HYPERMETROPIA

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CLASSIFICATION OF REFRACTIVE ERROR Emetropia-parallel incident rays come

to focus on the retina when accommodation is at rest

Ametropia-parallel incident rays are not focused on the retina when accommodation is at rest

EMMETROPINISATIONHyperopic (infant)

Emmetropic (10 years old)

Myopic (25 years old)

Hyperopic (60 years old)

Less hyperopic (80 years old)

REFRACTIVE ERRORS

HYPERMETROPIA

MYOPIA

ASTIGMATISM

HYPERMETROPIA Parallel rays come to focus BEHIND the

retina when accommodation is at rest The common name for this refractive

error is FAR-SIGHTEDNESS Patient cannot see near object

CLASSIFICATION Physiological Due to normal etiological conditions Imperfect emmetropinisation Hereditary factors

Pathological Prenatal maldevelopment of eye Corneal or lenticular changes due to

orbital inflammation Neurologic or pharmacologic based

causes

AETIOLOGY Axial length

The axial length of the eye is shorter than normal due to imperfect emmetropization

Refractive power The refractive power of the eye is too weak

Curvature hyperopia Cornea or lens has a flat curvature

Increase index of refraction Due to increase 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

CLASSIFICATION

Hypermetropia

Latent Manifest

Facultative Absolute

LATENT HYPERMETROPIA

Overcome physiologically by the tone of ciliary muscle

Amounts to only one diopter Can be revealed only after cycloplegia

MANIFEST HYPERMETROPIA FACULTATIVE HYPERMETROPIA Can be overcome by an effort of

accommodation ABSOLUTE HYPERMETROPIA Cannot be overcome by an effort of accommodation

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

In general, there are no significant differences between males and females

Hyperopia is more common in females

SIGNS Miotic pupil

Enables accommodation and increased depth of focus

Esophoria Inward deviation of the eyesWith accommodation, eyes tend to

converge Decreased visual acuities at distance

and near, especially the latter Occasional diplopia or double vision

SYMPTOMS Asthenopia or

ocular fatigue Frontal

headaches Avoidance of

visual tasks, especially at near

Blurry vision at near

Intermittent blurring of vision

CLINICAL TESTS

Visual acuity tests – distance and near

Accommodation tests Retinoscopy Subjective refraction

CONVERGING LENS CONTACT LENS REFRACTIVE SURGERY

MANAGEMENT

MANAGEMENT SPECTACALS Single vision CONVEX

glasses

CONTACT LENS Soft contact lenses Rigid gas permeable

contact lenses

MANAGEMENT SURGICAL

IOL implantation Photo-refractive keratoplasty LASIK

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

REFERENCES Optometry, journal of American optometric

association Duke-Elder, David Abrams (1986). The

Practice of Refraction (9th ed.). Bennett AG, Rabbetts RB (1984) Clinical

Visual Optics ‘care of patients with hypermetropia’,

American optometric association

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