1. الجامعة الإسلامية-غزة كلية العلــــــــــــــــوم قسم البصريات الطبية
Islamic University - Gaza
Faculty of Science
Department of Medical Optics
الجامعة الإسلامية-غزة
كلية العلــــــــــــــــوم
قسم البصريات الطبية
Fundus camera

2. Fundus Camera
Fundus camera optics are very similar to those of the indirect ophthalmoscope.

3. A fundus camera or retinal camera is a specialized low power microscope with an attached camera designed to photograph the interior surface of the eye, including the retina, optic disc, macula, and posterior pole (i.e. the fundus).
Fundus cameras are used by optometrists, ophthalmologists, and trained medical professionals for monitoring progression of a disease, diagnosis of a disease (combined with retinal angiography), or in screening programs, where the photos can be analysed later.

4. fundus camera

5. Instruments for Imaging the Retina
Optical Instruments
Instruments for Imaging the Retina

6. Optical principles
The optical design of fundus cameras is based on the principle of monocular indirect ophthalmoscopy.A fundus camera provides an upright, magnified view of the fundus. A typical camera views 30 to 50 degrees of retinal area, with a magnification of 2.5x, and allows some modification of this relationship through zoom or auxiliary lenses from 15 degrees which provides 5x magnification to 140 degrees with a wide angle lens which minifies the image by half. The optics of a fundus camera are similar to those of an indirect ophthalmoscope in that the observation and illumination systems follow dissimilar paths. The observation light is focused via a series of lenses through a doughnut shaped aperture, which then passes through a central aperture to form an annulus, before passing through the camera objective lens and through the cornea onto the retina.The light reflected from the retina passes through the un-illuminated hole in the doughnut formed by the illumination system. As the light paths of the two systems are independent, there are minimal reflections of the light source captured in the formed image.

7. The image forming rays continue towards the low powered telescopic eyepiece. When the button is pressed to take a picture, a mirror interrupts the path of the illumination system allow the light from the flash bulb to pass into the eye. Simultaneously, a mirror falls in front of the observation telescope, which redirects the light onto the capturing medium, whether it is film or a digital CCD. Because of the eye’s tendency to accommodate while looking though a telescope, it is imperative that the exiting vergence is parallel in order for an in focus image to be formed on the capturing medium.
Since the instruments are complex in design and difficult to manufacture to clinical standards, only a few manufacturers exist: Topcon, Zeiss, Canon, Nidek, and Kowa.

8. principle of indirect ophthalmoscope
same principle for fundus camera

10. Practical Retinal Illumination System
GTT 04

12. GTT 05

13. hole in 45o mirror

14. Fundus camera
camera or CCD

15. Applications
Practical instruments for fundus photography perform the following modes of examination:
Color, where the retina is illuminated by white light and examined in full color.
Red-free, where the imaging light is filtered to remove red colors, improving contrast of vessels and other structures.

16. Angiography, where the vessels are brought into high contrast by intravenous injection of a fluorescent dye. The retina is illuminated with an excitation color which fluoresces light of another color where the dye is present. By filtering to exclude the excitation color and pass the fluorescent color, a very high-contrast image of the vessels is produced. Shooting a timed sequence of photographs of the progression of the dye into the vessels reveals the flow dynamics and related pathologies. Specific methods include sodium fluorescein angiography (abbreviated FA or FAG) and indocyanine green (abbreviated ICG) angiography.

17. Some pictuers was take by fundus camera..

18. Intraretinal Hemorrhage

19. PDR with Regressed NVD. Previous PRP

20. Mild NPDR

21. HTN retinopathy with AV nicking and mild vascular tortuosity

22. Picture artifact. Large optic cup Prominent foveal reflex

23. Hypertensive retinopathy with Arteriolar attenuation
Hypertensive retinopathy with Arteriolar attenuation. Increased arterial reflex. AV nicking.

24. Proliferative retionpathy with regressed NVD. Previous PRP

25. Myopic degeneration with PPA and macular Chorioretinal atrophy

26. Nonexudative AMD with Drusen and RPE dropout..

27. Tigroid Fundus. Large optic cup

28. Proliferative retinopathy with previous PRP

29. Diabetic retinopathy with microaneurysms with macular exudates

30. Vitreous haze. Fleck Retinopathy
Vitreous haze. Fleck Retinopathy

31. Subfoveal CNVM with surrounding subretinal hemorrhage and exudates

32. Advanced AMD with Geographic Atrophy involving fovea
Advanced AMD with Geographic Atrophy involving fovea

33. Chorioretinal scar with fibrovascular stalk secondary to focal chorioretinitis

34. POHS with regressed macular CNVM, PPA, and punched out CR scar
POHS with regressed macular CNVM, PPA, and punched out CR scar

35. AMD with Mild intermediate drusen

36. Myopic Degeneration

37. AMD with severe large drusen

38. Diabetic retinopathy with Macular exudates at foveal edge, with possible CSME

39. Flat choroidal Nevus adjacent to optic nerve

40. Conjunctival nevus

41. Diabetic retinopathy with Macular exudates

42. POHS with regressed macular CNVM, PPA, and punched out CR scar