ArticlePDF Available

Correlation Between Visual Field Functional and Optic Nerve Disc Structural Damage of Patients With Glaucoma

Authors:

Abstract and Figures

Introduction.Retrospective study were made to find out the correlation between visual field functional and optic nerve disc structural damage of patients with glaucoma in early and late stage of disease. Aim of the study. The aim of the present research was to characterize the relationships between visual field functional and optic nerve disc structural damage of patients with glaucoma in different stage of disease and create the basis of correlation. Material and methods. Together 94 patients (137 eyes) were analyzed from Pauls Stradins clinical university hospital ophthalmology clinic, whom during years 2010 - 2012 were made computerized visual field at least more than 3 times and optical coherence tomography (OCT) research in one day. Following data as retinal nerve fiber layer scan with OCT of optic nerve disc and visual field were analyzed. Patients were divided into two groups according to the vision field functional damage severity. First group - patients in moderate stage of glaucoma, but second - in late stage of disease. From visual field examination was rated numerical corrected/pattern deviation map from age related norm values and compared with OCT Spectralis optic nerve retinal nerve fiber layer measurements using Garway - Heath map. Results. The average age of patients were 73.94 years ± 6.95 years. Glaucoma in moderate stage was diagnosed in 96 (70.1%) of patients eyes, but in late stage - 41 (29.9%) eyes. In moderate stage the positive correlation was found in 72.9%% (70/96), but in 27.1% the correlation was not found with one of the diagnostic methods. (p
No caption available
… 
No caption available
… 
Content may be subject to copyright.
ACTA CHIRURGICA LATVIENSIS • 2015 (15/1)
46
SUMMARY:
Introduction.Retrospective study were made to find out the correlation between visual field functional and optic nerve disc structural
damage of patients with glaucoma in early and late stage of disease.
Aim of the study. The aim of the present research was to characterize the relationships between visual field functional and optic
nerve disc structural damage of patients with glaucoma in different stage of disease and create the basis of correlation.
Material and methods. Together 94 patients (137 eyes) were analyzed from Pauls Stradins clinical university hospital ophthalmology
clinic, whom during years 2010 – 2012 were made computerized visual field at least more than 3 times and optical coherence
tomography (OCT) research in one day. Following data as retinal nerve fiber layer scan with OCT of optic nerve disc and visual
field were analyzed. Patients were divided into two groups according to the vision field functional damage severity. First group -
patients in moderate stage of glaucoma, but second – in late stage of disease. From visual field examination was rated numerical
corrected/pattern deviation map from age related norm values and compared with OCT Spectralis optic nerve retinal nerve fiber layer
measurements using Garway – Heath map.
Results. The average age of patients were 73.94 years ± 6.95 years. Glaucoma in moderate stage was diagnosed in 96 (70.1%) of
patients eyes, but in late stage – 41 (29.9%) eyes. In moderate stage the positive correlation was found in 72.9%% (70/96), but in
27.1% the correlation was not found with one of the diagnostic methods. (p<0.01). Looking trough out the results in moderate stage
of disease the structural damage was recognized in 91.66% (88/96) cases, but functional visual field loss in 81.25% (78/96) cases.
In severe stage of glaucoma the positive correlation between the diagnostic methods was in 92.68% (38/41), but in 7.32% (3/41)
the OCT didn’t show the damage as wide as visual field. (p<0.18).
Conclusion. Correlation between functional changes diagnosed by OCT RNFL scan and structural damage shown by computerized
perimetry data seems to depend on the stage of glaucoma.
Key words: glaucoma, visual field functional damage, optic nerve disc structural damage, optical coherence tomography retinal
nerve fiber layer scan, computerized perimetry
ORIGINAL ARTICLE
Correlation Between Visual Field Functional
and Optic Nerve Disc Structural Damage
of Patients With Glaucoma
Eriks Elksnis*,** Ilze Lace*
*Riga Stradins University, Riga, Latvia
**Department of Ophthalmology, Pauls Stradins Clinical University hospital, Riga, Latvia
AIM OF THE STUDY
The aim of the present research was to characterize the
relationships between visual field functional and optic
nerve disc structural damage of patients with glaucoma
in different stage of disease and create the basis of
correlation.
MATERIAL AND METHODS
In this retrospective study, wich was conducted in Pauls
Stradins Clinicac University Hospital, Ophthalomogy
clinic, together 94 patients with before diagnosed
glaucoma were analyzed, whom during years 2010
– 2012 were made computerized visual field and
OCT spectralis optic disc retinal nerve fiber layer scan
researches in the same day. Patients were divided
into two groups according to visual field damage
criteria from American Academy of Ophthalmology
ICD-9 glaucoma staging. First group of patients,
who had moderate-stage of glaucoma (optic nerve
disc abnormalities consistent with glaucoma and
glaucomatous visual field abnormalities in one hemi
field, second group consisted of patients with severe-
stage of glaucoma, advanced-stage glaucoma, end-stage
glaucoma (optic nerve abnormalities consistent with
INTRODUCTION
Functional loss in glaucoma is usually insidious and
starts peripherally, leaving patients asymptomatic in the
early stages of the disease. Currently, we do not have
any clinically applicable direct way to measure neuronal
loss in glaucoma and we use, instead, different surrogate
measures to estimate the functional and structural loss
in this disease. It is a paramount importance to have
sensitive and specific tests to detect subtle optic nerve
and/or visual field changes both for early diagnosis of
the disease and for monitoring it. Optic disc and visual
field assessments are a complex task, that have become
an integral part of glaucoma management. Until
recently, most studies have relied on subjective and
nonquantitative ways to assess structural damage. With
the advantage of automated imaging techniques, we
have, for the first time, the capability to reliably quantify
structural loss in glaucoma. (10) It is fair to say that these
new structural tests as optical coherence tomography
(OCT) and functional tests as automated perimetry are
allowing us to reexamine the nature and the strength of
structure – function correlation in glaucoma.
10.1515/chilat-2016-0009
Unauthenticated
Download Date | 5/16/16 3:02 PM
ACTA CHIRURGICA LATVIENSIS • 2015 (15/1)
47
glaucoma and glaucomatous visual field abnormalities
in both hemi fields. (9)
To assess functional damage, the numerical corrected/
pattern deviation map according to age related norm
values from the glaucoma hemifield test of computerized
visual field were rated, which is highly believed the
single most useful statistical analysis for glaucoma
diagnostics and monitoring. (1) To differentiate the
glaucomatous visual field damage from normal visual
field, only deviation of -5dB or greater from age related-
normal sensitivity, wich is quite unusual-and therefore
statistically significant, was accepted for further analysis.
(3) To measure the damage of optic disc the optical
coherence tomography (OCT spectralis) retinal nerve
fiber layer (RNFL) scan and analyses were overlooked.
(Table 1. Table 2.)
To evaluate the structure-function relationship the
Garway-Heath dot map was used as an example of
topographic map for correlating areas of visual field to
the optic disc. (11)
In Pauls Stradins Clinical University Hospital,
ophthalmology clinic for glaucoma diagnostics generally
30-2 point system of glaucoma hemifield visual field is
used, which measure visual sensitivity at 76 locations,
but Garway-Heath map is designed for 24-2 visual field
point test, which consists of 54 test points, which are
the most central test locations and subset of those in the
30-2 test pattern. Essentially a 24-2 test is just a 30-2
with all of the outer ring of test points removed, except
for the nasal-most two. (2)
All the comparison of data named before consisted of
3 steps:
1. Modification of the visual field 30-2 pattern test
analyses to 24-2 pattern test.
2. Finding out statistically significant (-5 dB or more)
visual field damage points.
3. Converting the appropriate visual field areas to
OCT retinal nerve fiber layer scan test according to
Garway-Heath dott map.
Data were analyzed using SPSS statistical program
version 21.0 and Microsoft Office Excel 2007. The
obtained results were compared using χ square method
correlation test. The p value < 0.05 was accepted as
statistically valid.
RESULTS
As mentioned before 94 glaucoma patients (137 eyes)
with different stage according to damage of the visual
field were included in the study. The average age of
patients was 73.94 years ± 6.95 years. 62.5% females,
37.5% males. Glaucoma in moderate stage was
diagnosed in 96 (70.1%) of patients eyes, but in late/
severe stage – 41 (29.9%) eyes. In moderate stage of
glaucoma the positive and statistically proved correlation
between functional and structural damage was found
in 72.9%% (70/96) of cases, but in 27.1% (26/96) the
damage was not found with one of diagnostic methods.
(Table 3.) (p<0.01 χ square method). Looking trough out
the results in moderate stage of disease the structural
damage was recognized by OCT in 91.66% (88/96)
eyes, but functional visual field loss in 81.25% (78/96)
eyes. (Table 4.) In late stage of glaucoma patients the
positive correlation between the diagnostic methods
was found in 92.68% (38/41) eyes, but in 7.32% (3/41)
the OCT didn’t show the damage as wide as visual field.
(Table 5.) Unfortunately the correlation between those
two diagnostic tests in the late stage of the disease was
not statistically proved. (p<0.18 by χ square method).
DISCUSSION
There is no discussion that structure and function are
correlated in glaucoma and both are important for
making diagnosis of the disease and/or for monitoring
it. Studies that examined in grater details the structure-
function relationship in glaucoma patients have
produced variable results. (5; 7) The strength of the
relationship seems to depend strongly on the stage of
the disease, as well as on the techniques used to measure
the structure and function. (8) It is frequently believed
that optic disc changes and, particularly, RNFL changes
often occur before detectable visual field loss. According
to our results optic disc examination is more useful at
earlier stages in glaucoma.
As the disease progresses, and in end-stage glaucoma,
visual field examinations become increasingly important
in monitoring glaucoma, since often in advanced
glaucoma the tests measuring structure do not have
any dynamic range left to allow for meaningful clinical
decisions. (6) In individuals with well-established
glaucoma, there is often disconnection between
structural and functional progression, due in part of
limitations in our ability determine progression with
current clinical measures.
There are a number of limitations in the assessment
of the relationship between structure and function
in glaucoma: (1) problems related to variability of
functional and structural measures; (2) the fact that
stimulus size in automated perimetry is typically
uniform across the visual field, leading to a mismatch
between stimulus size and the respective field size,
which increases with eccentricity; (3) the debate as to
whether there is selective loss of certain subpopulations
of retinal ganglion cells in glaucoma; (4) problems with
background luminance in automated perimetry; and (5)
peripheral optical defocus due to peripheral refractive
errors. (4)
It is only fairly to say that there is no irreplaceable
diagnostic method for glaucoma diagnostics and
monitoring. The computerized visual field, OCT optic
nerve disc retinal nerve fiber layer scan compliments
each other.
CONCLUSION
Correlation between functional changes diagnosed
by OCT RNFL scan and structural damage shown by
computerized perimetry data seems to depend on the
stage of glaucoma. Optic disc examination with OCT
retinal nerve fiber layer scan is more useful at earlier
stages in glaucoma, but in advanced disease the visual
field become more important for monitoring glaucoma.
Unauthenticated
Download Date | 5/16/16 3:02 PM
ACTA CHIRURGICA LATVIENSIS • 2015 (15/1)
48
Table 1. OCT RNFL scan of moderate stage glaucoma.
From Ophthalmology department of Pauls Stradins clinical university hospital.
Table 2. OCT RNFL scan for severe stage glaucoma.
From Ophthalmology department of Pauls Stradins clinical university hospital.
TS
57
(129)
NS
71
(102)
N
74
(72)
RNFL Thickness [ųm]
300
240
180
120
60
0
0 45
TMP SUP NAS
position [0]
INF TMP
90 135 180 225 270 315 360
NI
66
(103)
TI
56
(134)
T
61
(69)
G
65
(94)
NS
29
(102)
TS
35
(128)
T
45
(69)
RNFL Thickness [ųm]
300
240
180
120
60
0
0 45
TMP SUP NAS
position [0]
INF TMP
90 135 180 225 270 315 360
TI
67
(134)
NI
47
(103)
N
33
(72)
G
42
(94)
Unauthenticated
Download Date | 5/16/16 3:02 PM
ACTA CHIRURGICA LATVIENSIS • 2015 (15/1)
49
Conflict of interest: None
REFERENCES
1. Anders Heijl, Vincent Michael Patella, Boel
Bengtsson. The field analyzer primer 4th edition,
Effective perimetry 2012, Chapter 1: The essentials
of perimetry: 6.
2. Anders Heijl, Vincent Michael Patella, Boel
Bengtsson. The field analyzer primer 4th edition,
Effective perimetry 2012, Chapter 4: Choosing a
test: 29.
3. Anders Heijl, Vincent Michael Patella, Boel
Bengtsson. The field analyzer primer 4th edition,
Effective perimetry 2012, Chapter 5: STATPAC
Analysis of Single Fields: 47.
4. Anderson RS. The psychophysics of glaucoma:
improving the structure/function relationship. Prog
Retin Eye Res 2006; 25(1): 79-97.
5. Artes PH, Chauhan BC. Longitudinal changes in the
visual field and optic disc in glaucoma. Prog Retin
Eye Res 2005; 24(3):333-354.
6. Blumenthal EZ, et al. Correlating structure with
function in end-stage glaucoma. Ophthalmic Surg
Lasers Imaging 2006; 37(3):218-223.
7. Garway-Heath DF, et al. Relationship between
electrophysiological, psychophysical, and
anatomical measurements in glaucoma. Invest
Ophthalmol Vis Sci 2002; 43(7):2213-2220.
8. Girkin CA. Relationship between structure of
optic nerve/nerve fiber layer and functional
measurements in glaucoma. Curr Opin Ophthalmol
2004; 15(2):96-101.
9. Ronald L Fellman, MD, OCS, Cynthia G Mattox,
MD, Kim M Ross, OCS, CPS, Academy Coding
Specialist, Sue ViccHrilli, COT, OCS, Academy
Coding Executive. Eye Net Magazine/October
2011/Know the Glaucoma Staging Codes.
10. Tarek M Shaarawy, Mark B Sherwood, Roger A
Hitchings, Jonathan G Crowston. Glaucoma vol.
one, Medical diagnosis & therapy 2009, Section 3,
Chapter 20, Structure and Function Relationships
in Glaucoma: 251.
11. Tarek M Shaarawy, Mark B Sherwood, Roger A
Hitchings, Jonathan G Crowston. Glaucoma vol.
one, Medical diagnosis & therapy 2009, Section 3,
Chapter 20, Structure and Function Relationships
in Glaucoma: 253-254.
Address:
Eriks Elksnis
Department of Ophthalmology,
Pauls Stradins clinical university hospital
Pilsonu 13, Riga, Latvia LV 1003
e-mail: eriks.elksnis@inbox.lv
Table 3. Sternght of function-structure in
moderate stage of glaucoma
Table 4. Moderate stage of glaucoma
Table 5. Strenght of function-structure in severe
stage of glaucoma
Unauthenticated
Download Date | 5/16/16 3:02 PM
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
To evaluate the relationship between electrophysiological, psychophysical, and structural measurements in normal and glaucomatous eyes and to test the hypothesis that there is a continuous structure-function relationship between ganglion cell numbers and visual field sensitivity. Thirty-four normal subjects and 40 patients with glaucoma were examined with the pattern electroretinogram (PERG), perimetry and retinal tomography. Transient and steady state (SS) PERGs were recorded, and peak (P)-to-trough (N) amplitude was measured. The unit of differential light sensitivity (DLS) in perimetry is the decibel. The decibel is 10. log(1/Lambert), where the Lambert is the unit of test spot intensity. PERG amplitudes were correlated with decibel and 1/Lambert DLS for the central 18 degrees of the visual field and with neuroretinal rim area in the temporal part of the optic disc. Age-related changes in the structural and functional measurements were sought. The correlation between variables was investigated by linear and quadratic regression analysis. A quadratic (y = ax + bx(2) + c) fit was taken to be significantly better than a linear fit, if the coefficient (b) for the x(2) term was significant at P < 0.05. A quadratic fit between decibel DLS and PERG amplitude (transient PERG: R(2) = 0.40, P = 0.0000; SS PERG: R(2) = 0.32, P = 0.0000) was significantly better than a linear fit. There was a linear correlation between 1/Lambert DLS and PERG amplitude (transient PERG: R(2) = 0.44, P = 0.0000; SS PERG: R(2) = 0.35, P = 0.0000). There was a linear correlation between temporal neuroretinal rim area and PERG amplitude (transient PERG: R(2) = 0.17, P = 0.0003; SS PERG: R(2) = 0.20, P = 0.0001). A quadratic fit between decibel DLS and temporal neuroretinal rim area (R(2) = 0.38, P = 0.0000) was significantly better than a linear fit. There was a linear correlation between 1/Lambert DLS and temporal neuroretinal rim area (R(2) = 0.30, P = 0.0000). Both DLS and PERG amplitude declined with age in the normal subjects. The rate of decline was -0.17%, -0.74%, -0.75%, and -0.78% per year for decibel DLS, 1/Lambert DLS, transient PERG, and SS PERG, respectively. There is a curvilinear relationship between decibel DLS and both PERG amplitude and neuroretinal rim area, and a linear relationship between 1/Lambert DLS and PERG amplitude and neuroretinal rim area. These findings support the hypothesis that there is no ganglion cell functional reserve but a continuous structure-function relationship, and that the impression of a functional reserve results from the logarithmic (decibel) scaling of the visual field.
Article
Full-text available
To correlate structure and function in eyes with end-stage glaucoma. Fifty-six eyes of 48 patients with glaucoma presenting with end-stage glaucoma underwent scanning laser polarimetry (SLP) imaging using a commercially available GDx-variable corneal compensator unit (GDx-VCC; Laser Diagnostics Technologies, Inc., San Diego, CA). End-stage glaucoma was defined by both disc appearance and standard automated perimetry visual field criteria. Standard automated perimetry parameters included: mean deviation, pattern standard deviation, and total deviation plot. GDx parameters included: TSNIT average, superior average, inferior average, TSNIT standard deviation, and nerve fiber indicator. The visual field mean deviation was -26.75 +/- 3.50 dB. The remaining retinal nerve fiber layer measured in this group of eyes was: TSNIT average, 29.76 +/- 5.81 microm; superior average, 30.76 +/- 6.25 microm; and inferior average, 31.14 +/- 7.20 microm. A low structure-function correlation was found when analyzing separately the superior and inferior hemifields (R2 = 0.00001, R2 = 0.0016, respectively). In eyes with end-stage glaucoma, very thin but existing retinal nerve fiber layer is found on SLP. Such values rarely dropped below 10 to 20 microm. A flattening of the GDx TSNIT pattern was seen, and the correlation between structure and function was not evident.
Article
The nature and mode of functional and structural progression in open-angle glaucoma is a subject of considerable debate in the literature. While there is a traditionally held viewpoint that optic disc and/or nerve fibre layer changes precede visual field changes, there is surprisingly little published evidence from well-controlled prospective studies in this area, specifically with modern perimetric and imaging techniques. In this paper, we report on clinical data from both glaucoma patients and normal controls collected prospectively over several years, to address the relationship between visual field and optic disc changes in glaucoma using standard automated perimetry (SAP), high-pass resolution perimetry (HRP) and confocal scanning laser tomography (CSLT). We use several methods of analysis of longitudinal data and describe a new technique called "evidence of change" analysis which facilitates comparison between different tests. We demonstrate that current clinical indicators of visual function (SAP and HRP) and measures of optic disc structure (CSLT) provide largely independent measures of progression. We discuss the reasons for these findings as well as several methodological issues that pose challenges to elucidating the true structure-function relationship in glaucoma.
Article
Perimetry of some kind remains an important tool in the detection, diagnosis and monitoring of glaucomatous damage to the visual pathway. However, recent studies have served to reinforce the suspicion that conventional perimetry does not possess the sensitivity to detect the earliest signs of functional loss resulting from glaucoma. The relationship between differential light threshold and ganglion cell loss is extremely weak and, in the early stages of glaucoma, non-existent. Alternative, more novel perimetric techniques seem to offer promise of better detectability for early loss by claiming to tap in to one or other of the separate parallel pathways of the visual system. While some of these tests show potential for better detection and monitoring of glaucoma, the reasons why this might be so are not always clearly formulated or represented. This leads to misunderstanding of what the test actually measures and of the glaucomatous disease process itself. This paper seeks to revisit and review the theory underlying psychophysical testing of visual function related to glaucoma and stresses the importance of developing tests that are based on a firm theoretical understanding of visual function and processing in order to both detect glaucoma at an earlier stage and better understand the mechanisms of loss from the disease process.
Article
Glaucoma is a progressive optic neuropathy characterized by structural changes of the optic nerve and retina that are associated with the development of visual functional defects. The temporal relation between structural signs of the disease with psychophysical measures such as visual field tests is important to clarify to determine the best methods to detect glaucoma and progressive glaucomatous damage in the clinical setting. This paper reviews recent advancement in the perception of this structure-function relation. Quantitative measurement of optic disc and nerve fiber layer integrity have shown initial promise in early longitudinal studies in detecting progressive glaucoma before the development of progression using standard perimetry. Additionally, selective measures of visual function may be able to detect glaucoma before conventional methods as well; however, the relation between these newer specialized functional tests and optic disc analyzers in detecting progression awaits further study. Defining the clinical relation between structure and function cannot be done outside of the context of the instrumentation used to assess these parameters. Unfortunately, longitudinal studies that compare newer clinical instruments that measure the structural and functional characteristics of the optic nerve to current conventional testing are lacking, but are required to validate these emerging technologies.
The field analyzer primer 4th edition, Effective perimetry 2012
  • Anders Heijl
  • Vincent Michael Patella
  • Boel Bengtsson
Medical diagnosis & therapy Structure and Function Relationships in Glaucoma
  • M Tarek
  • Shaarawy
  • B Mark
  • Sherwood
  • A Roger
  • Hitchings
  • G Jonathan
  • Crowston
The field analyzer primer 4 th edition
  • Anders Heijl
  • Vincent Michael Patella
  • Boel Bengtsson
Anders Heijl, Vincent Michael Patella, Boel Bengtsson. The field analyzer primer 4 th edition, Effective perimetry 2012, Chapter 4: Choosing a test: 29.
  • M Tarek
  • Shaarawy
  • B Mark
  • Roger A Sherwood
  • Jonathan G Hitchings
  • Crowston
  • Glaucoma
Tarek M Shaarawy, Mark B Sherwood, Roger A Hitchings, Jonathan G Crowston. Glaucoma vol. one, Medical diagnosis & therapy 2009, Section 3, Chapter 20, Structure and Function Relationships in Glaucoma: 251.
  • M Tarek
  • Shaarawy
  • B Mark
  • Roger A Sherwood
  • Jonathan G Hitchings
  • Crowston
  • Glaucoma
Tarek M Shaarawy, Mark B Sherwood, Roger A Hitchings, Jonathan G Crowston. Glaucoma vol. one, Medical diagnosis & therapy 2009, Section 3, Chapter 20, Structure and Function Relationships in Glaucoma: 253-254.