6.1.5. Recognises common ocular abnormalities and refers when appropriate.

Question 1

What’s the benefits of using OCT?

Answer 1

1. 3D structure
   Retina, vitreous & optic nerve head
   High resolution ~5µm Axial / ~15µm Transverse
   Anterior eye & choroid also possible
2. Quantifiable measures
   Intra-retinal layer thicknesses & volumes
   ONH parameters & manual callipers. Scleral lenses 200um, Disc size changes for glaucoma, Melanoma changes in choroid, Oedema for DR
3. Statistical analysis
   Normative values & progression
4. No need for pupil dilation in many people

Question 2

Where is OCT indicated?

Answer 2

• Suspected maculopathy
  
  • Distortion on amsler
  • AMD (standard in hospitals)
  • Diabetes
  • Macula detachments, holes, swelling, etc.
• Glaucoma
  
  • RNFL thickness
  • Optic disc
  • Macula thickness
• Choroidal Melanoma
• Drusen Vs Exudates
• ERMs
• CRVO

Question 3

What principle does OCT work upon?

Answer 3

Light interferometry

Depth at which light is reflected within the sample is measured. Splitter splits beam of light. One arm of the light is reflected from a mirror & the other from the retina. They then recombine to undergo interference, allowing depth & reflectivity measurement.

A scan - represents depth & reflectivity of a point in the scan

B scan - combines multiple A scans to form a cross sectional image (what we normally see!)

C scan - combines multiple B scans to form a 3D image. Looks cool but has little value except to impress the px!v

Question 4

Types of Retinal Oedema & Common Associated Conditions

Answer 4

• 3 Types
  1. Diffuse retinal thickening (thick & loss of regularity)
  2. Cystoid oedema (dark black pockets)
  3. Sub retinal fluid (between RPE & neural retina)
• Commonly Associated Conditions
  
  • Wet AMD
  • Diabetic maculopathy
  • CSR
  • Secondary to cataract/ocular surgery

Question 5

Drusen Vs Hard Exudates

Answer 5

Drusen are formed between Bruch’s membrane and the retinal pigmented epithelium

Hard exudates form within the retina predominantly at the level of the outer plexiform layer

Exudates normally by area of oedema - therefore if you see exudates, suspect oedema!

Question 6

Types of PEDs & Common Associated Conditions

Answer 6

Lid lesions (signs of malignancy)

• Bleeding
• Asymmetrical shape
• Change in colour
• Ulceration, irregularity, telangiectasia, pearly appearance, and loss of eyelid margin architecture (notching)
• Diplopia or Proptosis indicating orbital invasion!

Question 7

Cataract technique

Answer 7

• Retroillumination of the lens
• Optic section of the lens

Question 8

Glaucoma or Glaucoma suspects technique

Answer 8

• Vertical elongation of cup
• Thinking of ISNT - may do OCT to double check
• Disc haems

Question 9

Chalazion

Answer 9

• Descript - Sterile inflammation of meibomian gland (cyst) causing stagnation of secretion from the gland, leading to a more chronic lesion. Can follow an internal hordeolum
• Cause - May occur spontaneously or follow an acute hordeolum (internal), chronic bleph
• Sxs - painless lid lump, rarely induced astigmatism
• Management - warm compress & massage. Steroid or excision

Question 10

Hordeolum

Answer 10

• Descipt - Either external (stye-acute bacterial infection of eyelash glands) or internal (meibomian gland)
• Causes - chronic bleph
• Sxs - tenderness, pain if internal sometimes, watering
• Management - warm compress & massage, if mucous discharge then antibiotic treatment using chloramphenicol

Question 11

Trichiasis

Answer 11

• Descript - misdirected lashes
• Causes - chronic blepharitis, infection like herpes zoster, surgery, trauma
• Management - removal, laser ablation

Question 12

Distichiasis

Answer 12

• Descript - growth of abnormal number of lashes
• Causes - intense chronic inflammation like steven johnsons, or OCP. Can be congenital!
• Management - removal, ablation, cryotherapy

Question 13

Sqamous cell papilloma

Answer 13

• Descript - benign epithelial tumour, skin-tag & wart like
• Causes - human papilloma virus
• Management - normally goes by itself, excision, cryotherapy & laser or chemical ablation

Question 14

Serborrhoeic Keratosis (basal cell papilloma)

Answer 14

• Descript - light- to dark-brown plaque with a friable, greasy, verrucous surface and a ‘stuck-on’ appearance
• Causes - elderly, common, numerous
• Management - shave biopsy, excision, laser, cryotherapy

Question 15

Actinic Keratosis

Answer 15

• Descript - hyperkeratotic plaque with distinct borders and a scaly surface that may become fissure, sandpaper like, possible malignancy
• Causes - elderly, UV, white
• Management - routine referral, excision, cryotherapy

Question 16

Melanocytic naevus

Answer 16

• Descript - can be congenital (kissing naevus possible), compound naevus (rasied & scaly), junctional naevus (uniform & brown), intradermal naevus (most common, no malignancy potential)
• Management - complete excision if suspect melanoma

Question 17

Molluscum Contagiosum

Answer 17

• Descript - viral infection; caused by poxvirus, very young or adults immuno compromised
• Causes - linked with AIDs, eczema, swimming pools
• Sxs - Skin nodule(s) (typically 2-3 mm diam), often with a central depression (‘umbilicated’), Can cause conjunctivitis - follicles, redness, watering, photophobia, epitheliopathy etc
  
  • White cheesy material can be discharged
• Management - self-limiting (goes after few weeks or months), referral if no resolve for excision

Question 18

Basal cell carcinoma

Answer 18

• Risk Factors - Old, White, UV exposure
• Types:
  
  • Nodular - pearl like, few dilated vessels
  • Nodulo-ulcerative - centre ulcerated, pearly rolled edges, telangiectasia
  • Sclerosing - looks clear, margins hard to define. Don’t mistake for blepharitis!
• Management - needs referral (soon) for biopsy

Question 19

Squamous cell carcinoma

Answer 19

• Risk Factors - Old, White, UV exposure, Immunocompromised
• Types:
  
  • Nodular - hyperkeratotic with crusting, erosions, fissures
  • Ulcerating - red base, defined “hard looking” borders with a slight crusty look
  • Cutaneous horn
• Management - needs referral (urgent within a week) for biopsy

Question 20

Other eyelid cysts:

Answer 20

• Cyst of Zeiss - cyst of anterior lid margin
• Cyst of Moll - retention cyst near canthus
• Sebaceous cyst
• Epidermal inclusion cyst - implantation of epidermis into dermis following trauma or surgery, round, firm & whitish-yellowish looking due to keratin
• Dermoid cyst
• Xanthelasma

Question 21

Ectropian

Answer 21

• Outward rotation of lid margin
• TESTS:
• Distraction test
  
  • if lower lid can be pulled >6mm from globe, it is lax, positive test indicates canthal tendon laxity
• Snap-back test
  
  • with finger, pull lower lid down towards inferior orbital margin
    release: lid should snap back
    lid slow to return to its normal position: indicates poor orbicularis tone
• Types - Involutional (age related causing laxity), Cicatricial (scarring of skin), Paralytic (facial palsy i.e. Bell’s), Mechanical (tumour, lid swelling etc), Congenital (rare bilateral condition)
• Management - less lid rubbing (induces laxity), drops, routine referral if severe

Question 22

Entropian

Answer 22

• Inward rotation of lid margin
• TESTS:
• Distraction test
  
  • if lower lid can be pulled >6mm from globe, it is lax, positive test indicates canthal tendon laxity
• Snap-back test
  
  • with finger, pull lower lid down towards inferior orbital margin
    release: lid should snap back
    lid slow to return to its normal position: indicates poor orbicularis tone
• Test of Induced Entropion (TIE-2 test)
  
  • ask patient to look down
    hold upper lid up as high as possible
    ask patient to close the eyes as tightly as possible
    The TIE-2 test is positive if this provokes an intermittent lower lid
    entropion
• Types - Involutional, Cicatricial (scarring & contraction of palp conj e.g. in chronic bleph), Spastic (random orbicularis contraction e.g. after surgery or blepharospasm), Congenital (rare)
• Management - Lash epilation, Lubrication, routine referral if severe

Question 23

Keratocanthoma

Answer 23

• Descript - Rare, rapidly growing, keratin filled crater, pink dome
• Causes - white, UV, immunosuppresive therapy
• Management - spotaneous involution after growing for 2-3 months, taking up to a year!! leaving a scar! Excision also works

Question 24

Conjunctival lesions

Answer 24

• Pinguecula
  
  • UV protection. Lubricants. If inflammed, steroids. Referral if vision affected or cosmetically unacceptable
• Pterygium
  
  • UV protection. Lubricants. If inflammed, steroids. Referral if vision affected or cosmetically unacceptable or astigmatism induced
• Retention cyst
  
  • Goes by itself, or punctured with a needle using a topical anaesthetic
• Conjunctivochalasis
  
  • Lubrication & treat chronic bleph. Conjunctival resection (cutting out tissue) if severe.
• Concretions
  
  • Lubrication. Removed using needle under topical anaesthesia.

Question 25

AMD & Macular abnormalities

Answer 25

- PED - If drusenoid, then regular AMD management - If serous or fibrous with signs of AMD, then most likely urgent within 1-2 weeks as suspect wet AMD - Macula hole - If Lameller hole & not causing trouble with vision or too much distortion, then worth monitoring over next 6 months whilst giving amsler - ERM - Monitor, 1 yr recall - If VMT, then separate management as may progress to macula hole so might require referral within 3-4 weeks if vision worse than 6/7.5 - CSR - Routinely referred soon 3-4 weeks - Some HES will only want to see CSR if chronic for at least 4 months because normally it will resolve itself in 6 or so weeks. Photodynamic laser - Oedema - Referred urgently within 2 weeks e.g. proliferative DR, CRVO, after cataract surgery

Question 26

Retinitis Pigmentosa

Answer 26

- Descript - inherited diffuse retinal degenerative disease affecting rods then cones - Cause - genes - Signs - Dark adaptation trouble, VF loss, Bone-spicules, Narrower A/V, Disc pallor, Possible maculopathy - Management - Genetic counselling, LVAs & adaptations like expanding FOV

Question 27

# Congenital anomalies of the Optic Disc Without systemic associations:

Answer 27

- Tilted disc - Disc drusen - Optic disc pit - Myelinated nerve fibres

Question 28

# Congenital anomalies of the Optic Disc With systemic associations:

Answer 28

- Coloboma - Morning glory - Hypoplasia - Megalopapilla - Peripapillary staphyloma - Dysplasia

Question 29

Iris Melanoma

Answer 29

- Descript - pigmented area of iris, normally inferior - Causes - UV, white - Signs & Sxs - pupil distortion, causes cataracts & uveitis, raised, has surface vessels (DD from iris naevus), 3-5mm - Management - take a photo & refer routinely for iridectomy. If angle invaded, iridocylotomy. Radiotherapy

Question 30

Fuch’s Dystrophy

Answer 30

- Descript - bilateral endothelial loss, >women - Causes - inherited, middle age onset - Signs - blurring more in morning due to oedema, corneal guttata, beaten bronze appearance

Question 31

Choroidal Naevus Vs Melanoma

Answer 31

- C - Close to ON - O - Orange pigment lipofuscin - N - No drusen - S - Symptoms (F+F, visual disturbance if raised) - T - Thickness (>2mm) - A - Absence of halo (ring of pallor) - N - New - T - Too big (>5mm)

Question 32

CHRPE

Answer 32

common benign lesion, usually congenital. Can be single or grouped (bear tracks) Linked to FAP (familial adenomatous polyposis) (liver condition) if 4 or more CHRPEs that are separated more than bear tracks are detected. - Low malignancy risk so just monitor

Question 33

Macula scan: raster cube scan

Answer 33

 50% total RGCs at macula  GCC (ganglion cell complex i.e. innermost 5 layers, ILM, RNFL, GCL, IPL, INL)  GChart only measures thickness of GCC i.e. NRR, not things like disc swelling  Peripheral macular thickness asymmetry can occur in healthy eyes, but central macular thickness is highly symmetrical

Question 34

Retinal nerve fibre layer: circumpapillary scan

Answer 34

* Provides thickness measurements of RNFL * Produces a RNFL thickness map beginning and ending nasally, with superior, temporal and nasal quadrants in between * Thickness compared to normative data base, plotted on a probability graph depicting 95%, 5% and 1% confidence limits * The greater amount of nerve fibre layers coming from superior and inferior sections of the disc is highlighted by the double hump of RNFL thickening at those poles (absence of double hint = indicates nerve fibre loss in these areas

Question 35

Macular hole

Answer 35

 Routine referral to ophthalmology if full thickness / VA drop  Vitrectomy which can help to close hole with some slow recovery to normal VA

Question 36

ERM & wrinkling of retinal surface

Answer 36

 Routine referral if symptomatic / px wants surgery  Vitrectomy & membrane peel