1. OCT:BASIC CONSEPT F.FAZEL.MD

2. Optical Coherence Tomography 1995-1996 introduced in to clinical practice Retina,glaucoma,anterior segment Rapid,easy,non- contatc,noninvasive,sensitive,highly reproducible and repeatable Qualitative and quantitative

3. How the OCT work The OCT uses an interferometer that measures the time it takes for light to be reflected back from structures in the retina, as compared to the time it takes for light to be reflected back from a reference mirror at specific distances. The process is similar to that of ultrasonography, except that light is used instead of sound waves.

4. Retinal layer scanning

5. Differences of OCT and sonography Light(830nm) vs.. Ultrasound Speed Resolution(10 micron vs100) Noncontact vs. contact

6. OCT vs SONO

7. Scan protocol

8. Line scan

9. Circle scan

10. Radial line scan

11. Reflectivity Qualitative analysis of the OCT scan includes observation of the reflective qualities of the retinal structures. The OCT software assigns "cooler" colors (green, blue) to structures with lower reflectivity. It assigns "warmer" colors (yellow, orange, red) to more highly reflective structures. White represents the most highly reflective structures, and black represents the least reflective structures. On the OCT scan of a normal retina, the NFL and RPE are highly reflective, the middle retinal layers are medium reflective, and the photoreceptors (just above the RPE layer) are low reflective.

12. Normal retinal layers in OCT

13. Anterior segment OCT Angle assessment ■ Pachymetry ■ Glaucoma surgery evaluation ■ Evaluation of corneal transplant ■ Visualization of the sclera/suprachoroidal space ■ Identification of iris lesions ■ Evaluation of crystalline lens, pseudophakic IOLs

14. Visante OCT

15. Top hat approach PKP

16. Donor tissue depth

17. Zigzag approach PKP

18. Endothelial keratoplasty

19. Normal AC angle

20. Narrow angle

21. Open PI in plateau iris

22. Peripheral Anterior Synechia

23. Iris cyst

24. irridoschisis

25. Anerior ChamberAngle tumor

26. Suprachoroidal effusion

27. IOL tilt

28. Shallow AC needs lensectomy