PHOTO DOCUMENTATION AND OCULAR IMAGING

Question 1

how frequent should we conduct eye exams for normal px

Answer 1

below 16 and above 60: annually

everyone else: every 2 years

Question 2

how frequent should we conduct eye exams for at risk px

Answer 2

below 16 and above 60: every 6 months or earlier if indicated
everyone else: annually or earlier if indicated

Question 3

why do we need photo documentation?

Answer 3

provide record of anomalies
future comparison
communication betw px and us
px education

Question 4

where are photos taken and what machines are used?

Answer 4

1. anteriorly: slit lamp (anterior structures) , specular microscopy (endo cells, check for pleomorphism and polymegathism), ext ocular photography
2. posteriorly: fundus photography

Question 5

what does gonioscopy and volk lens photography do?

Answer 5

gonioscopy: ant chamber angle

volk lens: fundus

Question 6

what are the 3 devices available for fundus photography?

Answer 6

1. optos daytona
2. zeiss fundus cam
3. topcon

Question 7

what are the 3 advantages of optos daytona?

Answer 7

1. able to perform on small pupils
2. large view of fundus (200 deg)
3. no dilation required

Question 8

what are the 4 disadvantages of optos daytona?

Answer 8

1. expensive
2. not actual retina colour image
3. px need to be able to sit up (mobile)
4. difficult if px does not understand instruction

Question 9

describe the function of zeiss fundus camera. what is one disadvantage?

Answer 9

provide 45 deg view of the fundus.

can be tricky with small pupils or media opacities

Question 10

in general what are the 3 challenges faced in fundus photography?

Answer 10

1. small pupils
2. media opacities
3. poor fixation (cannot stay still)

Question 11

what is used for ocular imaging?

Answer 11

optical coherence tomography (OCT)

Question 12

describe 3 characteristics of OCT

Answer 12

1. non invasive
2. non contact
3. produce cross sectional images of layers of structures (anterior and posterior)

Question 13

what structures are shown in anterior OCT?

Answer 13

1. corneal thickness

2. ant chamber angle

Question 14

what structures are shown in posterior OCT?

Answer 14

1. macula
2. retina
3. optic nerve

Question 15

what are 3 limitations of OCT?

Answer 15

1. pupil size (>4mm)
2. medial clarity (edema, dense cataract and vitreous haemorrhage)
3. high astig / decentered IOL

Question 16

what are the 3 artificial defects of OCT scans?

Answer 16

1. blinking (appear as black gaps)
2. movement of eye (wavy retinal contour)
3. improper alignment of ONH (RNFL analysis abnormalities)

Question 17

what to do if these defects are seen?

Answer 17

retake scan

true defects and pathology will appear in repeated scans