Childhood Cataract
Conditions
Brief summary
Sensitivity and specificity of current screening methods for childhood cataracts is poor. This results in delayed diagnosis and management which can decrease the visual prognosis following cataract surgery. It also results in many false positives with resultant unnecessary healthcare costs in specialist paediatric ophthalmology services. This study compares the accuracy of cataract screening using infrared light compared to white light in a population of children attending eye clinic.
Detailed description
All babies born in the United Kingdom (UK) undergo eye screening to enable the early diagnosis and management of childhood cataract, a treatable but potentially blinding condition affecting 1 in 2000 newborns. The current technique involves the assessment of the red-reflex - the orange/red glow in the pupil seen during ophthalmoscopy (or flash photography) due to reflectance of light from the back of the eye. In reality, testing can be technically difficult because the pupil constricts to light during the examination and, particularly in babies of Asian and Afro-Caribbean ancestry, the red-reflex can be dim due to the effect of ocular pigmentation. As a result less than 50% of congenital cataracts are currently identified up by screening. Early visual experience is required for good visual development and a delay in the surgical management of cataracts results in sub-optimal visual development and visual impairment. There are theoretical advantages to using Infrared (IR) light rather than white light to assess choroidal reflectance, including avoidance of pupil constriction. The study aims to determine if the assessment of the IR-reflex, using a prototype device, rather than the red-reflex, using a direct ophthalmoscope, improves screening accuracy in the detection of ocular media opacities in a pathology enriched childhood cohort. Eligible children attending an eye clinic will be screened for cataract by a medical student (masked to the pathology) using the existing standard direct ophthalmoscope technique for red-reflex assessment and IR-reflex assessment using the prototype imaging device. A gold standard examination by an ophthalmologist will follow the screening examinations. Sensitivity and specificity of each screening technique will be calculated and compared.
Interventions
DIAGNOSTIC_TESTRed-reflex assessment
The red reflex was examined in the standard manner using direct ophthalmoscope by medical student examiner
DIAGNOSTIC_TESTInfrared-reflex assessment
The infrared reflex was examined using a modified smart phone camera by a medical student examiner
Sponsors
Cambridge University Hospitals NHS Foundation Trust
Study design
Observational model
CASE_CROSSOVER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
1 Months to 5 Years
Healthy volunteers
Yes
Inclusion criteria
* All children between 1 month and 5 years of age attending paediatric ophthalmology clinic
Exclusion criteria
* Parents / carers with poor conversant English
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard | 1 day | True positives: the number of eyes with cataract correctly identified True negatives: the number of eyes without cataract correctly identified False positives: the number of eyes without cataracts incorrectly identified as having cataract False negatives positives: the number of eyes with cataract incorrectly identified as not having cataract |
| Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing | 1 day | Sensitivity (percentage of eyes with cataract correctly identified) and specificity (percentage of eyes without cataract correctly identified) of red-reflex and infrared-reflex testing in percentage terms with 95% Confidence Intervals. Sensitivity and specificity are recorded as a percentage, with 100% indicating best accuracy. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | 1 day | True positives: the number of eyes with cataract correctly identified in caucasian children's eyes and in BAME children's eyes. True negatives: the number of eyes without cataract correctly identified in caucasian children's eyes and in BAME children's eyes. False positives: the number of eyes without cataract incorrectly identified as having cataract in caucasian children's eyes and in BAME children's eyes. False negatives: the number of eyes with cataract incorrectly identified as not having cataract in caucasian children's eyes and in BAME children's eyes. |
| Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing Stratified by Ethnicity | 1 day | Sensitivity (percentage of eyes with cataract correctly identified) and specificity (percentage of eyes without cataract correctly identified) of red-reflex and infrared-reflex testing in percentage terms with 95% Confidence Intervals. Sensitivity and specificity are recorded as a percentage, with 100% indicating best accuracy. |
Countries
United Kingdom
Participant flow
Recruitment details
Diagnostic accuracy comparison trial: children from 1 month to 5 years of age (with no previous history of ophthalmic surgery) attending a specialist paediatric out-patient clinic were enrolled into the study over a 3 month period.
Participants by arm
| Arm | Count |
|---|---|
| Children Recruited to Diagnostic Comparison Study The data from right eyes of 110 children recruited to diagnostic accuracy comparison trial from clinic. These patients had initial red-reflex assessment (Intervention 1) and then infrared-reflex assessment (intervention 2) performed by a medical student prior to gold standard examination by a paediatric ophthalmologist | 110 |
| Children Recruited to Diagnostic Comparison Study The data from right eyes of 110 children recruited to diagnostic accuracy comparison trial from clinic. These patients had initial red-reflex assessment (Intervention 1) and then infrared-reflex assessment (intervention 2) performed by a medical student prior to gold standard examination by a paediatric ophthalmologist | 110 |
| Total | 220 |
Baseline characteristics
| Characteristic | Children Recruited to Diagnostic Comparison Study |
|---|---|
| Age, Continuous | 4 years STANDARD_DEVIATION 3.45 |
| Evaluator assessment of reflex | 110 Participants |
| Race/Ethnicity, Customized ethnicity black, asian, minority ethnic | 21 Participants |
| Race/Ethnicity, Customized ethnicity white | 89 Participants |
| Sex: Female, Male Female | 60 Participants |
| Sex: Female, Male Male | 50 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 110 |
| other Total, other adverse events | 0 / 110 |
| serious Total, serious adverse events | 0 / 110 |
Outcome results
Primary
Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard
True positives: the number of eyes with cataract correctly identified True negatives: the number of eyes without cataract correctly identified False positives: the number of eyes without cataracts incorrectly identified as having cataract False negatives positives: the number of eyes with cataract incorrectly identified as not having cataract
Time frame: 1 day
Population: 110 children were eligible for the study, each had their right eye assessed by a medical student using 1) red-reflex assessment 2) Infrared-reflex assessment. Findings were compared to a gold standard examination by an ophthalmologist.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard | Red-reflex test true positive | 17 eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard | Red-reflex test true negative | 54 eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard | Red-reflex test false positive | 32 eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard | Red-reflex test false negative | 7 eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard | Infrared-reflex test true positive | 24 eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard | Infrared-reflex test true negative | 86 eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard | Infrared-reflex test false positive | 0 eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard | Infrared-reflex test false negative | 0 eyes |
Primary
Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing
Sensitivity (percentage of eyes with cataract correctly identified) and specificity (percentage of eyes without cataract correctly identified) of red-reflex and infrared-reflex testing in percentage terms with 95% Confidence Intervals. Sensitivity and specificity are recorded as a percentage, with 100% indicating best accuracy.
Time frame: 1 day
Population: 110 eyes (of 110 children) recruited to the study
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Eyes Tested in the Diagnostic Comparison Study | Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing | Sensitivity of red-reflex | 71 percentage of eyes |
| Eyes Tested in the Diagnostic Comparison Study | Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing | Sensitivity of infrared-reflex | 100 percentage of eyes |
| Eyes Tested in the Diagnostic Comparison Study | Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing | Specificity of red-reflex | 63 percentage of eyes |
| Eyes Tested in the Diagnostic Comparison Study | Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing | Specificity of infrared-reflex | 100 percentage of eyes |
Comparison: Sample size was based on a cataract prevalence of 20% in the enriched population and a predicted difference of 15% sensitivity and specificity between tests.p-value: <0.05McNemar
Secondary
Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity
True positives: the number of eyes with cataract correctly identified in caucasian children's eyes and in BAME children's eyes. True negatives: the number of eyes without cataract correctly identified in caucasian children's eyes and in BAME children's eyes. False positives: the number of eyes without cataract incorrectly identified as having cataract in caucasian children's eyes and in BAME children's eyes. False negatives: the number of eyes with cataract incorrectly identified as not having cataract in caucasian children's eyes and in BAME children's eyes.
Time frame: 1 day
Population: of 110 eligible children, 89 (81%) were caucasian, 21(19%) were of Black, Asian or minority ethnicity (BAME)
| Arm | Measure | Group | Value (COUNT_OF_UNITS) |
|---|---|---|---|
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Red-reflex true positives in BAME children's eyes | 2 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Red-reflex true negatives in BAME children's eyes | 5 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Red-reflex false positives in BAME children's eyes | 14 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Red-reflex false negatives in BAME children's eyes | 0 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Red-reflex true positives in white children's eyes | 15 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Red-reflex true negatives in white children's eyes | 49 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Red-reflex false positives in white children's eyes | 18 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Red-reflex false negatives in white children's eyes | 7 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Infrared-reflex true positives in BAME children's eyes | 2 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Infrared-reflex true negatives in BAME children's eyes | 19 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Infrared-reflex false positives in BAME children's eyes | 0 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Infrared-reflex false negatives in BAME childrens' eyes | 0 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Infrared-reflex true postives in white children's eyes | 22 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Infrared-reflex true negatives in white children's eyes | 67 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Infrared-reflex false positives in white children's eyes | 0 Eyes |
| Eyes Tested in the Diagnostic Comparison Study | Results of Red-reflex and Infrared-reflex Tests Compared to Gold Standard Stratified by Ethnicity | Infrared-reflex false negatives in white children's eyes | 0 Eyes |
Secondary
Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing Stratified by Ethnicity
Sensitivity (percentage of eyes with cataract correctly identified) and specificity (percentage of eyes without cataract correctly identified) of red-reflex and infrared-reflex testing in percentage terms with 95% Confidence Intervals. Sensitivity and specificity are recorded as a percentage, with 100% indicating best accuracy.
Time frame: 1 day
Population: 89 (81%) were the eyes of caucasian children, 21(19%) were the eyes of Black, Asian or minority ethnicity (BAME) children
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Eyes Tested in the Diagnostic Comparison Study | Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing Stratified by Ethnicity | Sensitivity of red-reflex in caucasian eyes | 69 percentage of eyes |
| Eyes Tested in the Diagnostic Comparison Study | Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing Stratified by Ethnicity | Sensitivity of red-reflex in BAME eyes | 100 percentage of eyes |
| Eyes Tested in the Diagnostic Comparison Study | Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing Stratified by Ethnicity | Specificity of red-reflex in caucasian eyes | 72 percentage of eyes |
| Eyes Tested in the Diagnostic Comparison Study | Sensitivity and Specificity of Red-reflex and Infrared-reflex Testing Stratified by Ethnicity | Specificity of red-reflex in BAME eyes | 32 percentage of eyes |
Comparison: Evidence of superiority of intervention 2 over intervention 1 requires a significant difference in specificity of the intervention 1 and 2 between ethnicity groups.p-value: <0.05Fisher Exact