Download Hyperopia

Hyperopia
Walter Huang, OD
Yuanpei University
Department of Optometry
Definition
The common name for this refractive error
is far-sightedness
Patients with hyperopia are known as
hyperopes
Definition
When parallel rays of light enter the eye
(with accommodation relaxed) and come
to a single point focus behind the retina
Etiology
Axial length

The axial length of the eye is shorter than
normal due to imperfect emmetropization
Etiology
Refractive power

The refractive power of the eye is too weak
Curvature hyperopia

Cornea or lens has a flat curvature
Decreased index of refraction

Due to decreased density in some parts of the optical
system of the eye
Loss of accommodation

Due to age, drug medications
Aphakia (no lens)

Due to cataract removal
Prevalence
Hyperopia is more common than myopia
Prevalence
Age




The mean refractive error is +2.00D in
newborns
The mean refractive error is +1.00 to +0.50D
in children at age 6
The mean refractive error is plano in children
at age 10
The mean refractive error is skewed toward
myopia in children after age 10
Prevalence
Gender

Hyperopia is more common in females than in
males
Prevalence
Ethnicity

Higher prevalence in American Indians,
Blacks, Caribbean, South Sea Islanders, and
Eskimos
Compensating Accommodation
Factors

Fatigue – general and ocular
Due to continuous focusing of images in and out
on the retina




Illness (e.g., cold, fever)
Mental state (e.g., stress)
Alcohol
Drugs and medications (e.g., antihistamines)
Antihistamines may relax accommodation and
dilate the pupils
Facultative Hyperopia
Definition

The amount of hyperopia that can be
overcome by accommodation
Absolute Hyperopia
Definition

The amount of hyperopia that cannot be
overcome by accommodation
Manifest Hyperopia
Definition

The amount of hyperopia revealed with a noncycloplegic refraction (i.e., when no
pharmacological drugs are used to dilate the
eyes)
Latent Hyperopia
Definition

The amount of hyperopia revealed with
cycloplegic refraction (i.e., when
pharmacologic drugs are used to dilate the
eyes)
Latent Hyperopia
Causes

Drugs and progressive near work, resulting in
accommodative spasms so that
accommodation may not be relaxed
Total Hyperopia
Definition

The sum of manifest hyperopia and latent
hyperopia
Absolute Hyperopia and Visual
Acuity
Uncorrected VA
Refractive Error (D)
20/30
0.50
20/40
0.75
20/60
1.00
20/80
1.50
20/120
2.00
20/200
2.50
Symptoms
Asthenopia or ocular fatigue
Frontal headaches
Avoidance of visual tasks, especially at
near
Blurry vision at distance and near
Intermittent blurring of vision
Signs
Miotic pupil

Enables accommodation and increased depth
of focus
Esophoria


Inward deviation of the eyes
With accommodation, eyes tend to converge
Decreased visual acuities at distance and
near, especially the latter
Occasional diplopia or double vision
Clinical Tests
Visual acuity tests – distance and near
Binocular vision tests (e.g., cover test)
Accommodation tests
Retinoscopy
Subjective refraction
Management
Accommodation training (especially in
young patients)
Convergent or plus lenses in spectacles or
contact lenses
Refractive surgery
Management
Spectacles

Single vision glasses
Management
Contact lenses


Soft contact lenses
Rigid gas permeable contact lenses
Management
Refractive surgery


Photorefractive keratectomy (PRK)
Laser in-situ keratomileusis (LASIK)