A COMPARATIVE ANALYSIS OF VARIOUS AUTOMATED PERIMETERS

1
A PRESENTATION FROM RIO-GOH CHENNAI
2
A COMPARATIVE ANALYSIS OF VARIOUS AUTOMATED
PERIMETERS

• Author Prof. Dr. V. Velayutham
• Co-Authors Dr. D. Ranjit Prabhu
• Dr. Nirmal Fredrick
• Dr. Suma Elangovan

3
AIM

• Comparison of visual field plotting in glaucoma
  patients with
• Octopus Interzeag 1-2-3,
• Humphrey Field Analyzer II and
• Frequency Doubling Perimetry.

4
Design

• Prospective, Comparative study
• Participants
• 100 eyes of 50 patients who attended glaucoma
  clinic in RIO-GOH during Jan 2005 and March 2006.
• All patients were randomly selected

5
Inclusion Criteria

• Primary open angle glaucoma, Normo-tensive
  glaucoma and Glaucoma suspect
• Best corrected visual acuity 6/12 or better
• Gonio open angle ( gt2 by Shaffers Grading)
• Patients co-operative for visual field analysis

6
Exclusion Criteria

• Closed angles by gonioscopy
• Secondary and Congenital glaucoma
• Ocular diseases showing similar visual field
  defects
• Patients with media opacities - corneal edema /
  opacity, lens changes and retinal pathology
• Patients who underwent intraocular surgeries or
  laser treatment

7
Patient Evaluation

• Slit Lamp Examination
• Measurement of Intraocular pressure
• Slit Lamp Biomicroscopy Fundus
• Gonioscopy Angle Grading

8
Visual Field Examinations

• Octopus Interzeag 1-2-3 TOP
• Humphrey Field Analyzer II, central 30-2
  threshold test (SITA standard)
• Frequency Doubling Technology Full threshold
  (C-20)
• All tests were carried out within a period of one
  week by trained personnel.

9
Parameters Analysed

• Mean Deviation / Mean Defect and Pattern Standard
  deviation / Loss variance of both eyes were
  compared and correlated between these perimeters
  using the Pearson correlation and Scatter diagram
  with regression estimate
• Linear regression analysis was used to calculate
  the correlation coefficients.
• Statistical comparison between groups used
  unpaired 2-tailed-t-test.
• The average time taken to perform each test was
  analysed

10
Correlation of Mean Deviation / Defects between
the perimeters
RE
LE

• O-MD vs H-MD r -0.520, plt0.001
• O-MD vs F-MD r -0.723, plt0.001
• H-MD vs F-MD r 0.628, plt0.001

• O-MD vs H-MD r -0.581, plt0.001
• O-MD vs F-MD r -0.648, plt0.001
• H-MD vs F-MD r 0.683, plt0.001

11
Correlation of Pattern Standard Deviation / Loss
Variance between the perimeters
RE
LE

• O-LV vs H-PSD r 0.312, plt0.002
• O-LV vs F-PSD r 0.283, plt0.05
• H-PSD vs F-PSD r 0.427, plt0.002

• O-LV vs H-PSD r 0.544, plt0.001
• O-LV vs F-PSD r 0.568, plt0.001
• H-PSD vs F-PSD r 0.650, plt0.001

12
Time Duration taken to perform the test
13
Discussion

• Octopus Mean Defects
• negatively correlates with Humphrey and FDT
• Humphrey Mean Deviation
• positively correlates with FDT
• P lt 0.001 statistically significant
• Octopus Loss Variance
• positively correlates with PSD of Humphrey and
  FDT
• Humphrey PSD
• positively correlates with FDT
• RE p lt 0.05 LE p lt 0.001 --- correlation
  statistically significant
• Test duration least in Octopus

14
Summarizing

• Visual field plotting with Octopus (TOP) is
  shortest
• Global indices arrived at field plotting with all
  three perimeters are comparable

15
THANK YOU