Comparing paediatric optometric vision care in Canada over a 14-year period.

PURPOSE: In Canada, teaching in paediatric eye care has increased in the past decade both within the optometry curriculum and as continuing education to optometrists. Paediatric vision care guidelines have also been established by North American optometric associations. This study examined whether this exposure was associated with changes in paediatric eye care in Canada over a 14-year period. METHODS: Canadian optometrists were invited to participate in an anonymous 35-item survey in 2007 and 2021. The surveys sought to investigate optometrist's recommendations for first eye examinations, the number of paediatric patients seen in a typical week and preparedness to provide eye examinations to children. Response frequencies were determined for each survey item. RESULTS: Across Canada, 133/1000 (13.3%) and 261/~6419 (~4.1%) optometrists responded to the survey in 2007 and 2021, respectively. No significant difference was found in the number of years practicing, days per week in practice and total number of patients seen per week. The modal age optometrists recommended children be seen for their first eye examination changed from 3-4 years in 2007 (53%) to 6-12 months in 2021 (61%). In 2007, 87% of respondents provided eye examinations to children <2 years, increasing to 94% in 2021 (p = 0.02). Despite a reduction in the recommended age between the two survey years, the most frequent age children were seen for their first eye examination was 3-4 years (30% in both surveys) and the most common age seen in a typical week remained unchanged (4-6 years-56% 2007; 66% 2021). CONCLUSION: Although optometrists' willingness to provide paediatric eye care increased over the past 14 years, the number of children seen in a typical week did not change. Barriers to determine why more children are not being seen at an earlier age need to be investigated.

Validation of the Waterloo Differential Visual Acuity Test (WatDAT) and Comparison With Existing Pediatric Tests of Visual Acuity.

Purpose: The new Waterloo Differential Acuity Test (WatDAT) is designed to allow recognition visual acuity (VA) measurement in children before they can typically undertake matching tests. The study purpose was to validate WatDAT in adults with normal and reduced VA. Methods: Eighty adults (18 to <40 years of age) participated (32 normal VA, 12 reduced VA, and 36 simulated reduced VA). Monocular VA was measured on two occasions in random order for WatDAT (versions with 3 and 5 distractors for Faces and Patti Pics house among circles), Lea Symbols, Kay Pictures and Patti Pics matching tests, Teller Acuity Cards, Cardiff Acuity Test, and Early Treatment Diabetic Retinopathy Study (ETDRS) letter chart. Pediatric tests were validated against ETDRS using limits of agreement (LoA), sensitivity, and specificity. The LoA for repeatability were also determined. Results: WatDAT showed minimal bias compared with ETDRS, and LoAs, which were similar to pediatric matching tests (0.241-0.250). Both preferential looking tests showed higher bias and LoAs than ETDRS. Matching tests showed good agreement with ETDRS, except for Kay Pictures and Lea Uncrowded test, which overestimated VA. WatDAT showed high sensitivity (>0.96) and specificity (>0.79), which improved with criterion adjustment and were significantly higher than for the preferential looking tests. LoA for repeatability for WatDAT 3 Faces and WatDAT 5 Faces were comparable with the ETDRS. Conclusions: WatDAT demonstrates good agreement and repeatability compared with the gold-standard ETDRS letter chart, and performed better than preferential looking tests, the alternative until a child can undertake a matching VA test. Translational Relevance: Good validity of the Waterloo Differential Acuity Test was demonstrated in adults as a first step to showing its potential for detecting childhood visual disorders.

Systemic sarcoidosis presenting as acute rapidly progressive proptosis / Sarcoidose sistêmica apresentando-se como proptose aguda rapidamente progressiva

ABSTRACT Sarcoidosis is a generalized systemic chronic inflammation that rarely involves the orbit. As a chronic inflammation, sarcoidosis typically manifests with an insidious onset and slowly progressive course. We report a case of acute-onset proptosis resulting from a rapidly growing diffuse orbital mass that simulated malignant growth, which was biopsy proven to be the first manifestation of systemic sarcoidosis. The patient demonstrated complete resolution of proptosis and systemic involvement with long-term corticosteroid treatment.

RESUMO A sarcoidose é uma inflamação sistêmica generalizada que raramente envolve a órbita. Sendo uma inflamação crônica, a sarcoidose geralmente se manifesta com um início insidioso e uma evolução lentamente progressiva. Neste artigo, é relatado um caso de proptose de início agudo, resultante de uma massa orbitária difusa de rápido crescimento, simulando um crescimento maligno, mas cuja biópsia comprovou ser a primeira manifestação de uma sarcoidose sistêmica. O paciente apresentou resolução completa da proptose e do envolvimento sistêmico com tratamento de longo prazo com corticosteroides.

Cytogenetic Abnormalities for Predicting the Risk of Metastases in Choroidal and Ciliary Body Melanoma.

Purpose: Choroidal melanoma (CM) and ciliary body melanoma (CBM) are the two most common subtypes of uveal melanoma. Starting from the observation that CBM tends to have a higher metastatic potential than CM, we hypothesized that specific cytogenetic abnormalities could be associated with tumor location - reflecting distinct genetic signatures that would drive the risk of distant spread. Methods: Chromosomal alterations were investigated by molecular cytogenetic techniques in 217 and 97 patients with CM and CBM, respectively. Cox proportional hazards regression analysis was used to identify the independent predictors of distant metastasis. Results: Patients with CBM had larger tumor sizes (P < 0.001), higher disease stages (P < 0.001), and more frequently showed distant metastasis (P = 0.002) than those with CM. On analyzing the entire study cohort, we found that specific chromosomal alterations - including chromosome 8p loss (P < 0.001), 1p loss (P < 0.001), and monosomy 3 (P < 0.005) - were independent predictors of distant metastasis. Based on a decision-tree learning algorithm, we identified three specific subgroups of patients with uveal melanoma at high risk of distant spread. Monosomy 3 occurred significantly more frequently in patients with T3 CBM tumors. Conclusions: Specific cytogenetic abnormalities - including chromosome 8p loss, 1p loss, and monosomy 3 - are independent risk factors for distant metastasis in uveal melanoma. Larger tumor size at presentation and monosomy 3 contribute to a higher metastatic risk in patients with CBM.

Measuring recognition visual acuity in young children - testability with the Waterloo Differential Acuity Test (WatDAT).

CLINICAL RELEVANCE: Visual acuity measurement is important for the detection and monitoring of eye disorders. Developing accurate and sensitive visual acuity tests suitable for young children is therefore desirable. BACKGROUND: Recognition or form visual acuity (VA), which is measured with matching in children aged 3 years and up, is more sensitive for detecting visual deficits compared to resolution VA. The Waterloo Differential Acuity Test (WatDAT) is a proposed recognition VA test using the concept of identifying the "odd one out" among distractors. The WatDAT is expected to be cognitively easier than matching tests and therefore may be used in younger children. The purpose of this study is to investigate the testability of the WatDAT paradigm in children aged 12-36 months, and to determine the optimum format and number of distractors. METHODS: Fifty-one typically-developing children aged 12-36 months participated in the study. Data for Patti Pics (PP) and Face targets (FT) were collected for formats with 3, 4 and 5 distractors. The targets were presented binocularly on a computer touch screen at 30 cm. The task was to touch the face among identical non-faces or a house among circles. Following initial training, there were 5 presentations for each distractor format. Testability was defined as correctly identifying at least 4/5 presentations and was also determined for uncrowded PP symbols using matching. RESULTS: Of participants aged 18-36 months, 87% could perform the WatDAT PP targets with 3 distractors compared to 68% for the FT, while 48% could perform matching with PP. The testability for FT increased to 85% for children ≥22 months. Younger children showed lower testability. For the 3 distractor format, PP targets gave 9% testability in children 12 to <18 months, and FT gave a testability of 16% in children 12 to <22 months. CONCLUSION: WatDAT testability is higher than matching VA tests. This indicates that the newly developed WatDAT has potential for measuring recognition VA in children 18 months and older.

Systemic sarcoidosis presenting as acute rapidly progressive proptosis.

Sarcoidosis is a generalized systemic chronic inflammation that rarely involves the orbit. As a chronic inflammation, sarcoidosis typically manifests with an insidious onset and slowly progressive course. We report a case of acute-onset proptosis resulting from a rapidly growing diffuse orbital mass that simulated malignant growth, which was biopsy proven to be the first manifestation of systemic sarcoidosis. The patient demonstrated complete resolution of proptosis and systemic involvement with long-term corticosteroid treatment.

Pigment-induced glaucoma secondary to bilateral diffuse uveal melanocytic proliferation.

We report the first case of pigment-induced glaucoma in a patient presenting with bilateral diffuse uveal melanocytic proliferation (BDUMP) syndrome. Despite treatment with plasma exchange, the patient developed progression of her lesions and bilateral glaucoma. Surgical treatment with Ahmed valve implant was performed to control her increased intra-ocular pressure. This case demonstrates that BDUMP can be a cause of a refractory pigment-induced glaucoma.

Retinal perfusion changes in radiation retinopathy.

PURPOSE: To investigate retinal blood flow and oxygen saturation changes in patients diagnosed with retinopathy following plaque radiation treatment to treat choroidal melanoma. METHODS: Eight patients (mean age 55.75 years, SD 12.58 years) who have developed unilateral ischaemic radiation-related retinopathy as confirmed by wide-field fluorescein angiography were recruited for the study. The fellow eye with no other ocular or retinal pathology was used as control. Both eyes underwent measurement of total retinal blood flow (TRBF) and retinal blood oxygen saturation using prototype methodologies of Doppler Spectral Domain Optical Coherence Tomography (OCT) and Hyperspectral Retinal Camera, respectively. RESULTS: The average TRBF in the retinopathy eye was significantly lower compared to the fellow eye (33.48 ± 12.73 µl/min versus 50.37 ± 15.26 µl/min; p = 0.013). The arteriolar oxygen saturation (SaO2 ) and venular oxygen saturation (SvO2 ) were higher in the retinopathy eye compared to the fellow eye (101.11 ± 4.26%, versus 94.45 ± 5.79%; p = 0.008) and (62.96 ± 11.05% versus 51.24 ± 6.88%, p = 0.051), respectively. CONCLUSION: The ionizing radiation seems to have an impact on the TRBF, SaO2 and SvO2 , clinically presenting similar to a rapidly developing diabetic retinopathy. The results show an altered retinal vascular physiology in patients with radiation-related retinopathy.

Preliminary investigation of multispectral retinal tissue oximetry mapping using a hyperspectral retinal camera.

Oximetry measurement of principal retinal vessels represents a first step towards understanding retinal metabolism, but the technique could be significantly enhanced by spectral imaging of the fundus outside of main vessels. In this study, a recently developed Hyperspectral Retinal Camera was used to measure relative oximetric (SatO2) and total hemoglobin (HbT) maps of the retina, outside of large vessels, in healthy volunteers at baseline (N = 7) and during systemic hypoxia (N = 11), as well as in patients with glaucoma (N = 2). Images of the retina, on a field of view of ∼30°, were acquired between 500 and 600 nm with 2 and 5 nm steps, in under 3 s. The reflectance spectrum from each pixel was fitted to a model having oxy- and deoxyhemoglobin as the main absorbers and scattering modeled by a power law, yielding estimates of relative SatO2 and HbT over the fundus. Average optic nerve head (ONH) saturation over 8 eyes was 68 ± 5%. During systemic hypoxia, mean ONH saturation decreased by 12.5% on average. Upon further development and validation, the relative SatO2 and HbT maps of microvasculature obtained with this imaging system could ultimately contribute to the diagnostic and management of diseases affecting the ONH and retina.

Intervisit Repeatability of Retinal Blood Oximetry and Total Retinal Blood Flow Under Varying Systemic Blood Gas Oxygen Saturations.

PURPOSE: The aim of the study is to validate and calibrate the Doppler spectral-domain optical coherence tomography (SD-OCT) derived total retinal blood flow (TRBF) and metabolic hyperspectral retinal camera (MHRC) derived oxygen saturation (SO2) of major retinal vessels in human volunteers using a novel and exact provocation technique (RespirAct) that allows the precise control of the end-tidal partial pressure of oxygen (PETO2). Between visit repeatability of the TRBF and retinal blood SO2 also were studied. METHODS: One eye of 11 young healthy subjects was chosen randomly for the study. Total retinal blood flow and retinal SO2 measurements were obtained under conditions of normoxia, hyperoxia, and hypoxia. The order of hyperoxia and hypoxia was randomized between subjects. The measurements were repeated after a week interval. RESULTS: When the arterial PETO2 was increased from baseline (PETO2 = 100 mm Hg) to 200 and 300 mm Hg, the TRBF significantly reduced (P = 0.02) from 44.60 (±8.9) to 40.28 (±8.9) and 36.23 (±4.6) µL/min. Lowering the arterial PETO2, from baseline to 80, 60, and 50 mm Hg, TRBF significantly increased (P = 0.04) from 43.17 (±12.7) to 45.19 (±5.5), 49.71 (±13.4), and 52.89 (±10.9) µL/min with simultaneous reduction in the arterial blood SO2 content from 99.3% (±5.8) to 95.6% (±5.1), 89.6% (±2.8), and 83.3% (±3.9), respectively (P = 0.00). The coefficient of repeatability (COR) of TRBF, retinal arterial, and venous blood SO2 values are 21.8 µL/min, 18.4%, and 15.2%, respectively. CONCLUSIONS: Total retinal blood flow and retinal blood SO2 measurements performed under safe levels of hypoxia and hyperoxia were repeatable in healthy adults over the range of SO2 investigated.

Grader learning effect and reproducibility of Doppler Spectral-Domain Optical Coherence Tomography derived retinal blood flow measurements.

PURPOSE: To investigate grader learning effect and to quantify intergrader reproducibility of Doppler Spectral-Domain Optical Coherence Tomography (SD-OCT) derived retinal blood flow measurements. METHODS: Fifteen healthy young subjects (mean age 28.44; SD 3 years) underwent Doppler SD-OCT scans of one eye using the circumpapillary double circular scan protocol of the Optovue RTVue by one of two experienced operators. One trained (i.e. having undergone certification) and one novice (i.e. preliminary training comprising five standard practice data sets) individual then graded a standardized set of scans, consisting of 15 data sets (session 1) using custom Doppler Optical Coherence Tomography of Retinal Circulation (DOCTORC) software. One week later (session 2), the novice grader underwent further training by grading an additional 15 practice data sets and then both graders subsequently regraded the original 15 data sets. RESULTS: Measurements achieved by a novice grader during session 1 showed a trend to be higher in terms of total retinal venous blood flow (TRBF) and also to be significantly (p = 0.03) higher for venous area, compared with a trained grader. Session 2 results were not significantly different for either grader. The mean TRBF for session 2 for the trained and novice grader was 45.29 ± 9.28 µl/min and 44.39 ± 7.36 µl/min, respectively. The coefficient of repeatability (COR) of session 2 TRBF values between the trained and novice grader was 8.09 µl/min. CONCLUSIONS: There is a grader learning effect which impacts the venous area measurements. Reproducible and repeatable retinal blood flow measurements were achieved among trained graders using DOCTORC software.

Retinal blood flow and vascular reactivity in chronic smokers.

PURPOSE: The aim of this study was to investigate the impact of cigarette smoking in otherwise healthy young individuals on retinal blood flow (RBF) and vascular reactivity (RVR). METHODS: An automated gas flow controller (RespirAct) was used to achieve normoxic hypercapnia in 10 nonsmokers (mean age 28.9; SD 4.6 years) and nine smokers (mean age 27.55; SD 4.7 years). Retinal blood flow measurements were obtained using a prototype Doppler spectral-domain optical coherence tomographer (SD-OCT) and bidirectional laser Doppler velocimetry and simultaneous vessel densitometry during baseline, normoxic hypercapnia, and recovery. Group mean PETCO2 (end-tidal partial pressure of CO2) was increased by 15.9% in the nonsmoking group and by 15.7% in the smoking group, with a concomitant increase in PETO2 (end-tidal partial pressure of O2) by approximately 1.5% to 2% in both groups. RESULTS: In nonsmokers, retinal arteriolar diameter (P < 0.0001), centerline velocity (P = 0.0004), and blood flow (P < 0.0001) significantly increased during normoxic hypercapnia. Similarly, the venous area (P = 0.0418), venous velocity (P = 0.0068), and total venous RBF (P < 0.0001), as measured by the prototype Doppler SD-OCT, significantly increased. In smokers, normoxic hypercapnia resulted in a significant increase in velocity (P = 0.0019), flow (P = 0.0029), and total venous RBF (P = 0.002). Comparing smokers and nonsmokers, the percentage change in arteriolar diameter (P = 0.0379) and blood flow (P = 0.0101) was significantly lower in the smoking group. There was no significant difference in baseline PETCO2 level between smokers and nonsmokers. CONCLUSIONS: Retinal vascular reactivity in response to normoxic hypercapnia is significantly reduced in young, healthy smokers compared with nonsmokers.