Prediction of visual gain after cataract surgery depends on the assessment of retinal function.

1. Macular Function test before cataract surgery Ophthaglance 2, Sept 4-5 2010 Dr AnandSudhalkar, Vadodara 1 sudhalkareyehospital.health.officelive.com

2. Expectations after cataract surgery Improvement in vision Achieve “Full” vision (6/6) ? Achieve “Better than normal” vision (6/5) ? sudhalkareyehospital.health.officelive.com 2

3. The answer depends on: Surgical success? Achieve the best “Optical Correction” Visual Success: Function of retina, visual pathway and occipital lobe, neuroadaptation and other “higher” functions. sudhalkareyehospital.health.officelive.com 3

4. Macular Functions Fovea: Acuity of vision Colour vision Day time adaptation Peri and Paramacular region: Mesopic and night vision Refixation reflexes sudhalkareyehospital.health.officelive.com 4

5. Macular Function tests Basic preop assessment Refraction: Snellen Acuity Amblyopia NEAR vision (Vryghem Macular Function Test charts) Pinhole vision, Ishihara charts Maddox rod Two point discrimination Photostress test Amsler grid Entoptic phenomenon Slit-Lamp: Post sub capsular Dilated fundus: Macular pathology Special tests for fovea Contrast sensitivity Glare disability Potential acuity meter Perimetry Optokineticnystagmus FFA B-scan OCT ERG VEP sudhalkareyehospital.health.officelive.com 5

6. Maddox Rod test Simplest, most reliable test(opaque med). Rod consists of several cylinders of glass placed side by side in a frame. Pt is asked to fixate light at a distance of 1/3 m through M.R. with opposite eye occluded. Image formed is a straight line(vertical/horizontal streak) running perpendicular to the axis of rods. Any breaks/holes; discoloration/distortion indicates a macular lesion. RED: more sensitive, tells us about colour perception Rotate the rod to test different meridians. sudhalkareyehospital.health.officelive.com 6

7. Two point discrimination test The ability to distinguish two illuminated points of light suggests good retinal function. •“Rule of 2” : Two illuminated points of 2 mm diameter size and 2 inches apart are placed 2feet away from the patient’s eye. The patient is then asked to indicate whether he canperceive the two points separately sudhalkareyehospital.health.officelive.com 7

8. The blue field entoptic phenomenon or Scheerer's phenomenonBlue field entoptic phenomenon in cataract patients. Arch Ophthalmol. 1979 Jun;97(6):1092-5. Sinclair SH, Loebl M, Riva CE. In predicting normal macular function: 87% for the two-light discrimination test 94% for the BFE test. In pathological conditions: BFE test identified more than 75% of the poor maculae; the Purkinje vascular entoptic test and the two-light discrimination test, only 22%; and the colour perception test, 11%. A positive response to the BFE test indicated a .98 probability of good macular function; a negative response indicated a .82 probability of poor macular function, predictions that were better than the other three tests or their combination. sudhalkareyehospital.health.officelive.com 8

9. Preop Retinal ExaminationIndirect Ophthalmoscopy sudhalkareyehospital.health.officelive.com 9

10. Practical Pearls Awareness regarding macular Pathology Diagnose and Identify Treatable pathologies and give them the priority over the cataract surgical procedure Patient counseling and spending preop “Chair time” “Acceptable” visual gain and success in an otherwise perfectly executed cataract surgery. sudhalkareyehospital.health.officelive.com 10