The Eye exam:
Taking the ocular history is no different than taking a history for any other medical field. It is the key to the diagnosis. It is a record of the patient’s story and symptoms and immediately suggests certain diagnostic possibilities.
Taking a history is not simple. it requires an expert knowledge of symptoms which different diseases produce as well as
diplomacy, understanding in a sympathetic manner, a quick and accurate appraisal of personality patterns, and an approach
That puts the patient at ease.
Most Frequent complaints:
distorted vision, ocular pains and headaches, diplopia, irritation of the eyes, inability to keep eyes open
Physical Exam:
The examination begins the first time you lay eyes on the patient;:
-pic of normal eye: the face is symmetrical, eyes are symmetrical. The limbus, where the white of the eye meets the glassy window of the eye (the cornea) falls at the lower lids equally on both sides. The upper lids cover by at least 2.5 to 3 mm. When symmetry is not aligned, you suspect something is wrong.
-pic: Face looks symmetrical, the eyes look protuberant, the eyelids are away from the limbus above and below.
Forehead is smooth, face looks mask like. If you ask patient to look down you will note that the upper eyelids will stay in the same position while eyes will move down. This is von Graefe’s sign of hyperthyroidism. Also you see
decreased labial folds on the right and the mouth is pulled to left. There is also asymmetry of the lids. This person may have had a vascular accident or maybe Bell’s palsy
Anatomy of the eye:
-The cornea is separated by the plane of the leaves of the iris. The hollow space is the vitreous cavity, comprised of collagen bundles. The cornea is comprised of five layers, all of which are important but the epithelium, the first layer, and the last layer, the endothelium, are the most important. The endothelial layer does not regenerate. Under the first layer is a thin membrane, Bowman’s membrane followed by the large span of tissue, the corneal stroma. Below that is Descemet’s membrane. These keep the cornea clear, deturgid.
-The anterior chamber and posterior chamber are bounded by fibers that hold the lens in place. The lens itself is layered: the lens capsule, lens nucleus at the center and the vitreous cavity.
-Up front and juxtaposed to the iris is the ciliary musculature, necessary for accommodative activities in helping you to focus.
-Continuing posteriorly is the sensory retina and it sends its fibers back to the back end of the eye forming the optic nerve.
-Under this is a layer of blood vessels, the choriocapillaries, followed by the larger choroids vessels which converge back at the optic nerve on its way to the occipital lobe.
-The eyeball rests in the orbit bounded above by the frontal sinuses which are separated from the orbit by a very thin line. In the central line is the ethmoid bone which is also very thin and can be blown out easily. Below that are the maxillary sinuses, at the floor of the orbit. All of the emissaries pass through the optic foramen on their way posteriorly. Anything happening in your paranasal sinuses can affect the globe.
-Looking inside the eye you see the optic nerve head and at its center is a round pit which is the optic cup. The cup should not exceed 50% of the diameter of the nerve head itself. The nerve heads should be symmetrical although about 5-8% will be asymm. If they are asymmetrical, look for anomalies perhaps pertaining to ocular fluid dynamics.
-The arteriolatry: temporal, inferior temporal, inferior nasal, superior nasal and corresponding veins.
-We use the diameter of the nerve head as a unit of measure when we look inside the eye. These are termed disc diameters. The diameter of the disc is 1.5 mm in diameter. We visually superimpose this width as we move about the fundus.
-At the temporal side of the patient, we locate the macula which is the acute center of vision in the eye, in which resides the fovea, located 2.5 disc diameters temporally and on a junction with the lower 1/3 of the disc. When u look in a opthalmoscope and move toward the ear you will see the macula lutea with its golden brownish color and a silver spot in the center, the fovea centralis.
Pathology
Nobody gets word about what’s going on with their vision until they are not seeing clearly.
-Blurry vision in childhood and adolescence may point to a myopia or an ocular suprasellar tumor
-In middle age you see presbyopia, an age related extension of the near point. Presbyopia is the hardening of the lens and inability of the lens to be pulled into shape to allow focus at desired focal point.
-In later years blurry vision may mean cataracts. Presbyopia is hardening of lens and inability of the lens to be pulled into shape to allow focus at desired focal point.
-Episodic blindness: spots before the eyes, bordered by bright lines. This begins with bright lines, headaches and nausea and may indicate migraine. If it is unilateral it may indicate an increase in ICP and papilledema
The Ventral surface of the brain:
Directly over the sella, if you have a mass here it puts pressure on these structures and may result in visual changes; may cause the optic disc to swell. A lesion at the sella causes a visual field defect. Bitemporal hemianopsia caused by a sellar tumor
-Image seen: Muddy and cloudy, irregular optic disc and hemorrhages about the margin. Abnormal vasculature. Crinkly cellophane appearance about the retina is papilledema
-Pic: 16yo who upon awakening every morning had blurry vision
You see Tumefaction; this is malignant melanoma. In supine position, fluid from the mass would leak into the retina, flood the macula and upon arising she would be blurry eyed. Upon standing it would drain out. This was bad because there was large mass.
-Diplopia: eyes are mal-aligned
Slide shows importance of corresponding retinal points. If we take this to be the fovea, it is aligned with point F on the curvileaner line we call the oropter. It’s aligned with F prime on the corresponding point on the other eye. For every point in the retina of one eye there is a corresponding point in the other eye which allows us to not see double. This usu does not happen in children because they are able to turn the offending eye off like a switchmonocular
-Visual acuity should be one of the first things done when you approach a patient
The Snellen chart is designed so that each part of the large letter subtends an angle of five minutes at 20 feet.
1 minute represents each part of the larger object, with five minutes needed to see the detail of an abject at 20 feet.
At the optometrist, you are seated before the chart and if you wear glasses u take them off and you cover one eye, read the chart down being seated 20 feet from the chart. Wherever u stop that’s what is recorded as a fraction- the numerator is the distance form the chart and the denominator is the line at which u are able to read. You repeat the same with the other eye. Then you repeat with ur glasses on.
U can use pocket cards but if patient is above 40 years tell patient to take glasses off to get more accurate gage.
In optics we measure the strength of the lens in diopters. The diopter is the reciprocal of a meter. If u have a lens of 1 diopter and u let a light shine through it the focus would come at one meter from the lens surface. If u double the diopter then the focus would be one half of that. The various refractive states-
Emitopia (?)- light strikes the cornea and impinges the retina perfectly; person has 20/20 vision
Myopia: person has a long eyeball and the focus is in front of the retina; near sighted
Hypermyopia- Light strikes the cornea, enters the eye and focus is behind the retina, far sighted
You are able to measure this by shining light in the eye with a retinoscope and the doctor can calculate what it will take to correct with glasses.
Astigmatism: cornea isn’t perfectly round but looks like the back surface of a soup spoon. You have one curve that is short and one that is long. One point will shine in front of the cornea and the other will shine behind
-If you’re myopic u will need a lens that will extend the focus so you get a concave or minus lens
-If you’re hypermyopic u will need lens that shortens the lens, a convex lens, plus lens
Keratomileusis: procedure in which u slice the cornea and implant a lenticulus from another eye.
Lasiks: laser assisted in situ keratomileusis. This helps the bear sighted person. The far sighted person can do dermokeratoplasty. Electromagnetic rays they act on collagen content of cornea to reduce the length. Recall we are talking about microns in correction.
The red eye:
-Conjunctivitis results in a red eye; there may be transient discharge and the eye is gritty, there usu is no visual disturbance
-Herpes simplex: if patient comes in with redness, pain, photophobia. One of the things u look for is the character of the retina vasculature. The vessels approach the limbus at a perpendicular fashion. If you look at the cornea under magnification u see branching filaments and you use sodium fluorocide (?) to stain the surface of the eye.
-Herpes zoster opthalmacus: lesion respects the midline, very painful. The virus resides in the ganglion and cases occur around some incident of trauma, either emotional or otherwise. The patients are usu beyond 5th decade of life. When u see lesions involving the tip of the nose we can assume that the cornea is affected because it has entered the nasociliary nerve.
-HIV can cause the appearance of all of these within the period of days- herepes zoster and simplex and even syphilis
-Acute angloplasia glaucoma: these patients have chemosis of the conjunctiva and a steamy looking cornea. You can hardly see the outline of people. Many will also have nausea and vomiting. The iris and lens diaphragm have come forward to close off the egress to Slemm’s canal and the pressure builds up. You relieve this by cutting a whole in the iris and, recall that the iris divided the anterior and posterior chambers. The hole allows another way for aqueous humor to flow from the post to anterior channel. We make this whole with a laser.
-Keratoconjunctivits sicca or dry eye syndrome (u will commonly see this): cornea becomes pock marked and the eye becomes red. Diagnose by schermer test; performed by a calibrated filter strip placed in eye and patient closes eye with it for 5 minutes. If the patient has less than 10ml of wetting then this person is tear deficient. Occurs in females 10:1. If you see this in a man then you need to look for a systemic problem!!!
-You will see this among college students who wear contacts for too long. The eye solutions to disinfect contain lamerosol (?).
-Keratoconus among near sighted people: if u have patient look down, the lower lid would become indented with the cornea forming something of a V. This is Lenson’s (?) sign. Patients do not see very well.
-Wilson’s disease: macular lenticular degeneration. Copper is deposited in the cornea at the level of Decimet’s membrane in the periphery usu beginning superiorly and inferiorly creating a golden brown color. If the patient has brown eyes it is difficult to see. If the patient also has a pseudo-parkinsonian gate then u can be suspicious of this. Otherwise will look normal until they show up with bronze diabetes or cirrhosis
-Congenital glaucoma: Another corneal clue is a cloudy cornea, photophobia and if the pressure is high enough they may experience pain. This is a bilateral disease although you may not be able to tell. Appears 6-8 months after birth.
Picture meant to show example of Herr’s disease although this is not it but it appears like this. Small boy whose mother claimed that he had scarred eyes since 6 mos of age.
-Arcus senilis: grayish white line ring occurring around the periphery of the cornea and separated from the periphery by clear cornea; comes about by deposition of calcium salts and fats in the peripheral cornea. Used to be viewed as normal part of aging processes although we now are getting away from that because about 30% are associated with abnormal lipid metabolism such as hypertriglyceridemia.
-Strain keratopathy: grayish infiltrate at periphery of cornea; deposition of calcium salts in the peripheral cornea; usu beigins in the palpebral opening. This one was stained with sodium flurocite. Right across the cornea the patient had long standing sarcoidosis and later came up with this disorder. There is a familial type that is bilateral and becomes very accentuated in the fourth decade of life
Scleral Clues:
-yellow scerlotics: you have to be careful in judging this as jaundice because many colored people of the world have pigmented eyes that looks yellow and jaundiced
-Osteogenesis imperfecta: these are usu young people with blue sclerae; brought about by selective absorption of UV rays by the pigment underlying the eyes. These patients sustain multiple fractures as well.
-Patient seen who flushed her eyes with silver azural?- She thought htat by doing this daily it would keep the eyes sterile. U can see silver deposited in the conjunctiva of the eyes
-Scleromalagia preferens: a patient with arthritis where the wall of the eye became weakened and ruptured spontaneously. The extraocular muscles and a strong conjunctiva hold the eye in place. Can be repaired with a scleral graft.
Lens clues:
-Cataract of congenital galactosemia: also called the oil in water cataract. When u dilate the pupil u see a droplet in the center looking like a drop of oil on water. This is manageable if you can eliminate galactose from the diet the cataract reverses. This is in contrast to a senile cataract where the cortex of the limbs becomes disorganized and turns a grayish white.
-Hypoparathyroidism: baggy eyes and wrinkled skin, developing cataracts.
-Dislocation of the lens with subsequent development of a cataract. This patient is very tall, lengthy, ectomorphic. Fingers are spiderlike and lens is ectopic. This is Marfan’s syndrome. When the lens becomes dislocated it depends on the fluids in the eye to nourish it, and with dislocation it becomes opalescent.
Heterophorias and Heterotropias:
These deal with the deviation of the eyes. What keeps the eyes straight is the process of fusion. This is the cerebral integration of the images as received by the 2 eyes.
-Heterophorias
Exophoria: eye deviates outward
Esophoria: if eye deviates inward
-Heterotropias
These are manifest deviations of the eye.
You look at person and the deviation is there.
-Image of child with right eye deviated, then left eye deviated. Alternating deviation so that each eye is straight enough of the time so that both maculae are stimulated. This is important to occur up to 7 years of age. If after this time both maculae are not stimulated you can end up with amblyopia. Some are born with this and this is amblyopia exanopthos.
-Another category of strabismus is paralytic strabismus: may be of developmental causes, due to blood supply as well as due to trauma or even iatrogenic means. With iatrogenic incidence, the patient complains that when they look to one side they see double due to scar tissue from lesion that was operated on.
Inflammation:
-Sinusitis- it can affect the musculature since they lie against the walls of the sinuses. Patient may complain that it hurts to read.
-Neurogenic:
-Syphilis
(Note: There was a surge of paralytic strabismus in the Great Lake regions from poisoning due to botulinum toxin. This was then harvested to use in strabismus cases)
-Image of person who complained of seeing double. Left eye is turned to the left. Decreased nasolabial fold with mouth shifted to other side when looking to the right. Medial rectus is paralyzed, supplied by CN III.
Looking up and to the left- right inferior oblique is in tact and left superior rectus is paralyzed. Looking down and to the left superior oblique is intact but inferior rectus is damaged
If patient has a fixed and dilated pupil and presents with a third nerve problem, that patient has an aneurysm until proven otherwise!!! If person presents with third nerve problems and normal pupil that reacts directly and indirectly to light, he has diabetes until proven otherwise!!!!
The most important thing you can do if you have nothing else is to examine the person’s pupil. They should be equal and react directly and consensually. Diameters should be about 2-3mm.
The iris:
Light colored iris tends to have a larger pupil than the dark iris. The pupil may be irregular for many reasons
- Pic: This one looks like some inflammation. An iridectemy was done, an old operation. Person winds up with grotesque pupil
-At the 6 o clock position defect of both pupils show failure of closure of embryonic cleft which occurs at about 5-6 weeks of gestation.
-some pupils stay static and somewhat dilated and u may see a cup around it.
-One that is very small- this occurs in the aged
-an iris affected by inflammatory disease; see blotches of pigment on the lens where the iris is seen gluing itself to the lens in a posterior synechia. If it sticks to the cornea anteriorly this is anterior synechia. Patient had sarcoidosis and some nodules are in the periphery of the anterior chain.
-Adies pupil- One pupil that is slightly larger than the other and acts slowly to light and the near point; usu unilateral. If put in the darkness it dilates normally. It constricts with 2.5 solution of mecolil and the normal pupil will not respond. Use 0.5% pilocarpine, a parasympathomimetic
-Pupil is very very small- miotic; this represents the Argyll-Robinson pupil which is classic for syphilis. Patient is sensitive to light to evoke a pupil motor response. The pupil does not constrict directly on exposure to light, the pupil contracts at the near point which is about 13-14 inches when the eyes converge, the pupil dilates poorly with tropines or cocaine and no dilation in the darkness. They like to stick this on exams!!!!
-Marcus-Gund pupil: pupil does not respond, stays dilated forever
Answer to question
With thyroid exopthalmos u have an infiltration of cells into the orbit. More frequenlyt than not it subsides but the patient may never look the same. Many have to undergo orbital decompression so the patient wont suffer damage to optic nerve. About 25% will have to undergo decompression. 10-15% vwill return to same state. Most patients present more with lid retraction than exopthalmos. This is measured with an exopthalmometer which sits across the eyes. Occasionally patients may be able to be treated with systemic steroids but the vast majority will not present with a frank exopthalmos
