Taking Your Fundus Exam to the Next Level Dr. Kelly Thompson Cincinnati VA Medical Center Taking Your Fundus Exam to the Next Level Resident Assistants Student Subjects Fundus Biomicroscopy Indirect High plus Auxiliary lenses Aerial, reversed, and inverted image 1
Fundus Biomicroscopy Indirect Higher power lenses results in larger field of view, less magnification ONH evaluation 78D, Super 66, 60D Posterior pole evaluation 90D, 78D, Super 66, Superfield Peripheral retina evaluation 90D, Superfield, Super Vitreo Fundus Fundus Biomicroscopy Direct Contact lenses-uses fluid Neutralizes power of the eye Non-mirror or Mirrored Mirrors- peripheral retina 3 Mirror Goldmann Lens Contact lens Central lens for examining posterior pole with mirrors at varying angles for viewing from mid-periphery to anterior chamber angles. 2
Fundus Biomicroscopy Goldman lens Central lens 64 Diopter Excellent for examining macula and optic nerve Useful to detect subtle macular changes i.e. mild CME and elevation Fundus Biomicroscopy Goldman lens mirrors 59 degrees Smallest mirror Gonioscopy, ora serrata, pars plana 67 degrees Middle sized mirror Anterior equator to posterior ora serrata 75 degrees Largest mirror Equator Image inverted anterior to posterior but not laterally Goldmann Lens Technique Patient is dilated, anesthetic instilled Place viscous ophthalmic soln or gel on lens, avoiding air bubbles Instruct patient to look up, insert lens onto lower lid then bring the lens into contact with cornea as patient returns to primary gaze Fundus opposite the mirror is being viewedrotate on eye as needed to position mirrors 3
Goldmann Lens Tips To obtain more peripheral views, have patient look toward clock hour being examined while keeping lens in contact with cornea To remove have patient blink forcefully Binocular Indirect Ophthalmoscopy Configuration Headband with light source, low plus oculars, and prisms or mirrors to effectively reduce PD Condensing lens to focus light source, form aerial image of retina, and further reduce examiner s effective PD BIO with 20D lens together effectively reduce examiners IPD to 3mm allows examiner s pupils to be imaged within patient s pupil allowing stereopsis Binocular Indirect Ophthalmoscopy Optics Condensing lens = real, inverted aerial image 14D, 20D, 28D, 30D As condensing lens power increases: Image size and stereopsis decrease Field of view increases Higher power condensing lenses (eg. 28D, 30D) effectively reduce IPD even further = better for smaller pupils Working distance decreases 4
Binocular Indirect Ophthalmoscopy Procedure Dilate pupil Position patient- seated or reclining Put on headband, adjust rheostat and position of light, center oculars Direct light to pupil and insert condensing lens with more convex lens surface facing examiner Adjust condensing lens to clarify and maximize image Move your head, condensing lens, and light beam as one system on an axis Use a protocol regarding fields viewed for retina examination BIO Tips Familiarize and orient yourself to peripheral fundus landmarks Vortex Vein Ampullae Long Ciliary Nerves Ora Regions/terminology Posterior pole Midperiphery Far Periphery BIO Tips 5
Estimating size and distance 20D fov ~ 8DD across Nearly 3 widths of a 20D lens from optic disc to ora BIO Tips Palpates retina through light pressure on the sclera Allows visualization of: More anterior retina Vitreo-retinal interface Aids detection in small retinal breaks enhances the contrast of the RPE and choriocapillaris compared to surrounding sensory retina Retina in profile Appreciate elevation Instruments Thimble style Pencil style Dual heads Cotton tip applicator Depression through lids vs conjunctiva 6
Procedure Position- reclined vs seated examined with BIO and condensing lens 180 degrees from area of observation Instruct patient to look in direction opposite of desired area of observation, position the depressor, then have the patient look back toward the desired field while rotating the depressor back into place. The BIO, condensing lens and depressor must all be positioned along the same axis. Observe roll or mouse under the rug effect Patient Comfort Greatest concern for many clinicians is causing undue discomfort While some pressure sensation is expected, procedure should not be painful with correct technique Only light pressure is needed- focus not so much on depressing the eye as simply laying the instrument along the globe Proper positioning is essential Patient Comfort Anatomic considerations: On average the ora serrata begins less than 1 cm posterior to limbus and the equator is only 13mm posterior to the limbus Apply instrument 7-14mm from the limbus Applying pressure within 7mm of limbus will depress the ciliary body and cause pain Position above the tarsal plate for superior indentation Do not use the orbital rim as a lever-this could exert undue pressure and cause pain if skin is pinched or the supraorbital nerve is compressed. 7
Tips If elevated retina not observed, do not press harder!! Adjust yourself, light source, and condensing lens so that you are lined up correctly to view depressed area Higher power condensing lens will increase field of view, i.e. 28D, 30D Indications Recent onset of flashes/floaters New PVD Schaeffer sign Retinoschisis Useful in differentiating schisis cavity from detachment Vitreous hemorrhage With no history of trauma Lattice Degeneration small holes within lattice or tears along the edges of lattice Contraindications: Recent intraocular surgery Potential open globe i.e. suspected penetrating trauma, globe rupture, or corneal melt Hyphema Orbital injuries Caution with advanced glaucoma Do not depress over bleb 8
References 1. Atlas of Primary Eyecare Procedures Linda Casser, Murray Fingeret, H. Ted Woodcome Copyright 1997 by Appleton and Lange, pp 234-237, 74-87 2. Clinical Procedures in Optometry J. Boyd Eskridge, John F. Amos, Jimmy D. Bartlett Copyright 1991 by J.B. Lippincott Company, pp 462-469 3. A Better Way to Do BIO John W. Potter, O.D. Review of Optometry 9/15/1999, pp 69-76 4. Peripheral Ocular Fundus, 3 rd ed. William L. Jones Copyright 2007, 1998 by Butterworth-Heinemann, pp 1-13 Thank you Special thanks to: Char Robinson (Volk Optical Inc.) Supplying lenses Linda Fette Coordinating student volunteers Dr. Patrick Till Help coordinating this workshop and presentation 9