing age. For the youngest age group (20-29 years old), binocular resolution threshold was 39% better (~1.5-line improvement on the clinical letter chart) than monocular resolution threshold for CM noise letters, but only 15% better (~0.5-line improvement) when measured with LM noise letters. Binocular performance for CM noise letters declines at a faster rate with increasing age compared to that for LM noise letters. Visual function measurement with contrast-modulated stimuli might be useful to detect subtle binocular vision anomalies that may occur in early adulthood, which may be missed if measured with luminance-based stimuli alone