Chapter 2: Ophthalmologic Examination
List of Figures
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Figure 2-1: Common imperfections of the optical system of the eye (refractive errors). Ideally, light rays from a distant target should automatically arrive in focus on the retina if the retina is situated precisely at the eye's natural focal point. Such an eye is called emmetropic. In hyperopia ("farsightedness"), the light rays from a distant target instead come to a focus behind the retina, causing the retinal image to be blurred. A biconvex (+) lens corrects this by increasing the refractive power of the eye, and shifting the focal point forward. In myopia ("nearsightedness"), the light rays come to a focus in front of the retina, as though the eyeball is too long. Placing a biconcave (-) lens in front of the eye diverges the incoming light rays; this effectively weakens the optical power of the eye enough so that the focus is shifted backward and onto the retina. (Modified and reproduced, with permission, from Ganong WF: Review of Medical Physiology, 15th ed. Lange, 1991.) |
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Figure 2-2: Refraction being performed using a "phoropter." This device contains the complete range of corrective lens powers which can quickly be changed back and forth, allowing the patient to subjectively compare various combinations while viewing the eye chart at a distance. (Photo by M Narahara.) |
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Figure 2-3: "Illiterate E" chart. |
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Figure 2-4: Slitlamp examination. (Photo by M Narahara.) (Courtesy of the American Academy of Ophthalmology.) |
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Figure 2-5: Slitlamp photograph of a normal right eye. The curved slit of light to the right is reflected off of the cornea (C), while the slit to the left is reflected off of the iris (I). As the latter slit passes through the pupil, the anterior lens (L) is faintly illuminated in cross section. (Photo by M Narahara.) |
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Figure 2-6: Technique of lid eversion. A: With the patient looking down, the upper lashes are grasped with one hand as an applicator stick is positioned at the superior edge of the upper tarsus (at the upper lid crease). B and C: As the lashes are lifted, slight downward pressure is simultaneously applied with the applicator stick. D: The thumb pins the lashes against the superior orbital rim, allowing examination of the undersurface of the tarsus. (Photos by M Narahara.) |
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Figure 2-7: Three types of goniolenses. Left: Goldmann three-mirror lens. Besides the goniomirror, there are also two peripheral retinal mirrors and a central fourth mirror for examining the central retina. Center: Koeppe lens. Right: Posner/Zeiss-type lens. (Photo by M Narahara.) |
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Figure 2-8: Diagram of Schiotz tonometer. The plunger is shown with the 5.5-g weight attached at one end. |
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Figure 2-9: Schiotz tonometer placed on cornea. Handle is being held by thumb and third finger of right hand in this photo. (Photo by Diane Beeston.) |
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Figure 2-10: Applanation tonometry, using the Goldmann tonometer attached to the slit lamp. (Photo by M Narahara. Courtesy of the American Academy of Ophthalmology.) |
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Figure 2-11: Appearance of fluorescein semicircles, or "mires," through the slit lamp ocular, showing the end point for applanation tonometry. |
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Figure 2-12: Direct ophthalmoscopy. The examiner uses the left eye to evaluate the patient's left eye. (Photo by M Narahara. Courtesy of the American Academy of Ophthalmology.) |
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Figure 2-13: Photo and corresponding diagram of a normal fundus. Note that the retinal vessels all stop short of and do not cross the fovea. (Photo by Diane Beeston.) |
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Figure 2-14: Diagram of a moderately cupped disk viewed on end and in profile, with an accompanying sketch for the patient's record. The width of the central cup divided by the width of the disk is the "cup-to-disk ratio." The cup-to-disk ratio of this disk is approximately 0.5. |
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Figure 2-15: Cup-to-disk ratio of 0.9 in a patient with end-stage glaucoma. The normal disk tissue is compressed into a peripheral thin rim surrounding a huge pale cup. |
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Figure 2-16: Examination with head-mounted binocular indirect ophthalmoscope. A 20-diopter hand-held condensing lens is used. (Photo by M Narahara.) |
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Figure 2-17: Comparison of view within the same fundus using the indirect ophthalmoscope (A) and the direct ophthalmoscope (B). The field of view with the latter is approximately 10 degrees, compared with approximately 37 degrees using the indirect ophthalmoscope. In this patient with diabetic retinopathy, an important overview is first seen with the indirect ophthalmoscope. The direct ophthalmoscope can then provide magnified details of a specific area. (Photos by M Narahara.) |
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Figure 2-18: Diagrammatic representation of indirect ophthalmoscopy with scleral depression to examine the far peripheral retina. Indentation of the sclera through the lids brings the peripheral edge of the retina into visual alignment with the dilated pupil, the hand-held condensing lens, and the head-mounted ophthalmoscope. |
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Figure 2-19: Goldmann perimeter. (Photo by M Narahara.) |
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Figure 2-20: Computerized automated perimeter. (Photo Courtesy of Humphrey Instruments.) |
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Figure 2-21: A: Numerical printout of threshold sensitivity scores derived by using the static method of computerized perimetry. This is the 30-degree field of a patient's right eye with glaucoma. The higher the numbers, the better the visual sensitivity. The computer retests many of the points (bracketed numbers) to assess consistency of the patient's responses. B: Diagrammatic "gray scale" display of these same numerical scores. The darker the area, the poorer the visual sensitivity at that location. |
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Figure 2-22: Amsler grid. |
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Figure 2-23: Hardy-Rand-Rittler (H-R-R) pseudoisochromatic plates for testing color vision. |
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Figure 2-24: Contrast sensitivity test chart. (Courtesy of Vistech Consultants, Inc.) |
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Figure 2-25: A: Computerized corneal topography system utilizing video keratoscope and personal computer. B: Color-coded topographic display of curvature and refractive power (in diopters) across the entire corneal surface. (Photos courtesy of EyeSys Technologies, Inc.) |
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Figure 2-26: Gonioscopy with slitlamp and Goldmann type lens. (Photo by M Narahara.) |
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Figure 2-27: Normal angiogram of the central retina. The photo has been taken after the dye (appearing white) has already sequentially filled the choroidal circulation (seen as a diffuse, mottled whitish background), the arterioles and the veins. The macula appears dark due to heavier pigmentation which obscures the underlying choroidal fluorescence that is visible everywhere else. (Photo courtesy of R Griffith and T King.) |
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Figure 2-28: Abnormal angiogram in which dye-stained fluid originating from the choroid has pooled beneath the macula. This is one type of abnormality associated with age-related macular degeneration (see Chapter 10). Secondary atrophy of the overlying retinal pigment epithelium in this area causes heightened, unobscured visibility of this increased fluorescence. (Photo courtesy of R Griffith and T King.) |
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Figure 2-29: Fluorescein angiographic study of an eye with proliferative diabetic retinopathy demonstrating variations in the dye pattern over several minutes' time. A: Fundus photograph of left eye (before fluorescein) showing neovascularization (abnormal new vessels) on the disk and inferior to the macula (arrows). This latter area has bled, producing the arcuate preretinal hemorrhage at the bottom of the photo (open arrow). B: Early phase angiogram of the same eye, in which fluorescein has initially filled the arterioles and highlighted the area of the disk neovascularization. C: Midphase angiogram of the same eye in which dye has begun to leak out of the hyperpermeable areas of neovascularization. In addition to the irregular venous caliber and the microaneurysms (white dots), extensive areas of ischemia are apparent by virtue of the gross absence of vessels (and therefore dye) in many areas (see arrows). D: Late-phase photo demonstrating increasing amounts of dye leakage over time. Although the preretinal hemorrhage does not stain with dye, it is detectable as a solid black area since it obscures all underlying fluorescence (arrows). (Photos courtesy of University of California, San Francisco.) |
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Figure 2-30: Top: Normal VER generated by stimulating the left eye ("OS") is contrasted with the absent response from the right eye ("OD"), which has a severe optic nerve lesion. "LH" and "RH" signify recordings from electrodes over the left and right hemispheres of the occipital lobe. Bottom: VER with right homonymous hemianopia. No response is recorded from over the left hemisphere. (Courtesy of M Feinsod.) |
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Figure 2-31: Hertel exophthalmometer. (Photo by M Narahara.) |
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Figure 2-32: Ultrasonography using B-scan prote. The image will appear on the oscilloscope screen. visible in the background.(Photo by M Narahara.) |
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Figure 2-33: A scan (left and (right of an intraocular tumor (melanoma). C + cornea; I + iris; L + posterior lens surface; O + optic nerve; R + retina; T + tumor. (Courtesy of RD Stone.) |
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10.1036/1535-8860.ch2