Corneal Disorders Flashcards
Red flags for corneal disorders?
8
- Reduction of visual acuity
- Severe deep eye pain (NOT just an irritation)
- Ciliary flush: A pattern of injection in which the redness is MOST pronounced in a ring at the limbus (the limbus is the transition zone between the cornea and the sclera)
- Photophobia
- Severe foreign body sensation that prevents the patient from keeping the eye open
- Corneal opacity
- Fixed pupil
- Severe headache with nausea
Cloudy greyness of the cornea indicates what?
infection
How do we treat Subconjunctival Hemorrhage?
we don’t. its just a popped blood vessel (not injection of conjunctiva which is stringy looking)
How do we diagnose a Subconjunctival Hemorrhage?
4
Normal visual acuity
Absence of discharge
Absence of photophobia
Absence of foreign body sensation
What is keratoconus?
A degenerative disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than its normal gradual curve.
What is the presentation of the keratoconus?
4
- Substantial distortion of vision
- Photophobia.
- Typically diagnosed in the patient’s adolescent years.
- If both eyes, patients may have difficulty with driving or reading.
How do we treat keratoconus?
usually with corrective lenses
Further progression of the disease may need surgery. what kinds?
4
- intrastromal corneal ring segments
- cross-linking
- mini asymmetric radial keratotomy
- in 25% of cases, corneal transplantation
What is term most often applied to any defect in the corneal surface epithelium?
corneal abrasion
What are the different classifications of corneal abrasions?
4
- Traumatic
- Foreign-body related
- Contact lens related
- Spontaneous (also known as recurrent erosions-dont know what caused it)
How is traumatic corneal abrasion identified?
mechanical trauma to the eye which results in defect in epithelial surface
- usually patient can tell you how it was injured
How is foreign body related corneal abrasions identified?
Defects in corneal epithelium that are left behind after removal or spontaneous dislodging of a corneal foreign body
Typical causes? Wood Rust Glass Plastic Fiberglass
How do contact lens abrasions occur?
2
defects in corneal epithelium that are left behind after
- removal of over-worn, improperly fitting or improperly cleaned contact lens
OR
- Caused by physical contact with the lens or poor handling of the lens during insertion or removal
How are recurrent (spontaneous) corneal abrasions characteristized?
a disturbance at the level of the corneal epithelial basement membrane, resulting in defective adhesions and recurrent breakdowns of the epithelium
How does a corneal abrasion present?
4
- Usually a lot of eye pain (Remember… the cornea is richly innervated with sensory pain fibers)
- Inability to open eye due to foreign body sensation
- Photophobia
- Patients are often too uncomfortable to work, drive, or read
Any patient who complains of eye pain with foreign body sensation preventing opening of the eye is presumed to have what until proven otherwise?
corneal abrasion
After we believe that the patient has a corneal abrasion what do we have to rule out?
2
- Rule out penetrating trauma (make sure there isnt anything sticking in the eye)
- Rule out infectious infiltrate (is it infectious or not-just a scratch)
How does the pupil usually respond in a corneal abrasion?
pupil is usually small from a reactive mitosis (pupillary constriction may be difficult to detect in light of this fact)
What should you suspect if you have a large nonreactive or irregular pupil?
injury to pupillary sphincter from penetrating trauma or blunt trauma… need to call the ophthalmologist (blown pupil)
What should you suspect when hyphema or hypopyon is present?
penetrating trauma. send straight to the ophthalmologist
What is the first thing we do when someone’s chief complaint is eye pain?
ALWAYS DO A VISUAL acuity test
If you cannot disclude penetrating trauma what should you do?
discontinue the exam, shiel the eye and call the ophthomologist
In a corneal abrasion how will the vision be impaired?
It depends if its in the visual axis. If its not then the vision is normal.
If its in the visual axis then vision will be abnormal
What will be apparent on the eye after a corneal abrasion as long as its over an hour or two old?
conjuntiva injection
Will there be discharge if the diagnosis is a corneal abrasion?
no
WIll there be corneal opacity is the diagnosis is corneal abrasion?
no
When should a fluoroscien stain be done?
If corneal abrasion is suspected and there is a lack of signs of other disorders
Keys to a fluoroscien stain?
3
- make sure the fluoroscein strip doesnt touch any part of the eye
- Use the magnifying glass on a head lamo or the wood’s lamp
- foreign bodies and abrasions can be very small and can easily be missed
If there is abrasions on the upper portion of the eye (linear epithelial defects) what should we look for?
suggestive of a foreign body under the lid
In the absense of contact lens what do we want to prescribe our patient for traumatic and foreign bosy abrasions?
Erythromycin and sulfacetamide OINTMENT are excellent choices.
(ointment functions as a lubricant)
Usually give every 4-6 hours.