ocular Photography

1. Ocular Photography

2. Introduction
• Ophthalmic imaging is an
integral part of the work of all
ophthalmic departments .Great
changes have arisen in recent
years with the advent of digital
techniques ,giving an excellent
opportunity to exploit these
advances to the benefit of the
way in which
ophthalmologists/optometrists
work.

3. Types
• This may involve :
1. Digital cameras
2. Scanning Laser Ophthalmoscopy {SLO}
3. Ultrasound
4. Optical Coherence Tomography {OCT}
5. Visual electrophysiological investigations,
6. Visual fields
7. Corneal topography.

4. External photography
• Facial picture and eye movement photography
should be available in all departments ,whether
undertaken in the department or in a department
or in a department of medical illustratio.

5. DSLR(Digital single-lens-reflex) cameras are
the best tool for high-quality external
photography

6. Anterior segment photography
• The demand for anterior segment photography
is considerably less then for retinal imaging,
but nevertheless this is an important technique
for the documentation of anterior segment
disease ,and should be available in every eye
department .Currently there is only a limited
choice between available machines.

7. Slit-lamp Photography
• The slit-lamp biomicroscope routinely used by eye
care professionals to light and examine structures
in the eye at magnifications up to 40x.

8. Gonio photography
• Auxiliary lenses are sometimes used with a photo
slit‐lamp to photograph the inner structures of the
eye that cannot be directly viewed with the slit‐lamp.
The most common lens type is the gonio contact lens
that utilizes internal mirrors angled at approximately
60° to provide observation of the filtering angle of the
anterior chamber.

9. Corneal tomography
• Tomography derives from the Greek words “to cut or
section” (tomos) and “to write” (graphein).
• In medicine, the classic term computed tomography
(CT) scanning is used for referring to the radiographic
technique for imaging a section of an internal solid
organ, producing a three-dimensional image.
• Corneal tomography should be used for the
examination of the front and back surfaces of the
cornea, along with pachymetric mapping, considering
it computes a three-dimensional image of the cornea
• These systems allow evaluation of the posterior
corneal surface and thus generation of corneal
thickness maps, as well as greater coverage of the
peripheral cornea

11. Corneal Topography
• Topography derives from the Greek words “to place”
(topo) and “to write” (graphein), which means to
describe a place.
• Corneal topography represented a true revolution in
the diagnosis and management of corneal disease.
• The term “corneal topography,” however, is a
misnomer, in that most of these systems measured
slope and produced a derived curvature map.

13. Specular microscopy
• is a non-contact technique allowing visualisation
and analysis of the corneal endothelium.

15. Corneal and anterior segment Optical
Coherence Tomography (OCT)
• OCT uses interferometry to provide high resolution
cross-sectional images of the cornea and anterior
segment in a non-invasive manner.

16. Posterior segment photography
•Retinal photography is a standard
technique that must be available in all
eye departments

17. Fundus photography
Fundus photography involves
capturing a photograph of the back of
the eye i.e. fundus. The main
structures that can be visualized on a
fundus photo are the central and
peripheral retina, optic disc and
macula. The optical design is based on
the principle of monocular indirect
ophthalmoscopy. Fundus photography
can be performed with colored filters,
or with specialized dyes including
fluorescein and indocyanine green.

18. Modes
• Color
• Red free fundus photography :Red free photography is
also regularly used as a base line photo prior to
Angiography
• Angiography : is a process of photographing/ recording
vascular flow within the retina and surrounding tissue by
injecting a fluorescent dye into the blood stream
• Simultaneous stereo fundus photos :photographing the
retina from two slightly different angles. These two images
are later used together to create a 3D image.

20. Optic disc imaging
• Imaging of the optic disc is becoming an
increasingly important part of the
monitoring of patients with glaucoma.
• Imaging modalities in common use include
• stereophotography,
• confocal scanning laser ophthalmoscopy,
• scanning laser ophthalmoscopy scanning laser
polarimetry and
• OCT

22. Optical Coherence Tomography
• Optical coherence tomography (OCT) is a relatively
new imaging procedure that is useful in the
diagnosis of several retinal disorders that have
traditionally been imaged with fundus photography
or fluorescein angiography
• OCT imaging provides direct cross-sectional images
of the macula(diagnosis, treatment and
monitoring), retinal nerve fiber layer and optic
nerve for objective measurement and clinical
evaluation in the detection of retinal diseases and
glaucoma.

24. Ultrasonography
• Very high frequency, low energy and short duration
ultrasonic pulses are transmitted into theocular and
orbital structures from a ‘probe’1via a coupling
agent. In the time intervals between pulse
transmissions, reflections from tissues are received
by the same probe and the signals can be used to
produce various types of detailed images of the eye
and orbit.

25. A-Scan ultrasound
• A rountine part of the preoperative calculation of
intraocular lens power via the means of measuring
axial length and must be available in all
departments undertaking cataract surgery

26. B scan ultrasound
• The B-scan technique produces a cross-sectional
image of the eye and obit. Greater value in the
evaluation of vitreoretinal disease.