24.11.20 - ESOTROPIA - TYPES AND EVALUATION.pptx

a short and quick review on how to evaluate a case of Esotropia

1. ESOTROPIA TYPES & EVALUATION Presented By : Dr. Shreyan Dani (PG) Guided By : Dr. Srikanth K (Prof & HOD)

2. ACTIONS OF EXTRAOCULAR MUSCLES: MUSCLE PRIMARY ACTION SECONDARY ACTION TERTIARY ACTION MEDIAL RECTUS ADDUCTION LATERAL RECTUS ABDUCTION SUPERIOR RECTUS ELEVATION INTORSION ADDUCTION INFERIOR RECTUS DEPRESSION EXTORSION ADDUCTION SUPERIOR OBLIQUE INTORSION DEPRESSION ABDUCTION INFERIOR OBLIQUE EXTORSION ELEVATION ABDUCTION

3. ACTIONS OF EXTRAOCULAR MUSCLES:

4. ESODEVIATION : A latent or manifest convergent misalignment of the visual axis. ESOPHORIA: Latent convergent misalignment ESOTROPIA: Manifest convergent misalignment Esodeviations are the most common type of childhood strabismus.

5. ACCOMODATIVE CONVERGENCE : Convergence is induced by the act of accommodation as a part of synkinetic -near reflex. Each Diopter change of Accommodation is accompanied by a constant increment in accommodative convergence. Accomodative Convergence is the amount of convergence in prism dioptres (∆) per dioptre (D) change in accommodation. Normal AC:A Ratio = 3 to 5 ∆

6. MAJOR TYPES OF ESODEVIATION : CONCOMITANT ESOTROPIA INCOMITENT ESOTROPIA Accomodative : Normal AC/A Ratio High AC/A Ratio VI Cranial Nerve Palsy Slipped or lost Lateral Rectus Muscle (following Sx ) Globe Prolapse associated with high myopia Congenital Cranial Disinnervation Disorders Duane Syndrome Mobius Syndrome Congenital MR Fibrosis Postsurgical and Periocular Implants Medial Rectus Muscle Restriction Thyroid Eye Disease Medial Orbital Wall Fracture with Entrapment Following Excessive Resection Partially Accomodative Infantile (Congenital) Acquired & Non- Accomodative : Basic Cyclic Sensory Convergence Excess Divergence Insufficiency Primary – Adult Onset Disease Secondary 6. Spasm of Near Reflex 7. Consecutive: Spontaneous Post-Surgical NYSTAGMUS & ESOTROPIA: Fusional Maldevelopment Nystagmus Syndrome Nystagmus Blockage Syndrome

7. Sensory Adaptations to Strabismus: Suppression Central : to avoid Confusion Peripheral : to avoid Diplopia Monocular : when dominant eye always predominates Alternating: amblyopia is less likely to develop Facultative: occurs only when the eyes are misaligned Obligatory: present all the time 2. Abnormal/Anomalous Retinal Correspondence (ARC) – non-corresponding retinal elements acquire a common subjective visual direction

8. CONSEQUENCES OF STRABISMUS: Fovea of the squinting eye is Suppressed to avoid Confusion Diplopia will occur, since corresponding retinal elements will receive different images To avoid diplopia, the patient will develop either Peripheral Suppression of the squinting eye or Anomalous Retinal Correspondence (ARC). If constant unilateral suppression occurs – this may lead to Strabismic Amblyopia

9. Motor Adaptations to Strabismus: Involves the adoption of a Compensatory Head Posture (CHP) Face Turn : to control a Purely Horizontal Deviation Head Tilt : to compensate for Torsional &/or Vertical Diplopia Chin Elevation / Depression : to compensate for weakness of an elevator or depressor muscle or to minimize the horizontal deviation when an ‘A’ or ‘V’ pattern is present

10. STEPS IN EVALUATION OF STRABISMUS: History Inspection Vision Assessment & Refraction Hirschberg Test / Corneal Reflex Ocular Movements Anterior Segment & Fundoscopic Evaluation Tests for Stereopsis: TNO Test Titmus Fly Test Frisby Test Lang Test Tests for Motility: Ocular Movements & Forced Duction Test NPC & NPA

11. STEPS IN EVALUATION OF STRABISMUS: Measurements of Deviation: Hirschberg Test Krimsky Test/Prism Reflection Test Modified Krimsky Test Cover Uncover Test & Alternate Cover Test Prism Cover Test Maddox Wing Maddox Rod Visual Fields: Perimetry Tests for Diplopia: Diplopia Charting & HESS Charts Tests for Sensory Anomalies: Worth Four Dot Test Bagolini Striated Glasses Synoptophore

12. HISTORY: Symptoms: Discomfort, blurring of vision, diplopia, suppression Onset, Sudden/Gradual, Type of Diplopia Variability General Health & Developmental Problems Birth History – including period of gestation, birth weight, problems in-utero/with delivery/after delivery/neonatal period. Family History – might be important, but no genes have been identified Previous Ocular History – refractive prescription & compliance to spectacles, Previous Surgery, Prisms etc …

13. VISUAL ACQUITY: TESTING IN PREVERBAL CHILDREN Fixation & Following Comparision – b/w behavior of two eyes – may reveal a unilateral preference Fixation Behavior 10 Prism Test Rotation Test Preferential Looking : based on that infants prefer to look at a pattern rather than a homogenous stimulus. Teller & Keeler Acuity Cards Cardiff Acuity Cards Visual Evoked Potential : give a representation of spatial acuity, but are more commonly used for optic neuropathy

14. VISUAL ACQUITY: TESTING IN PREVERBAL CHILDREN 10 Diopter Fixation Test : useful test for detecting amblyopia in children without a manifest deviation and in whom a reliable visual acuity assessment is difficult. Procedure: by placing a 10 dioptre vertical prism over one eye, we induce a vertical deviation. Once the eyes are dissociated, fixation preference is evaluated and used to predict the present of amblyopia.

15. VISUAL ACQUITY: TESTING IN PREVERBAL CHILDREN

16. VISUAL ACQUITY: TESTING IN PREVERBAL CHILDREN CARDIFF ACQUITY TEST

17. VISUAL ACQUITY: TESTING IN VERBAL CHILDREN At 2 years Age: - sufficient language skills – picture naming Crowded Kay Pictures Test

18. VISUAL ACQUITY: TESTING IN VERBAL CHILDREN At 3 years Age: - most children will be able to undertake the matching of letter optotypes as in Keeler logMAR Test Sonksen Crowded Test

19. VISUAL ACQUITY: TESTING IN OLDER CHILDREN & ADULTS

20. REFRACTION: - more commonly, strabismus is secondary to refractive errors : hypermetropia, myopia, astigmatism, anisometropia – ass must be ruled out INSPECTION: Hirschberg Test / Corneal Reflex Ocular Movements / EOM Anterior Segment Fundus Evaluation – to rule out underlying ocular pathology like macular scarring, optic disc hypoplasia or retinoblastoma as the cause of deviation

21. MEASUREMENT OF DEVIATION: HIRSCHBERG Test Krimsky Test / Prism Reflection Test Modified Krimsky Test Cover – Uncover Test Alternate Cover Test Prism Cover Test Maddox Wing Maddox Rod

22. HIRCHBERG TEST : MEASUREMENT OF DEVIATION:

23. Krimsky Test / Prism Reflection Test : MEASUREMENT OF DEVIATION: Involves placement of prisms in front of the deviating eye until the corneal light reflections are symmetrical Modified Krimsky Test : Involves placement of prisms in front of the fixating eye, until the corneal light reflections are symmetrical. This test reduces the problem of parallax and is more commonly used.

24. MEASUREMENT OF DEVIATION: COVER-UNCOVER TESTS: Must be performed for both Near & Distant Targets Consists of 2 parts : Cover & Uncover Test Cover Test : detects Heterotropia Uncover Test: detects Heterophoria Alternate Cover Test: induces dissociation to reveal the total deviation when fusion is disrupted. It should be performed only after Cover-Uncover Test

25. Cover Test: Notice that first the fixing eye is Covered Detect Heterotropia Uncover Test : Notice that first the deviated eye is Covered Detect Heterophoria

26. MEASUREMENT OF DEVIATION: Prism Cover Test: performed as follows Alternate Cover Test – to approximate direction and estimation of deviation Prisms of increasing strength are placed in front of one eye with base opposite the direction of deviation . The Alternate Cover Test is performed continuously as stronger prisms are introduced. The amplitude of the re-fixation movement should gradually decrease as the strength of prism approaches the extent of deviation The end point is approached when no movement is seen. Thus, the angle of deviation is taken from the strength of the prism

27. MEASUREMENT OF DEVIATION: Prism Cover Test:

28. MEASUREMENT OF DEVIATION: Maddox Wing Test:

29. MEASUREMENT OF DEVIATION: Maddox Wing Test: Separates the Eye’s View Right Eye sees Numbers Left Eye sees Arrows

30. MEASUREMENT OF DEVIATION: Maddox Rod Test:

31. TEST FOR STEREOPSIS: Steriopsis is measured in Seconds of Arc 1 o = 60’ of arc, 1’ = 60’’ The lower the value the better is the stereoacuity. Random Dot Tests ( Eg. TNO Test , Frisby Test ) – provide the most definitive evidence of high grade BSV (Binocular Single Vision) Contour-based Tests ( Eg. Titmus Fly Test ) – may provide more reliable information

32. TEST FOR STEREOPSIS: TITMUS FLY TEST: Consists of 3-d polarized vectograph , comprising two plates in the form of a booklet viewed through polarized spectacles . The spectacles should be worn before the plates are viewed. On the right is a large fly & on the left is a series of nine squares (within each of which there are four circles) & animals

33. TEST FOR STEREOPSIS: TITMUS FLY TEST: The FLY: test of gross stereopsis (3000 seconds) and is especially useful for young children. The ANIMAL: consists of 3 rows of stylized animals (400-100 seconds) – one of which will appear forward from the plane of reference. The CIRCLES: graded series measuring 800-40 seconds – one of a set of four circles should appear to stand out from the plate surface.

34. TEST FOR STEREOPSIS: TNO Test: Consists of seven plates of randomly distributed paired red and green dots viewed with red-green spectacles and measures from 480 to 15’’ of arc at 40cm. Control shapes are visible without the spectacles. The TNO test includes seven plates:  Plates I–III :  Screening plates with test images that appear to float above the plate when viewed through the glasses  Plate IV : A plate for testing eye suppression   Plates V and VI : Quantitative plates for testing stereo acuity

35. TEST FOR STEREOPSIS: FRISBY TEST: Consists of 3 transparent plastic plates of varying thickness. On the surface of each plate are printed four squares of small randomly distributed shapes. One of the squares contains a hidden circle, in which the random shapes are printed on the reverse of the plate.

36. TEST FOR STEREOPSIS: FRISBY TEST: Consists of 3 transparent plastic plates of varying thickness. On the surface of each plate are printed four squares of small randomly distributed shapes. One of the squares contains a hidden circle, in which the random shapes are printed on the reverse of the plate.

37. TEST FOR STEREOPSIS: LANG TEST: The Lang stereotest uses targets (such as a moon, star or an animal) With normal stereopsis, the subject will be able to identify the target on the card.

38. TEST FOR MOTILITY: OCULAR MOVEMENTS & FORCED DUCTION NEAR POINT OF CONVERGENCE NEAR POINT OF ACCOMODATION

39. TEST FOR MOTILITY: FORCED DUCTION TEST

40. TEST FOR MOTILITY: NEAR POINT OF CONVERGENCE Nearest point on which the eyes can maintain binocular fixation. Measured with the RAF Ruler, which rests on patient’s cheeks. A target is slowly moved along the rule towards the patient’s eyes until one eye loses fixation and drifts laterally ( OBJECTIVE NPC ) SUBJECTIVE NPC is the point at which the patient reports diplopia

41. TEST FOR MOTILITY: NEAR POINT OF ACCOMODATION: Nearest point on which the eyes can maintain focus. Measured with the RAF Ruler, which rests on patient’s cheeks. Patient fixates a line of print, which is then slowly moved towards the patient until it becomes blurred. The distance at which this is first reported is read off the rule and denotes the NPA. NPA recedes with age. Ex: at the age of 20 years the NPA is ~ 20 cm. By the age of 50 years, it recededs to ~ 46 cm (presbyopia)

42. TEST FOR FIELD OF BINOCULAR VISION: PERIMETRY MANUAL AUTOMATED CONFRONTATION OCTOPUS LISTERS FIELD MASTER CAMPIMETRY/BJERRUM TANGENT SCREEN HUMPHREY FIELD ANALYZER GOLDMANN PERIMETER

43. TEST FOR FIELD OF BINOCULAR VISION: HUMPHREY FIELD ANALYZER GOLDMANN PERIMETER

44. TEST FOR DIPLOPIA: DIPLOPIA CHARTING General Features: Dark room is chosen Red before Right Eye Light Source with a Vertical Slit @ 50 cm away Vertical Slit is usually used when patient is having a Horizontal Deviation Horizontal Slit is usually used when patient is having a Vertical Deviation Horizontal: Uncrossed – ESOTROPIA Horizontal: Crossed – EXOTROPIA Vertical: Straight/Tilt Maximum Separation is in the quadrant of field of action of the Paralyzed Muscle Image that appears Farthest, belongs to the Deviating eye

45. TEST FOR DIPLOPIA: DIPLOPIA CHARTING Remember: ESODEVIATION : Horizontal Separation with uncrossed images (as in LR Paralyses) EXODEVIATION : Horizontal Separation with crossed images (as in MR Paralyses) Vertical Recti : Vertical Separation with crossed images Oblique Muscle : Vertical Separation with uncrossed images

46. TEST FOR DIPLOPIA: DIPLOPIA CHARTING

47. TEST FOR DIPLOPIA: DIPLOPIA CHARTING Strengths: Very helpful in identifying bilateral palsies Can be used in bedridden patients, where a Hess Chart is not possible Weakness: Purely a subjective test Reliability Reproducibility Follow-up Comparison is difficult

48. TEST FOR DIPLOPIA: HESS CHARTING

49. TEST FOR DIPLOPIA: HESS CHARTING

50. TEST FOR DIPLOPIA: HESS CHARTING

51. TEST FOR DIPLOPIA: HESS CHARTING

52. TEST FOR SENSORY ANOMALIES: WORTH FOUR DOT TEST

53. TEST FOR SENSORY ANOMALIES: BAGOLINI STRIATED GLASSES NORMAL DIPLOPIA SUPPRESSION CENTRAL SUPPRESSION

54. TEST FOR SENSORY ANOMALIES: SYNOPTOPHORE

55. PSEUDOSTRABISMUS : Clinical impression of strabismus with no squint present Epicanthic Folds: may stimulate Esotropia Abnormal Interpupillary Distance: If Short  Pseudo-esotropia If Long  Pseudo-exotropia Angle Kappa: If Large  Pseudo-exotropia If Negative  Pseudo-esotropia

56. SUMMARY

57. References : AAO-6: Pediatric Ophthalmology and Strabismus Anatomy & Physiology of Eye : AK Khurana & Indu Khurana Parsons Diseases of the Eye AAO – Practical Ophthalmology Kanski’s Clinical Ophthalmology

58. THANK YOU

59. What are these glasses known as ?

60. TEST FOR DIPLOPIA: HESS CHARTING What might be the Diagnosis ?

61. Normal Angle Pseudo-Exotropia Pseudo-Esotropia