Direct & indirect ophthalmoscopy

Direct & indirect ophthalmoscopy

1. Direct & Indirect Ophthalmoscopy Presenter- Dr. Rohit Agrawal Moderator- Dr. S. Banait Sir Conductor- Dr . Chandak Sir 5/02/2018

2. Direct Ophthalmoscope Babbage invented 1 st direct ophthalmoscope in 1848 Hermann von Helmholtz revolutionised it in year 1850

3. Modern Ophthalmoscope : Here light source from the batteries is reflected at 90 using a mirror placed in the head portion at 45o angle . The examiner looks through a hole in the mirror that is through the light.

4. Illumination with semi-reflecting mirror (Helmholtz) Illumination with mirror or prism (modern)

5. Distant Direct Ophthalmoscopy Performed with the help of self illuminating ophthalmoscope or a plane mirror with a hole in centre Distance – 20 to 25 cm Applications- To diagnose opacity in the refractive media To differentiate between a mole and a hole of the iris To recognize detached retina or a tumour arising from the fundus

6. Image Virtual / Erect Field of view 2 DD = 10° Magnification 15 X Area of fundus seen 50-70 % Image brightness 4 Watts Working distance 1-2 cm Stereopsis None

7. Procedure of Direct Ophthalmoscopy Performed in a semi-dark room with the patient seated and looking straight ahead and observer standing to the side of the eye to be examined . The observer should reflect beam of light from the ophthalmoscope into the patient’s pupil . Once the red reflex is seen, the observer should move as close to the patient’s eye as possible.

8. Accessories- A slit diaphragm is often provided to allow slit-lamp type observation of elevated retinal lesions A pinhole or half-circle diaphragm may be used to reduce reflections by limiting the illumination beam. It is also helpful in the observation of certain fine retinal details that are seen best in the transitional zone between illuminated and non-illuminated retina . A “red-free” filter . Lack of red light makes the red elements very dark so that vessels and pinpoint haemorrhages stand out more clearly.

9. A blue filter may be provided to enhance the visibility of fluorescein , for use in fluorescein angioscopy and as a handheld light source for fluorescein staining of the cornea A fixation star , a dot or a star-shaped figure, may be used to determine the patient's fixation . A set of crossed polarizing filters in illuminating and viewing beam, is sometimes used to reduce reflections

10. Parts of Direct Ophthalmoscope-

11. Indirect Ophthalmoscopy Introduced by Nagel in 1864 PRINCIPLE- Indirect Ophthalmoscopy (IDO) involves making the eye highly myopic by placing a high power convex lens in front of the eye so that a real, inverted and laterally reversed image is formed close to the principle focus of the lens, between the lens and the observer.

12. History of Indirect Ophthalmoscope- Ruete in 1852 designed first monocular indirect ophthalmoscope

13. Marc-Antoine Giraud- Teulon of France invented binocular hand-held indirect ophthalmoscope in 1861. It had a weak source of illumination. In 1946 – Charles Schepens invented modern binocular indirect ophthalmoscope .

14. Gullstrand’s Principle- The illuminating and viewing beams must be totally separated through the cornea, pupillary aperture , and lens (to avoid reflections) but must coincide on the retina to permit viewing.

15. Parts of Indirect Ophthalmoscope-

16. Convex lenses in the eyepieces of +2.00 D to relax the accommodation and view aerial image Condensing hand held lens ( +30D ; + 20D; +14D ) Scleral depressors

17. Procedure- Dark rooms preferred whenever possible. Preferable to have a patient chair that fully reclines , enabling the practitioner to move around the patient and hence gaining a full 360° traverse of the fundus . Place the ophthalmoscope on the head and adjust the straps for maximum comfort .

18. Face a wall approximately 40 cms away, and adjust the illumination mirror such that the illumination field is vertically centralized to the observation ports OR Focus the light on an outstretched thumb to set the IPD

19. Eye pieces are as close to the pupil as possible Eye pieces should be perpendicular to pupillary axis The practitioner should first illuminate the patient’s pupillary area Interpose the condenser lens close to the eye about 2 cm, and centre the lens on to the pupil. The lens should be held with the more convex side towards the practitioner

20. Condensing lens grasped between bulb of thumb & tip of flexed index finger. Middle finger acts as a pivot, used to adjust the distance between lens and patient’s eye Most lenses are coded either with a white or silver ring , this side is placed toward the patient's eye

21. Pull back the lens away from the patient’s eye, at the same time taking care to keep the illumination centred on the pupil . Having obtained an image filling the lens, the fundus may then be examined by moving around the patient if reclining, or by redirecting the patient’s fixation if seated. Characteristics of image formed are- Real Inverted Magnified Magnification depends upon- Dioptric power of the convex lens Position of lens in relation to the eyeball Refractive state of the eyeball

22. Eye is rotated in the direction of the quadrant to be examined Stand 180° away from the quadrant to be examined Observer should align his head with the long axis of the pupil. This will allow wider exit pupil for stereoscopic view

23. Using scleral indenter- The examiner should choose a type of depressor tool that feels comfortable to hold Sitting to one side of the patient, the examiner should gently place the probe on the outside of the lid. A starting position would be a little higher than the inner canthus, and at 180° to the observation angle The practitioner should very gently and tangentially move the probe into the fold of the lid ( approx 8mm from the limbus ) If this is difficult, indentation can be done applying the probe to the sclera without the intervening lid, but topical anaesthesia should be used to make your patient comfortable

24. Advantages of IDO Larger field of view Lesser distortion of retinal image Easier to examine if patients eye movements are present and with high spherical or astigmatic refractive errors Stereopsis Useful in hazy media due to its bright light and optical property Can be used intraoperatively Vitreous can be examined easily

25. Disadvantages of IDO Difficult to learn Less magnification, therefore details of a small lesion not visualized properly Impossible with very small pupils More uncomfortable to the patient

26. Fundus drawing Amsler-dubois chart EQUATOR ORA SERRATA JUNCTION OF PARS PLICATA AND PARS PLANA

27. Colour Coding- RED SOLID Retinal arterioles Neovascularization Vascular anomalies Attached retina Vascular tumors Hemorrhages ( Pre- retinal and retinal ) Open interior of retinal breaks (tears , holes)

28. Colour Coding- RED CROSSED Open portion of Giant Retinal Tears or large dialyses Inner portion of thin areas of retina Open portion of retinal holes in inner layer of retinoschisis

29. Colour Coding- BLUE SOLID Detached retina Retinal veins Outlines of retinal breaks Outlines of ora serrata

30. Colour Coding- BLUE SOLID VR traction tuft Outline of lattice degeneration (inner X) Outline of thin area of Retina

31. Colour Coding- BLUE CROSSLINES Inner layer of retinoschisis White with or without pressure (label) Detached parsplana epithelium anterior to separation of ora serrata Rolled edges of retinal tears / inverted flap in GRT ( curved lines )

32. Colour Coding- GREEN SOLID Opacities in the media Vitreous haemorrhage Vitreous membranes Hyaloid ring IOFB

33. Colour Coding- GREEN DOTTED Asteroid hyalosis Frosting or snowflakes on Retinoschisis or lattice degeneration

34. Colour Coding- BROWN SOLID Uveal tissue Pigment beneath detached retina

35. Colour Coding- BROWN SOLID Pigment epithelial Detachment Choroidal melanomas Nevus Choroidal detachment

36. Colour Coding- BROWN OUTLINE Edge of buckle beneath detached retina Outline of Posterior Staphyloma

37. Colour Coding- YELLOW SOLID Hard exudate S/R gliosis Deposits in the RPE

38. Colour Coding- YELLOW SOLID Post- cryo retinal edema Substance of long & short ciliary Nerve Retinoblastoma (Yellow – stippled) Drusen (Yellow Crossed) Chorioretinal coloboma

39. Colour Coding- BLACK SOLID Hyperpigmentation as a result of previous Rx with cryo /laser/Diathermy Completely Sheathed vessels Pigment within detached retina (Lattice)

40. Colour Coding- BLACK SOLID Pigment within choroid or pigment epithelial hyperplasia within attached retina (e.g. RP) Pigment demarcation line at margin of attached and detached retina

41. Colour Coding- BLACK OUTLINE Edge of buckle beneath attached retina Outline of Chorio - Retinal anastomosis

42. Recent Advances in Ophthalmoscopes Spectacle mounted Indirect Ophthalmoscope P anOptic Ophthalmscope

43. Spectacle mounted Indirect Ophthalmoscope It is a small, portable & lightweight indirect ophthalmoscope designed for office, hospital and home visits . Flip up optics allow unobstructed use of the entire spectacle when needed.

44. PanOptic Ophthalmoscope 5X larger view of the fundus vs. standard ophthalmoscopes in an undilated eye Greater working distance improves comfort for both practitioner and patient Dynamic focusing wheel allows continuous, smooth action and more precise control

45. Digitally capture, store, and share fundus images by combining with iExaminer Welch Allyn iExaminer turns the PanOptic Ophthalmoscope into a mobile digital imaging device. The adapter aligns the optical access of the PanOptic Ophthalmoscope to the visual axis of the iPhone camera to capture high resolution pictures of the fundus .

46. THANK YOU….

47. PG ACTIVITY ON 6/02/2018 CASE PRESENTATION Presenter- Dr. Shreya Jaiswal Moderator- Dr. Kamble Madam Conductor- Dr. Nagpure Madam