RGP conditions

Question 1

3 and 9 oclock staining

Answer 1

Aetiology:-
- Drying at nasal and temporal area at lens edge
- may result from lens riding laterally

Causes:-
- Poor blinking
- Wide AHP
- Sph lens and toric lens
- Insuffiicen edge clearance
- lens material - poor surface wetting properties
- thick edge design - TD too small

Symptoms:-
- Often assymptomatic
- Gritty red eyes
- Decreaes wear time

Signs:-
- triangular area of epi punctate at 3 and 9 oclock
- tufts of vessels
- nasal and temporal bulbar redness
- severe - Dellen, erosion, ulceration, vascularisation and scarring

Management:-
- discontinue lens wear
- thin lenses
- alter lens periphery
- change to toric design
- modiiy wear time
- Fit SCL
- lubricanats
- lid attached lenses
- Increase TD - 9.5

Question 2

Vasculised limbal keratitis

Answer 2

Aetiology:-
- rare inflammatory complications, involves conjunctiva, limbus and cornea
- secondary to 3 and 9

Causes:-
- Large TD
- Mechanical abrasion s
- steep fit with low edge fit
- EW or lid adhrearance

Symptoms:-
- Minimal in early stage
- symptoms increase redness, pain, photophobia adn lacrimation
- gradual increase in discomfort, lens awarness and reduced wear time.

Signs:-
- Opaque epi lesion and ill defined borders
- Localised corneal injection
- tufts of vessels
- limbal vessel engrogment
- corneal and conjunctival staining

management:-
- discontinue lens wear (temp)
- reduce AC
- Reduce wear time
- lubricants and deconghestion

Question 3

Lid adhearance

Answer 3

• common after overnight wear and worse with a flat fitting lens
• may be due to limited movement of the lens and lid pressure

Symptoms
- often asymptomatic
- mild awareness
- blurred vision
- dryness
- tiredness
- ocular pain
- FB sensation
- Spec blur following lens removal

Signs
- Lens is bound to cornea and often decentred (usually nasal)
- Indentation and lens edge with corneal distortion
- Staining, increased at 3 and 9

Management
- Alterations are unlikely to prevent adherence is susceptible wearers
- Patient education – assess, lubricants, mobilise lens with lid pressure
- Possibly fit lens with slightly Apical pooling
- Reduce TD

Question 4

BiTOT spots

Answer 4

• Build up of keratin debris located superficially in the conjunctiva
• Common in long term RGP wearers
• Associated with long term conjunctival drying secondary to bridging effect of lens
• Px may have a vitamin A deficiency

Symptoms
- Generally asymptomatic, mild redness towards the end of the day

Signs
- Elevated conjunctival lesion
- White foamy area which may be oval/triangle or irregular in shape
- Located along the horizontal meridian

Management
- Consider thinner lens
- Follow for changes in patient’s symptoms/appearance

Question 5

Dellen

Answer 5

• Localised thinning of the cornea in a saucer like depression
• NaFl pooling due to localised tear film disturbance
• Long term consequence of desiccation

Management
- Determine cause
- Minimise 3 and 9 staining
- Temporary discontinue lens wear and monitor recovery
- Ocular lubrication

Question 6

Corneal ulcer

Answer 6

• Uncommon in RGP wearers
• Failure to heed early warning signs
• Most common in EW
• Epithelial breakdown from other factors e.g. 3 and 9 or lid adherence
• Most ulcers are culture negative

Symptoms
- Mild to severe pain/FB sensation
- Photophobia
- Tearing
- Redness

Signs
- Associated 3 and 9
- Underlying focal infiltrate in the anterior stroma with diffuse surrounding

Management
- Discontinue, eliminate 3 and 9 if precursor
- Chloramphenicol
- Generally will resolve with scarring

Question 7

Dimple veil staining

Answer 7

• Gas or air bubbles trapped in a poor of tears beneath the CL can act as FBs
• They give dramatic appearance with NaFl but they are not true staining
• One lens is removed and eye rinsed, irregular depressions can be seen on cornea – small hemispherical pits in the epithelium
• May be due to poor lens/cornea relation i.e. too flat (more common) or too steep
• Px is general asymptomatic however may have a decrease in vision due to irregular topography
  Management
• Alter fit
• Use non aerosol saline

Question 8

FB tract

Answer 8

• Causes – FB/makeup brush/clumsy insertion/excessive eye rubbing
• Staining is generally superficial and linear with curved or zig zag pattern

Symptoms
- Sharp pain or discomfort
- Photophobia
- Lacrimation
- Lens intolerance

Management
- Px education
- Remove lens and rinse
- Lens design – minimise edge clearance (steeper)

Question 9

Lens warpage

Answer 9

• Heavy handling
• Lens case issues

Signs
- Irregular mires
- No precise end point with over refraction
- Altered fit/fluorescein pattern

Management
- Replace and re-educate