Understanding visual snow syndrome: A retrospective study from a tertiary eye care center.

PURPOSE: Visual snow syndrome is a debilitating neurological condition. A comprehensive eye examination may not detect any abnormalities in this condition. Presently the condition is recognized only through the history elicited. Hence, it becomes important to understand the presenting complaints and profile of these patients. A retrospective study at a tertiary eye care center was undertaken to achieve this goal. METHODS: Electronic medical records of patients presenting to a Binocular Vision and Orthoptics clinic were reviewed. Records of the patients containing keywords such as "light sensitivity, shadowing, visual snow, multiple images, and night vision" were retrieved and inspected. Those matching the diagnostic criteria of visual snow syndrome were included in the study. RESULTS: A total of 33 patients (average age ± standard deviation: 29.7 ± 9.8 years) were identified. Majority of the patients were males (69%). All the patients had logMAR visual acuity 0 or better in each eye. The most prominent (84.4%) presenting symptom was palinopsia (or afterimage or trailing). About 34.4% complained of floaters (including snow-like appearance). More than half (54.6%) of the patients also had binocular dysfunction. CONCLUSION: Visual snow syndrome is a relatively new condition on the rise, with unclear pathology. The symptoms of this condition can easily be confused with regular floaters or black spots seen in vitreous and retinal pathologies. In the absence of such pathology, an elaborate history should be elicited, and the distress of the patient should be acknowledged. The patient should also be reassured that this is not a blinding condition.

Parent-Reported Visual Concerns in Children with Cerebral Visual Impairment Presenting to a Pediatric Neurology Clinic.

Purpose: Children with cerebral visual impairment (CVI) present with delayed developmental milestones. Pediatricians and pediatric neurologists are usually the first point of contact, and eye exam largely remains referral based. This study documented the visual concerns reported by parents of children with CVI visiting a pediatric neurology clinic. Additionally, we investigated the association between visual concerns, functional vision measures and visual functions. Patients and Methods: A cross-sectional study was undertaken in children with CVI (chronological age range: 7 months-7 years). Visual concerns reported by the parents/caregivers were documented as open-ended statements. Additionally, a functional vision assessment was conducted using the CVI Range instrument with phase 1, 2 and 3 indicating low, moderate and high visual functioning, respectively. Grating acuity and contrast sensitivity were measured using Teller acuity cards-II and Ohio contrast cards respectively. Results: A total of 73 children (mean age of 2.84 ± 1.87 years) were recruited. Sixty-eight parents reported visual concerns that were broadly grouped into 14 unique concerns. Nineteen parents (27.9%) reported more than one visual concern. Difficulty maintaining eye contact and recognizing faces were the top two visual concerns in phases 1 and 2. Missing objects in the lower visual field was the top concern in phase 3. A larger number of visual concerns were reported in phase 1 (43%) than phase 2 (40.6%) and phase 3 (16.2%). Multiple regression analysis revealed that grating acuity, contrast sensitivity and chronological age were able to predict the functional vision, F (3, 55) = 63.0, p < 0.001, r2 = 0.77. Conclusion: Targeted questions enquiring about eye contact and face recognition can be included in history elicitation in children with CVI in pediatric neurology clinics. In the presence of visual concerns, it will be important to assess grating acuity and contrast sensitivity. A poor functional vision score requires referral for eye examination and vision rehabilitation services.

Refractive error changes and associated asthenopia observed after COVID-19 infection: Case reports from two continents.

COVID-19 infection has been linked to various ocular complications and complaints, but not to refractive errors. In this case report, we present ethnically diverse patients who reported asthenopic symptoms shortly after recovering from COVID-19 infection. The hyperopic shift in the refractive error, post-COVID could indicate the ciliary body muscle's inability to sustain accommodation, resulting in asthenopia. Hence, refractive errors should also be considered as a post-COVID complication, even if the magnitude is small, especially when patients have a headache and other asthenopic symptoms. Performing dynamic retinoscopy and cycloplegic refraction will also aid in the better management of these patients.

Unraveling congenital ptosis with the aid of the pediatric perimeter device.

Background: Ocular morbidity with an early onset can have a significant impact on the long-term development of an individual. Hence, careful assessment of visual functions early on is very important. However, testing infants always poses a challenge. Standard tools to assess infants' visual acuity, ocular motility, and so on rely on the clinician's quick subjective judgments of an infant's looking behavior. Eye movements are usually observed from head rotations or spontaneous eye movements in infants. Judging eye movements in the presence of strabismus is even more challenging. Purpose: This video shows a 4-month-old infant's viewing behavior captured during a visual field screening study. The recorded video aided in the examination of this infant that was referred to a tertiary eye care clinic. The additional information captured through the perimeter testing is discussed. Synopsis: The Pediatric Perimeter device was developed to address visual field extent and gaze reaction time assessment in the pediatric population. As a part of a large-scale screening study, infants' visual fields were tested. During this screening, a 4-month-old infant presented with a ptosis in the left eye. The infant was consistently missing the light stimuli presented in the left upper quadrant in the binocular visual field testing. The infant was referred to a tertiary eye care center to a pediatric ophthalmologist for further examination. During clinical examination, the infant was suspected to either have congenital ptosis or monocular elevation deficit. But the diagnosis of the eye condition was unsure owing to the poor cooperation of the infant. With the aid of Pediatric Perimeter, the ocular motility was consistent with limitation of elevation in abduction, indicating a possible monocular elevation deficit with congenital ptosis. The infant was also noted to have Marcus Gunn jaw-winking phenomenon. The parents were assured and asked for a review in 3 months. In the subsequent follow-up, the Pediatric Perimeter testing was performed, and the recording showed a full extraocular motility in both eyes. Hence, the diagnosis was changed to only congenital ptosis. The probable explanation for missing the target in the left upper quadrant in the first visit is postulated further. The left upper quadrant is the superotemporal visual field of the left eye and the superonasal visual field of the right eye. As the left eye had ptosis, the superotemporal visual field could have been obstructed and hence the stimuli missed. The normative extent for the nasal and superior visual field is just about 30° for a 4-month-old infant. Hence, the right eye also perhaps missed the stimuli in its superonasal visual field extent. This video highlights the utility of the Pediatric Perimeter device in providing a magnified view of the infant's face along with greater visibility of ocular features from the infrared video imaging. This can potentially help the clinician to easily observe different ocular/facial abnormalities such as extraocular motility disorders, lid functions, and in identifying unequal pupil size, media opacities, and nystagmus. Highlights: The presence of congenital ptosis in younger infants might predispose as superior visual field defect and could also masquerade as a limitation in elevation. Video link: https://youtu.be/Lk8jSvS3thE.

Impact of induced pseudomyopia and refractive fluctuations of accommodative spasm on visual acuity.

CLINICAL RELEVANCE: High-contrast visual acuity is disproportionately poor in patients with accommodative spasm subtype of near reflex (SNR-A), relative to uncorrected refractive errors of equivalent magnitude. This exaggerated loss of performance in SNR-A may be explained by the combination of pseudomyopia and its fluctuations, vis-à-vis, each factor considered separately. BACKGROUND: To determine how combinations of pseudomyopic refraction and its temporal variations in SNR-A impact high-contrast visual acuity by inducing these patterns in healthy cyclopleged adults, relative to their baseline acuity. METHODS: Refractive profiles of 15 patients with SNR-A were obtained from a previous study, averaged, and induced before the right eye of 14 cyclopleged adults (mean ±1 SD age: 22.7 ± 2.6 yrs) by feeding the profile into a coaxially placed, motorised, Badal optometer. LogMAR acuity was measured using the method of constant stimuli: (1) before cycloplegia, (2) after cycloplegia and post-cycloplegia with (3) combination of pseudomyopia and its temporal fluctuations, (4) only pseudomyopia, (5) only temporal fluctuations in refraction about emmetropia, (6) condition 5 with double the amplitude of induced fluctuations and (7) condition 5 with half the amplitude of induced fluctuations. RESULTS: The induced refractive fluctuations ranged from -0.80 to -1.75D, around a mean pseudomyopia of -1.20D. Visual acuity deterioration was maximum for the combination of pseudomyopia and temporal fluctuations condition (0.51 ± 0.07logMAR), followed by only pseudomyopia (0.27 ± 0.05logMAR) and only refractive fluctuations conditions (0.17 ± 0.04logMAR), all relative to baseline post-cycloplegia (0.13 ± 0.04logMAR) (p < 0.001). Visual acuity loss increased with doubling of refractive fluctuations (0.20 ± 0.04logMAR), relative to native fluctuations or halving the amplitude (0.15 ± 0.03logMAR) (p < 0.01). Task precision, as adjudged from the slope of psychometric function, followed a similar pattern of loss as visual acuity. CONCLUSION: Combination of induced pseudomyopia and temporal fluctuations in refraction produces an additive loss of visual acuity and task precision, relative to baseline and each factor considered separately.

Grating acuity tests for infants, young children and individuals with disabilities: A review of recent advances.

BACKGROUND: Accurate measurement of visual acuity is important in managing any ocular condition. Measuring visual acuity has always remained a challenge in infants, young children and individuals with disabilities who are unable to respond verbally. A variety of pediatric acuity tests that include both grating and recognition acuities have been described in the literature, some of which are outdated. This review paper aims to summarize the currently available and recently developed grating acuity tests that can be used for infants, young children and individuals with disabilities. METHODS: A review of literature was carried out to identify tests that were currently available and recently developed. Additionally, search was also done on popular search engines and websites of companies. Tests identified were screened for availability and investigated for validity through published research in peer-reviewed journals. RESULTS: A total of eight grating acuity tests were identified, out of which six of them were paper-based tests. The remaining two tests were app-based tests with established data for the typically developing pediatric cohort. The repeatability indices were available only for four grating acuity tests. CONCLUSIONS: This review paper summarizes the basic features of the grating acuity tests and importantly, the parameters that determine the clinical utility of the tests such as the testability, acuity range, specific cohort studied, testing time and reliability indices. The paper also discusses the recent technological advancements in the field of acuity testing for the pediatric cohort and its comparisons with the conventional methods when available.

Children With Amblyopia Make More Saccadic Fixations When Doing the Visual Search Task.

Purpose: Individuals with amblyopia are known to have functional vision deficits (e.g., reduced reading speed) in spite of good visual acuity in the nonamblyopic eye. We studied and compared eye movements in children with and without amblyopia to examine how a visual scene is explored during visual search. Methods: Children (six to 16 years of age) in the control group (n = 14) and cases group with anisometropic amblyopia (n = 23) participated in a visual search study, in which they looked for targets in real-world images displayed on a computer monitor. Eyelink 1000 Plus was used to track the eye movements. Three viewing conditions were randomized: dominant/fellow eye, nondominant/amblyopic eye, and binocular viewing. Visual search performance was measured by combining search time and accuracy. Results: As expected, poorer visual search performance was observed in the amblyopic eye when compared to the controls and fellow eye (P < 0.005). However, the reaction time was longer even in binocular and fellow eye viewing conditions than the controls (P < 0.028). Children with amblyopia made more saccades (17 vs. 12, P = 0.007), without the need to fixate longer (P = 0.312), but with more fixations in the target interest area (4.65 vs. 3.14, P = 0.002) when compared to controls. These eye movement patterns were observed in both the fellow eye and binocular viewing conditions. Conclusions: In spite of good visual acuity in the fellow eye, children with amblyopia needed to sample the scene with more fixations. Even upon gazing at the target location, they made more fixations before confirming a hit. These search patterns suggest a possible narrower spatial visual span to process the visual information in children with amblyopia.

Feasibility study for measuring patients' visual acuity at home by their caregivers.

Purpose: To assess the feasibility of measuring patients' visual acuity (VA) in their homes by their caregivers. Methods: Patients consulting in a tertiary eye care institute were prospectively enrolled with informed consent. All underwent standard COMPlog distance VA testing. Patients and caregivers were oriented to test distance VA using the Peek Acuity app. The app was installed on the caregiver's or patient's smartphone. The patient's VA was measured by the caregiver in the clinic (baseline value) under supervision. After 1 week, the caregivers recorded the patient's VA with the Peek Acuity app at their home and reported the value in a telephone consultation. A questionnaire to assess the ease of using the app was administered at both the baseline visit and 1 week later. Results: A total of 100 patients (age group: 13 to 76 years) and 100 caregivers (age group: 17 to 65 years) participated. VA measurements with the Peek Acuity app were comparable with COMPlog (P > 0.1) both during the baseline and after 1-week measurement, regardless of the underlying ocular condition or educational level of the caregivers/patients. Most caregivers (95%) felt the app was easy to use. Conclusion: Though the Peek Acuity app was originally developed for health care workers to be used in field visits, we found that with proper orientation, the layperson can also use it. Such orientation can enable caregivers to effectively measure VA at home. Such a tool would enhance teleophthalmology consultations and can minimize the need for short follow-up visits.

Clinical Utility of 'Peekaboo Vision' Application for Measuring Grating Acuity in Children with Down Syndrome.

Peekaboo Vision is an iPad grating acuity app built with typically developing children in mind. Given the ease of using this app in the pediatric age group, this study determined its clinical utility in children with Down syndrome. Two groups of participants (children with Down syndrome and age-matched controls) were included. Presenting binocular grating acuity was measured using Peekaboo Vision and Teller acuity cards II in random order. Parents' feedback about their child's engagement and time taken to complete each test was documented. Thirty-seven children with Down syndrome (males = 23; mean age = 8.1 ± 4.2 years) and 28 controls (males = 15; mean age = 8.71 ± 3.84 years) participated. Time taken to complete the tests was comparable (p = 0.83) in children with Down syndrome. Controls were significantly faster with Peekaboo Vision (p = 0.01). Mean logMAR acuities obtained with Peekaboo Vision (0.16 ± 0.34) and Teller acuity cards II (0.63 ± 0.34) were significantly different (p < 0.001) in children with Down syndrome (mean difference in acuities: -0.44 ± 0.38 logMAR (95% LoA: -1.18 to 0.3). For controls, the mean logMAR acuity with Peekaboo Vision (-0.13 ± 0.12) and Teller acuity cards II (0.12 ± 0.09) was also found to be significantly different (p < 0.001) (mean difference in acuities: -0.24 ± 0.14 logMAR (95% LoA: -0.51 to 0.03) Peekaboo Vision test can be used on children with Down syndrome. Peekaboo Vision and Teller acuity cards II can be used independently but not interchangeably. The differences in the acuity values between the two tests could be a result of the differences in the thresholding paradigms, different testing mediums and the range of acuities covered.

Fluctuations of Steady-State Accommodation Is a Marker for Screening Spasm of Near Reflex.

Purpose: To determine the utility of root mean squared (RMS) deviations of steady-state accommodation as a noncycloplegic marker for spasm of near reflex (SNR) vis-à-vis regular refractive errors. Methods: Binocular steady-state responses of accommodation, pupil, and vergence of 20 patients with accommodative spasm subtype of SNR (SNR-A; 9-23 years) and 91 with regular refractive errors (29 emmetropes, 41 myopes, 21 hyperopes; 19-38 years) was recorded in the uncorrected refractive error state for 120 seconds using a dynamic (50 frames per second), infrared photorefractor. Mean and RMS deviation of raw data was calculated for three 20-second-long epochs and their diagnostic utility was determined using standard ROC curves. Results: RMS deviations of accommodation increased with mean refractive error in SNR-A (y = -0.23x + 0.38; r2 = 0.69; P < 0.001) and regular refractive error (y = -0.02x + 0.10; r2 = 0.14; P = 0.002) cohorts, albeit with steeper slope and higher y-intercept in the former rather than the latter cohort. RMS deviation of 0.19D reliably distinguished SNR-A from regular refractive errors with a sensitivity and specificity of 95.2% and 92.2%, respectively [mean (±1 SEM) area under ROC curve: 0.98 ± 0.01]. The sensitivity, specificity, and area under ROC curve for RMS deviations of pupil (66.7%, 80%, and 0.70 ± 0.09) and vergence (52.4%, 84.6%, and 0.68 ± 0.08) were smaller than accommodation. Conclusions: RMS deviations of steady-state accommodation is a robust noncycloplegic marker for differentiating SNR-A from regular refractive errors. Pupil and vergence fluctuations have limited utility in this regard. Translational Relevance: RMS deviations of accommodation may be easily obtained using commercial photorefractors, and the cut-off values reported herein may be implemented to identify SNR-A during refractive error screening.

Quantification of gaze reaction time in infants with Pediatric Perimeter.

PURPOSE: We quantified the eye/head (gaze) reaction time in infants to establish a normative database for the Pediatric Perimeter device. Additionally, we tested the hypothesis that gaze reaction time will reduce with age. METHODS: A cross-sectional study was conducted. Healthy infants between 3 to 10 months of age were recruited. Peripheral visual field stimuli (hemifield and quadrant stimuli) were presented in the Pediatric Perimeter device. Infant's gaze to these stimuli was observed, documented in real time, and video recorded for offline analysis. RESULTS: A total of 121 infants were tested in three age group bins [3-5 months, n = 44; >5-7 months, n = 30 and >7-10 months, n = 47]. Overall, 3-5 months old had longer reaction time when compared to the older infants particularly for stimuli presented in the quadrants (Kruskal-Wallis, p<0.038). A significantly asymmetric difference (p = 0.025) in reaction time was observed between the upper (median = 820ms, IQR = 659-1093ms) and lower quadrants (median = 601ms, IQR = 540-1052ms) only for the 3-5 months old infants. CONCLUSION: This study provides the normative gaze reaction time of healthy infants. With increase in age, there is reduction in reaction time and disappearance of reaction time asymmetry in quadrant stimuli. The longer reaction time for upward gaze could be due to delayed maturation of neural mechanisms and/or decreased visual attention.

Validation of visual acuity applications for teleophthalmology during COVID-19.

PURPOSE: The objective of this study was to identify and validate smartphone-based visual acuity (VA) apps that can be used in a teleophthalmology portal. METHODS: The study was conducted in three phases: A survey to investigate if the SmartOptometry App was easy to download, understand and test (phase I), an in-clinic comparison of VA measured in a random testing order with four tools namely COMPlog, Reduced Snellen near vision, Peek Acuity (Distance VA) and SmartOptometry (Near VA) (phase II) and a repeatability study on these 4 tools by measuring VA again (phase III). The study recruited the employees of our institute and adhered to the strict COVID-19 protocols of testing. RESULTS: Phase I Survey (n = 40) showed 90% of participants used android phones, 60% reported that instructions were clear, and all users were able to self-assess their near VA with SmartOptometry App. Phase II (n = 68) revealed that Peek Acuity was comparable to COMPlog VA (P = 0.31), however SmartOptometry was statistically significantly different (within 2 log MAR lines) from Reduced Snellen near vision test, particularly for young (n = 44, P = 0.004) and emmetropic (n = 16, P = 0.04) participants. All the 4 tests were found to be repeatable in phase III (n = 10) with a coefficient of repeatability ≤0.14. CONCLUSION: Smartphone-based apps were easy to download and can be used for checking patient's distance and near visual acuity. An effect of age and refractive error should be considered when interpreting the results. Further studies with real-time patients are required to identify potential benefits and challenges to solve.

Quantifying Suppression in Anisometropic Amblyopia With VTS4 (Vision Therapy System 4).

Purpose: Visual acuity (VA) of the amblyopic eye is usually considered for monitoring improvement with therapy. However, participation of the amblyopic eye under binocular viewing conditions is also important. This study investigated the use of a clinically available tool VTS4 (Vision Therapy System 4) to quantify the participation or suppression of the amblyopic eye under binocular viewing conditions. Methods: A cross-sectional study on patients with anisometropic amblyopia was undertaken. Monocular VA was thresholded. Stereo acuity was measured with Randot stereo test. Simultaneous macular perception (SMP) targets in VTS4 were dichoptically presented. SMP target size was reduced till the amblyopic eye's target disappeared (suppression scotoma size). An average of three measurements was taken for the suppression scotoma size. Results: Twenty-eight patients participated (aged 6 to 21 years). The mean interocular VA difference was 0.50 ± 0.27 logMAR. The mean scotoma size was 8.2° ± 5.4°. Mean stereo acuity was 2.06 ± 0.34 log arc seconds from 21 patients on whom stereopsis could be measured. Suppression scotoma size showed a significant (P < 0.001) positive correlation with both interocular VA difference (r = 0.59) and stereoacuity (r = 0.72). Conclusions: Participation of the amblyopic eye under binocular viewing condition can be assessed by measuring the suppression scotoma size in VTS4, even when stereoacuity is poor or not measurable. Smaller the suppression scotoma, better is the amblyopic eye's participation. Translational Relevance: VTS4 can be used in monitoring amblyopia therapy by quantifying suppression of the amblyopic eye.

Spasm of Near Reflex: Objective Assessment of the Near-Triad.

Purpose: To characterize binocular steady-state accommodation, pupil and convergence responses (near triad) in spasm of near reflex (SNR) before and after optical and pharmacological intervention. To identify the putative source of SNR in the neural control schema of accommodation-vergence interaction using controls-engineering modeling. Methods: Near-triad of 15 patients with SNR (9 to 23 years) was recorded using an infrared photorefractor at 2m viewing distance for 120s during clinical presentation, after optical fogging intended to relieve spasm, with cycloplegia, post-cycloplegia and long-term follow-up visits. Data were also collected without cycloplegia in 15 age-matched controls. Schor (1999) model was used to computationally simulate accommodation and vergence responses of controls and SNR. Results: Both eyes of SNR exhibited significant myopia and refraction fluctuations (<1.0Hz) during clinical presentation [median (25th to 75th IQR) refraction: -1.7D (-3.2 to -0.8D); root mean squared (RMS) deviation: 1.1D (0.5 to 1.5D)], relative to controls [0.8D (-0.03 to 1.4D); 0.2D (0.1 to 0.3D)] (p < 0.001). These decreased after optical fogging, largely eliminated with cycloplegia and partially re-appeared in the post-cycloplegia and follow-up visits. SNR responses could be modeled by increasing the gain and decay time of tonic accommodation, vis-à-vis, controls. Pupil and convergence responses in SNR were similar to controls at all visits (p > 0.1). Conclusions: Exaggerated fluctuations of steady-state accommodation may be a signature feature of SNR, even while their pupil and convergence responses may remain unaffected. These fluctuations may arise from the tonic accommodation controller, the properties of which could be potentially altered after optical fogging to relieve the disorder.

Construction and Validation of LEA Hindi Chart: A Multicenter Study.

SIGNIFICANCE: This study explains the construction and validation of a chart in Hindi language, one of the commonly spoken languages in the world. The new visual acuity chart is called LEA Hindi chart. The calligraphy construction method described here can help develop other such acuity charts. PURPOSE: The purpose of this study was to construct and validate a new logMAR Hindi visual acuity chart (LEA Hindi chart) using principles similar to that of LEA symbols acuity chart. METHODS: A multicenter (three centers) study was conducted in two phases. The first phase consisted of identifying and constructing the Hindi optotypes using calligraphy techniques. The Hindi optotypes were calibrated against the Landolt C optotypes by measuring the threshold distance for visual acuity. In the second phase, the newly constructed LEA Hindi chart was validated against the Early Treatment Diabetic Retinopathy Study (ETDRS) and Landolt C visual acuity charts. Sixty participants were enrolled for the first phase (centers 1 and 2) and for the second phase of the study (centers 1 and 3). Additional 15 participants were enrolled (center 1) for testing repeatability. RESULTS: Four Hindi optotypes were identified and used for the construction of the chart (first phase). In the second phase, the LEA Hindi chart was found to be comparable with both the Landolt C, (logMAR acuity difference, 0.03 ± 0.13; P > .18) and ETDRS (logMAR acuity difference, -0.02 ± 0.09; P > .25) charts. All the three charts were also found to be repeatable (95% limits of agreement within 0.24 logMAR). CONCLUSIONS: The newly constructed LEA Hindi visual acuity chart gave comparable levels of visual acuity as that measured in an ETDRS or Landolt C charts. The repeatability was also similar to the standard charts. The LEA Hindi visual acuity chart can be used for patients comfortable with Hindi language and also in studies requiring multiple measurements of visual acuity, to avoid familiarity to a given chart.

Prevalence of visual hallucinations.

BACKGROUND: To determine the prevalence of visual hallucinations and to report its associations with demographic and clinical factors in a population-based survey in India. METHODS: Prevalence of visual hallucinations was determined as a part of a large prospective, cross-sectional, population-based study that was carried out in two districts of Telangana, namely Khammam and Warangal. Multi-stage cluster random sampling was used in this study. The administration of the questionnaire preceded the clinical examination of the subjects. Associations with factors such as age, sex, education level and visual impairment categories were studied using univariate analysis and multiple logistic regression. RESULTS: Out of the 6,000 subjects who were enumerated from the 120 clusters in Khammam and Warangal districts, a total of 4,936 (82.3 per cent) responded. The mean age of the participants was 55.6 ± 11.8 years. Only the older age group (> 70 years of age) was associated with visual hallucinations on univariate analysis (p < 0.001). On multiple logistic regression, subjects with moderate visual impairment were found to have higher odds of experiencing visual hallucinations (odds ratio 1.48; 95% confidence interval 1.12-1.96, p = 0.006) and those who were older also had higher odds (odds ratio 1.35, p = 0.06). CONCLUSION: The prevalence of visual hallucinations among those with visual impairment in this population-based study was 13.8 per cent. The older age group and moderate visual impairment were noted to be the associated factors among individuals experiencing visual hallucinations.