Major Epidemiological Studies in Optometry Flashcards
Lecture objectives
1) recall the development process for the modified clinical technique
2) recall the distinguishing characteristics and major findings of key studies
3) identify how key studies have affected the practice of optometry
Prevalence
disease burden of the population
Incidence
how fast the population gets sick
relative risk
which groups are at higher risk for developing a disease
Orinda Vision Screening Study Summary
hybrid study design, prevalence of visual disorders in children, clinical trial: best screening protocol in the hands of an ECP, modified clinical technique: gold standard for vision screenings
What is the gold standard for vision screenings?
modified clinical technique from Orinda Study
Vision in Preschoolers Study Summary
clinical trial phase I: best single screening tests in the hands of an ECP; phase II: best single screening test in the hands of lay people; combining tests and creating a protocol can be much more effective: increases direct cost and time and decreases the adverse outcomes from screening tests
Framingham eye study Summary
prospective cohort, incidence of cataract/ARMD/diabetic ret/POAG
Goal of Orinda vision screen study
to design the least expensive, least technical and most effective screening program for finding essentially all elementary-school children with vision problems
What was the Orinda hybrid study design?
descriptive epidemiology and retrospective clinical trial
What is the modified clinical technique?
snellen acuity, retinoscopy with lens rack, distance and near cover test, ophthalmoscopy
Where is orinda?
near Berkeley, CA
What was the first interdisciplinary effort to establish the validity of a vision screening protocol?
Orinda vision screening study 1954 to 1956
Who was involved in the Orinda study?
OD, OMD, biostatisticians, school psychologists, parents and teachers
T/F Orinda is an example of evaluating diagnostic and therapeutic modalities as well as the delivery of health care services
true
What made Orinda retroscpective?
worked backwards from the comprehensive examinations; distilled information to minimum set of distinguishing visual characteristics, compared distilled information to screening programs for best fit
What is a critique of the Orinda study?
criteria determined by committee, not strict data analysis
What was the sensitivity and specificity of the Orinda vision screening program?
96% and 98% respectively
What were ancillary findings of the Orinda study?
> 50% of children with previous eye care still failed the screening, the incidence of vision problems increases with age (1.6%/yr), direct cost of $0.45 per student
What are weaknesses of Orinda?
not applicable to all populations, must be performed by clinicians, not lay people, does not include visual skills testing; many alternatives have been proposed (like NYSOA)
Goal of Vision in Preschoolers Study
developing evidence-based guidelines for preschool vision screening test
What disorders did the Vision in Preschoolers Study find?
amblyopia, strabismus, significant refractive error, unexplained reduced visual acuity
What study design was VIP?
experimental
Phase I VIP
set target sensitivity and specificity, used a mobile test center for screening and full exam; best tests for detecting vision disorders by ECP, tested 2588 3-5 year old Head Start students
VIP test specificity
set at 90%; the best tests detected approximately thirds of children with >/= 1 targeted conditions and nearly 90% of children with the most important/severe levels of each conditions
What are the best tests for detecting vision disorders by ECP (VIP Phase I)?
non-cycloplegic retinoscopy, retinomax, sure sight, crowded linear lea symbols at 10 feet
Phase II VIP
nurses and lay screeners, tested inside the schools, 1452 3-5 year old Head Start preschoolers
What are the best tests for detecting vision disorders by lay screeners (VIP Phase II)?
refractive error, retinomax autorefractor; strabismus: sure sight + stereo smile II
What kind of study was framingham?
cross-sectional study, prevalence data for common eye disease and disorders out of Framingham, MA 1948
What general things did Framingham indicate?
vision impairment prevalence was lower than though and POAG prevalence was higher
What ocular findings did Framingham identify?
15% cataract, 3% diabetic ret and POAG, 8% ARMD
What was the Baltimore eye survey?
an evaluation of glaucoma screening tests: tonometry, VF, stereo fundus photo, detailed PMHx and POHx
What kind of study was Baltimore eye?
prospective, cross-sectional out of Baltimore, Maryland 1985
Which was more diverse, Framingham or Baltimore?
baltimore
What percent of participants in Baltimore eye survey were identified as having glaucoma than were unaware they had the disease at the time of diagnosis
50%
What risk factors for POAG did the Baltimore eye survey discover?
race, IOP, systemic HTN, perfusion pressure, family history, ONH appearance
T/F Baltimore eye confirmed association between higher IOP and ONH damage
true, particularly at levels of 30 mmHg (narrowest NRR width and C/D ratio were not as predictive)
What visual impairment findings were identified by Baltimore eye survey?
cataract, ARMD, diabetic ret, retinal disorders, glaucoma
How did race affect findings in the Baltimore eye survey?
blacks 1.75x more likely than whites to be blind or have vision loss
What did Beaver dam eye study look into?
prevalence and incidence of cataract, AMD and diabetic ret
What kind of study was beaver dam?
prospective cohort study with follow up exams every 5 years out of Beaver Dam, WI 1988-2008
What were the key findings of Beaver Dam eye study?
cigarette smoking is associated with cataract and AMD; retinal drusen/retinal pigment are associated with progression of AMD
Which study created an imaging system and standard scale for eye disease epidemiological studies?
beaver dam eye study
What kind of study was Wisconsin epidemiologic study of diabetic retinopathy?
prospective cohort study follow ups every 4 years out of Wisconsin 1979, funded by the national eye institute
What was the Wisconsin epidemiologic study of diabetic ret investigating?
incidence and progression of diabetic complications (diabetic retinopathy, vision loss, diabetic nephropathy)
What risk factors of diabetic complications did the Wisconsin epidemiologic study identify?
poor glycemic control, smoking, high blood pressure
T/F BG control is associated with risk of incidence and progression of diabetic ret and kidney disease
true, identified increased DR risk at HbA1c above 6.5%
What kind of study was LA Latino Eye study?
prospective cohort study, LA, CA; 4,600 latino adults from 2000-2010
What was LA Latino Eye study investigating?
incidence and prevalence of diabetic ret, POAG, ARMD, cataracts
What were the major LALES findings?
60% of eye disease in Latinos is undiagnosed, Latinos develop visual impairment and blindness more than any other ethnic group in the US, Latinos are at high risk for developing diabetic retinopathy (34% developed ret during the study and 39% with ret showed progression)
What kind of study was the Barbados eye study?
simple random sample
What was the Barbados eye study investigating?
incidence, prevalence and risk factors for POAG, age-related cataract, diabetic retinopathy, ARMD
What was the largest glaucoma study ever conducted in a black population?
Barbados eye study
What did Barbados discover in terms of blindness/low vision?
higher in this study population than elsewhere in the world, 75% due to cataracts and POAG
What likely led to high rates of blindness in Barbados?
access to care, cultural factors, economic factors
What kind of study is the Multi-ethnic/Baltimore pediatric eye disease study? (MEPEDS/BPEDS)
cross-sectional study in LA, CA and Baltimore, MD with 10,000 children
According to MEPEDS, what race has the most myopia?
black children
According to MEPEDS, what race has the most hyperopia?
white children
According to MEPEDS, what race has the most astigmatism?
hispanic children
T/F maternal smoking had no effect of risk of vision disorder?
false, maternal smoking increased risk 1.5x RR for hyperopia and astigmatism and 2x RR for strabismus
How did lack of health insurance increase risk of amblyopia?
3x RR of amblyopia
What is CLEK?
collaborative longitudinal study of keratoconus: natural history of disease and risk factors associated with developing the disease
What is PERK?
prospective evaluation of radial keratotomy; RK was effective for myopia x 10 years for most patients, risk factors for hyperopic shift over time include thickness and number of incisions
What is CLEERE?
collaborative longitudinal evaluation of ethnicity and refractive error
What risk factors were identified for myopia in CLEERE?
parents are myopic, and refraction in 3rd grade is a fair predictor of need for glasses in 4th/5th grade
What are recent public health studies?
association of ambient air pollution with age-related macular degeneration and retinal thickness in UK; pediatric eye injuries by hydroalcoholic gel in the context of the coronavirus disease 2019 pandemic; multicenter head to head real world validation study of seven automated AI diabetic retinopathy screening systems
