Posterior Segment Exam

• What is one reason for dilating the eyes during an examination?

  To improve the view of the retina
• How does dilation enhance image quality during an eye examination?

  It allows for binocular viewing, which enhances image quality
• What did Siegel et al. (1990) find regarding peripheral retinal anomalies?

  Dilated BIO found 287 peripheral retinal anomalies not seen undilated
• What percentage of posterior pole anomalies were missed with natural pupils according to Siegel et al. (1990)?

  51% of posterior pole anomalies were missed
• What did Parisi et al. (1996) discover about peripheral retinal anomalies in children?

  Dilated BIO found 69 peripheral retinal anomalies not seen undilated
• What percentage of posterior pole anomalies were missed in children according to Parisi et al. (1996)?

  33% of posterior pole anomalies were missed
• What did Canzano & Handa (1999) find regarding infants with retinoblastoma?

  Dilated BIO found 69 peripheral retinal anomalies not seen undilated
• What percentage of posterior pole anomalies were missed in infants according to Canzano & Handa (1999)?

  70% of posterior pole anomalies were missed
• What are the indications for dilating the eyes?

  • New patient
  • Routine every 2 or 3 years
  • Flashes and/or floaters
  • Unexplained vision reduction/loss
  • Progressive retinal diseases (e.g. diabetic retinopathy)
  • Systemic conditions (e.g. hypertension)
  • History of head injuries or ocular trauma
  • History of chronic uveitis
  • History of peripheral retinal degenerations (e.g. lattice) or holes
  • Yearly for history of ocular surgery
  • Moderate to high myopia: 3-7D (2 yearly), 8D or more (yearly)
  • Limited or no view of posterior pole (e.g. due to cataract)
• What considerations should be taken before performing a dilated fundus examination (DFE)?

  • History to determine suitability for DFE
  • Visual acuity assessment
  • Pupils testing
  • Accommodation tests
  • Assess potential for angle closure
• What is a contraindication for dilating the eyes?

  Angle closure glaucoma
• What are some contraindications for dilation?

  • Petite/anorexic individuals
  • Children (due to liver enzyme activity)
  • Sick/febrile patients
  • Angle closure glaucoma
  • Hypersensitivity to mydriatic eye drops
  • Recent ocular injury
• What is a method to minimize systemic absorption of mydriatic drops?

  Digital occlusion of the eyes
• What is the role of sympathomimetics in dilation?

  They stimulate the dilator muscle causing mydriasis
• What is the onset time for Phenylephrine 2.5% for dilation?

  Onset is in 10 minutes
• What is the effect of Tropicamide on the pupil?

  It causes maximal dilation and affects accommodation
• What are the differences between Tropicamide and Atropine in terms of side effects and duration?

  • Tropicamide:
  • Drug of choice, quick onset, short duration
  • Atropine:
  • Most systemic adverse effects, lasts days to weeks
• What is the purpose of Alcaine 0.5% in eye examinations?

  It is a local anesthetic used to reduce discomfort
• What should be checked for all drugs used in eye examinations?

  • Patient allergy
  • Known side effects
  • Label, concentration, dosage, and expiry date
• What are the key points regarding the conclusion of DFE?

  • DFE is generally safe and routinely done
  • Assess patient profile before dilation
  • Benefits outweigh risks
  • Know when to dilate and how to manage side effects