Anisokonia

for OD students by kausar ali .

1. Anisokonia By kausar Ali Student at OD Pef university college

2. Anisokonia : Anomalies of binocular vision . Ocular images are unequal in size or shape or both . Its important lies in case of eye strain which is difficult to assess . Etiology: Optical anisokonia Retinal anisokonia Cortical anisokonia

3. Optical anisokonia : inherited . Acquired . Anisometropia of high degree . Retinal Anisokonia : Displacement of retinal image towards nodal point in one eye . Cortical Anisokonia : A symmetrical simultaneous perception in spite of equal size of two images .

4. Clinical types: Spherical : Image may be magnified or minified equally in both merida . Cylindrical: Image is magnified of minified symmetrical in one meridia . A symmetrical : Prismatic . Image difference increases progressively in one direction

5. Pincushion: Image distortion increases progressively in both direction as seen with high plus correction in aphakia . Barrel . Image distortion decreases progressively in both direction as seen in high minus lenses . Oblique : Image size remain the same but there occurs oblique distortion of shape .

6. Symptoms : Asthenopic symptoms : Occurs when the difference in image size of the two images between 0.75 to 5% Headache , difficulty in reading , photophobia , difficulty in fixation , vertigo etc . Disturbance of binocular vision . Diplopia occur only if the difference exceeds 5%. Disturbance in the depth perception and spatial dis –orientation. Suppression of one eye

7. Treatment Optical < IOL in Aphakia . contact lenses. Refractive surgery. Retinal Anisokonia : corrected by treating the causative disease. Cortical Anisokonia : Difficult to treat .