Contact Lens Pathology Review Flashcards
This is a comprehensive deck containing 2-5 different images for each pathology to ensure you can recognize different examples and not just memorize a single image. (Under Construction)
Bullous Keratopathy
- degenerative condition in which the cornea becomes permanently swollen because the corneal endothelium has been damaged and is not pumping fluid properly
- pockets of fluid (‘bullae’) form in corneal tissue and rise to the epithelial surface where they break and become painful
- endothelial damage may be from trauma, glaucoma, or inflammation after some types of ocular surgery
- NO CONTACT LENSES
Conjunctivitis
- inflammation of the conjunctiva
- allergic – discontinue contact lens wear for the duration
- viral or bacterial – discontinue contact lens wear for the duration, and dispose of soft contact lenses (or disinfect GPs) to prevent reinfection
Trichiasis
- misdirection of the eyelashes toward the globe
- often associated with entropion or blepharitis, but can also occur on its own
- surgical management involves rotating the marginal part of the eyelid outwards, away from the globe, so that the lashes are no longer in contact with the eye
- prior to treatment a therapeutic (bandage), soft contact lens can be used to protect the eye from the irritating lashes
Corneal Edema
- swelling due to hypoxia (lack of oxygen)
- causes include: tight lenses, low Dk soft or RGPs, PMMA lenses, extended wear of regular hydrogel lenses
- symptoms of acute edema include: extreme pain, excessive lacrimation, reduced vision, photophobia, intolerance of CL wear
- may cause microcysts in the epithelium
- symptoms of chronic edema are more subtle - less pain, an little to no effect on vision
- CLs must be discontinued until edema resolves
Blepharoptosis/Ptosis
- drooping of the upper eyelid
- may cause difficulty with contact lens centration, but if a satisfactory fit can be obtained, contact lens wear can be successful
Hudson-Stähli Line
- an orange-brown iron line at the level of the basement membrane of the epithelium in the band region of the normal cornea
- roughly horizontal line found in the middle third of the cornea. It is
- common in older corneas, and injured corneas at any age
Bacterial Conjunctivitis
inflamation of the conjunctiva caused by a bacterial infection, often characterized by the presence of a purulent discharge
Bacterial Corneal Ulcer
- presents with dense grayish white opacity associated with epithelial loss and stromal involvement –ulceration, stromal abscess formation, surrounding corneal edema, and anterior segment inflammation are characteristic of this disease – requires laboratory evaluation
- rapid progression; corneal destruction may be complete in 24-48 hours with some of the more virulent bacteria
- loss of vision or of eye are possible
- contact lens use increases the risk (bacteria can reside in deposits on lenses)
Marginal Keratitis
- unilateral painful watery eyes with sandy/gritty sensation
- treatment depends on the degree of presentation and includes warm compresses, broad-spectrum antibiotics, and steroids. cycloplegic drops decrease pain by limiting pupil dilation and contraction
- discontinue CLs until condition clears
- staphylococcal exotoxins form intraepithelial infiltrates in the mid-peripheral cornea. Lesions (0.5 to 1.5 mm in diameter and may be flat or raised) are always islands, single or multiple on the peripheral margin, separated by clear cornea
- mild to moderate and can produce a haze around the infiltrates. Corneal involvement is most vulnerable at the 4 o’clock and 8 o’clock positions, but lesions may also be superior or circumlimbal. The bulbar conjunctiva is hyperemic
Recurrent Corneal Erosion (Image: Corneal Abrasion)
- symptoms: acute pain associated with lacrimation, photophobia, and a foreign body sensation - usually occur on waking
- may be associated blepharospasm and blurring of the vision
- symptoms may subside over the course fo the day and start again in the morning upon opening the eyes - unpredictable, leads to anxiety
- vision is rarely permanently affected, but complications include infectious keratitis, corneal scarring, possibility of decreased VA
- treat with lubricating ointment nightly for three months (even after symptoms subside), or sometimes a bandage/therapeutic lens
Cataract
clouding of the crystalline lens
Hypoxia
Corneal Hypoxia
- caused by an insufficient supply of oxygen to the cornea as a result of contact lens wear
- the underlying cause of many complications of contact lens wear and the most common cause of corneal edema
- to treat hypoxia, the water content or oxygen permeability of the lenses should be increased by reducing lens thickness or changing lens material. patient can also remove and rehydrate lenses more frequently
Microcornea
- a smaller than normal cornea with an HVID of 10mm or less, often very steep
- fit with an appropriately steep base curve
Recurrent Corneal Erosion (Image: Corneal Abrasion)
- symptoms: acute pain associated with lacrimation, photophobia, and a foreign body sensation - usually occur on waking
- may be associated blepharospasm and blurring of the vision
- symptoms may subside over the course fo the day and start again in the morning upon opening the eyes - unpredictable, leads to anxiety
- vision is rarely permanently affected, but complications include infectious keratitis, corneal scarring, possibility of decreased VA
- treat with lubricating ointment nightly for three months (even after symptoms subside), or sometimes a bandage/therapeutic lens
Scars from Radial Keratotomy
a surgery performed to correct myopia
Acanthamoeba Keratitis
- caused by parasites that can be found in soil, fresh, brackish, and sea water, hot springs, sewage, swimming pools, or on improperly cleaned contact lens equipment
- affects primarily the cornea and sclera
- If not treated properly and immediately, this disease can result in complete loss of vision
- more common in CL wearers because deposits on lenses can give the parasite something to hold onto and prevent it from being flushed out by tears
Dimple Veiling
a bubble under a RGP that has broken up into lots of tiny bubbles
this makes “dimples” in the epithelium that will pool with fluorescein immediately after the lens is removed but will disappear within a few minutes
Acanthamoeba Keratitis
- caused by parasites that can be found in soil, fresh, brackish, and sea water, hot springs, sewage, swimming pools, or on improperly cleaned contact lens equipment
- affects primarily the cornea and sclera
- If not treated properly and immediately, this disease can result in complete loss of vision
- more common in CL wearers because deposits on lenses can give the parasite something to hold onto and prevent it from being flushed out by tears
Blepharoptosis/Ptosis
- drooping of the upper eyelid
- may cause difficulty with contact lens centration, but if a satisfactory fit can be obtained, contact lens wear can be successful
Conjunctivitis
- inflammation of the conjunctiva
- allergic – discontinue contact lens wear for the duration
- viral or bacterial – discontinue contact lens wear for the duration, and dispose of soft contact lenses (or disinfect GPs) to prevent reinfection
Superior Limbic Keratoconjunctivitis (SLK)
- an inflammatory reaction induced by wearing soiled hydrogel lenses, which cause excessive movement
- signs include intense laxity and hyperemia of the superior bulbar conjunctiva, fine papillary hypertrophy of superior tarsal conjunctiva, epithelial and subepithelial infiltrates, and superior corneal and limbal punctate staining
- treatment is temporary discontinuation of lens wear for several weeks to months – old lenses should be discarded, and frequent replacement of lenses or switching to GPs is urged
- Theodore SLK (associated with thyroid disfunction) must be ruled out
Fleischer’s Ring
- a type of pigmented dystrophy consisting of partial or complete iron deposition in the deep epithelium encircling the base of the cone in eyes with keratoconus
- appears as a yellowish to dark-brown coloured ring and can best be seen using a cobalt blue light with a slit lamp
Krukenberg’s Spindle
- brownish, vertical, spindle-shaped pigment deposits on the posterior cornea
- look for old uveitis or pigment dispersion syndrome
- all patients who have Krukenberg’s spindle should be closely monitored for glaucoma
Corneal Abrasion
an abrasion of the cornea caused by a foreign body or other mechanical irritation
makes the eye more susceptible to infection
contact lens wear should be discontinued until it heals unless there is recurrent corneal abrasion/erosion (where the eyelid opening in the morning removes the newly formed epithelial cells – in this case a bandage lense can be used to facilitate healing by giving the new epithelial cells more time to become integrated into the corneal structure
Nevus (plural = nevi)
a benign pigment deposit on the eye
(similar to a mole or freckle on your skin)
Corneal Dystrophy
- Epithelial basement membrane dystrophy (EBMD), also known as Cogan’s dystrophy or map-dot-fingerprint dystrophy, consists of grayish patches (maps), clear or white microcysts (dots), or swirls or lines (fingerprints)
within the epithelium, best seen with retroillumiation - GP lenses often help improve acuity and are not contraindicated for EBMD unless there is erosion of the epithelium
- epithelial erosions (recurrent erosion) occur in approximately 10% of all cases and cause great pain, patients may be fit with a high-water soft bandage contact lens, if needed
Microcysts
- an accumulation of fluid in the intracellular space resulting from ruptured epithelial cell membranes, usually caused by adverse reaction to chemicals in
some preserved contact lens solutions - easily viewed with retroillumination
- symptoms include discomfort on lens insertion, photophobia, and epiphora
- discontinue use of offending chemicals (ie change CL solutions)
Dendritic Ulcer
- characteristic of the herpes simplex type 1 virus
- distinctive “tree-branch” formation
- can recur over the lifetime of the patient
- discontinue CL wear until outbreak subsides and discard soft lenses or disinfect GPs
Cataract
clouding of the crystalline lens
Hordeolum
- AKA stye — a tender lump within the eyelid causing redness of the skin
- An internal hordeolum is caused by an infected meibomian gland and may evolve into a chalazion
- An external hordeolum is caused by an infection of the glands of Zeiss or Moll
Corneal Neovascularization
- blood vessels growing into the normally avascular cornea, frequently due to oxygen deprivation from over-worn or improperly fit contact lenses
- neovascularization of more than 2mm is considered abnormal
- may result in lipid degeneration, pannus, scarring, intra-stromal hemorrhages, and eventually, reduced visual acuity
- treatment is to remove the causative factor (eg refit or discontinue CLs); the vessels may empty and become “ghost vessels.”
Nevus (plural = nevi)
a benign pigment deposit on the eye
(similar to a mole or freckle on your skin)
Dimple Veiling
a bubble under a RGP that has broken up into lots of tiny bubbles
this makes “dimples” in the epithelium that will pool with fluorescein immediately after the lens is removed but will disappear within a few minutes
Kayser-Fleischer Ring
- an orange-brown/golden-brown/greenish-brown coloration visible around the edges of the cornea
- located in the posterior cornea at the level of Descemet’s membrane.
Microcysts
- an accumulation of fluid in the intracellular space resulting from ruptured epithelial cell membranes, usually caused by adverse reaction to chemicals in
some preserved contact lens solutions - easily viewed with retroillumination
- symptoms include discomfort on lens insertion, photophobia, and epiphora
- discontinue use of offending chemicals (ie change CL solutions)
Subconjunctival Hemorhage/Hematoma
blood pooling under the conjunctiva and creating a red patch on the sclera
Keratoconus
- progressive thinning of the cornea causing it to bulge forward in a cone shape and causing irregular astigmatism among other vision problems
- once moderate to advanced, eyeglasses cannot achieve adequate visual acuity
- fit with GP or scleral lenses
Subconjunctival Hemorhage/Hematoma
blood pooling under the conjunctiva and creating a red patch on the sclera
Pterygium
- a triangle-shaped overgrowth of the conjunctiva that crosses the limbal border and encroaches onto the cornea
- often caused by UV exposure
- can start as a pinguecula
- patients with pterygium should be carefully evaluated prior to consideration of contact lens fitting, as pterygium may lead to dellen formation
Entropion (upper lid)
- eyelid rolling inward
- patients with entropion generally require eyelid surgery or removal of some
- lashes, prior to which a therapeutic (bandage), soft contact lens can be used to protect the eye from the irritating lashes
Corneal Dystrophy
- Epithelial basement membrane dystrophy (EBMD), also known as Cogan’s dystrophy or map-dot-fingerprint dystrophy, consists of grayish patches (maps), clear or white microcysts (dots), or swirls or lines (fingerprints)
within the epithelium, best seen with retroillumiation - GP lenses often help improve acuity and are not contraindicated for EBMD unless there is erosion of the epithelium
- epithelial erosions (recurrent erosion) occur in approximately 10% of all cases and cause great pain, patients may be fit with a high-water soft bandage contact lens, if needed
Pannus
- deep stromal neovascularization (as compared to fine, superficial neovascularization)
- fibrovascular connective tissue proliferates into the anterior layers of the peripheral cornea in inflammatory corneal disease
- can be caused by overwear of contact lenses
- patients with pannus should not be fit with contact lenses
- if a patient is currently wearing lenses, lenses should be discontinued
Eyelid Retraction in Graves’ Disease
- Graves’ disease is an autoimmune disease that can cause hyperthyroidism
- patients may also present with optic neuropathy
- RGP contact lenses are generally unsuccessful due to poor centration
- soft contact lens wear may be successful, frequently with supplemental artificial tears
Entropion (lower lid)
- eyelid rolling inward
- patients with entropion generally require eyelid surgery or removal of some
lashes, prior to which a therapeutic (bandage), soft contact lens can be used to protect the eye from the irritating lashes
Corneal Abrasion
an abrasion of the cornea caused by a foreign body or other mechanical irritation
makes the eye more susceptible to infection
contact lens wear should be discontinued until it heals unless there is recurrent corneal abrasion/erosion (where the eyelid opening in the morning removes the newly formed epithelial cells – in this case a bandage lense can be used to facilitate healing by giving the new epithelial cells more time to become integrated into the corneal structure
Hyphema
blood in the anterior chamber
Meibomian Gland Dysfunction
- The meibomian glands over-secrete and become blocked/plugged
- MGD is a major cause of both chronic blepharitis and keratoconjunctivitis sicca (dry eye)
Corneal Folds and Striae
- Folds appear as long, straight lines and striae appear as fine white vertical lines in the posterior stroma
- both may occur in the presence of corneal edema
- more commonly seen in patients who wear extended wear lenses or high plus hydrogel lenses.
- patient may be asymptomatic or have issues with glare
- management requires refitting the patient in a higher Dk lens or changing to daily wear lenses.
Corneal Dystrophy
- Epithelial basement membrane dystrophy (EBMD), also known as Cogan’s dystrophy or map-dot-fingerprint dystrophy, consists of grayish patches (maps), clear or white microcysts (dots), or swirls or lines (fingerprints)
within the epithelium, best seen with retroillumiation - GP lenses often help improve acuity and are not contraindicated for EBMD unless there is erosion of the epithelium
- epithelial erosions (recurrent erosion) occur in approximately 10% of all cases and cause great pain, patients may be fit with a high-water soft bandage contact lens, if needed
Pterygium
- a triangle-shaped overgrowth of the conjunctiva that crosses the limbal border and encroaches onto the cornea
- often caused by UV exposure
- can start as a pinguecula
- patients with pterygium should be carefully evaluated prior to consideration of contact lens fitting, as pterygium may lead to dellen formation
Giant Papillary Conjunctivitis (GPC)
- identifiable by papillae (large bumps) over the tarsal palpebral conjunctiva of the upper lid, visible when inverted.
- caused by a foreign body (frequently an improperly cleaned, damaged, or over-worn contact lens) mechanically irritating the eye
- discontinue contact lens use until the problem is resolved, and re-educate on cleaning and wear time if necessary