Soft Contact Lens Complications

Question 1

How does CLs break down normal defence mechanisms?

Answer 1

• damage to the corneal epithelium
• distribution normal homeostatic surface renewal
• reduction of tear flow and stagnation of post -lens tear film
• Breakdown of defence mechanism predispose the cornea to infection
• Preservatives in MPS can alter the epithelial cell desquamation and further increase the risk of MK

Question 2

What is the treatment for infections?

Answer 2

• cease lens wear
• immediate treatment/referral required
• aggressive antimicrobial treatment

Question 3

What is bacterial keratitis?

Answer 3

• It is an infection of the cornea
  this requires urgent medical attention due to the serious risk of corneal perforation and sight loss

Question 4

What is the clinical presentation of bacterial keratitis?

Answer 4

• Slit lamp examination reveals an excavation with underlying infiltrate
• generally central or paracentral
• AC reaction may be present

Question 5

What are the symptoms of bacterial keratitis?

Answer 5

severe pain/photophobia, epiphora, conjunctival chemosis, lid oedema

Question 6

What is inflammation?

Answer 6

Accumulation of proteins, lipids or by-products that adhere to the surface of a contact lens can cause inflammation in the cornea or conjunctiva

Question 7

What is the treatment for inflammation?

Answer 7

• cease lens wear immediately
• address any causative factors
• topical steroid +- prophylactic antibiotic, ocular lubricant
• reduce wear time
• increase replacement frequency
• increase lens movement

Question 8

What is CL associated peripheral ulcer?

Answer 8

• non infectious, infiltrative response to bacteria
  This requires urgent medical attention due to the serious risk of corneal perforation and sight loss

Question 9

What is the clinical presentation of CL associated ulcer?

Answer 9

epithelial excavation or non staining white spot in the peripheral regions of the cornea

Question 10

What are the symptoms of CL associated peripheral ulcer?

Answer 10

• FB sensation, mild irritation, awareness of redness an infiltrate
• reduced wear time

Question 11

What is CL associated Red eye (CLARE)?

Answer 11

Related to the overwear of contact lens, toxins under the lens. This requires active mx to prevent reoccurance

Question 12

What is the clinical presentation of CLARE?

Answer 12

• global conjunctival redness and chemosis
• watery discharge
• +- diffuse scattered infiltrates/SPK

Question 13

What is superior limbic keratitis?

Answer 13

Can lead to micropannus, papillary hypertrophy and corneal warpage if left untreated

Question 14

What is the clinical presentation of SLK?

Answer 14

• Punctate NaFl staining on the superior cornea, associated infiltrates and limbal hyperemia

Question 15

What are the symptoms of SLK?

Answer 15

Irritation/discomfort, increased lens awareness, may develop photophobia

Question 16

What is hypoxia?

Answer 16

Reduced oxygen = change in corneal metabolism - build up of lactic acid - osmotic load = drawing water into the cornea faster than it can be removed = corneal oedema
- Lens induced hypoxia key mediator for microbial invasion by pseudomonas

Question 17

What is the treatment for hypoxia?

Answer 17

• cease lens wear
• increase Dk/t
• reduce wear time
• change lens type

Question 18

What is limbal hyperemia?

Answer 18

• swollen limbal vessels
  If left untreated could lead to discomfort, inflammatory response or infection

Question 19

What is the clinical presentation for limbal hyperemia?

Answer 19

Annular or sectoral redness/injection

Question 20

What are the symptoms of limbal hyperemia?

Answer 20

• pain which suggests corneal involvement
• asymptomatic suggests conjunctival involvement

Question 21

What is neovascularisation?

Answer 21

• invasion of new blood vessels in the cornea
  Indication that the cornea is under hypoxic stress, if ignored it has potential to extend to pupil zone = visual loss

Question 22

What is the clinical presentation of neovascularisation?

Answer 22

• stromal extension of limbal vascular network
• start superficial at limbus then branch and go deeper into stroma

Question 23

What are the symptoms of neovascularisation?

Answer 23

asymptomatic

Question 24

What is stromal oedema?

Answer 24

vertical lines visible within the stroma under moderate to high magnification

Question 25

What are the symptoms of stromal oedema?

Answer 25

- asymptomatic if mild - reduced wear time, blur and discomfort if more severe

Question 26

What is the clinical impact of stromal oedema?

Answer 26

can lead to stromal thinning or opacification in long-term

Question 27

What are microcysts/vacuoles?

Answer 27

The sphere of necrotic cells that develop within the epithelial layers and migrate to the surface - these indicate chronic hypoxia or recovery from hypoxia

Question 28

What is the clinical presentation of microcysts/vacuoles?

Answer 28

minute scattered spherical dots observable under high magnification

Question 29

What is toxicity?

Answer 29

Combination of chemical preservatives used in lens care produces and specific SiH lens polymers can have adverse impact on the ocular surface

Question 30

What is solution-induced corneal staining?

Answer 30

Bilateral mild punctate staining observed, maximum intensity at 2 hr of wear and resolved by 6 hrs - seen in SCL weares using MPDS

Question 31

What are the symptoms for solution-induced corneal staining?

Answer 31

asymptomatic or dryness and discomfort

Question 32

What is the mx of solution-induced corneal staining?

Answer 32

- cease lens wear until staining resolves - change away from lens materials or lens care that induces SICS

Question 33

What is dryness?

Answer 33

Accumulation of inflammatory molecules, stagnant tear film and less mucins = destruction of tight junctions and sloughing of epithelia

Question 34

What is the mx of dryness?

Answer 34

- ocular lubricants - vitamin A, omega 3 and/or omega 6 fatty acid supplementation - consider lens design/modality -consider care system

Question 35

What is tear film instability?

Answer 35

Unstable tear film that has reduced TBUT, increased debris/oily surface

Question 36

What is the clinical impact of tear film instability?

Answer 36

- Leads to conjunctival hyperemia, corneal staining, lid wiper epitheliopathy - Lens surface deposits - CL may not be very successful in moderate/severe dry eye px

Question 37

What are the symptoms of tear film instability?

Answer 37

blur, burning, itching, grittiness, mild photophobia

Question 38

What is CL associated dry eye?

Answer 38

conjunctival or limbal redness - corneal desiccation (corneal not resurfaced with tears) - poor tear film

Question 39

What are the symptoms of CL associated dry eye?

Answer 39

- asymptomatic with no lens wear - develops dry eye symptoms with lens wear: soreness, irritation, burning, redness - worse as day progresses

Question 40

What is mechanical impact?

Answer 40

Mechanical factors causing irritation to the ocular surface or tarsal conjunctival have an impact on corneal physiology - factors include: lens material, inappropriate lens design, improper lens fitting

Question 41

What is conjunctival staining?

Answer 41

staining result of the lens fit; either tight, little movement or lens edge positive impression - may be an indication of CL associated dry eye

Question 42

What is the clinical presentation of conjunctival staining ?

Answer 42

localised indentation arc- apparent with NaFl and LG staining - physical trauma from lens edge or excessive movement

Question 43

What are conjunctival folds?

Answer 43

chemosis of epithelium leading to folds/flaps - associated with higher modulus lenses

Question 44

What is the tx for conjunctival folds?

Answer 44

- refit with lower modulus lens - reduce wear time - ocular lubricants

Question 45

What is CLAPC ?

Answer 45

combo allergic reaction to lens adherent proteins/lipids and response to mechanical irritation - related to extended/over wear

Question 46

What is the clinical presentation CLAPC?

Answer 46

- Usually upper lid, increased redness, localised papillae - NaFl exaggerates apperance

Question 47

What is the Mx for CLAPC?

Answer 47

- cease/reduce cl wear - refit with alternate lens type - reduce wear time/proper care - AH/MCS combo for weeks-months. topical steroids (qid for weeks) if mod-severe

Question 48

What is a superior epithelial arcuate lesion?

Answer 48

- progressive in nature, increasing discomfort - increased risk of infection - will lead to lens discontinuation

Question 49

What is the clinical presentation of a superior arcuate lesion?

Answer 49

superior corneal staining parallel to upper limbus - can cause discomfort

Question 50

What is the mx for a superior arcuate lesion?

Answer 50

- cease lens wear until healed - alter lens design - prophylactic antibiotics while healing

Question 51

What are foreign body lesions?

Answer 51

trapped foreign body that result in epithelial disruption highlighted by NaFl - this increases risk of infection - recurrent lesion can indicate poor tear exchange

Question 52

What is the mx for foreign body lesions?

Answer 52

- cease lens wear - prophylactic antibiotic (depending on severity) - change in lens design

Question 53

What are mucin balls?

Answer 53

observed during lens removal, initially immobile round spherical objects