Direct Ophthalmoscopy PDF

DIRECT OPHTHALMOSCOPY Dr. Ariette Acevedo, O.D. PPO 2 Direct Ophthalmoscopy ◦ Instrument for fundus examination ◦ This skill is essential for the development of a good diagnostic ability ◦ When used correctly it provides the ability to evaluate anterior segment, grossly, lens, vitreous and retina ◦...

DIRECT OPHTHALMOSCOPY Dr. Ariette Acevedo, O.D. PPO 2 Direct Ophthalmoscopy ◦ Instrument for fundus examination ◦ This skill is essential for the development of a good diagnostic ability ◦ When used correctly it provides the ability to evaluate anterior segment, grossly, lens, vitreous and retina ◦ Practice with your fellow classmates, family members, roommates, ect… Monocular Indirect Ophthalmoscope PanOptic Direct Ophthalmoscope Direct Ophthalmoscope ◦ Head ◦ On/Off ◦ Light Bulb ◦ Battery ◦ Reflecting mirror/view ◦ Wheels for lenses ◦ Convex and concave ◦ Aperture sizes and filters Apertures/Filters Technique ◦ The clinician uses their right eye and right hand to evaluate the patients right eye. ◦ Start at ~40cm from the patient using plano to a +2.00 dioptric power. ◦ Compare the pupils shape, roundness, red reflex Ophthalmoscopy ◦ Use the large diameter aperture and bright illumination to make external observations of the patient’s OD ◦ As you get closer increase in dioptric plus power ◦ Observe: ◦ Lashes, lid margin, palpebral conjunctiva and sclera ◦ Iris color and integrity ◦ Pupil size and shape ◦ After examining both compare between the eyes Ophthalmoscopy ◦ Adding plus as you get closer to the patient and observe the vitreous ◦ Vitreous is supposed to be clear, free of floaters, blood or any moving opacity ◦ A red-orange reflex should be seen ◦ Opacities: anything that interferes with the light returning from the retina will be seen as a black opacity or an irregularity of the red reflex: ◦ Floaters ◦ Corneal Scars ◦ Cataracts ◦ Lens Pigmentation Opacities Movement ◦ Using the plus lenses, while examining the red-reflex as the clinician moves the ophthalmoscope up or down slightly ◦ If the opacity moves in the opposite direction of the ophthalmoscope, then it lies anterior to the lens (i.e. cornea or anterior chamber) ◦ Example: tear film debris ◦ If the opacity remains stationary, then it is in the pupil plane ◦ Example: cataract, Mittendorf dot ◦ If the opacity moves in the same direction of ophthalmoscope, then it lies posterior to the lens ◦ Example: PVD, floaters Vitreous Evaluation with Ophthalmoscopy ◦ Vitreous floaters are best seen with a +6.00D or +10.00D lens in place ◦ Approximately 10 to 16 inches from the patient's eye ◦ Observed with retro illumination ◦ As the patient moves their eyes the floaters will be seen swirling across as dark cobwebs or filaments within the retinal glow Weiss Ring ◦ https://www.youtube.com/watch?v=u0soBWbsEWY Retinal Structures in Ophthalmoscopy ◦ Slowly move closer to the patient and decrease power until the fundus becomes clear, get as close to the patient that your hand holding the instrument touches the patient’s face ◦ The power of the lens necessary to focus on the fundus will depend on the patient’s and observer’s uncompensated refractive error and accommodation ◦ In high hyperopes (aphakic) you might have to increase plus power to reach the fundus ◦ If refractive error is too high you might use loose lenses to clear the image ◦ Controlling your accommodation allows for a close estimation of the patient's refractive error ◦ Estimation of the refractive error is made when the optic disc comes into focus Retinal Structures in Ophthalmoscopy ◦ Position the instrument about 10-16cm from the patient’s eye and about 15 degrees temporal to the line of sight ◦ Once the vessels are in focus, move along the vessel and follow one of them until you find the optic disc ◦ Follow one of the 4 major blood vessels ◦ Around 15 degrees temporal from line of sight the optic disc should be visible Evaluated by sections Keep mental image of findings Optic Nerve Head Evaluation ◦ Disc Shape: round, oval, small, large, tilted ◦ Disc margins: distinct vs indistinct (blurry) ◦ Neuroretinal Rim (NRR): salmon pink vs pallor, follow the ISNT rule, notching ◦ C/D ratio: H/V ◦ SVP: present (+) or absent (-) ◦ Crescents: pigmentary, scleral ◦ Peripapillary area NFL appearance: NFL drop out or intact, PPA ◦ Depth of physiological cup Optic Nerve Head Evaluation ◦ Cup to disc ratio (C/D ratio) ◦ Always evaluate the ratio for horizontal and vertical dimensions ◦ The red-free filter is useful when judging the C/D ratio, easier to evaluate the NFL ◦ Evaluate the presence of Spontaneous venous pulsation (SVP) ◦ SVP is absent in approximately 10-20% of normal individuals, if not seen it must be induced. ONH Variations in shape Horizontally oval cup, oval disc Round Horizontal Oval Vertical Oval** Irregular Neuroretinal Rim (NRR) Color vs Normal NRR Color Variations Symmetry Between Eyes Asymmetric: different size and shape Symmetric: similar size and shape Disc Margins (Scleral Ring) Vessel Inflection Color Change vs Vessel Bending Observations ◦ Disc: observe the color, margin and cup ◦ Is there any pigmentary, choroidal or scleral crescents around the disc? ◦ Peripapillary atrophy? ◦ Differentiate between a color cup and a contour cup Calculate Cup to Disc Ratio ◦ C/D ratio is an estimate of the diameter of the cup as related to the diameter of the disc in horizontal and vertical aspects ◦ Expressed as a decimal fraction ◦ Average 0.40/0.40 0.40 0.40 ONH Evaluation ◦ There are a lot of components to learn when evaluating an optic nerve head ◦ Basic Evaluation: 1. Disc size, shape, margins 2. C/D ratio H/V - Color vs contour 3. NRR Appearance - ISNT Rule t 0.80/0.80 0.90/0.90 Myelinization of RNFL Posterior Pole ◦ Examine the midperiphery (S,T,I & N quadrants) ◦ Sometimes its necessary to ask the patient to move their eyes ◦ Evaluate artery to vein ratio (A/V ratio), A/V crossings, retinal background ◦ Check for color and evenness of pigmentation ◦ Evaluate macula ◦ Move to the patient’s line of sight to observe the macula ◦ Determine color of macula, reflex of fovea present or absent (FR), pigment changes, hemorrhages, elevation or depression ◦ Do not record only BFR or FR (+) Observations ◦ Retinal blood vessels should be examined in each quadrant after locating the disc ◦ The veins are relatively large and dark red while the arteries are thinner and brighter red Macula Observation ◦ It may be useful to use a smaller aperture beam for the macular ◦ Especially is miotic pupils ◦ Macula is between the superior and inferior temporal blood vessel arcade ◦ In the center is the fovea and in young healthy patients it presents with a bright foveal reflex (BFR) Posterior Pole ◦ Ask the patient to look at the eight cardinal directions to allow you to view the peripheral fundus ◦ ”look up” to view superior periphery and so on… ◦ In young patients with large pupils, you will be able to get as far as the equator of the eye ◦ This means that for good peripheral observation you need dilation of the pupil ◦ Only ~60% of retina is seen without a DFE ◦ As you move in the periphery you may need to adjust the power slightly since the periphery is closer that the optic disc and will requiring more plus power Retinal Vasculature ◦ Artery to vein ratio (A/V) ◦ Note the caliber of the arteries and veins ◦ Look for abnormalities, irregularities in the caliber ◦ Arterial Light Reflex ◦ Normal, cooper wire, silver wire ◦ Branching of Vessels to all Four Quadrants ◦ Any constriction, beading, tortuosity, plaques ◦ Hollenhorst (cholesterol) or calcium plaques ◦ Pulsation ◦ Venous or arterial ◦ Crossing Phenomenon ◦ Evaluate A/V crossing, banking, nicking, Gunn Sign, Salus Sign A/V Ratio ◦ After the first bifurcation, a retinal artery normally has a caliber slightly less than the corresponding vein. ◦ Usually expressed as 2:3 or 3:4 ◦ Hypertensive Retinopathy (HTR) makes arteries constrict, decreasing the ratio to 1:2 or 1:3 ◦ May present focal constriction of arteries, irregularities in the veins such as dilations, tortuosity, venous beading A/V Crossings ◦ Gunn’s Sign: Tapering of vein on either side of crossing ◦ Thinner on one end, vein appears to taper down either side of the artery ◦ Bonnet’s Sign: Banking of vein distal to the crossing site. ◦ Thicker on one end, vein is twisted on the distal side of the artery and forms a dark, wide knuckle ◦ Salus’ Sign: deflection of veins at crossing site A/V Crossings ◦ A/V Nicking: due to compression of hard artery on veins ◦ Vein thinner on both ends, the vein appears to stop abruptly on either side. Early Compression Deviation of vein Normal Humping Tapering Banking Tapering (Gunn's signtapers down) of vein on either side of crossing. (is thinner in one end, vein appears to taper down either side of the artery) Banking (Bonnet's sign) of Vein distal to the crossing site is twisted forming a wide dark knuckle appearance. thicker in one end. Salus' sign: deflection of Veins at crossing site. Bonnet’s Sign Gunn’s Sign Salus’ Sign Arterial Light Reflex ◦ The light streak reflected in the artery represents the column of blood. ◦ If the arterial wall becomes sclerotic, the light streak in the artery is accentuated and widened ◦ It can acquire a copper wire or silver wire appearance Arterial and Venous Pulsation ◦ Spontaneous Central Venous Pulsation (SVP) is normal and seen in 80% of patients ◦ If observed should be recorded, in the case it becomes absent ( impending CRVO and Papilledema) ◦ Pulsation of the Central Retinal Artery (CRA) is abnormal ◦ Occurs when IOP exceeds the diastolic pressure of the retinal artery and indicates a patient is suffering a glaucoma attack ◦ Optic Nerve Head Spontaneous Venous Pulsations – YouTube Extravascular Changes ◦ Microaneurysms: most visible by Fundus Fluorescein Angiography (FAN) ◦ Occur at localized areas of capillary wall weakness. ◦ Retinal Hemorrhages: pre-retina, intra-retina, sub-retinal ◦ Each characteristic of certain systemic conditions ◦ Retinal and macular edema: due to either transudation of choroidal fluids after breakdown of RPE or failure of autoregulation of retinal capillaries. ◦ Retinal Lipid Deposits (hard exudates): elsewhere and also in the macula ◦ Cotton wool spots: due to focal nerve fiber infarcts/sign of ischemia, hypoxia. Hollenhorst Plaques Venous Beading Cotton Wool Spots Cotton Wool Spot Myelinated NFL Sub-retinal Pre-retinal Intra-retinal Exudates Fundus Evaluation Healthy Fundus Drusens Macula ◦ Normally appears darker than the rest of the retina ◦ If there is pigment clumping, hypopigmentation (salt and pepper), beaten bronze appearance, bull’s eye appearance all of this is NOT NORMAL ◦ Should not present hemorrhages, yellow or white deposits ◦ There should be a foveal pit, but not a “hole "in the area ◦ If the area does not present abnormalities record as healthy and presence or absence of foveal reflex ◦ Recording +FR or BFR is not enough!! Pigment clumping and drusens Macular Hole Soft drusens Bull’s Eye Maculopathy Healthy Macula Beaten Bronze Appearance Fundus Background ◦ Usually there is thinning of the retinal pigment epithelium towards the periphery, this makes choroidal vessels more visible ◦ An even red fundus ◦ Dense even pigmentation, choroidal vessels obscured ◦ Tessellated fundus (Tigroid, Brunette) ◦ Choroidal vessels are visible as red and intervascular spaces are black/brown ◦ Blond Fundus (Albinotic) ◦ Visible choroidal vessels seen as red net on yellow-white scleral background Even Red Fundus Tessellated Fundus Blonde Fundus (Albinotic) Recording ◦ Disc: ◦ C/D ratio (H/V) ◦ Margins: distinct or indistinct, edematous, crescents, tilted discs ◦ Neuroretinal Rim: color, ISNT rule ◦ SVP: present or absent (+) or (-) ◦ Vasculature: ◦ A/V ratio ◦ Reflex ◦ Venous beading, tortuosity ◦ Neovascularization ◦ Macula: ◦ Healthy, pigmentary changes, foveal reflex (+) or (-) ◦ Background (posterior pole): ◦ Any significant pathology or healthy ◦ Periphery ◦ Healthy as far as seen (HAFAS) only if not dilated ◦ If DFE was performed, record findings (no tears, holes or detachments 360) ◦ Media ◦ Lens ◦ Vitreous ◦ Clear, hazy, cells, floaters ◦ OK, Normal, Fine, Good are not appropriate responses for medicolegal records. Posterior pole: ONH, macula and superior and inferior arcades Equator: up to 3mm from vortex veins Periphery: up to ora serrata Pars Plicata and Pars plana Ora Serrata Equator 12 9 3 6 Systemic Assessment of ON ◦ The 5-Rs in Glaucoma Suspect ONH ◦ Scleral Ring: Observe the scleral ring to identify the limits of the optic disc and its size ◦ Blurred or defined margins ◦ Rim: identify the size of the NRR (small, medium or large) ◦ C/D ratio and ISNT rule ◦ Retinal Nerve Fiber Rim and Layer (NRR/NFL): examine the RNFL and NRR ◦ Intact or missing ◦ Region of Peripapillary Area: examine the peripapillary area ◦ PPA present or missing, Alpha zone or beta zone ◦ Retinal and Optic Disc Hemorrhages: look for retinal or optic disc hemorrhages Alpha vs Beta Zones ◦ Central Beta zone: (bordering the optic disc) ◦ Characterized by visible sclera, visible large choroidal vessels, RPE atrophy and absolute scotoma ◦ Peripheral Alpha zone: ◦ Characterized by irregular pigmentation, apparent thinning of the chorioretinal tissue and relative scotoma ◦ Present in almost all normal eyes and is thus more common than beta zone (found in 15-20%) Optic Disc Size ◦ Race dependent: AA tend to have larger disc sizes than Caucasians ◦ Caucasians < Hispanics < Asians < Afro- Americans ◦ Corelate the size of the optic cup and neuroretinal rim (NRR) ◦ Normally large disc have large cups, small disc have small cups ◦ Average disc diameter is 1.5mm ◦ Small: 1.0-1.3 ◦ Medium: 1.4-1.7 ◦ Large: 1.8-2.0 Gunn’s Dots PRACTICE https://youtu.be/7lhvhKvK_iM Case #1 C/D ratio? A/V findings? Macular findings? Posterior pole findings? Case #2 C/D ratio? A/V findings? Macular findings? Posterior pole findings? Case #3 C/D ratio? A/V findings? Macular findings? Posterior pole findings?