Ophthalmology Flashcards
1
Q
What are Meibomian Glands?
A
Sebaceous glands located within the tarsal plate of the eyelid that secretes a lipid rich substance that keeps the tears over the cornea (lipid component of tear film)
2
Q
Where does the optic nerve pass through the sclera?
A
The Lamina Cribrosa
3
Q
Which regions of the sclera are more prone to rupture?
A
- Insertion of Optic Nerve
2. Insertion of Extraocular Muscles
4
Q
Describe the histology of the layers of the sclera
A
- Episclera- external, loose CT
2. Sclera Proper- Dense collagen fibers (No Vasculature or Fibroblasts, so poor healing)
5
Q
What can cause a blue sclera?
A
- High IOP
- Scleritis
- Osteogenesis Imperfecta
- Pigmented Congenital Nevus
6
Q
What is the Limbus?
A
The transition from the clear cornea to the opaque sclera
7
Q
What makes up the anterior surface of the iris?
A
Fibroblasts and Melanocytes
8
Q
What controls the Dilator of the Iris?
A
Sympathetics
9
Q
What controls the Sphincter of the Iris?
A
Parasympathetics
10
Q
What is Anisocoria?
A
A difference in the sizes of the pupils
11
Q
What is the layer of the Conjunctiva that covers the inner surface of the eyelid and is attached to the tarsal plate?
A
Palpebral Conjunctiva
12
Q
Describe the histology of the superior and inferior conjunctival fornices
A
- Pseudostratified columnar epithelium
- Lots of Goblet Cells
- Site of the Lacrimal ductules (which pierce this layer of conjunctiva to –> tears)
13
Q
Which layer of the conjunctiva covers the eye?
A
Bulbar Conjunctiva
14
Q
What is the histology of the bulbar conjunctiva?
A
- Non-keratinizing Stratified Squamous Epithelium
2. Few Goblet Cells
15
Q
What makes up the majority of refraction?
A
Cornea + Tear Film
16
Q
What is Bowman’s Membrane?
A
A basement membrane separating the external epithelium of the cornea from the stroma. This acellular layer protects the spread of malignant cells from the epithelium
17
Q
Describe the histology of the stroma of the cornea
A
It has aligned collagen fibers (for transparency) and is normally dehydrated
18
Q
What is the membrane deep to the stroma of the cornea?
A
Descemet Membrane
19
Q
What is the site of Kayser-Fleischer Ring deposits seen in Wilson’s disease (copper)?
A
Descemet Membrane
20
Q
An eye that is too long is what?
A
Myopic
21
Q
An eye that is too short is what?
A
Hyperopic
22
Q
Describe the flow pattern of Aq Fluid
A
- Produced by Ciliary Body
- Moves through Posterior Chamber and bathes the lens
- Passes through iris into the Anterior Chamber
- Drains through the Trabecular Meshwork
23
Q
What are the consequences of infoliation of the lens?
A
- Presbyopia (loss of elasticity with age –> inability to accommodate for near vision)
- Cataracts (accumulation of old epithelium and proteins)
24
Q
What is the Posterior Chamber?
A
Small area anterior to the lens but posterior to the iris
25
Aq Fluid that becomes trapped in the posterior chamber is a cause of what condition?
Acute Angle Closure Glaucoma
26
What is the Vitreous Humor?
Avascular gel that is located between the retina and posterior surface of the lens that contains collagen + Hyaluronic Acid
27
What occurs to the Vitreous with aging and what are the consequences?
The Vitreous undergoes liquefaction and collapse with aging which --> floaters and may cause vitreous detachment from the retina
28
From what embryological structure are the sensory cells of the retina derived?
Diencephalon
29
What is the function of the Retinal Pigment Epithelial Cell Layer?
To absorb light that penetrates all layers of the retina and reduce scattering of light --> increased visual acuity
30
What are the order/functions of sensory cells of the retina?
1. Photoreceptors (Rods and Cones, perception of light)
2. Bipolar Cells (Lateral Inhibition to increase contrast)
3. Ganglion Cells (transmit to brain)
31
What is the center of the retina where visual acuity is the sharpest?
The Macula (especially Fovea)
32
What is the choroid?
The vascular layer between the retina and the sclera
33
What is the innermost layer of the Choroid that serves as the basal lamina?
Bruch's Membrane
34
What structures make up the Uveal Tract?
Ciliary Body + Iris + Choroid
35
The Optic Nerve is surrounded by meninges posterior to the globe; what are the connection sites of the (1) Dura and (2) Leptomeninges?
1. Sclera
| 2. Choroid
36
What are the Glands of Zeis?
Sebaceous glands located at the margin of the eyelid that produce an oily substance onto the hair follicles
37
What are the Glands of Moll?
Apocrine Sweat glands located at the margin of the eyelid
38
What is the function of eye lashes?
1. Protect the eye from debris
| 2. Early warning sign of something approaching the eye (causes reflexive closing)
39
Inflammation of what gland results in a Chalazion?
Meibomian Gland
40
What is the lacrimal gland?
An eccrine gland that produces the Aqueous layer of the tear film
41
What condition causes swelling of regional lymph nodes?
Viral Conjunctivitis
42
What lymph nodes drain the lateral conjunctiva?
Preauricular
43
What lymph nodes drain the medial conjunctiva?
Submandibular
44
What provides the superficial mucous layer of the tear film?
Goblet Cells within the Conjunctiva
45
What are the layers of the tear film?
1. Superficial Oil/Lipid (prevents evaporation)
2. Aqueous Layer
3. Mucous Layer (Holds tear film to eye)
46
What is the function of the tear film?
1. Lubrication
2. Smooth Optical Surface
3. Oxygen and Nutrient Delivery
4. Contains Lysozymes and immunoglobulins
47
What is the embryologic origin of the anterior surface of the Cornea?
Ectoderm
48
What attaches the basal Columnar cell layer of the cornea to its basement membrane?
Hemidesmosomes
49
What makes up the stroma of the Cornea?
1. Parallel rows of Collagen
| 2. Ground Substance (mucoprotein and glycoprotein)
50
What is the function of Corneal Endothelium?
It is a single layer of hexagonal cells that actively pump fluid from the stroma
51
What is the punctum?
A small opening at the medial aspect of each eyelid that works to capture tears and funnel them into the nasolacrimal system
52
Describe the Nasolacrimal/Canalicular System's path
Punctum --> Superior and Inferior Canaliculus --> Common Canaliculus --> Lacrimal Sac --> Nasolacrimal Duct --> Inferior Turbinate of the Nasopharynx
53
What causes Acute Angle Closure Glaucoma?
Blockage of Aq outflow due to closure of the angle by the peripheral iris
54
What are some clinical features of Acute Angle Closure Glaucoma?
1. Red Eye
2. Pain
3. Nausea
4. Cloudy Cornea
55
What are treatment options for Acute Angle Closure Glaucoma?
1. Peripheral Iridotomy
| 2. Diuretics (acetazolamide and mannitol)
56
What is Iritis/Iridocyclititis?
Inflammation of the iris/iris + ciliary body
| *Called Anterior Uveitis
57
What condition causes a ciliary flush and hypopyon?
Iritis
58
What are symptoms of iritis?
1. Redness
2. Pain worse with light
3. Ciliary Flush
4. Decreased vision
5. Lacrimation
6. Cellular Depositis
59
What is the treatment for iritis?
Topical Steroids or systemic anti-inflammatory treatment if severe
60
Which condition that causes red eye is associated with a dendritic ulcer of the cornea?
Herpes Simplex Keratitis
61
What is a Pseudodendrite?
A corneal abrasion that has healed similar to the shape of the dendritic ulcer seen with HSV
62
What agents are the common cause of Bacterial Keratitis?
1. Staph aureus
| 2. Strep pneumo
63
What is the common clinical finding of bacterial keratitis?
An oval white/yellow dense lesion in the cornea
64
What is typically necessary to get a bacterial infection of the cornea?
Contact wear or corneal trauma
65
What is the treatment for Bacterial Keratitis?
Topical Antibiotics (Tobramycin and Cefuroxime)
66
What is bacterial keratitis?
Bacterial infection of the cornea
67
What are the types of Conjunctivitis?
1. Bacterial
2. Viral
3. Allergic
4. Neonatal
68
What is conjunctivitis?
Inflammation of the conjunctiva
69
What organisms cause Bacterial Conjunctivitis?
1. Staph epidermidis
2. Staph aureus
3. Strep pneumo
4. H. influenza
5. Moraxella
70
What condition presents with acute redness, gritty itchy eyes, burning and discharge that makes it difficult to open eyes upon waking?
Bacterial Conjunctivitis
71
What is the treatment for bacterial conjunctivitis?
1. Broad Spectrum Antibiotics
| 2. Antibiotic Ointment at night
72
What is the common cause of viral conjunctivitis?
Adenovirus
73
How is viral conjunctivitis spread?
1. Respiratory or ocular secretions
| 2. Contaminated towels, pillowcases ect
74
What is the incubation period of viral conjunctivitis?
4-10 days
75
What is the treatment for viral conjunctivitis?
Supportive and Symptomatic treatment
76
Which type of conjunctivitis presents with itchy, watery red eyes, sneezing, mild edema and milky pink conjunctiva?
Allergic Conjunctivitis
77
What is the treatment for allergic conjunctivitis?
Topical Antihistamines
78
Which causative agent of neonatal conjunctivitis presents 5-19 days after birth?
Chlamydial Conjunctivitis
79
Chlamydial Conjunctivitis in neonates can be associated with what other diseases?
1. Otitis
2. Rhinitis
3. Pneumonitis
80
What is the treatment for Chlamydial Conjunctivits?
Topical Tetracycline and Erythromycin
81
Which causative agent of neonatal conjunctivitis presents 1-3 days after birth?
Gonococcal Conjunctivitis (Neisseria gonorrhoeae)
82
What is the treatment for Gonococcal Conjunctivitis?
Topical and Systemic Penicillin
83
What condition presents as unilateral discomfort, redness, tenderness and watering of the eye?
Episcleritis
84
What is the treatment for Episcleritis?
1. Topical Steroids (Loteprednol)
2. Topical NSAIDs
3. Systemic NSAIDs
85
What is Scleritis?
A granulomatous inflammation of the sclera that ranges for mild severity to a severe necrotizing process that leads to loss of vision
86
What disease is associated with Scleritis?
Rheumatoid Arthritis
87
What is the treatment of Scleritis?
1. Oral NSAIDs and Steroids
| 2. Immunosuppressive drug like Cyclosporine (for necrotizing type)
88
What are Adnexal Diseases?
Inflammatory diseases of structures adjacent to the eye
89
What is Blepharitis?
A bilateral inflammation of the eyelid margin that results in burning, grittiness, mild photophobia and redness/crusting of the lid margin
90
What conditions are associated with Blepharitis?
1. Staph infections
| 2. Rosacea
91
What are the treatment options for Blepharitis?
1. Lid hygiene
2. Antibiotic and Steroid Drops
3. Tetracyclines for chronic use
4. Fish Oil
5. Warm Compresses
92
Which condition causes exophthalmos?
Thyroid Eye Disease
93
How does Thyroid Eye Disease cause exophthalmos?
- Changes due autoimmune process involving IgG
1. Hypertrophy of Extraocular Muscles due to increase in glycosaminoglycans
2. Compression of Optic Nerve
3. Proliferation of Orbital Fat, CT and Lacrimal glands
4. Retention of Fluid
94
What condition describes an infection of the lacrimal sac?
Dacryocystitis
95
What are the treatment options for Dacryocystitis?
1. Broad Spectrum Antibiotics
2. Warm Compresses
3. Incision and Drainage
96
What is a Hordeolum?
A small abscess caused by Staph infection of the Meibomian glands or lash follicles that results in a tender, inflamed swelling in the eyelid that points anteriorly
97
What are the treatment options for a Hordeolum?
1. Warm Compresses
2. Epilation
3. Oral Antibiotics
4. Incision and Drainage
98
What is a Chalazion?
A chronic lipogranulomatous inflammatory lesion caused by blockage of a Meibomian gland or stagnant secretions
99
What condition increases the risk of developing a Chalazion?
Acne Rosacea
100
What is the presentation of a Chalazion?
A painless nodule that may blur vision due to compression of the cornea
101
What are the treatments for a Chalazion?
1. Topical Steroid
2. Warm Compress
3. Incision and Drainage
4. Tetracycline for recurrent cases
102
Which condition results from a ruptured episcleral blood vessel?
A subconjunctival hemorrhage
103
What is a Pterygium/Pingueculum?
A fibrovascular sheet that grows over the cornea (Pingueculum does not cross the limbus)
104
What is the cause of a Pterygium/Pingueculum?
It is a response to hot climates, chronic dryness and exposure to the sun
105
What is the treatment for a Pterygium?
Surgical excision
106
What is the term for dry eye caused by Aq tear deficiency?
Keratoconjunctivitis sicca
107
What are symptoms of Keratoconjunctivitis sicca?
1. Irritation
2. Sensation of a foreign body in the eye
3. Burning
4. Stringy mucus discharge
108
What is the function of Cyclosporine in treating Keratoconjunctivitis Sicca?
Decreases mononuclear cell function
109
Why is there more corneal exposure in patients with Balle Palsy?
Because it causes lagophthalmos and the patient cannot close their eye completely
110
What is entropion?
A painful condition where the eyelids (usually lower) are turned inward due to laxity of the lower lid and an over riding orbicularis muscle
111
What is the treatment for entropion?
Surgery
112
What is ectropion?
A condition where the lower eyelid is turned away from the eye
113
What is epiphora?
Condition when tears run down the cheeks (often seen with ectropion)
114
Surgical reattachment of the lateral canthal tendon to the orbital wall is used to treat what condition?
Ectropion
115
What is blood in the anterior chamber from trauma called?
A hyphema
116
What is the first step in treatment of a chemical injury to the eye?
Copious irrigation of the eye
117
What is the function of the zonules?
They suspend the lens and allow it to change shape in response to changes in the ciliary body, resulting in a new focal point
118
Eyestrain, difficulty seeing in dim light and problems focusing are early signs of what condition?
Prebyopia
119
Increased glare from point light sources, such as car headlights at night, is an early sign of what condition?
Cataracts
120
Loss of a normal red reflex may indicate what?
Advanced cataracts
121
Dark spots in the red reflex may indicate what?
Moderate nuclear cataract
122
What condition may result in bilaterally displaced lenses due to compromised zonules?
Marfan Syndrome
123
What gene is mutated in Marfan Syndrome?
Fibrillin Gene
124
What is phacoemulsification?
Use of ultrasound to break up the existing lens in an artificial intraocular lens transplant
125
Describe the pathway of visual transmission
Retina --> Optic Nerve --> Chiasm --> Optic Tract --> Optic Striations --> Occipital Lobe
126
Where is the first place in visual transmission that has input from both eyes>
The optic tract
127
What innervates sensation to the cornea and eyelids?
Trigeminal Nerve
128
What nerve innervates the orbicular is oculi for lid closure?
Facial Nerve
129
Pupil dilation is controlled by what?
Sympathetics
130
What is the syndrome which affects sympathetics?
Horners
131
Pupil constriction is controlled by what?
Parasympathetics
132
What can cause a disruption of the parasympathetics (and CNIII) to the eye?
Aneurysm of the Circle of Willis (Posterior Communicating Artery)
133
What is the pathway of the Pupillary Light Reflex?
1. Retina --> Pretectal Nucleus (decussate)
2. Pretectal Nucleus --> Edinger Westphal Nucleus
3. Edinger Westphal Nucleus --> Ciliary Ganglion
4. Ciliary Ganglion --> Constrictor of the Pupil
134
What does a unilaterally dilated pupil indicate?
Third Nerve Palsy
135
What do bilaterally dilated pupils indicate?
Drug use
136
What is Adie's Tonic Pupil?
A unilateral, large and regular pupil with an absent light reflex that is caused by denervation of the postganglionic supply to the sphincter pupillage and ciliary muscle caused by a viral illness
137
In addition to the large pupil, what else may be seen with Adie's Tonic Pupil?
1. Diminished deep tendon reflexes
| 2. Autonomic Nerve Dysfunction
138
What is a relative afferent pupillary defect?
Condition where the optic nerves conduct in an asymmetric fashion - likely caused by problem of one of the optic nerves
139
How do you detect a relative afferent pupillary defect?
Swinging flashlight Test
140
What would a unilateral small pupil indicate?
Horner's Syndrome
141
What is the triad of Horner's Syndrome?
1. Miosis (lack of innervation to Dilator Muscle)
2. Ptosis (Meuller Muscle)
3. Anhydrosis
142
Does a Horner's Eye respond to light and accommodation?
Yes
143
Where could the deficit be for Horner's?
1. Hypothalamospinal Tract above T1
2. Preganglionic Neurons going to the Superior Cervical Ganglia
2. Postganglionic Neurons projecting from the Superior Cervical Ganglia
144
What are potential causes of Horner's?
1. Vertebrobasilar Artery Infarction
2. Tumors
3. MS
4. Internal Carotid Dissection
5. Pancoast Tumor
145
The parasympathetic fibers riding with CNIII go to what?
Pupillary Sphincter
146
What is the triad of a Third Nerve Palsy?
1. Misalignment
2. Ptosis
3. Mydriasis
147
If the pupil is NOT involved in a Third Nerve Palsy what is the cause?
Vasopathic (Diabetes)
148
If the pupil is involved in a Third Nerve Palsy what is the cause?
Aneurysm of the Posterior Communicating Artery or some other cause of compression- Urgent
149
Which nerve/extraocular muscle is most sensitive to increased ICP?
VI- Lateral Rectus
150
Which nerve/extraocular muscle is frequently affected by microvascular disease?
IV- Superior Oblique
151
Diplopia that worsens as the day goes on is a sign of what condition?
Myasthenia Gravis
152
What is Nystagmus?
Repetitive, involuntary oscillation of the eyes
153
What are 4 conditions that cause opted disc elevation?
1. Disc Drusen
2. Papilledema
3. Optic Neuritis
4. Ischemic Optic Neuropathy
154
What is Disc Drusen?
Deposits that make the optic nerve look bumpy
155
What can differentiate optic neuritis from papilledema?
Optic Neuritis is typically unilateral
156
What is a common cause of optic neuritis?
Multiple Sclerosis
157
What are the two types of Ischemic Optic Neuropathy?
1. Arteritic (Giant Cell Arteritis- Temporal Artery Biopsy))
| 2. Non-Arteritic (HTN, -Aspirin Therapy)
158
What is Amaurosis Fugax?
A transient loss of vision in one eye (TIA of optic nerve)
159
What is a Scotoma?
An area of the visual field where vision is either absent or diminished
160
Where would the lesion be for a Homonoymous Hemianopia (knock out of one side of vision)?
Behind the Chiasm
161
Where would the lesion be for bitermporal hemianopia (tunnel vision)?
The chiasm
162
Where is the Vitreous located?
Between the retina and lens
163
How can you distinguish vessels on ophthalmoscopic exam?
Arterioles- smaller and in front
| Venules- larger and deep
164
What is the Retinal Pigment Epithelium?
Pigmented cell layer beneath the neurosensory retina that provides nutrients to the retinal visual cells; it is attached to the Choroid
165
What is the pigmented yellow spot near the center of the retina?
the Macula
166
What is the fovea?
A small pit in the center of the macula that has the largest concentration of cone cells for high resolution vision
167
Floaters and Flashes are symptoms that suggest what?
Vitreoretinal Disorders
168
What is the first sign of a retinal detachment?
Flashes
169
What is the underlying cause of blurring or distorted vision?
Subretinal Fluid
170
What is the cause of minimalization?
Edema that is stretching out the photoreceptors
171
What causes abrupt progressive dimming of vision in one eye?
1. Retinal Detachment
| 2. Vitreous Hemorrhage
172
What causes an abrupt loss of peripheral visual field?
Peripheral Retinal Detachment
173
Cataracts, Retinoblastoma and Retinal Detachment can all result in what finding?
Loss of the normal red reflex
174
Hemorrhage and Cataracts can result in what?
Dark spots on the red reflex
175
What is the cause and pathology of Non-proliferative Diabetic Retinopathy?
Microvascular Occlusion results in loss of Pericytes which allow leakage from the capillaries --> Edema, dot/blot hemorrhages and hard lipid exudates which all --> retinal ischemia
176
What is the treatment option for non-proliferative diabetic retinopathy?
Focal Laser Therapy
177
What is Proliferative Diabetic Retinopathy?
Proliferation of abnormal vessels in response to chronic ischemia --> profound vision loss
178
What is the treatment for Proliferative Diabetic Retinopathy?
Pan-retinal Photocoagulation
179
Which systemic diseases have important findings on fundoscopic exam?
1. Diabetes
2. Systemic HTN
3. Embolic CV Disease
4. HIV
5. Metastatic Cancer
180
What is Sclerotic Retinopathy?
Narrowing of the arterioles (HTN)
181
Central (or Branch) Retinal Vein Occlusion is caused by what?
Increased pressure in the artery compresses the vein, leading to diffuse hemorrhaging and vision loss
182
What condition appears as unilateral diabetic retinopathy, and what test should be done?
Ocular Ischemia (Carotid Disease); do a Carotid Study
183
Central Retinal Artery Occlusions are caused by what type of occlusion?
Thromboembolic
184
What occurs as a result of retinal artery occlusion?
Severe rapid vision loss
185
Branch Retinal Artery Occlusions are caused by what type of occlusion?
Embolic
186
What virus causes severe retinopathy in HIV patients with low CD4 counts?
CMV
187
Where in the eye are cancers likely to metastasize and why?
The choroid because it is highly vascular
188
What disease is associated with a white pupil (leukocoria)?
Retinoblastoma
189
In addition to leukocoria, what finding may be present in Retinoblastoma patients?
Non-paralytic strabismus
190
Which type of Rb increases the risk of bilateral Rb?
Hereditary
191
What is the gene that results in the abnormal tumor suppressor seen in Rb?
13q14
192
What is the inheritance of Rb?
Autosomal Dominant
193
Why is sporadic Rb rare?
Because it would require 2 somatic mutations
194
What is non-paralytic strabismus?
When the eyes cannot focus on the same point simultaneously (not due to muscle paralysis, seen in Rb)
195
What is rhegmatogenous Retinal Detachment?
Occurs when there is a break in the retina and fluid has entered the sub retinal space
196
What is the treatment for retinal detachment
Urgent Surgery
197
What is a virectomy?
Removal of Vitreous Material
198
Why could you see an altered red reflex in retinal detachment?
Because fluid has entered the potential space
199
What two structures work to remove Aq Fluid from the eyes?
1. Trabecular Meshwork
| 2. Venous Outflow from the Uveoscleral Tract
200
What condition is an optic neuropathy caused by elevated IOP?
Glaucoma
201
Where are axons commonly injured in glaucoma?
The Lamina Cribrosa
202
An elevated cup/disc ration indicates what?
Glaucoma
203
What vision is typically lost first in glaucoma?
Peripheral
204
What are the risk factors for Open Angle Glaucoma?
1. IOP > 21
2. African or Caribbean
3. Age
4. Family Hx
205
What are the risk factors for Angle Closure Glaucoma?
1. Narrow Anterior Chamber
2. Hyperopia
3. Dilation of pupil
4. Age
5. Asians
206
What condition presents with red eye, pain and nausea?
Angle Closure Glaucoma
207
What are the two general mechanisms for treating open angle glaucoma?
1. Increasing Aq outflow
| 2. Decreasing Aq production
208
What drugs increases Aq outflow for Open Angle Glaucoma and how do they work?
1. Parasympathomimetics (by constricting the pupil and pulling the ciliary muscle they open the trabecular meshwork)
2. Prostaglandins (increase outflow through the uveoscleral tract)
209
Which drugs may cause redness and lash growth?
Prostglandins
210
What drugs are used to decrease Aq production for Open Angle Glaucoma and how do they work?
1. Topical Beta Blockers (decrease production by ciliary body)
2. Carbonic Anhydrase Inhibitors (inhibit enzyme)
3. Alpha 2 Agonists (decrease Aq production and increase uveoscleral outflow)
4. Adrenergic Agonists (increase Aq outflow - due to Beta Agonist effects)
211
What are the surgical options for Acute Angle Closure Glaucoma?
1. Peripheral Iridectomy
| 2. Laser Peripheral iridotomy
212
What are the surgical options for Open Angle Glaucoma?
1. Laser Trabeculoplasty (enlarging meshwork)
2. Filtering Surgery (cut sclera for new outflow)
3. Tube
4. Cyclodestruction (decreasing amount of functional ciliary body)
213
Which muscles receive their blood supply from the lateral branch of the ophthalmic artery?
1. Lateral Rectus
2. Superior Rectus
3. Superior Rectus
4. LPS
214
Which muscles receive their blood supply from the medial branch of the ophthalmic artery?
1. Medial Rectus (also from lacrimal artery)
2. Inferior Rectus (also infraorbital artery)
3. Inferior Oblique (also infraorbital artery)
215
What is Amblyopia?
Potentially permanent loss of vision due to asymmetric visual input or from vision deprivation
216
What is Strabismic Amblyopia?
Where input from the deviating eye is suppressed (#1 cause of unilateral decreased vision in kids)
217
What is refractive amblyopia?
Where the input from the eye with the poorer refractive power is ignored
218
What is Form/Occlusion Amblyopia?
Depravation of visual stimuli due to cataracts or eye lid mass/ptosis
219
What type of strabismus is it if the size of the deviation does not vary with the direction of the gaze?
Concomitant
220
What type of strabismus is it if the direction of gaze does affect the size of the deviation?
Incomitant
221
Which type of strabismus is caused by neuro/mechanical/myogenic problems with the extra ocular eye muscles?
Incomitant
222
What is esotropia?
Cross eyed
223
What is exotropia?
Wall eyed
224
What is hypertropia?
Eyes pointed upward
225
What is hypotropia?
Eyes pointing downward
226
What is the most common cause of childhood blindness?
Cortical Blindness
227
What is the initial blood supply to the eye?
Hyaloid Artery (reabsorbed in 34 weeks)
228
When do vessels appear in the retina?
15-18 weeks (nasal first, temporal last)
229
What is retinopathy of prematurity?
Second leading cause of childhood blindness- hypoxia, hypotension and free radicals damage new vessels --> edema and hemorrhage --> traction on retina --> retinal detachment
230
What is the treatment for retinopathy of prematurity?
Ablation of the Peripheral Avascular Retina via photocoagulation
231
Other than Rb what else may present with leukocorea?
Cataract
232
What is contained in the Anterior Lamellae of the eyelid?
1. Skin
2. Eye Lash Follicles
3. Orbicularis Muscle
4. Levator Aponeurosis
233
What is contained in the Posterior Lamellae of the eyelid?
1. Tarsal Plate
2. Mueller's Muscle
3. Meibomian Gland orifices
4. Palpebral Conjunctiva
234
What supplies sensation to the eyelid?
V1 and V2
235
What is the motor supply of the eyelid?
CNIII (LPS), CNVII (Orbicularis Oculi) and Sympathetics (Muellers)
236
What is Blepharoptosis?
Low position of the upper eyelid
237
What is Ptosis?
Eyelid drooping
238
What are the causes of Ptosis?
1. Third Nerve Palsy
2. Horner's
3. Myogenic (Myasthenia Gravis or Dystrophy)
4. Aponeurotic (stretching of LPS aponeurosis)
5. Mechanical (due to lesions, ex-hemangioma)
239
What is dermatochalasis?
Excess skin of the upper eyelid
240
A Hutchinson's Sign if frequently seen with what condition?
Herpes Zoster Ophthalmicus
241
What are Xanthalasma?
Cholesterol Deposits due to hyperlipidemia
242
Which skin lesion has a "pearl like" shape?
Basal Cell Carcinoma
243
Which skin lesion appears more ulcerative?
Squamous Cell Carcinoma
