Procedures ARAVIND EYE CARE SYSTEM A RAVIND E

Procedures ARAVIND EYE CARE SYSTEM A RAVIND E YE H OSPITAL & Postgraduate Institute of Ophthalmology 1

OBJECTIVES & OUTCOMES After this course the MLOP will be able to: - Describe the different targets to be used in visual fields (size, intensity). - Demonstrate selection of the correct targets for different types of visual fields. - Discuss the analysis of the different types of visual fields. - A R A V I N D E Y E C A R E S Y S T E M

PROCEDURE FOR SELECTION OF TARGET SIZE, COLOR, ILLUMINATION LEVEL AND DISTANCE Colour : • Glaucoma • Retina • Neuro • Normal : Blue : Green : Red : White A R A V I N D E Y E C A R E S Y S T E M

Object Size : Select the object size depending upon the patients visual acuity. Distance : 1 mm distance : Bjerrum’s Screen 33 cm : Amsler 2 Feet : Confrontation method A R A V I N D E Y E C A R E S Y S T E M

DISTANCE The type of visual field test determines the distance patient should be placed for diagnosis. For Example: Armsler Grid Testing - 33 to 40 cm Bjerrum (1 meter screen) - 1 m Bjerrum (2 meter screen) - 2 m A R A V I N D E Y E C A R E S Y S T E M

BJERRUMS SCREEN It is used for measuring field of vision with 30° Font needs to be bigger Procedure of BJERRUM SCREEN testing • Seat the Pt At 1 Meter from the screen ( for a 1 metre chart ) • One eye is covered with the occluder. • • Examiner should select target depending upon the pts visual acuity. • While testing, non- seeing areas should be marked with pin. • After finishing the test, carefully transfer the details to the fields chart. A R A V I N D E Y E C A R E S Y S T E M

AMSLER GRID This is used to locate defects in the central 10 degrees of the visual field Amsler grid is a printed square of evenly spaced horizontal and vertical lines in a grid pattern. This is white on a black background A R A V I N D E Y E C A R E S 7 S T E M Y

METHOD Have the patient hold chart (card) at 33 cms. One eye should be closed Patient has to fix on the centre dot Ask the patient if he can see all the other lines while seeing the centre dot Can the patient see the four corners? Ask the pt to draw missing, distorted and blurred areas on the chart A R A V I N D E Y E C A R E S 8 S T E M Y

Humphrey • • • Manual Kinetic Perimetry Automated Static Perimetry Combination of both ( Armaly-Drance technique) A R A V I N D E Y E C A R E S Y S T E M

AUTOMATED STATIC PERIMETRY Stimuli of the same size ( default size Goldmann iii ) & different intensity are randomly presented in predetermined location of the visual field & subject response is noted. TYPES: Standard automated Perimetry (SAP) / Achromatic automated perimetry Short Wave Automated Perimetry (SWAP) Feiquency Doubling Technology (FDT) A R A V I N D E Y E C A R E S Y S T E M

PROCEDURE FOR LISTERS PERIMETER TEST • Seat the pt at 33 cm. • One eye is covered with the occluder. • Attach the fields chart to the machine. • After finishing the test, the non- seeing areas are marked on the chart carefully. A R A V I N D E Y E C A R E S Y S T E M

VALUE ADDED • Depending upon the patient’s visual acuity and eye problem the object size and color should be selected in order to avoid variation in field • Care to be taken to ensure patient is fixating on central target at all times. • Normal illumination is required. A R A V I N D E Y E C A R E S Y S T E M

1. While performing bjerrum screen, wand should be moved from periphery to the central fixation point 1. While performing amsler test all patients above 40 years who have near presbyopic correction, this correction should be added for the test 1. Test should be explained clearly and also the significance of this test. A R A V I N D E Y E C A R E S Y S T E M