CAUSES OF LOW VISION IN ADULTS

Presenter:-Harshali Jadhav

Moderator :-KUNAL KISHOR

Definition

Low vision:- According to WHOA person with low vision is are who has

impairment of visual function even after treatment and/or standard refractive correction and has an a acuity of less than 6/18 to light perception or visual field less than 10* from the point of fixation, but who uses or its potentially able to use vision for the planning execution of the task.

Introduction

The number of with low vision is increasing with ageing of the population

Visual loss in adult is associated with many factors, activity, limitation and lower quality of life

CAUSES OF LOW VISION IN ADULT

AGE RELATED MACULAR DEGENERATION

It is an acquired retinal disorder A degenerative change in retinal pigmented

epithelium

Subsequent degeneration of the over line rods and cones

It results in progressive irreversible loss of central vision

Due to fibrous scarring or geographic atrophy of the macular area

Risk Factors …Hyperopic Increase in cup disc ratioElevated serum cholesterol & hypertension Smoking and sunlight exposure

VISUAL ACUITY :-

V/A May vary with extent of degeneration with dry state ARMD

V/A can range from 20/20 to 20/400Wet state ARMD V/A shows worse than 20/400

VISUAL FIELD:-

Demonstrate a central or Para central Scotoma with normal peripheral findings

Most patient response well to magnification at distance and near

Non-optical systems filters, tint , and sun lenses for improve contrast and avoided glare and photophobia

CATARACT

It’s the opacification of crystaline lens

The types includes anterior and posterior subcapsular , cortical, equatorial and nuclear

ETIOLOGY:-TraumaticMetabolicToxicPharmacologicalAge relatedInflammatoryHereditory

VISUAL ACUITY:-

V/A varies greatly dividing on the degree and location of opacification

Acuity range from normal to severe vision impairment

VISUAL FIELD:-Central and peripheral visual field testing generally

source a relative generalize depression without focal defects

LOW VISION MANAGEMENT:-

Direct lighting is generally for near point activities

Glare can be reduce by use of Filters tint and sun lenses

Patients response to magnification at distance and near which may postpond the need of cataract surgery

Non-optical system such as large print reading material, bold line writing paper , typo scope .

DIABETIC RETINOPATHY

It’s a highly specific vascular complication Independent Diabetic mellitus and Non -

Independent Diabetic Meliates It is one of the leading cause of blindness

VISUAL ACUITY:-V/A ranges from 20/20 to total blindness

VISUAL FIELD:-In profilative disease retinal schemic loser scar and retinal detachment can cause corresponding field loss

LOW VISION MANAGEMENT:-

Refractive error should be checked during at least to different visits

Use of contact lens to correct refractive error Corning photochromatic filter and sunlens that block

blue wavelength may improve contrast and eliminate glare and photophobia

Direct illumination for near task

A flash light is helpful for poor night vision patient

Eccentric viewing technique along with magnification for distance and near

Non-optical device such as glucose monitor and insulin syringe aid are helpful for the patient.

MULTIPLE SCLEROSIS

It is demilinating nerve fibers have on impaired ability to conduct impulses at physiological frequencies

VISUAL ACUITY:-

V/A ranges from normal to severely impaired depending on the extend of ocular manifestation

VISUAL FIELD:-Several pattern of visual field loss occurs of patients

with optic neuritis secondary to multiple sclerosisCentral and ceco-central scotomas may be present

LOW VISION MANAGEMENT:-

Magnification device for near and distance are beneficial for patient with central vision loss

Spectacle mounted device Corning photo chromatic filter, Tints and sunglasses

help to eliminate glare Non-optical device such as direct lighting

MYOPIC DEGENERATION

It occurs due to accessive stretching of posterior segment of the eye

It associated with increasing axial length

VISUAL ACUITY:-V/A may be corrected by 20/20

High myopia can results in variety of visual field defect

In more advanced state sub-retinal neo-vascular membrane formation may occur causing further in decrease in central acuity

LOW VISION MANAGEMENT:-

Optical correction of refractive error with conventional spectacles or contact lenses usually improve V/A

Direct illumination for near

Cont……..When using spectacle lenses a small round frame,

high index lenses and anti reflection coating will help to reduce peripheral distortion

For poor night vision flashlight is helpful

RETINAL DETACHMENT

It results from accumulation of fluid between the sensory retina and retinal pigment membrane

VISUAL ACUITY:-V/A can be severely reduced , if there is involvement

of macular area

VISUAL FIELD :-Field defect develops corresponding to the sight of

retina detachment

LOW VISION MANAGEMENT:-

Using sunglasses and tint can be eliminate glare and photophobia

Direct illumination for near point task

Due to affected central vision a new correction may be indicated

Cont………

If bilateral temporal detachment occurs presence may be considered for improve mobility along with orientation and mobility services

GLAUCOMA

It is an optic neuropathy cause by reduce blood flow to the optic nerve resulting in peripheral visual field loss progressing to central vision loss with severe

ETIOLOGYFamily historyAdvanced age Systemic vascular diseaseBlunt ocular trauma Pigment dispersion Psuedo-exploxationRubio sis iriditisUse of steroid drugs Glaucoma in fellow eye

VISUAL ACUITY Central v/a is generally un affected until the end stage

of disease

VISUAL FIELDEarly glaucomatous visual field defects includes Para

central Scotoma , nasal field loss from this area occur as disease worse

LOW VISION MANAGEMENT:- Electronic Magnification system such as closed circuit

television ( C.C.TV) increased contrast and brightness Corning photo chromatic filter may reducing glare

and improving contrast

Minus lenses and reversible telescope helps the Patient with intact central acuity and peripheral visual field loss

To enhance visual field

Prisms or mirror system may stimulate peripheral awareness

Create Orientation and mobility in end stage visual field loss of galucoma patient

long cane travel can beneficial in end stage diseaseUse of flash light in night travel

THANK YOU…