type of visual field defect.

Type of visual field defects ...... common cause , sign and symptoms and there interventions.....
(low vision)......

1. Department of optometry Faculty of Paramedical College , U.P.U.M.S SAIFAI ETAWAH

2. Types of visual field defects presented by – Ishrat jahan

3. content: Introduction- visual field Types Types of visual field defect Central field defect - cause sign ,symptoms and their interventions Peripheral field defect – cause sign ,symptoms and their interventions Over all blur or media opacities Sign, symptoms and their interventions

4. Introduction Visual field - 3D area of a subject surroundings that can be seen at a time around a point of fixation. Extent of normal visual field – 60 degree superiorly 60 degree nasally 75 degree inferiorly 100 degree temporally

5. Visual field divided into central and peripheral field CENTRAL FIELD – area from the fixation to a circle 30 degree PERIPHERAL FIELD- rest of area SCOTOMA – area of depressed or lost vision surrounded by area of normal vision is called ‘scotoma

6. Type of visual field defect

7. Central field loss It may be complete or partial loss of central field defect. Diseases that cause CFD – chorioretinitis, diabetic maculopathy ,hypertensive retinopathy, macular degeneration, macular hole lesion degenerative myopia, optic atrophy, rod and cone dystrophy ,etc.

8. Patient with central field defect- will show following sign- Partial perception of people or object Poor color vision Cannot discriminate fine detail for distance and near Further reduction in visual acuity in bright light . following complaints are- Inability to see people faces &recognize people . Squint or abnormal eye posture to visualize object Can’t discriminate color Difficulty in reading and near tasks Lake of confidence on going outdoor

9. Interventions- Inability to recognize people can best be taced by the co- opration of relative and friend. Advise sitting close to the object like during watching TV. Reading disability is a major problem to solve ,reading can be possible by bringing the object as close possible. High plus add glasses with full field frame may help. Enhance contrast of the room and furniture Avoid tasks which require fine visual acuity for near.

10. Peripheral field loss This group refers to the patient how have lost their peripheral field of vision , totally or partially. These defects are likely in following pathologies- Chorioretinitis, colobomas, glaucoma , degenerative myopia, optic atrophy ,retinitis pigmentosa, retrobulbar neuritis, etc.

11. Patient with peripheral field defect- Will show following complains- Mobility problem both indoor and outdoors. Slow dark adaptation. Poor vision in dim light. Poor near reading vision depends upon the extent of field defect. Glare and photophobia. will have following complains- Knocking over objects, and uncertainty in moving around . Inability to find or locate objects. Difficulty in reading because the words get lost.

12. Interventions Teach systemic scanning. Keep minimum required furniture in the room with object well define areas. Field expender may be help. Give time to eyes from moving indoor to outdoor and vise versa to allow slow dark adaptation. Use sunglasses or glare cutting device outdoor. Reading vision can be improved by, high plus lenses or megnifiers .(magnification factor should be limited). CCTV system or electronic devices help more in such cases than those with other type of field defect . Patient should avoid traveling alone in dim ight and as far as possible carry a flash light with them.

13. Overall blur (media opacity) Quality of vision is affected . It is mainly three type- (A) corneal opacity (B) lenticular opacity (C) vitreous opacity

14. Corneal opacities Opacification of cornea due to scarring- CAUSES- healed corneal wounds , healed corneal ulcer , congenital opacities edema, lipid or mineral deposition , fibrosis , vascularization, melanosis. Lenticular opacities Loss of normal lens transparency or opacification of lens due to – Old age Trauma intraocular foreign bodies Radiation Systemic medications (steroids and phenothiazines ) Congenital Inherited abnormalities-Marfan’s syndrome , high myopia, myotonic dystrophy

15. patient with media opacities Will show following sign Reduced visual acuity Redused contrast Poor night vision Glare and photophobia These sign will manifest following complaints from pt Difficulty in recognizing far of objects and details If the vision is poor enough they will bump into objects and furniture with poor contrast. Difficulty in reading and writing Unable to write in straight lines Glare Loss of confidence in going outdoors at night.

16. Interventions- Increase contrast—in the house by using high contrast color schemes in furniture, door, windows etc. Enhance contrast in reading and writing—use bright light, fairly good contrast print and black bold tip pens to write Advise to carry a flash light, and install strong intensity light sources (preferably bulbs to fluorescent tubes) in staircase, kitchen, rooms, or work areas Absorptive lenses and filters will help outdoors to reduce glare These patients accept high plus add near glasses and magnifiers as LV devices.

17. Thank you