5
British Journal of Ophthalmology, 1987, 71, 489-493 A comparison of Goldmann and Humphrey automated perimetry in patients with glaucoma G E TROPE AND R BRITTON From the Department of Ophthalmology, University of Toronto, Toronto General Hospital, Toronto, Ontario, Canada SUMMARY Humphrey automated threshold perimetry (Program 30-2) was performed on 42 eyes of 25 patients with glaucoma to determine both the sensitivity and specificity of automated perimetry in detecting glaucomatous visual field defects. Automated perimetry sensitivity was 90-38%, while automated perimetry specificity was 91%. Fifty-two patients and a technician took part in a survey to determine their preference for either test. Patients generally preferred having Goldmann perimetry. The technician favoured Humphrey automated perimetry. Program 30-2 on the automated perimeter took 25% longer to perform than Goldmann perimetry. There are a number of automated perimeters on the market. These computerised perimeters all perform visual field tests using preprogrammed and/or pro- grammable test logics. Some of these perimeters can determine retinal threshold sensitivity, and their performance in patients with glaucoma has been favourably compared to that of standard, manual perimetry (Fig. 1).' The Humphrey automated perimeter is a new and relatively inexpensive automated perimeter that can perform both relatively rapid suprathreshold static perimetry for glaucoma screening and threshold static perimetry. Threshold perimetry allows for quantification and therefore follow-up of patients with glaucomatous visual field defects. Recent reports have indicated that the Humphrey perimeter can be favourably compared with conventional manual peri- meters.2' We are not, however, aware of studies comparing the sensitivity and specificity of this automated perimeter with standard Goldmann peri- metry in patients with glaucoma. The purpose of this study was two-fold. First we wished to determine patient and technician pre- ference for either machine. Secondly, we wished to determine the sensitivity and specificity of Humphrey automated perimetry using the Goldmann perimeter as standard in patients with glaucoma. Correspondence to G E Trope, FRCS cd, Toronto General Hospital, Department of Ophthalmology, Glaucoma Division, 200 Elizabeth Street, EN 5-308, Toronto, Ontario, Canada M5G 2C4. Fig. 1 Humphrey automated perimetry. 489 on 18 May 2018 by guest. Protected by copyright. http://bjo.bmj.com/ Br J Ophthalmol: first published as 10.1136/bjo.71.7.489 on 1 July 1987. Downloaded from

Acomparison of Goldmann and Humphrey …bjo.bmj.com/content/bjophthalmol/71/7/489.full.pdfAcomparisonofGoldmannandHumphreyautomatedperimetryinpatientswithglaucoma performedwithProgram30-2

  • Upload
    dotuong

  • View
    214

  • Download
    2

Embed Size (px)

Citation preview

Page 1: Acomparison of Goldmann and Humphrey …bjo.bmj.com/content/bjophthalmol/71/7/489.full.pdfAcomparisonofGoldmannandHumphreyautomatedperimetryinpatientswithglaucoma performedwithProgram30-2

British Journal of Ophthalmology, 1987, 71, 489-493

A comparison of Goldmann and Humphreyautomated perimetry in patients with glaucomaG E TROPE AND R BRITTON

From the Department ofOphthalmology, University of Toronto, Toronto General Hospital, Toronto, Ontario,Canada

SUMMARY Humphrey automated threshold perimetry (Program 30-2) was performed on 42 eyesof 25 patients with glaucoma to determine both the sensitivity and specificity of automatedperimetry in detecting glaucomatous visual field defects. Automated perimetry sensitivity was90-38%, while automated perimetry specificity was 91%. Fifty-two patients and a technician tookpart in a survey to determine their preference for either test. Patients generally preferred havingGoldmann perimetry. The technician favoured Humphrey automated perimetry. Program 30-2 onthe automated perimeter took 25% longer to perform than Goldmann perimetry.

There are a number of automated perimeters on themarket. These computerised perimeters all performvisual field tests using preprogrammed and/or pro-grammable test logics. Some of these perimeters candetermine retinal threshold sensitivity, and theirperformance in patients with glaucoma has beenfavourably compared to that of standard, manualperimetry (Fig. 1).'The Humphrey automated perimeter is a new and

relatively inexpensive automated perimeter that canperform both relatively rapid suprathreshold staticperimetry for glaucoma screening and thresholdstatic perimetry. Threshold perimetry allows forquantification and therefore follow-up of patientswith glaucomatous visual field defects. Recent reportshave indicated that the Humphrey perimeter can befavourably compared with conventional manual peri-meters.2' We are not, however, aware of studiescomparing the sensitivity and specificity of thisautomated perimeter with standard Goldmann peri-metry in patients with glaucoma.The purpose of this study was two-fold. First we

wished to determine patient and technician pre-ference for either machine. Secondly, we wished todetermine the sensitivity and specificity of Humphreyautomated perimetry using the Goldmann perimeteras standard in patients with glaucoma.

Correspondence toG E Trope, FRCS cd, Toronto General Hospital,Department of Ophthalmology, Glaucoma Division, 200 ElizabethStreet, EN 5-308, Toronto, Ontario, Canada M5G 2C4. Fig. 1 Humphrey automated perimetry.

489

on 18 May 2018 by guest. P

rotected by copyright.http://bjo.bm

j.com/

Br J O

phthalmol: first published as 10.1136/bjo.71.7.489 on 1 July 1987. D

ownloaded from

Page 2: Acomparison of Goldmann and Humphrey …bjo.bmj.com/content/bjophthalmol/71/7/489.full.pdfAcomparisonofGoldmannandHumphreyautomatedperimetryinpatientswithglaucoma performedwithProgram30-2

GE Trope and R Britton

Methods and materials

This study was divided into two parts.Part 1. This consisted of a patient and technician

survey. Fifty-two glaucomatous patients referred toour visual field service from a number oflocal ophthal-mologists were randomly allocated to Goldmannperimetry and Humphrey automated perimetry onthe same day. Program 30-2 was used on theautomated perimeter; Goldmann perimetry wasperformed by standard methods.4 Both eyes weretested on both machines.A number of questions were then asked of each

patient: (1) Which test did you prefer? (2) Withwhich machine was it easier to keep your eyesstraight? (3) Have you ever had a visual field test?The technician was then asked to fill out a question-

naire answering the following questions: (1) Withwhich perimeter was fixation superior? (2) Which

C E fy PIs^G4L

machine was easier to use? (3) Which perimeterwould you prefer to use in future on this particularpatient?The mean test time for both eyes on each perimeter

was recorded by the technician.Part 2. One or both eyes of 25 glaucomatous

patients attending the Toronto General HospitalGlaucoma Service were tested on both perimeters.Forty-two eyes in total were tested. Patients wererandomly allocated to either test. Some of thesepatients took part in part 1 of the study, but wereincluded in part 2 of the study (visual field com-parison study) only if the diagnosis of glaucoma hadbeen absolutely established in at least one eye in allcases by one of us (GT).

INSTRUMENTATIONGoldmann perimetry was performed by standardtechniques.4 Humphrey automated perimetry was

tf;IL:,tjI- i T

Fig. 2 A normalHumphrey visualfield.

0fI M L'.1-^ I R,I LI TeE 8 e EElE:-IN ';$P_1T '~~. :I E. 'I s

Fa~PTAP;LE:l CENTP4RLTPR TE5. FULL THREe-:-:HC L

FI X' T I LGEE E C0Ori*.OLIL1£fTr f tt'J'- 044 E1D 42FALSE PuC, ERIF4'F 0- I

,c-ALSE NEG EPPCQG'4 0-.I_;Z_:]I_':JPT!̂ ~tj CIFfr

sJWXITHI 4 OL, OF EJ.2ECTEP4CD.- DEFECTsCEPTH IN 0:

12 CIE `2ENTPRL REF L.VEV''

i CZ9. LEt 7L.: .L

PI- L; SE ID * "-

E: , PIs"I-HE ¢4 s :.! 4CE . 8A

'.,'sk

::.%f

i.. C1 F I7

.211LLt1:

t.4'.': " K K_, j ,, 'si.s: ?4

... .. t: 8: ." z ......................... >4 44

* -;- t- t -t °---- .Sm~wol-w+sj

^~~~~~~~~~......is...^'.̂ss..2...5^.sHTPuIFlH RlI 's,

NgXt-;N'TPUMENI`s--

490

..... ....................T

on 18 May 2018 by guest. P

rotected by copyright.http://bjo.bm

j.com/

Br J O

phthalmol: first published as 10.1136/bjo.71.7.489 on 1 July 1987. D

ownloaded from

Page 3: Acomparison of Goldmann and Humphrey …bjo.bmj.com/content/bjophthalmol/71/7/489.full.pdfAcomparisonofGoldmannandHumphreyautomatedperimetryinpatientswithglaucoma performedwithProgram30-2

A comparison ofGoldmann and Humphrey automatedperimetry in patients with glaucoma

performed with Program 30-2. This program tests thecentral 300 field at 76 points. Points tested are 6°apart. Initially, this automated perimeter determinesretinal threshold at four primary points-i.e., one ineach quadrant 10° from fixation. It does so bypresenting a stimulus which is very bright (supra-threshold). The intensity is then reduced in 4 dbdecrements until it is not seen. The stimulus thenincreases in 2 db increments until it is seen again. Thisvalue is recorded as the patient's retinal threshold.The four initial thresholds are then used as startingpoints to determine the thresholds of neighbouringpoints by means of the same bracketing technique.These points are used in a similar manner to deter-mine retinal thresholds of neighbouring points untilthe central 30° area has been fully tested. If a valuevaries from expected by more than 4 db, it isremeasured automatically.The Humphrey automated perimeter Program 30-2

uses a background illumination of 31-5 apostilbs witha 4 mm2 stimulus size (equivalent to Goldmannperimeter size III target); the appropriate near

correction for age is used.The nasal step was not tested in this study as the

nasal step program had not yet been installed in theperimeter. Fixation is monitored both by the tech-nician and indirectly by the machine.The blind spot is located at the beginning of the

test, and during the test approximately 10% of thestimuli are presented in the blind spot. If fixation isaccurate, the patient will not see any of the stimulipresented in the region of the blind spot. If thepatient responds that he does see a significantnumber of stimuli presented to the blind spot, a

beeping sound is emitted by the machine to alert thetechnician to encourage patient fixation. The numberof times fixation is lost is typed out on the result sheet.The test continues to run even if fixation is very poor.

The machine also assesses patient reliability byoccasionally producing just the sound associated withthe light stimulus without actually presenting thelight. If the patient responds to this sound, bypressing the response button, this is considered a

false positive result. Periodically a suprathresholdstimulus is presented to the patient that he/she shouldeasily see. If the patient fails to respond, this indicateslack of attention, a false negative result. Fixation lossand false positives and negatives are all printed outon the visual field chart together with a grey scale,decibel scale, and a scale that indicates deviationof retinal threshold from expected decibel values(Fig. 2).

ANALYSIS OF VISUAL FIELDSFor part 2 of this study (sensitivity and specificity) weused decibel criteria modified from papers published

by HeijI and Drance.' 5 The criteria for abnormalitywith the Humphrey automated perimeter were: (1)All peripheral test points were excluded to avoid lensrim artefact. (2) Test points immediately above andbelow the blind spot were excluded. (3) A 5 dbdifference between two neighbouring points in con-junction with a 10 db difference in mirror imagepoints between the upper and lower hemifield wereconsidered positive glaucoma visual field defects.(4) One or more points 15 db below the point ofhighest retinal sensitivity was considered an abnormalvisual field.

Sensitivity and specificity results were analysedaccording to standard methods.6 The sensitivity ofHumphrey automated perimetry was defined as thenumber of abnormal Humphrey visual fields dividedby the number of Goldmann abnormal visual fieldsexpressed as a percentage. Humphrey automatedperimetry specificity was determined by dividing thenumber of normal Humphrey automated perimetryfields by the number of normal Goldmann visualfields expressed as a percentage.

Results

Part 1. Table 1 reviews the results of the patientssurveyed. Sixty per cent of the patients preferredGoldmann perimetry. Patients generally thoughtfixation was easier to maintain with the Goldmannperimeter. Fifty four per cent of patients, however,had previously had a Goldmann visual field test.None of the patients had previously undergoneautomated visual field testing.Table 2 reviews the results of the technician

survey. Fixation appeared to be similar to thetechnician during both of the tests. The technicianfound automated perimetry overall a little easier toperform than Goldmann perimetry. Technician pre-ference strongly favoured Humphrey perimetry.The mean test time for both eyes was 26-2 minutes

Table 1 Fifty-two patient responses

Goldmann Humphrey Same

Patient preference 60% 17% 23%Fixation ease 44% 21% 35%Previous field test 54% 0% -

Table 2 Technician survey

Goldmann Humphrey Same

Fixation 15% 15% 70%Technical ease 10% 40% 50%Preference 13% 67% 20%

491

on 18 May 2018 by guest. P

rotected by copyright.http://bjo.bm

j.com/

Br J O

phthalmol: first published as 10.1136/bjo.71.7.489 on 1 July 1987. D

ownloaded from

Page 4: Acomparison of Goldmann and Humphrey …bjo.bmj.com/content/bjophthalmol/71/7/489.full.pdfAcomparisonofGoldmannandHumphreyautomatedperimetryinpatientswithglaucoma performedwithProgram30-2

GE Trope and R Britton

Table 3 Sensitivity and specificity ofHumphrey perimetryusing Goldmann perimetry as standard

Humphrey automated perimetry sensitivity:28 lOO0

- =90-3%31 1

Humphrey automated perimetry specificity:10 x100=91=91%11 1

for Goldmann perimetry and 32*6 minutes for auto-mated perimetry.

Part2. Table 3 reviews the sensitivity and specificityof Humphrey automated perimetry Program 32.

Sensitivity tests showed that the Humphrey auto-mated perimeter detected 28 abnormal glauco-matous visual fields out of a total of 31 abnormalfields (90.3%). Specificity tests showed that there

were 10 normal Humphrey fields compared with 11normal Goldmann fields (91%).

Discussion

The major purpose of this study was to determine thesensitivity and specificity of Humphrey automatedperimetry to detect glaucomatous visual field defectsusing the Goldmann perimeter as the standard. Theresults of this section of the study indicate thatProgram 30-2 is both highly sensitive and specific fordetecting glaucomatous visual field defects. Thesensitivity and specificity results reported here aresimilar to those reported for the Octopus perimeterusing Tubinger perimetry as the standard. 'Although the Humphrey automated perimeter is

both sensitive and specific for glaucomatous visualfield defects, it does have various drawbacks whencompared with Goldmann perimetry. Firstly, auto-

CENTR i-L 30 - 2 THF

STIMULUS II I m WHITE. ECKOND 31.5 R$SBLIND SPOT CHECK SIZE IrIFrXATION TRRGT CENTRRLSTRATEGY FULL FRON PRIOR DRTPREFERENCE TEST ORTE 09-OR-85S

R I. GHT

-WITHIN 4 De OF EXPECTED 1NO. DEFECT DEPTH IN DS.25 D05 .- CENITRAL REF LE'VEL

FeiE: S;HOL E T ESS T

NPME10 S8-53-40 BIRTHOATE O2-14-10DATE DR-O9-9S5 TIME 112O:52 AMPUPIL DIAMETER VA?X USED +3.50 DS MX DEG

FIXATI2J4 LOSSES 35.UiESTI-NS ASKED 540FALSE P05 ERRORS 1 ,17FPALSE NEC ERPR S G-1lFLT".TATION 5.9ED0

Q06 TEST TIME OO011724

..... :-

NO. THRESHOLD SI DRP(NO. SNCV'3R0 TIME

HUP H REEvgN INSTRUMEP-MT'

W_<w~~~_ s + - **_ 4 _~~lo- .wo

126~ ~ ~

JL a:L.I1_tCta tc

J

492

Fig. 3 An abnormal Humphreyvisualfield.

SJt 6 | r X

tf v z IO s §

9 , & ) § 8 , 9 4

'

e a 5 a .¢ t .< X 4 ,,,X =.. '; ' C Sh ^S k ' -t ..', Se ff : M:£9 oif v.7_e__&.

* ¢ ; -s!-f s Bt N 8 -fv .. w y .

} § 5 -tt ! r

a t r

t § ¢ r; v tS

on 18 May 2018 by guest. P

rotected by copyright.http://bjo.bm

j.com/

Br J O

phthalmol: first published as 10.1136/bjo.71.7.489 on 1 July 1987. D

ownloaded from

Page 5: Acomparison of Goldmann and Humphrey …bjo.bmj.com/content/bjophthalmol/71/7/489.full.pdfAcomparisonofGoldmannandHumphreyautomatedperimetryinpatientswithglaucoma performedwithProgram30-2

A comparison ofGoldmann and Humphrey automatedperimetry in patients with glaucoma

mated perimetry takes about 25% longer to performthan Goldmann manual perimetry. Further, patientsclearly prefer Goldmann perimetry to automatedperimetry, but this preference may be biased by thefact that nearly half the patients had previouslyundergone only Goldmann perimetry. Theprolonged test time, the rapid appearance anddisappearance of the light stimulus, and the fact thatthe test continues to run despite detection of poorfixation suggest to us that this automated perimeter inno way overcomes many of the major obstacles toaccurate visual field assessment such as accuratefixation, maintenance of concentration, and patientfatigue. A major advantage of the Humphrey auto-mated perimeter, however, is that it can be per-formed by less highly trained technicians. It alsoovercomes the tedium of manual perimetry, andoperator error is completely avoided.'

It is important to note that the use of only Program30-2 on the Humphrey automated perimeter,although highly sensitive and specific for glauco-matous visual field defects, will not detect visual fielddefects close to fixation nor in the nasal step area

beyond 30°. Furthermore, it will not detect defectsbetween the 76 points tested in the central 300 (Fig.3). The machine does, however, have a separateprogram to test the nasal step area and a macularthreshold program to test the visual field close to

fixation. Static profiles can also be tested. Otherprograms also exist which allow one to test areas nottested by Program 30-2. Clearly, however, the use ofProgram 30-2 with one or more of these other testprograms will add significantly to the already fairlylengthy test period. These combined programs will,however, allow for very accurate assessment of thevisual field in glaucoma.

We thank Mrs Mena Cali and other technicians at the TorontoGeneral Hospital for performing visual field tests. We also thankDr Clive Mortimer for his help and Mrs Gail Taylor-Cole for typingthe manuscript.References

1 Heijl A, Drance SM. A clinical comparison of three computerizedautomatic perimeters in the detection of glaucoma defects. ArchOphthalmol 1981; 99: 832-6.

2 Beck RW, Bergstrom TJ, Lichter PR. A clinical comparisonof visual field testing with a new automated perimeter, theHumphrey field analyzer and the Goldmann perimeter. Ophthal-mology 1985; 92: 77-82.

3 Mogil LG, Abramovsky-Kaplan I, Rosenthal S, Podos SM.Comparison of Goldmann, Humphrey and Octopus perimetry inglaucoma. Invest Ophthalmol Vis Sci 1985; 26: 225.

4 Rock WJ, Drance SM, Morgan RW. A modification of Armalyvisual field screening technique for glaucoma. Can J Ophthalmol1981; 6: 283-90.

5 Heijl A. Computerized perimetry. Trans Ophthalmol Soc UK1984; 104: 76-87.

6 Sommer A. Epidemiology and statistics for the ophthalmologist.New York: Oxford University Press, 1980: 11.

Acceptedfor publication 27August 1986.

493

on 18 May 2018 by guest. P

rotected by copyright.http://bjo.bm

j.com/

Br J O

phthalmol: first published as 10.1136/bjo.71.7.489 on 1 July 1987. D

ownloaded from