This booklet was developed as a part of Special Study Unit (Doctors as Teachers) at Peninsula Medical School. This booklet covers some of the important aspects of Ophthalmology. This booklet could be used as a quick revision guide before finals and also could be used along Ophthalmology placements. The purpose of this booklet is to provide some insight into the most common presentations of red eye and their management.
over 5 years ago
http://www.handwrittenturorials.com - This tutorial is a basic overview of the anatomy of the eye. It covers the gross structures of the eyeball and the causes of the conditions, Glaucoma and Papilloedema. For more entirely FREE tutorials and the accompanying PDFs visit http://www.handwrittentutorials.com
almost 4 years ago
One in our series on Easy Ways to remember tricky areas of anatomy covering the Autonomic Nerve Supply to the Eye and Principles of Pupil Control. Light and Near Reflexes you can find more material at www.instantanatomy.net
about 5 years ago
http://www.ophthobook.com This lecture covers basic eye anatomy. This is the first 6 minutes of the powerpoint, which can be viewed in its entirety at Ophthobook.com Here we discuss eyelid and external eye structures.
almost 4 years ago
Cranial Nerve 1- Olfaction This patient has difficulty identifying the smells presented. Loss of smell is anosmia. The most common cause is a cold (as in this patient) or nasal allergies. Other causes include trauma or a meningioma affecting the olfactory tracts. Anosmia is also seen in Kallman syndrome because of agenesis of the olfactory bulbs. Cranial Nerve 2- Visual acuity This patientâs visual acuity is being tested with a Rosenbaum chart. First the left eye is tested, then the right eye. He is tested with his glasses on so this represents corrected visual acuity. He has 20/70 vision in the left eye and 20/40 in the right. His decreased visual acuity is from optic nerve damage. Cranial Nerve II- Visual field The patient's visual fields are being tested with gross confrontation. A right sided visual field deficit for both eyes is shown. This is a right hemianopia from a lesion behind the optic chiasm involving the left optic tract, radiation or striate cortex. Cranial Nerve II- Fundoscopy The first photograph is of a fundus showing papilledema. The findings of papilledema include 1. Loss of venous pulsation 2. Swelling of the optic nerve head so there is loss of the disc margin 3. Venous engorgement 4. Disc hyperemi 5. Loss of the physiologic cup an 6. Flame shaped hemorrhages. This photograph shows all the signs except the hemorrhages and loss of venous pulsations. The second photograph shows optic atrophy, which is pallor of the optic disc resulting form damage to the optic nerve from pressure, ischemia, or demyelination. Images Courtesy Dr. Kathleen Digre, University of Uta Cranial Nerves 2 & 3- Pupillary Light Refle The swinging flashlight test is used to show a relative afferent pupillary defect or a Marcus Gunn pupil of the left eye. The left eye has perceived less light stimulus (a defect in the sensory or afferent pathway) then the opposite eye so the pupil dilates with the same light stimulus that caused constriction when the normal eye was stimulated. Video Courtesy of Dr.Daniel Jacobson, Marshfield Clini and Dr. Kathleen Digre, University of Uta Cranial Nerves 3, 4 & 6- Inspection & Ocular Alignmen This patient with ocular myasthenia gravis has bilateral ptosis, left greater than right. There is also ocular misalignment because of weakness of the eye muscles especially of the left eye. Note the reflection of the light source doesn't fall on the same location of each eyeball. Video Courtesy of Dr.Daniel Jacobson, Marshfield Clini and Dr. Kathleen Digre, University of Uta Cranial Nerves 3, 4 & 6- Versions • The first patient shown has incomplete abduction of her left eye from a 6th nerve palsy. • The second patient has a left 3rd nerve palsy resulting in ptosis, dilated pupil, limited adduction, elevation, and depression of the left eye. Second Video Courtesy of Dr.Daniel Jacobson, Marshfield Clini and Dr. Kathleen Digre, University of Uta Cranial Nerves 3, 4 & 6- Duction Each eye is examined with the other covered (this is called ductions). The patient is unable to adduct either the left or the right eye. If you watch closely you can see nystagmus upon abduction of each eye. When both eyes are tested together (testing versions) you can see the bilateral adduction defect with nystagmus of the abducting eye. This is bilateral internuclear ophthalmoplegia often caused by a demyelinating lesion effecting the MLF bilaterally. The adduction defect occurs because there is disruption of the MLF (internuclear) connections between the abducens nucleus and the lower motor neurons in the oculomotor nucleus that innervate the medial rectus muscle. Saccades Smooth Pursui The patient shown has progressive supranuclear palsy. As part of this disease there is disruption of fixation by square wave jerks and impairment of smooth pursuit movements. Saccadic eye movements are also impaired. Although not shown in this video, vertical saccadic eye movements are usually the initial deficit in this disorder. Video Courtesy of Dr.Daniel Jacobson, Marshfield Clini and Dr. Kathleen Digre, University of Utah Optokinetic Nystagmu This patient has poor optokinetic nystagmus when the tape is moved to the right or left. The patient lacks the input from the parietal-occipital gaze centers to initiate smooth pursuit movements therefore her visual tracking of the objects on the tape is inconsistent and erratic. Patients who have a lesion of the parietal-occipital gaze center will have absent optokinetic nystagmus when the tape is moved toward the side of the lesion. Vestibulo-ocular refle The vestibulo-ocular reflex should be present in a comatose patient with intact brainstem function. This is called intact "Doll’s eyes" because in the old fashion dolls the eyes were weighted with lead so when the head was turned one way the eyes turned in the opposite direction. Absent "Doll’s eyes" or vestibulo-ocular reflex indicates brainstem dysfunction at the midbrain-pontine level. Vergenc Light-near dissociation occurs when the pupils don't react to light but constrict with convergence as part of the near reflex. This is what happens in the Argyll-Robertson pupil (usually seen with neurosyphilis) where there is a pretectal lesion affecting the retinomesencephalic afferents controlling the light reflex but sparing the occipitomesencephalic pathways for the near reflex. Video Courtesy of Dr.Daniel Jacobson, Marshfield Clini and Dr. Kathleen Digre, University of Uta Cranial Nerve 5- Sensor There is a sensory deficit for both light touch and pain on the left side of the face for all divisions of the 5th nerve. Note that the deficit is first recognized just to the left of the midline and not exactly at the midline. Patients with psychogenic sensory loss often identify the sensory change as beginning right at the midline. Cranial Nerves 5 & 7 - Corneal refle A patient with an absent corneal reflex either has a CN 5 sensory deficit or a CN 7 motor deficit. The corneal reflex is particularly helpful in assessing brainstem function in the unconscious patient. An absent corneal reflex in this setting would indicate brainstem dysfunction. Cranial Nerve 5- Motor • The first patient shown has weakness of the pterygoids and the jaw deviates towards the side of the weakness. • The second patient shown has a positive jaw jerk which indicates an upper motor lesion affecting the 5th cranial nerve. First Video Courtesy of Alejandro Stern, Stern Foundation Cranial Nerve 7- Motor • The first patient has weakness of all the muscles of facial expression on the right side of the face indicating a lesion of the facial nucleus or the peripheral 7th nerve. • The second patient has weakness of the lower half of his left face including the orbicularis oculi muscle but sparing the forehead. This is consistent with a central 7th or upper motor neuron lesion. Video Courtesy of Alejandro Stern, Stern Foundatio Cranial Nerve 7- Sensory, Tast The patient has difficulty correctly identifying taste on the right side of the tongue indicating a lesion of the sensory limb of the 7th nerve. Cranial Nerve 8- Auditory Acuity, Weber & Rinne Test This patient has decreased hearing acuity of the right ear. The Weber test lateralizes to the right ear and bone conduction is greater than air conduction on the right. He has a conductive hearing loss. Cranial Nerve 8- Vestibula Patients with vestibular disease typically complain of vertigo – the illusion of a spinning movement. Nystagmus is the principle finding in vestibular disease. It is horizontal and torsional with the slow phase of the nystagmus toward the abnormal side in peripheral vestibular nerve disease. Visual fixation can suppress the nystagmus. In central causes of vertigo (located in the brainstem) the nystagmus can be horizontal, upbeat, downbeat, or torsional and is not suppressed by visual fixation. Cranial Nerve 9 & 10- Moto When the patient says "ah" there is excessive nasal air escape. The palate elevates more on the left side and the uvula deviates toward the left side because the right side is weak. This patient has a deficit of the right 9th & 10th cranial nerves. Video Courtesy of Alejandro Stern, Stern Foundatio Cranial Nerve 9 & 10- Sensory and Motor: Gag Refle Using a tongue blade, the left side of the patient's palate is touched which results in a gag reflex with the left side of the palate elevating more then the right and the uvula deviating to the left consistent with a right CN 9 & 10 deficit. Video Courtesy of Alejandro Stern, Stern Foundation Cranial Nerve 11- Moto When the patient contracts the muscles of the neck the left sternocleidomastoid muscle is easily seen but the right is absent. Looking at the back of the patient, the left trapezius muscle is outlined and present but the right is atrophic and hard to identify. These findings indicate a lesion of the right 11th cranial nerve. Video Courtesy of Alejandro Stern, Stern Foundation Cranial Nerve 12- Moto Notice the atrophy and fasciculation of the right side of this patient's tongue. The tongue deviates to the right as well because of weakness of the right intrinsic tongue muscles. These findings are present because of a lesion of the right 12th cranial nerve.
almost 7 years ago
Great people make mistakes. Unfortunately, medicine is a subject where mistakes are not tolerated. Doctors are supposed to be infallible; or, at least, that is the present dogma. Medical students regularly fall victim to expecting too much of themselves, but this is perhaps not a bad trait when enlisting as a doctor. If it weren’t for mistakes in our understanding, then we wouldn’t progress. Studying a BSc in Anatomy has exposed me to the real world of science – where the negative is just as important as the positive. What isn’t there is just as important as what is. If you look into the history of Anatomy, it truly is a comedy of errors. So, here are three top mistakes by three incredibly influential figures who still managed to be remembered for the right reasons. 3. A Fiery Stare Culprit: Alcmaeon of Croton Go back far enough and you’ll bump into someone called Alcmaeon. Around the 5th century, he was one of the first dissectors – but not an anatomist. Alcmaeon was concerned with human intellect and was desperately searching for the seat of the soul. He made a number of major errors - quite understandable for his time! Alcmaeon insisted that sleep occurs when the blood vessels filled and we wake when they empty. Perhaps the most outrageous today is the fact that he insisted the eyes contained water both fire and water… Don’t be quick to mock. Alcmaeon identified the optic tract, the brain as the seat of the mind (along with Herophilus) and the Eustachian tubes. 2. Heart to Heart Culprit: Claudius Galen Legend has it that Galen’s father had a dream in which an angel/deity visited him and told him that his son would be a great physician. That would have to make for a pretty impressive opening line in a personal statement by today’s standards. Galen was highly influential on modern day medicine and his treatise of Anatomy and healing lasted for over a thousand years. Many of Galen’s mistakes were due to his dissections of animals rather than humans. Unfortunately, dissection was banned in Galen’s day and where his job as physician to the gladiators provided some nice exposed viscera to study, it did not allow him to develop a solid foundation. Galen’s biggest mistake lay in the circulation. He was convinced that blood flowed in a back and forth, ebb-like motion between the chambers of the heart and that it was burnt by muscle for fuel. Many years later, great physician William Harvey proposed our modern understanding of circulation. 1. The Da Vinci Code Culprit: Leonardo Da Vinci If you had chance to see the Royal Collection’s latest exhibition then you were in for a treat. It showcased the somewhat overlooked anatomical sketches of Leonardo Da Vinci. A man renowned for his intelligence and creativity, Da Vinci also turns out to be a pretty impressive anatomist. In his sketches he produces some of the most advanced 3D representations of the human skeleton, muscles and various organs. One theory of his is, however, perplexing. In his sketches is a diagram of the spinal cord……linked to penis. That’s right, Da Vinci was convinced the two were connected (no sexist comments please) and that semen production occurred inside the brain and spinal cord, being stored and released at will. He can be forgiven for the fact that he remarkably corrected himself some years later. His contributions to human physiology are astounding for their time including identification of a ‘hierarchal’ nervous system, the concept of equal ‘inheritence’ and identification of the retina as a ‘light sensing organ’. The list of errors is endless. However, they’re not really errors. They’re signposts that people were thinking. All great people fail, otherwise they wouldn’t be great.
almost 4 years ago
This medication, also known as Diamox, is commonly used in ophthalmology (and optometry) for lowering eye pressure in cases of bad glaucoma. We also use this with pseudotumor cerebri (high intracranial pressure).
almost 4 years ago
Optic neuritis is swelling and inflammation of the optic nerve which may result in dull pain behind the eye, and cause visual impairments such as blurry and distorted vision as well as “blind spots,” and/or “flashing lights, which may become more apparent over the course of several hours, or days.
almost 2 years ago
Ptosis is the lagging of an eyelid. It has 2 distinct etiologies. Sympathetics going to the eye innervate Muller's muscle, a small muscle that elevates the eyelid. The III cranial nerve also innervates a much larger muscle that elevates the eye lid: the levator palpebrae. Thus, disruption of either will cause ptosis. The ptosis from a III nerve palsy is of greater severity than the ptosis due to a lesion of the sympathetic pathway, due to the size of the muscles innervated. As an aside, the parasympathetics run with the III cranial nerve and are usually affected with an abnormal III cranial nerve.
almost 4 years ago