(OCT) 2026 Expert Verifed Ace
the Test
Imaging & Biometry key elements - ANSWER ✔✔- Spatial
- Temporal
- Depth resolution
Principle of O C T - ANSWER ✔✔- Near-infrared light waves to
measure distances of anatomical structures
, - Low-coherence interferometry
Near infra-red light - ANSWER ✔✔- 800-1,310nm
• 830nm: increases the transparency of the aqueous and vitreous
humors.
•1,310nm: typical penetration depths in tissues between 1-3mm.
- A beam of light is directed onto the structure and the echo time delay of
light is then recorded.
Low coherence interferometry - ANSWER ✔✔- Light reflected from
the eye is compared to a reference value of a known length.
- A series of A-scans are combined to form 2-D images of the ocular
structures.
- Cross-sectional images are then generated by scanning the incident
optical beam.
- The resultant scans are displayed in a color scale.
Types of O C T - ANSWER ✔✔- Time domain
• Example: Stratus O C T (carl zeiss)