Clinical Optometry and Evidence-Based Practice Review

This set of vocabulary flashcards covers clinical biostatistics, study design, epidemiology of eye diseases (glaucoma, diabetic retinopathy, myopia), and key findings from major clinical trials such as ATS, OHTS, and ETDRS.

Confusion Matrix

A tool used to describe the performance of a test at predicting disease and to calculate sensitivity, specificity, prevalence, PPV, NPV, and false + or - rates.

Sensitivity

How often a test correctly detects a positive result, calculated as $\frac{\text{True+}}{\text{false-} + \text{true+}}$.

Specificity

How often a negative result is truly negative, calculated as $\frac{\text{True-}}{\text{false+} + \text{true-}}$.

ROC Curve (Receiver Operating Characteristics)

A graph used to determine the optimal threshold for a test and find the appropriate balance between sensitivity and specificity.

Validity

The ability of a test to measure what it claims to measure, often determined by comparison to a gold standard.

Repeatability

An assessment of the variability of results between testing occasions.

COR (Coefficient of Repeatability)

The size of a clinically significant change; any change smaller than this value may be due to chance.

Discriminative Ability

How well a test identifies individuals with and without a specific condition.

NNT (Number Needed to Treat)

The number of patients that must be treated to prevent one adverse outcome.

NNH (Number Needed to Harm)

The number of patients who receive a treatment before one patient is harmed by it.

Ascertainment Bias

A bias that occurs when a doctor is more likely to identify side effects in patients they perceive as getting worse.

Regression to the Mean

A statistical phenomenon where a measurement, such as a single high IOP reading, reflects statistical fluctuation rather than a true failure of a drug or treatment.

Uncorrectable Vision Impairment

The proportion of overall vision impairment that could be improved through currently available or appropriate treatment.

Meta-Analysis

A study that combines results from multiple independent studies to obtain a better estimate of treatment effects, increasing statistical power.

Randomized Controlled Trial (RCT)

A study design where participants are randomly assigned to different interventions or control groups to minimize bias and allow causal inference.

Hawthorne Effect

A procedural bias where patients show improvement (e.g., better lid hygiene in a dry eye trial) because they are being monitored rather than due to the medication.

Type I Error

A false positive where a result reaches statistical significance even though there is no actual difference between the groups.

Type II Error

A false negative where a result does not reach statistical significance despite there being a real difference between groups.

Power

The probability that the null hypothesis will be rejected during a study.

Bland Altman Plot

A plot used to compare two instruments and detect differences in bias (constant error), skew (error at high/low ends), and precision (variability).

Absolute Risk

The incidence or probability of an event occurring in a specific population under specific conditions.

Relative Risk

The likelihood of an event occurring in a group of people with different behaviors, physical conditions, or environmental factors.

AGIS (Advanced Glaucoma Intervention Study) Key Finding

Visual field progression risk was significantly reduced when IOP was maintained below $18\,mmHg$ at all visits.

4-2-1 Rule

The criteria for Severe NPDR: $> 20$ intraretinal hemorrhages in all 4 quadrants, prominent venous beading in $2+$ quadrants, or prominent IRMA in $1+$ quadrant.

Metabolic Memory

A concept from the EDIC study suggesting early intensive glycemic control provides durable benefits for decades, even if control later worsens.

ATS (Amblyopia Treatment Studies)

A series of clinical trials by PEDIG that shifted standard of care for amblyopia from consensus-based dogma to evidence-based practice.

Optical Treatment (Amblyopia)

The use of refractive correction alone as initial treatment, which can resolve up to $33\%$ of anisometropic and combined-mechanism cases.

Pharmacological Penalization

The use of one drop of $1\%$ Atropine daily or on weekends as an effective treatment for moderate amblyopia, comparable to patching.