Primary Eye and Vision Care

Comprehensive vocabulary flashcards covering primary eye care, epidemiology, refractive errors, accommodation, diagnostic testing, nutrition, and trachoma management based on the lecture notes.

Primary Eye Care (PEC)

The first level of contact between individuals and the health system for eye and vision-related needs, involving prevention, early detection, basic management, and referral.

Prevalence

Total number of cases (old + new) in a population at a given time.

Incidence

Number of new cases during a specific period.

Morbidity

Frequency of disease in a population.

Mortality

Frequency of death due to a disease.

Endemic Disease

Disease consistently present in a region, such as Trachoma in poor rural communities in Africa.

Epidemic

Sudden increase in disease occurrence, such as viral conjunctivitis outbreaks.

Pandemic

Worldwide spread of disease, such as COVID-19 or Myopia.

Uncorrected Refractive Errors

The most common cause of visual impairment worldwide.

Catarat

The leading cause of both blindness and reversible blindness worldwide.

Glaucoma

The leading cause of irreversible blindness.

Trachoma

The most common preventable infectious blindness.

Primary Prevention

Actions aimed at preventing eye diseases before they occur, such as UV protection and nutrition (Vitamin A).

Secondary Prevention

Early detection and treatment of disease through methods like vision, glaucoma, or diabetic retinopathy screening.

Tertiary Prevention

Reducing complications of established disease, such as cataract surgery or vision rehabilitation.

Refractive Status

The relation of the refracting system of the eye to its axial length by indicating the focal length or position of principal focus compared to the retina, with positive accommodation inactive.

Myopia

Nearsightedness where the eyeball is too long ($25\,mm$ and above) or corneal power is too steep ($45.00\,D$ and above).

Hyperopia

Far-sightedness (Hypermetropia) where the eyeball is too short ($23\,mm\text{ and below}$) or corneal power is flatter ($43.00\,D\text{ and below}$).

Astigmatism

A refractive error where the curvature of the eye is irregular, categorized as With-the-Rule, Against-the-Rule, or Oblique.

Presbyopia

Condition where the available nearpoint gradually recedes with age, typically starting around age 45 (or 39 for Filipinos).

D.I.M.S Technology

consists of a central zone with multiple honeycomb-like segments of lenslets with $+3.50\,D$ adds to slow myopia progression.

H.A.L.T TECHNOLOGY

utilizes 11 rings of 1021 contiguous aspherical lenslets to generate a Volume of Myopic Defocus (VoMD).

C.A.R.E TECHNOLOGY

uses individual cylindrical elements to project myopic defocus on the near periphery.

D.O.T TECHNOLOGY

based on the contrast theory, it uses dots to reduce retinal contrast and slow myopia progression.

Orthokeratology

The use of specially designed reverse geometry gas permeable contact lenses to temporarily reshape the cornea to correct myopia.

Triads of Accommodation

The three concurrent physiological responses: Constriction, Convergence, and Contraction.

Tscherning’s Theory or Increased Tension Theory

states that during far vision the suspensory ligaments are lax and the flattened state of the lens is natural.

Helmholtz’s Theory

states that suspensory ligaments maintain the lens in a flattened state, and during accommodation, the tension is released to decrease radius of curvature.

Amplitude of Accommodation (AA)

The maximum increase in optical power an eye can achieve; Minimum $AA = 15 - 0.25(\text{age})$.

AC/A Ratio

The measurement of convergence induced by accommodation per diopter of accommodation.

Minimum Visible (Detection)

The smallest object or detail that can be detected by the eye, even if not clearly identified.

Ishihara Plates

A color vision test using pseudoisochromatic plates with colored dots to detect red-green deficiencies (protan and deutan).

Anomaloscope

The gold standard for diagnosing red-green deficiencies, where a patient adjusts red and green light to match a yellow reference.

Amsler Grid

A grid used to test central vision and detect scotomas or metamorphopsia.

Tonometry

The procedure performed to determine the intraocular pressure (IOP).

Imbert-Fick Law

States that the pressure inside an ideal sphere ($P$) is equal to the force ($F$) required to flatten it divided by the area ($A$); used in Goldmann tonometry ($P = F / A$).

Vitamin A

A fat-soluble vitamin essential for phototransduction, dark adaptation, and maintenance of the conjunctival and corneal epithelium.

Schiotz Tonometer

An indentation tonometer based on the fact that a plunger will indent a soft eye more than a hard eye.

Arlt line

A characteristic white conjunctival scar at the junction of the lower third and upper two-thirds of the superior tarsus in Trachoma.

Herbert pits

Oval or pitted scars in the limbus characteristic of Trachoma sequelae.

SAFE Strategy

A WHO-endorsed strategy for Trachoma control consisting of Surgery, Antibiotics, Facial cleanliness, and Environmental improvements.