Slit Lamp

Question 1

What is the purpose of the slit lamp exam in CL wear?

Answer 1

• Routine CL exam – any sign/symptom requires further examination
• Just because CL px doesn’t meant there aren’t no-CL related problems
  o It’s fine to leave CL check to do another day in order to deal with what’s in front of you.
• Important to examine everything at fit for baseline measurement and then aftercare appointments to monitor change

Question 2

What are you looking at in the lid margin and lashes on SL?

Answer 2

• Look at px during H&S – any issues on periocular skin area? Redness? Dermatitis?
  o Looking for general hygiene too – can this px look after lenses?
• Looking for:
  o Meibomian Gland Dysfunction: capped glands, frothy tear film, uneven lid margin
  o Anterior Blepharitis: crusting, lashes stuck together -> ↑ chance of infection and poorer quality tear film
  o Ectropion/Entropion: can disrupt ocular surface and tear film
  o Trichiasis: misdirected lashes
  o Madarosis: missing lashes

Question 3

Describe blocked meibomian glands - on SL?

Answer 3

• Express glands: does oil come out at all? Completely blocked glands? Clear oils?
• Should be clear and not too viscous -> becomes more opaque and thickens as MGD worsens
• Oils coming out of lid margin should spread across tear film with each blink
• Get MGD under control before fitting CLs (or ↓ wear time if already a wearer)

Question 4

Describe anterior blepharitis - on SL?

Answer 4

• Crusts extend length of lashes
• May get hordeolum alongside – look at base of lashes
• Manage before fitting CLs to ↓ risk of complications

Question 5

Describe ectropion - on SL?

Answer 5

Eyelid moves slightly away so puncta no longer contacting ocular surface to allow for normal tear drainage, tear retention may not be as good and dry eye may result

Question 6

Describe trichiasis - on SL?

Answer 6

• Eyelash can be plucked out but can come back and usually in same location – regularly needs dealing with
• Could be an emergency and in a lot of pain

Question 7

Describe madarosis - on SL?

Answer 7

• Loss of eyelashes can indicate serious pathology or mental health issues but can also be seen in chronic blepharitis

Question 8

What are you looking for when examining bulbar conjunctiva on SL?

Answer 8

• Looking for:
  o Redness – indicates inflammation
  o Staining – any signs of compromise to that layer
  o Pinguecula/pterygium
  Redness: different grades of bulbar conjunctival redness from very mild at the top through to severe at the bottom
  Staining: Lissamine green dye is good for assessing bulbar conjunctival staining – whereas fluorescein is better for corneal staining. If don’t have access to Lissamine green dye fluorescein is still good.

Question 9

Describe pinguecula - on SL?

Answer 9

Can affect comfort and movement with contact lens. Monitor the pinguecula and give appropriate advice

Question 10

Describe pterygium - on SL?

Answer 10

All about location and how it will disrupt the usually smooth surface. Can affect placement of contact lens and how the patient sees

Question 11

What are you looking for in the palpebral conjunctiva on SL?

Answer 11

• Looking for:
  o Redness – signs of inflammation
  o Roughness – smooth? Disrupted due to papillae? – use white light (look at integrity of reflex) and fluorescein
  o Concretions – small white spots – if break through epithelium can cause a lot of irritation
  o Foreign body – more expect to find as an acute presentation
• Redness, roughness and concretions should be measured as baseline and then at follow up appointments

Question 12

What are you looking for on the cornea on SL?

Answer 12

• Looking for:
  o Staining – fluorescein
  o Scarring – more subtle, harder to see, can tell you about previous events in eye
• Describe any staining:
  o Type – FB? Punctate? Linear? Dots?
  o Depth – optical section to determine if epithelial, stroma etc
  o Location – Inferior? Nasal? Temporal? Use clock face
  o Size (if appropriate e.g. FB or ulcer) – use beam width and height to measure
  o E.g. inferior punctate epithelial staining – could also say 5 o’clock to 7 o’clock

Question 13

What are you looking for at the limbus on SL?

Answer 13

• Looking for:
  o Redness – suggests inflammation
  o Neovascularisation – new BV growth, indicates lack of O2 – could be caused by CL wear – lift top eyelid – measure

Question 14

What are you looking for in the tear film on SL?

Answer 14

• Looking for:
  o Debris – makeup, debris from lashes (hygiene, blepharitis)
  o Tear stability – tear break-up time
  o Look at tear film with blink, is it spreading evenly over ocular surface?

Question 15

Describe Tear Film Break-Up Time (TBUT)?

Answer 15

• Can be done invasively (with Fluorescein – FBUT)
• Can be done non-invasively (NITBUT) with keatometry mires (Bausch & Lomb) or a tearscope grid pattern
• FBUT: adding fluorescein which could disrupt tearfilm or add liquid giving artificially stable tearfilm
• Non-invasive: don’t always have the eqipment available
• Good to check at baseline as a risk factor for complications & to monitor changes with CL wear
• Low TBUT can help decide if they can wear CLs, which type, how long for
• Normal time:
  o TBUT >10 seconds

Question 16

Describe the effect of CLs on TBUT?

Answer 16

• CLs significantly ↑ tear evaporation rate and therefore ↓ tear stability
• Research shown this across different lens materials
• If patient is already a wearer don’t be surprised if the TBUT is ↓(important to have good stability pre-fitting)
  o Maximise chances of success and reduce risk of complications – may be advice on length of time wearing

Question 17

Describe FBUT?

Answer 17

Fluorescein BUT
Put fluorescein in then get px to take big blink and then stare trying not to blink. Count how long it takes for the first instance of black cracks in tear film to appear

Question 18

Describe NITBUT?

Answer 18

Non-invasive TBUT
* Observed by reflecting mires – grid pattern or placedo disc – from air-liquid interface.
* Px asked to blink normally then refrain from blinking for as long as possible.
* Time taken for first disruption or first distortion in reflected mire pattern is recorded.
* As lots of variabiltiy- an average of 3 measurements is normally taken.
* Corneal topographical instrumentation can allow objective assessment of placedo disc distortion that occurs with tear film thinning and break-up.
o Map of areas that break-up on ocular surface are provided

Question 19

Describe the grading scales used in SL exam?

Answer 19

• Types:
  o Efron – covers a lot of anterior eye – 5 point scale-0 to 4 – artist drawings – contains blepharitis and MGD – used often if doing dry-eye assessment
   Has an online version
  o CCLRU (Brien Holden Vision Institute) – photographs (less consistent progression)– 4 point scale
  o Alcon (Ciba) – 5 point scale – not as many categories as Efron and CCLRU
  o The Vision Care Institute/J&J – modeled on Efron – artist drawings – 0to4 scale
• Pros and cons to each, good record keeping is key, be consistent. Mark clearly on record card which one you have used.
• Grading to 0.5 is appropriate
  Write when things are normal e.g grade 0 no redness
  Importance of grading scales
  Practice drawing what you see
  Good baseline examination