Week 7 RF-Reading with central vision loss

Question 1

How does what you’re looking at effect the quality of detail?

Answer 1

• Directly looking at something = high detail
• Further out to the side/periphery from where you’re looking = much less detail/visual acuity

Question 2

What is the size of the Macula and Fovea?

Answer 2

■ Macula (5.5mm) (give us sharp vision)

■ Fovea (1.5 mm) – greatest visual acuity (inside the macula and gives greater visual acuity)

■ Rods (Roughly 91 million cells) – dark adapted vision, low acuity

■ Cones (Roughly 4.5 million cells) – colour vision, high detailed vision, high acuity –
located in the centre of the macula

Question 3

What is Age-related Macular Degeneration
(AMD)?

Answer 3

■ An eye disease which results in a loss of central vision – Macula

■ Macula is responsible for central vision / high detailed vision

■ Results in severe vision loss / blindness

■ Typically affects aged 50+

■ Causes: Unknown

■ Risk Factors: Smoking, genetic, poor diet

■ Treatments: Aim to stabilise vision (wet
macular degeneration, eye injections) (does not cure this however, just slows the rate of losing vision) used for Wet AMD not Dry AMD

Question 4

How does Dry AMD become Wet AMD?

Answer 4

1. Waste products (drusan:yellow lipid products) collect under the macula and disrupts the normal function of the retina (it thins the macular causing blurry vision)
2. New blood vessels grow behind the retina, causing swelling, bleeding, scarring and rapid vision changes.

-This affects everyday life and reduces the quality of it (e.g., reading is a big issue).

-Dry AMD always leads to Wet AMD causing central blindness (cannot see centrally but peripheral vision intact aka aschotoma)

Question 5

What is the Eye-movement system? (the oculomotor pattern)

Answer 5

-First will make a fixation (directly looking at the word)

-Then make a saccade (rapid change of eye movement) to jump to the next word

-Re-fixation is going back to look at the word

-We sometimes skip a few words but if we need to go back we do a regression

-A return sweep is a large regressive saccade (i.e., moving back to the start of the sentence but the next line).

Question 6

What are the characteristics leading to successful reading?

Answer 6

• Need highly detailed (central) vision for accurate perception of word form
• I.e. need to make a fixation on (almost) every word
• Make short saccades between the words

Question 7

What are some characteristics of oculomotor pattern?

Answer 7

• Fixations ~200ms
• Most words receive at least one direct fixation
• Skipping words ~20%
• Saccades ~15-40ms, ~5-9 chars
• Mostly progressive
• ~10-15% regressions
• = average reading speed ~250-350wpm

Question 8

Visual Impairments: What is Macular Degeneration?

Answer 8

• Most common cause of legal blindness
• Loss of central vision
• Visual distortion (metamorphopsia) (wavy blurry words)
• Fixation instability (can’t fixate on the word as they can’t see)
• Counterproductive attempts to foveate

Question 9

What is Eccentric Viewing?

Answer 9

■ A technique training the individual to direct their eye in a different position to see clearly and avoid their central scotoma.

■ Trains the brain to understand what it is
seeing using a different region of the
retina.

■ Using a Preferred Retinal Locus = area
of the retina that gives the best visual
acuity.

■ Individuals get training to use a different
region of the retina to see.

Question 10

What is Horizontally scrolling text?

Answer 10

• A line of horizontally scrolling text from right to left.
• News ticker, train board announcement.
• Dynamic text to support eccentric reading (Harvey, Walker & Anderson, 2019).
• Reading depends on sequence of *fixations and saccades (Findlay & Liversedge, 2000).

Question 11

What is Rapid Serial Visual Presentation (RSVP)?

Answer 11

One word is presented in the centre of the screen one after the other at varying speeds.

Question 12

RF: What is the purpose of the research?

Answer 12

To evaluate the potential of dynamic text formats (horizontal scrolling text and RSVP) as a way of enhancing reading with CVL by supporting effective use of the EV reading technique.

Question 13

RF: What are the methods of STUDY 1: SIMULATED CENTRAL SCOTOMA?

Answer 13

• Fifteen students (11 female), 18 to 32 years old (mean age, 20.40; SD = 3.94)
• normal or corrected-to-normal vision (best-corrected binocular visual acuity of 0.0 logMAR or better) (because they wanted to remove their central vision ethically)
• spoke English as their first language
• no language or reading deficits (self-report)

Question 14

RF: What is the apparatus of STUDY 1: SIMULATED CENTRAL SCOTOMA?

Answer 14

• 1920 × 1080-pixel monitor
• Viewing distance = 70 cm
• An EyeLink 1000 remote desktop-mounted eye-tracker recorded pupil and corneal reflection from the right eye at a sample rate of 1000 Hz (prevented central vision)
• The Experiment Builder program included custom Python code to mitigate some of the known limitations of gaze-contingent paradigms attributed to pupil size changes due to blinks

Question 15

RF: What is the design of STUDY 1: SIMULATED CENTRAL SCOTOMA?

Answer 15

-RSVP

-2 static text presentations (press space bar for next sentence)

-Multi-line paragraph format

-Asked participants to promote eccentric viewing and look below

Question 16

RF: What is the procedure of STUDY 1: SIMULATED CENTRAL SCOTOMA?

Answer 16

• LAB based – eye-tracker
• Speed of text – Previous pilot – aimed to match speed
• Participants read standardized passages of text (YARC Secondary) presented in each of the four text formats – passages of text were randomized
• Participants given practice passage before reading task
• Participants informed about eccentric viewing technique and to adopt this to the best of their ability
• Participants read aloud – scoring reading errors

*Comprehension questions completed after

Question 17

RF: What are the measures of STUDY 1: SIMULATED CENTRAL SCOTOMA?

Answer 17

• Reading performance (comprehension + errors) measured with each text
  display with artificial scotoma
• Comprehension – Literal (1-2 words), Inference (had to elaborate), Summary (had to summarise text), Total (total of each section)
• Adherence to eccentric viewing technique with each text display except multiline
  (ROI analysis).

Question 18

RF: What are the results of STUDY 1: SIMULATED CENTRAL SCOTOMA? (eye-movement behaviour)

Answer 18

• Majority of fixations made with static and
  scrolling text located on or below the text
• Fewer fixations at the upper EV location
• Ability to hold gaze at the EV location -
  better in the RSVP condition than for the
  static or scrolling sentences.
• Participants found it very difficult to avoid
  making fixations onto the text despite the
  presence of the central scotoma.
• For all four text formats, the participants tended to shift gaze onto the text
• Scrolling text and RSVP text, the participant’s eye movement behaviour was
  broadly similar to that observed for reading
  without a CVL.
• For the static text formats, many more leftward saccades were made to reinspect the text - suggesting that a horizontal scanning strategy had been used.

Question 19

RF: What are the results of STUDY 1: SIMULATED CENTRAL SCOTOMA? (reading performance)

Answer 19

• Literal comprehension better with RSVP than static texts, Scrolling better than static
  texts, no significant differences
  between scroll and RSVP
• Inferential Comprehension – significantly better with scrolling text and poorest with
  RSVP
• Percentage of key points remembered significantly better with scrolling than other
  text displays
• Overall comprehension better with scrolling text display

Question 20

RF: What is the participant sample of STUDY 2: MACULAR DEGENERATION?

Answer 20

• Diagnosis of Wet / Dry macular degeneration + CVL in either (RE, LE, BOTH)
• English as first language
• 37 participants (32 female, 5 male)
• Mean age = 77.54 years and SD = 10.89
• Mean years since diagnosis = 8.68 and SD = 5.14
• Six-Item Cognitive Impairment Test (to rule out dementia and Alzheimers)
• Exclusion criteria = ocular comorbidities and any language, reading, or cognitive impairment.
• All participants aware of EV technique.

Question 21

RF: What is the apparatus of STUDY 2: MACULAR DEGENERATION?

Answer 21

Same as Study 1 EXCEPT:
* Conducted in own homes

• YARC Primary Passages of text used
• Static / Scrolling = iPad
• RSVP = Samsung (custom coded in-house app)
• Static text (SL+ML) - PowerPoint
• Horizontally Scrolling text – MD_evReader app
• Scrolling text given before RSVP text (practice session ONLY)

Question 22

RF: What is the procedure of STUDY 2: MACULAR DEGENERATION?

Answer 22

• Binocular-distance visual acuity obtained
  using the Bailey–Lovie Visual Acuity
  chart (used in general eye tests)
• Near visual obtained using Digital
  MNRead app
• Font size based on MNRead digital
  reading test - set as two times each
  participant’s critical print size from the
  digital MNRead
• Practice passage given – speed of text
  set, RSVP and scrolling matched

Question 23

RF: What are the results of STUDY 2: MACULAR DEGENERATION?

Answer 23

• Overall reading comprehension better with scrolling than all other text displays, F(3,108) =13.02, p < 0.001, and η2G =
  0.18.
• Higher proportion of errors observed for the RSVP format (mean = 11.39%, SE = 2.76) than for all other text displays (scrolling text display mean = 1.35%, SE = 0.38; single-
  line static text mean = 2.13%, SE = 0.69; multiple-line paragraph format mean
  = 2.82%, SE = 0.69).

Question 24

RF: What are the summary and conclusions for both studies?

Answer 24

STUDY 1
* Adherence to EV in the simulated scotoma group was poor
* Adherence to EV was better with RSVP BUT resulted in poor comprehension and accuracy
* Static text and scrolling lines - participants adopted a strategy of scanning around the text itself and appear to have been reading by recognizing words on either side of the central scotoma
* Reading performance - best with the scrolling text format (cannot be attributed to better adherence to EV with a simulated CVL)

STUDY 2
* BETTER reading performance with scrolling text than with static text
* Reading performance POOR overall with RSVP

CONCLUSION: We suggest that studies of reading should include MORE than one
measure of performance, and that scrolling text may support effective reading in
people with CVL and as such has potential as a reading aid.