Psudo & latent squint
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The document discusses various clinical impressions related to ocular deviation when no squint is present. It notes that in high myopia the fovea lies nasal to the optic axis, causing the visual axis to cross temporal to the optic axis at the cornea, resulting in a negative angle alpha. In high hyperopia, the fovea lies more temporal to the optic axis than normal, causing the visual axis to cross nasal to the optic axis at the cornea and resulting in a large positive angle alpha greater than 5 degrees. It also discusses tendencies for eye deviation when fusion is blocked, types of phorias like esophoria and exophoria, instruments used to measure phorias like the Maddox
Psudo & latent squint
- 1. • Clinical impression of ocular deviation, when no squint is present
- 2. In high myopia, the fovea lies NASAL to the optic axis. So, the visual axis crosses temporal to the optic axis at the cornea. (-ve angle alpha)
- 3. In high hyperopia, the fovea lies more Temporal to the optic axis than normal. So, the visual axis crosses nasal to the optic axis at the cornea. (large +ve angle alpha, > 5 degrees)
- 4. • Tendency of the eye to deviate when fusion is blocked ميولانحرافية😂 A. Uncorrected error of refraction B. EOM imbalance • Exophoria خفي وحشي انحراف • Esophoria خفي أنسي انحراف 1. Esophoria 2. Exophoria 3. Hyperphoria 4. Hypophoria 5. Incyclophoria 6. Excyclophoria
- 5. • Nothing • Blurred vision • Running letters • Ocular strain • e.g. at time of stress or poor health
- 6. • The Maddox rod consists of a series of fused cylindrical red glass rods that convert the appearance of a white spot of light into a red streak • Exophoria • Esophoria • Orthophoria
- 7. • The Maddox wing dissociates the eyes for near fixation (1/3 m) and measures heterophoria. • The instrument is constructed in such a way that the right eye sees only a white vertical arrow and a red horizontal arrow, whereas the left eye sees only horizontal and vertical rows of numbers.
- 8. • Pencil to nose exercise
- 9. • e.g. base-out prism to exercise exophoria
- 10. • The instrument consists of two cylindrical tubes • Pictures are inserted in a slide carrier situated at the outer end of each tube
- 11. • for large deviations • e.g. base in prism to relieve exophoria