Pathology 1

• Epidemiology


  Study of disease in populations
• Aetiology


  Disease cause
• Pathogenesis


  How disease progresses
• Clinical manifestation / presentation

  Disease consequence/ symptoms
• Differential diagnosis


  Other diseases w/ similar presentation
• Prognosis


  Anticipated course of disease
• Causes of diseases


  • Genetics
  • Inflammation
  • Injury
  • Metabolic conditions
  • Degenerative conditions
• Inflammation


  Body response to allergy / infection / injury
• Inflammation


  • Acute = sudden
  • Chronic = over time
  • Self-limiting = goes away on own
  • Treated w/ steroids / NSAIDs
• Affecting lids/lashes


  • Ptosis = 1 eyelid = lower
  • Ectropion = eyelid turns / folds outwards
  • Trichiasis = eyelashes face eye
  • Entropion = eyelid turns inward
• Bleph-


  Lids
• Blepharitis


  Lid inflammation
• Types of blepharitis


  • Anterior
  • Posterior
• Anterior blepharitis


  Inflammatory response to bacteria at eyelash bases
• Posterior blepharitis


  Meibomian gland dysfunction
• Anterior blepharitis symptoms


  • Burning, gritiness, lid crusting, oedema
• Anterior blepharitis signs


  • Crusting, eye lash loss, dry eye, conjunctival hyperaemia, atopic dermatisis
• Seborrhoea


  Oily build up
• Seborrheic blepharitis


  Soft sticky scales, dry eye, seborrheic dermatisis
• Treating anterior blepharitis


  Warm compress
• Posterior blepharitis symptoms


  • Burning, grit, lid crusting, oedema
• Posterior blepharitis signs


  • Meibomian gland secretion, gland loss, oily foamy tears
• Treating posterior blepharitis


  Warm compress & massage / pressure on lid margin (squeeze)
• Demodex


  Mites that can cause anterior & posterior blepharitis, more common in older patients
• Cylindrical collarettes


  Clear sleave around lash margin (sign of demodex)
• Chalazion


  Meibomian cyst, non-infectious collection of inflammatory materials in meibomian glands
• Chalazion symptoms/signs


  • Enlarging painless lesion, firm nodule, meibomian gland oily secretion
• Treating chalazion


  Warm compress & massage / can be surgically drained
• Hordeolum


  Infected granulomatous inflammatory mats, caused by staphylococcus bacteria
• Hordeolum symptoms/signs


  • Enlarging painful lesion, firm nodule, meibomian gland oily secretion, anterior blepharitis
• Treating hordeolum


  Warm compress, can use antibiotics
• Malignant lid lesions


  • Basal cell carcinoma
  • Squamous cell carcinoma
• Basal cell carcinoma (BCC)


  Slow growing, local, routine referral
• BCC appearances


  • Nodular
  • Nodulo-ulcerative
  • Sclerosing
• Nodular BCC


  Shiny, firm nodule overlying blood vessels
• Nodulo-ulcerative BCC


  Pearly rolled raised edges, ulcerated centre, fine blood vessel over margins, erode a large area of eye
• Sclerosing BCC


  Rarer, infiltrates laterally under epidermis, feel easier to diagnose
• Squamous cell carcinoma (SCC)

  Fast growing, aggressive, metastasizes, urgent referral
• SCC appearances


  • Nodular
  • Nodulo-ulcerative
  • Associated w/ cutaneous horn
• Nodular SCC


  Hyperkeratotic, irregular margins, crusting, erosion, looks like BCC