Heterophoria.pptx

Very easy slide

1. Heterophoria

2. Orthophoria - Eyes are perfectly aligned i.e. no deviation even after disruption of fusional reflex. Heterotropia - Manifest misalignment Heterophoria - Latent misalignment Eye alignment in Primary position

3. Orthophoria Heterotropia

4. “A deviation kept latent by the fusional reflex” When heterophoria is present, both visual axes are directed towards the fixation point but deviate on dissociation. Heterophoria

5. Compensated heterophoria This means that there is a desire to deviate, but this desire is checked by the binocular vision. 3-4 heterophoria can be normally compensated Decompensated heterophoria Deviation occurs only when binocular vision is disturbed

6. Esophoria Tendency of inward deviation Exophoria Tendency of outward deviation Hyperphoria Tendency of upward deviation of one eye Incyclophoria Tendency of 12 o’clock point for inward deviation Excyclophoria Tendency of 12 o’clock point for outward deviation Types of heterophoria

7. Refractive errors Hypermetropia causes esophoria due to over accommodation leading to over convergence Myopia causes exophoria due to less accommodation leading to less convergence Oblique astigmatism may cause cyclophoria Causes of phoria

8. 2) Physiological causes : Prolonged neglect of near work causes weak convergence and complain of exophoria . Esophoria is common in children while exophoria in adults. Prolonged uniocular work may cause phoria 3)Weakness of one or more extra ocular muscles .

9. Symptoms Heterophoria is very common and it is usually asymptomatic (compensated). When it is decompensated the patient will complain of asthenopia : Eye strain -ocular pain, headache and redness Transient deviation of both eyes will cause transient diplopia . Clinical features

10. Difficulty in changing focus from near to far or vice versa Deviation in night or during fever Blurring of print

11. Signs Refraction may show -myopia in case of exophoria - hyperopia in case of esophoria Visual acuity is normal after correction of errors

12. Cover test Maddox Rod test is used to confirm phoria at distance Maddox wing test used to measure phoria for near . Investigation

13. If no symptoms (compensated) we give no treatment. If symptomatic ( decompensated ) we do: Correction of refractive error if present. Training of the weak muscles by exercises or training prisms (base of prism is placed towards direction of deviation) Surgery is indicated in few cases with very large degrees of latent deviation not responding to above treatment. Treatment