Indirect ophthalmoscopy and fundus drawing

Binocular indirect ophthalmoscopy and fundus/retinal drawings for fellows and residents.

1. DIVING DEEP INTO THE EYE Binocular Indirect Ophthalmoscopy & Fundus Drawing 29-09-20 CL Gupta Eye Institute Moradabad Presenter : Dr. Sonali Raj Singh Moderator: Dr. Abhishek Varshney

2. OBJECTIVES Brief History Working principle Examination technique Fundus Drawing / Color Coding Ergonomics

3. Ruete in 1852 designed first monocular indirect ophthalmoscope. History Of Indirect Ophthalmoscope

4. History Of Indirect Ophthalmoscope Marc-Antoine Giraud- Teulon of France (1861) -Weak source of illumination 1 1911-Thorner and Allvor Gullstrand – Reflex free ophthalmoscopy 2 1,2 Sherman, S.E. The history of the ophthalmoscope.  Doc Ophthalmol   71,  221–228 (1989)

5. History Of Indirect Ophthalmoscope 1946 – Charles Schepens - modern binocular indirect ophthalmoscope – “Father of Modern Retinal Surgery” 1 Schepens ’ model has undergone further modifications embracing new instrumentations and technologies.  1 Havener WH. Schepens ' binocular indirect ophthalmoscope. Am J Ophthalmol . 1958 Jun;45(6):915–8 .

6. Instrumentation Headpiece illumination condensing Oculars 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

7. Working Principle Of Indirect Ophthalmosope To make the eye highly myopic by placing a strong convex lens in front of patient’s eye. The emergent rays forms a real inverted image between the lens and observer’s eye. 1 Binocularity is achieved by artificially reducing the observer’s IPD to approximately 15mm by the help of prisms/mirrors. 1 Neal H Atebara , Penny A, Dimitri T Azar , Forrest J AllisEleanor E, Kenneth J, Rober E. Telescope and Optical instruments. Gregory l, Loius B, Jayne S, editor. Basic and clinical science course, Clinical optics section 03. San Francisco CA. 2011-2012. p. 245-248 .

8. Image Characteristics Real, inverted and magnified Magnification depends on: - - Dioptric power of the convex lens * -Position of lens in relation to the eyeball -Refractive state of the eyeball Field of view is directly proportional to power of lens while Magnification is inversely proportional . As the power of the condensing lens decreases, the field of view decreases but image magnification and working distance increase.

9. BIO LENSES Reference- www.volk.com

10. Procedure for IDO Explaining the procedure to the patient At least one attendant in examination room Make the patient feel comfortable Dilate pupils Darken the room Keep both eyes open

11. Procedure for IDO Adjust head band Eye pieces are as close to the pupil as possible (+2.0D in eyepiece to compensate for the accommodation) Eye pieces should be perpendicular to pupillary axis The scope not resting on the nose of the examiner

12. Adjust IPD Face a wall approximately 40 cms away. Adjust the illumination mirror such that the illumination field is vertically centralized to the observation ports.

13. Examining Positions Sitting position a. First b. Opacities may move out of the way in one position c. Change in retinal folds and expose retinal breaks which may not be otherwise visible Lying down position a. Easier for the patient b. Examination of periphery

14. PATIENT POSITIONING IDEAL POSITION Head flexed Head Extended

15. Handling Condensing Lens Condensing lens grasped between bulb of thumb & tip of flexed index finger. Middle finger – pivot Flex the wrist Most lenses are coded either with a white or silver ring, this side is placed toward the patient's eye.

16. EXAMINATION TECHNIQUE Start with minimum intensity Brief examination in sitting position from disc to equator Then patient lies down for detailed fundus examination and fundus charting Both eyes of the patient should be open Light is thrown into the patient’s eye from an arm’s distance and observe for red reflex Interpose the condensing lens Moving around the head of the patient to examine different quadrant 1 1 Modern Indirect Ophthalmoscopy / Brockhurst , Robert J. et al.American Journal of Ophthalmology, Volume 41, Issue 2, 265 - 272

17. EXAMINATION TECHNIQUE Maintain a common line of sight by imagining that the fundus under examination, the centre of the patient’s pupil, the centre of the condensing lens and the examiners visual axis are all connected by an imaginary line

18. PERIPHERAL FUNDUS EXAMINATION Correct position of the eye: - Provide a target like patient’s thumb Non seeing eye: - proprioceptive impulses

19. PERIPHERAL FUNDUS EXAMINATION During examination of fundus periphery, the patient’s pupil appears elliptic to the observer

20. While viewing fundus periphery much of the light is imaged outside the patient’s pupil. The light source should be adjusted to bring the image of the light source inside the elliptic pupil

21. Eye is rotated in the direction of the quadrant to be examined Stand 180° away from the quadrant to be examined Use scleral indenter

22. Observe all the parts of Retina (‘Sweeping of the fundus ’)

23. Using variable pupil function and altering the covergence angle of right and left image steropsis can be achieved.

24. ALTERNATIVELY Examination of both eyes at the same time For quick comparison of both peripheral fundi pigmentation and appearance

25. SOME TIPS… Tilt the BIO lens to remove undesirable reflections Adjust the illumination slightly higher or lower than center Moving closer towards the image will magnify the view but decrease the field Moving away from the image will increase the field of view but decrease the magnification

26. TYPES OF SCLERAL DEPRESSORS

27. SCLERAL INDENTATION Adjunct to see the peripheral/anterior parts of the fundus Dynamic examination (Rolling of lesion) TECHNIQUE Place the tip of indenter on the skin on eyelid tarsal plate over the area of sclera to be indented

28. Need to use indenter tangentially to the globe, with gentle pressure. If used perpendicularly, causes pain and squeezing of eyelids 1 1 Modern Indirect Ophthalmoscopy / Brockhurst , Robert J. et al.American Journal of Ophthalmology, Volume 41, Issue 2, 265 - 272

29. The examiner should see an elevated possibly " grayish mound" of the indented retina. So called “Mouse under the Blanket” phenomenon. 1 Indicates that the indenter is in correct position 1 Schepens , C. L., and Bahn , G. : Examination of the ora serrata : Its importance in retinal detachment. Arch. Ophth ., 44:677-690, 1950 .

30. DYNAMIC EXAMINATION Differentiating between a retinal tear and hemorrhage Hemorrhage will become elevated with indentation, holes will either gape open, look larger and/or appear darker with a Surrounding edematous (white) cuff.

31. Normal scleral indentation

32. Retinal breaks in detached retina without indentation Enhanced visualization of breaks with indentation

33. ADVANTAGES OF SCLERAL DEPRESSION Area near pars plana and ora can be examined Enhances contrast between lesions and surrounding retinal tissue Retinal lesions that are not well defined like suspected retinal hole , tears or vitreo retinal adhesions are examined with ease 1 1REVIEWOFOPTOMETRY.COM/ARTICLE/THELOSTARTOFOPTOMETRYPART1AREFRESHERONSCLERALDEPRESSION

34. CONTRAINDICATIONS OF INDENTATION Recent or suspected penetrating injuries Orbital injuries Intraocular surgery within 3 weeks phaco , 5-6 weeks for sics . Procedure may be painful in patients with high IOP

35. FUNDUS IMAGES AND REFRACTIVE ERRORS Magnification and extent of an aerial image depend on the refractive status of the eye. The fundus image is larger in hyperopic at the cost of a lesser field of view; this is more in case of an aphakic eye. In contrast, Myopic fundus details appear smaller with a larger field of view. Images in emmetropic eyes with posterior intraocular lens appears nearly 2% larger than phakic counterpart and corresponding slightly reduced field of view.

36. In the oil and gas-filled eyes, the overall refractive status changes and so, magnification and field of view changes accordingly. 3 In gas-filled phakic eyes, the posterior surface of the lens acts as a high concave lens causing a myopic shift. In Aphakia , the posterior surface of cornea acts as a high convex lens neutralizing anterior concave surface, this makes visualizing fundus without condensing lens.

37. Oil in phakic makes the posterior surface of lens low minus causing hyperopic shift and convex oil bubble in aphakic causes myopic shift bringing down aphakic hyperopia . 1 Depending on the distance at which aerial image is formed, the aerial image is brought into focus by moving the condensing lens closer or away from the examinee's eye. 1.  Stefánsson E, Tiedeman J. Optics of the eye with air or silicone oil.Retina . 1988;8 (1): 10-19

38. FUNDUS DRAWING JUNCTION OF PARS PLICATA AND PARS PLANA ORA SERRATA EQUATOR

39. CHART POSITION

40. PENNING FUNDUS FINDINGS ON PAPER Disregard Sup/ Inf and Temp/Nasal while drawing What ever appears closer to the observer in the condensing lens is peripheral (anterior) Observe the disc and follow a vessel to the periphery Observe the macula at the end for best patient cooperation

41. Draw as you see the lesion in the condensing lens

42. COLOR CODING – RED Hemorrhages ( preretinal and intraretinal , SHH) Attached retina Retinal arterioles Neovascularization Vascular abnormalities /anomalies

43. Vascular tumors Open interior of conventional retinal breaks ( tears,holes ) Open portion of Giant retinal tear (GRT) or large dialyses Inner portion of thin areas of retina

44. COLOR CODING - BLUE Detached retina Retinal veins Outlines of retinal breaks Outline of lattice degeneration Outline of thin areas of retina

45. COLOR CODING - BLUE Outlines of ora serrata Outline of change in area or folds of detached retina because of shifting fluid White with or without pressure Rolled edges of retinal tears Cystoid degeneration Outline of flat neovascularization CME

46. COLOR CODING - GREEN Opacities in the media Vitreous hemorrhage Vitreous membranes Hyaloid ring IOFB Outline of elevated neovascularisation Vitreous Substitute – Silicone Oil, Gas Asteroid hyalosis ERM

47. COLOR CODING - BROWN Uveal tissue Pigment beneath detached retina Pigment epithelial Detachment Choroidal melanomas Nevus Choroidal detachment Edge of buckle beneath detached retina Outline of Posterior Staphyloma

48. COLOR CODING - YELLOW I/R, S/R hard exudate S/R gliosis Post-Laser / cryoretinal edema Substance of long & short ciliary N Retinoblastoma Yellow – stippled Drusen Yellow Crossed Chorioretinal coloboma

49. COLOR CODING - BLACK Hyperpigmentation as a result of previous Rx with cryo /Laser/Diathermy Completely Sheathed vessels Pigment within detached retina (Lattice, HST) Pigment within choroid or pigment epithelial hyperplasia within attached retina (e.g. RP) Pigment demarcation line at margin of attached and detached retina

50. FILTERS Green light – Nerve fibre layer, Blood vessels, microaneurysms Red light – Subtle pigmentary abnormalities Blue light – used along with fluorescein dye for angioscopy Yellow filter – Reduces photophobia

51. CLEANING AND STERILIZING CONDENSING LENS (1) Clean the lens using contact lens cleaner and warm water, NOT HOT WATER. Then dry with a soft lint free cloth or paper towel. (2) Never autoclave or boil a condensing lens. (3) Place the lens completely in 3% hydrogen peroxide solution 2% Glutaraldehyde aqueous solution 20-25 mins Sodium Hypochlorite 1:10 parts 10 mins Pure 70% Isopropyl Alcohol for 5-10 minutes

52. INNOVATIONS Modifications in head-mounted IDO with newer accessories like real-time video recording/image capturing are recent additions to the traditional IDO. A digital camera is fitted above eyepiece with a USB port which can be connected to monitor or computer for documentation and teaching purpose

53. Smartphone-based indirect ophthalmoscopy is gaining popularity for its low cost and easy-to-make design. Smartphones are used as a light source and the indirect image is captured using a condensing lens. Both are fixed appropriately using an adapter and software for documentation. 1

54. Newer models like spectacle mounted IDO are known for their miniature size, ease of use, and lightweight. 1 Shanmugam MP, Mishra DK, Madhukumar R, Ramanjulu R, Reddy SY, Rodrigues G. Fundus imaging with a mobile phone: a review of techniques.Indian J Ophthalmol . 2014;62(9):960-962. doi:10.4103/0301-4738.143949

55. ERGONOMICS Several studies have evaluated the occurrence of occupation-related musculoskeletal diseases in ophthalmologists and report an incidence of 30% to 70% for neck pain and 40% to 80% for back pain. 1,2 These studies have additionally identified indirect ophthalmoscopy and laser photocoagulation surgery as the factors associated with neck and back pain in ophthalmologists 1 Dhimitri KC, McGwin G, McNeal SF, et al. Symptoms of musculoskeletal disorders in ophthalmologists. Am J Ophthalmol 2005;139:179–181 2 Kitzmann AS, Fethke NB, Baratz KH, et al. A survey study of musculoskeletal disorders among eye care physicians compared with family medicine physicians. Ophthalmology 2012; 119:213–220 .

56. Traditional technique for scleral depression. The examiner’s cervical spine is flexed while performing this technique, creating stress on the paraspinal ligaments and tendons and disk compression.

57. Ergonomic technique for scleral depression in the clinic. The patient has been reclined slightly, and the head has been tilted 45° towardthe examiner. The examiner’s head and neck are in neutral position Avoiding Neck Strain in Vitreoretinal Surgery: An Ergonomic Approach to Indirect Ophthalmoscopy and Laser Photocoagulation RETINA, THE JOURNAL OF RETINAL AND VITREOUS DISEASES 2013 VOLUME 33 NUMBER 2

58. Ergonomic technique for scleral depression in the operating room. The neutral position of the surgeon’s head and neck decreasing stress on the paraspinal ligaments and tendons. The patient’s head has been tilted 45° toward the surgeon Avoiding Neck Strain in Vitreoretinal Surgery: An Ergonomic Approach to Indirect Ophthalmoscopy and Laser Photocoagulation RETINA, THE JOURNAL OF RETINAL AND VITREOUS DISEASES 2013 VOLUME 33 NUMBER 2