Hyperopia Flashcards
Definition of Hyperopia:
with accommodation relaxed, parallel rays of light converge to focus behind the retina
he first identified and described the condition hyperopia
Kastner - 1855
suggested the term Hypermetropia
Donders - 1858
he used the word Hyperopia
Helmholtz 1859
Hyperopia is considered to be a _____ anomaly
Developmental
at birth practically all eyes are _______
Hyperopic
at birth practically all eyes are hyperopic, and from 80 to 90% are found to be so within the first _____ of life
first 5 years
During adolescence the degree of hyperopia decreases as axial length ______
Increases
Simple cause/Etiologies of Hyperopia:
- Axial Length
- Refractive system
- Anterior Chamber Depth
- Old age
Refractive status of eyes at birth:
+2.50D to +3.00 D
1mm short of axial length is equal to?
+3.00 D of Hyperopia
decreased or less Anterior Chamber depth results to?
Less refractive Power
Functional Etiology:
- paralysis of accommodation
- Spasm of accommodation
Classifications of Hyperopia:
- According to degree/amount
- According to Sorsby’s classification
- According to action of Accommodation
Pathological Causes of Hyperopia:
- Deformational
- Curvature
- Index of Refraction
- Absence of an element (aphakia)
- Displacement of Lens
sorbsby’s classification:
Correlative Hyperopia
Component Hyperopia
Correlative Hyperopia:
errors from +0.25D to +6.00D
Component Hyperopia:
errors above +6.00D
Low degree of hyperopia:
errors ranging from +0.25D to +3.00D
Medium degree of hyperopia:
+3.00D to +5.00D
High degree of Hyperopia:
+5.00D and Above
Hyperopia according to Action of Accommodation:
- Facultative Hyperopia
- Absolute Hyperopia
- Latent Hyperopia
- Manifest Hyperopia
- Total Hyperopia
the amount of hyperopia which can be overcome or still be corrected by accommodation
strongest convex lens with which the patient can still maintain full distance vision 6/6
Facultative Hyperopia
the amount of hyperopia which cannot be overcome by accommodation
patient cannot normally see 6/6 without a lens
Vision is subnormal
Absolute Hyperopia
the amount of hyperopia which cannot be revealed by customary refractive routine
can be compensated by accommodation of a younger hyperopic person
revealed during presbyopic age
Latent Hyperopia
Two types of latent hyperopia:
- Tonic Latent hyperopia
- Clonic Latent hyperopia
latent hyperopia that is relatively fixed or permanent state of spasm
Tonic Latent Hyperopia
Latent hyperopia that is temporary state of spasm
Clonic Latent hyperopia
the amount of hyperopia which can be revealed by routine method of refraction
subdivided into facultative and absolute
Manifest Hyperopia (MFA)
the entire amount of hyperopia that actually exist
the sum of latent and manifest hyperopia
Total Hyperopia (TLM)
Headache locations with hyperopia:
Frontal
Occipital
symptoms of hyperopia (subjective):
- Asthenopia
- BOV at near
- difficulties of fixation
- Nausea
- vomiting
- general fatigue
- Photophobia
- tearing
Signs of Hyperopia (objective):
- Constricted pupil
- conjunctival irritation
- convergent strabismus
- vertical brow wrinkles
- endophthalmic eyes
hyperopia correction where esotropia exist:
Maximum Plus correction
w/c does not severely handicap vision
hyperopia correction where esophoria exist:
Maximum plus correction
w/c does not blur vision
hyperopia correction where exophoria exist:
Partial Correction
if full correction it is accompanied by prism base-in or by orthoptic exercises
lens act to increase the index of refraction, to increase total refractive power and restore some elasticity of the lens, therefore presbyopia and hyperopia may diminish or disappear
Second Sight
amount of Hyperopia correction when there is:
- Constant intermittent blur
- Much near work required
- Marked eyestrain
- Markedly reduced amplitude of accommodation
Full Correction
amount of hyperopia correction when there is:
- Divergent strabismus or exophoria
- Large amount of latency
- Very young patients
- Maximum acuity needed at far distances
Partial Correction
Those with sedentary existence, or who
require to use eyes for fine detailed work may
require what amount of correction?
Stronger Plus Correction
correction that is recommended for those who live on outdoor or active existence
Lesser plus correction
farthest object point for which image point is focused on the retina
an imaginary point located behind the eye
Far Point of Accommodation
a real object point located in front of the eye
Near point of accommodation
extent to which the image may be located in front or behind the retina and still appear sharp and clear
Depth of Focus
extend to which the visual acuity chart may be moved toward or away from the and the optical image is focused on the retina
Depth of Field
