Hypermetropia ppt

Hypermetropia ppt
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1. hypermetropia www.knowyoureye.com

2. 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

3. Emmetropinisation Hyperopic (infant) Emmetropic (10 years old) Myopic (25 years old) Hyperopic (60 years old) Less hyperopic (80 years old)

4. REFRACTIVE ERRORS HYPERMETROPIA MYOPIA ASTIGMATISM

5. 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

6. 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

7. 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

8. Classification Hypermetropia Latent Manifest Facultative Absolute

9. Latent hypermetropia Overcome physiologically by the tone of ciliary muscle Amounts to only one diopter Can be revealed only after cycloplegia

10. MANIFEST HYPERMETROPIA FACULTATIVE HYPERMETROPIA Can be overcome by an effort of accommodation ABSOLUTE HYPERMETROPIA Cannot be overcome by an effort of accommodation

11. 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

12. Prevalence Gender In general, there are no significant differences between males and females Hyperopia is more common in females

13. 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

14. symptoms Asthenopia or ocular fatigue Frontal headaches Avoidance of visual tasks, especially at near Blurry vision at near Intermittent blurring of vision

15. Clinical Tests Visual acuity tests – distance and near Accommodation tests Retinoscopy Subjective refraction

16. CONVERGING LENS CONTACT LENS REFRACTIVE SURGERY Management

17. Management SPECTACALS Single vision CONVEX glasses CONTACT LENS Soft contact lenses Rigid gas permeable contact lenses

18. MANAGEMENT SURGICAL IOL implantation Photo-refractive keratoplasty LASIK

19. 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

20. 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

21. Questions…??

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