Dr. Rinkle Phusate, G09648
Background:
Whenever a new study is done, it explores the newer techniques and ideas to be incorporated in day to day practice. This study goes retrograde and tries to reassess the viability of an old not so explored modified Bagolini starlight test in present clinical set up.
Visual field assessment is important aspect of evaluation of neurological diseases and automated perimetry is routinely used for it.
Bagolini test is used to assess binocular vision status and this modified Bagolini starlight test was introduced as an easy cost effective method of screening binocular visual fields.
Aim :
To assess viability and possible uses of starlight test as screening test for detecting neurological field defects.
Method :
According to standards prescribed in previous study by T Hirai 1 a hand made customised board was made of size 75 cm x 75 cm . Nine electric bulbs of 2.5 v each were mounted in three horizontal rows and three vertical columns of lights forming a grid of nine lights .This device hangs on wall and each light can be separately operated.
Patient is examined at distance of 140 centimetres from the board.
Bagolini striated glasses mounted on trial frame are used aligned at 135 degrees in right eye and 45 degrees in left eye.
Patient is then asked to draw images as perceived with both eyes open. First with central light on, then with vertical row on, horizontal row on and finally with all nine lights on.
In case suppression is noted in one eye on binocular testing, the suppressed eye is tested separately again.
Positive results were noted in form of absent lines, broken lines, smaller arms of lines noted on the diagram drawn by the patients.
Inclusion criteria
Neuro ophthalmological cases were included. This included optic disc pallor, optic disc edema, pituitary adenoma and patients with suspected neurological cause for headache.
Exclusion criteria:
Patients with nystagmus, poor comprehension, very young patients and patients with retinal disease were excluded.
Total 39 patients with neuroophthalmological problem or those referred by neurophysician were screened with starlight test and visual field was then done by automated perimetry. Cases were studied to establish if screening with starlight can give any clue about possible field defect and to try to correlate if any particular pattern on starlight was associated with any specific field defect.
Results:
Total 78 eyes of 39 patients were included in the study. 51% were male and 49% were females. (Table 1 )
Age of patients ranged from 12 to 77 yrs. (Table 1 )
33% were under evaluation of disc pallor, 12% were under evaluation for headache.Disc edema was present in 7.6%, optic neuritis in 7.6% and traumatic optic neuropathy in 7.6%
Other diagnosis included occipital infarct, toxic neuropathy and advanced glaucoma with suspected neurological deficits.(Table 2 )
On automated perimetry, out of 39 patients, defined defects were present in 18(46.15%) in right eye and 14 (35.89%) in left eye. Grossly depressed field was present in 7 (17.94-%)in right eye and 5 (12.82%)in left eye. 9 patients (23.07%) showed unreliable fields in both eyes.
Right eye field was normal in 5 (12.82%) and left eye field was normal in 11 (28.20%) patients.(Table 3 )
On modified Bagolini starlight test, 29 patients (74.35%) showed positive result. 5 patients (12.82%) had normal results and 5 (12.82%) had unreliable results. This denotes sensitivity of the test. (Table 4 )
When starlight results were correlated to automated perimetry results, out of 39 patients were:
29 patients showed positive starlight results. i.e 74.38% patients gave some form of pattern on starlight as compared to 26 patients i.e. 66.66%.
Out of these 21 patients (53.84%) showed positive defects on both starlight and perimetry. (72.41% sensitivity/ true positive) (Tablet 5)
8 (20.51%) patients showed positive defects on starlight but unreliable reports no defects on perimetry.
( false positives) . In other words, starlight indicated some defect in up 20.5% cases which were normal on perimetry or had unreliable readings. (Table 5 )
Out of 10 patients who showed negative starlight results,
5 patients (12.82%) who showed positive defects on automated perimetry showed normal starlight results. (False negative). In other words, starlight test missed 12.8% cases positive on automated perimetry. (Table 5)
5 patients (12.82%) showed no positive defects on both starlight and perimetry. (Table 5)
Considering 26 patients who showed defects on perimetry, 21(80.76%) showed positive starlight results and 5(0.96%) showed no defect on starlight. In other words, starlight correlated with perimetry findings in 80.76% .
Out of 13 patients in whom automated perimetry was normal or unreliable, 8 (61.53%) showed defect on starlight. i.e starlight helped in 61.53% patients where automated perimetry was inconclusive. This denotes that starlight might give idea about field loss in eyes with highly unreliable fields.
Out of 12 patients who showed pattern defects on perimetry in form of hemianopia or quadrantanopia , 11 showed starlight findings corresponding to the defects.
Discussion:
Visual fields assessment is important in the evaluation of lesions involving the visual pathways.
Automated perimetry is gold standard for evaluation of visual fields in ophthalmic set up.
Pituitary tumour comprises 12-15% of intracranial tumours . Prevalence of visual field defects reported in 37-96%, many a times only visual symptoms manifesting early. 4 Screening suspected patients for visual field defects can help early diagnosis especially in asymptomatic patients.
Visual fields can be performed by a number of different techniques including confrontation, tangent screen, Goldman kinetic perimetry and automated static perimetry.2
The sensitivity of confrontation techniques is about 20% for detection of arcuate field defects and about 70% for detection of hemianopia when compared to Goldmann and automated perimetry. 3
Octopus 900 perimeter has been used to assess neural field defects in previous studies. 5
This study is a small study with aim to assess whether a economic model of Bagolini striated glasses with starlight board can be used for screening of visual field defects in neurologists clinic set up .
Out of 13 patients in whom automated perimetry was normal or unreliable, 8 (61.53%) showed defect on starlight. i.e starlight helped in 61.53% patients where automated perimetry was inconclusive.This denotes that starlight might give idea about field loss in eyes with highly unreliable fields.
8 (20.51%) patients showed positive defects on starlight but unreliable perimetry. (27.58% false positives) . In other words, starlight indicated some defect in up 20.5% cases which were normal on perimetry or had unreliable readings. (Table 5)
Out of 10 patients who showed negative starlight results,
5 patients (12.82%) who showed positive defects on automated perimetry showed normal starlight results. ( false negative ) . In other words, starlight test missed 12.8% cases positive on automated perimetry
Diagnosis wise analysis of data showed that,
In 13 patients with disc pallor: starlight results correlates with automated perimetry findings in 8 patients.
11 patients had positive starlight report.
9 patients had positive automated perimetry reports.
3 patients with inconclusive automated perimetry showed positive defects on starlight.
In 2 patients with pituitary tumour,
1 patient had normal results on automated perimetry as well as starlight.
1 patient had unreliable fields but showed positive results on starlight in form of inferior temporal defects.
In 3 patients with optic neuritis
2 had left optic neuritis with unreliable fields in both eyes and showed grossly depressed fields in eye with optic neuritis with normal pattern in other eye. Here starlight helped pick up normal fields in normal eye with otherwise unreliable fields parameters.
1 patient had fields and starlight results correlating.
3 patients had disc edema of which 2 showed increased blind spot on automated perimetry but these defects were missed on starlight. One patient showed inferior field defect which was also noted on starlight.
When visual acuity was worse than 3/60, starlight showed suppression of affected eye on binocular testing. Occlusion of better eye was done to assess if any defect patterns can be detected.
1 patient had sixth nerve palsy with normal fields and starlight but starlight showing diplopia.
1 patient had left third nerve palsy with left homonymous hemianopia. Starlight showed suppression of left eye on binocular testing and uniocular testing with each eye revealed defects on left hemifield .
Starlight showed to be more helpful in gross peripheral field defects and hence looks promising in screening neurological visual field defects.
Conclusion
Clinical basic tests hold immense importance in evaluation of a patient.
Starlight test can be used as screening tests for contemplating possible neurological field deficits . Being very economical on time and resources can aid neurologist for office screening where expensive and time consuming automated perimetry cannot be done.
Limitations:
This is study with small sample size, very limited patients were chosen and observer bias is possible. Larger sample size, comparative study, mass screening, standardization of notation of results are some aspects which can further add value to this small case series.
References
1. Modified Bagolini striated glass test : clinical applications of starlight test in binocular visual field screening.
T Hirai, M Arai, Y Ito, M Sato
Br j oph 1998; 82:1288-1293
2. Trobe JD, Acosta PC, Krischer JP, Trick GL .
Confrontation visual field techniques in the detection of anterior visual pathway lesions .
Ann Neurol. 1981; 10:28-34
3. Johnson LN, Baloh FG. The accuracy of confrontation visual field test in comparison with automated perimetry. J Natl Med Assoc. 1991; 83:895–8.
4. Cross sectional study of visual field defects in pituitary gland tumours.
S Ananth Bhandary, Satyendranath B Shetty, Prarthana Bhandary, Shruti P Babu.
Journal of Evolution of Medical and Dental Sciences 2014 ; vol 3 , Issue 36 , August 18 ; page 9389-9397
5. Comparison of Octopus Semi-Automated Kinetic Perimetry and Humphrey Peripheral Static Perimetry in Neuro-Ophthalmic Cases
Fiona J. Rowe,Carmel Noonan,and Melanie Manuel
ISRN Ophthalmology
Volume 2013, Article ID 753202, 8 pages https://dx.doi.org/10.1155/2013/753202
Table no. 1
| Total number of patients | 39 | |
| Male | 20 | 51% |
| Female | 19 | 49% |
| Age | 12 to 77 yrs |
Table no 2
| Clinical diagnosis | Number of patients |
| Disc pallor under evaluation | 13 |
| Headache under evaluation | 5 |
| Optic neuritis | 3 |
| AION | 1 |
| Occipital infarct | 1 |
| Pituitary adenoma | 2 |
| Disc edema | 3 |
| Traumatic optic neuropathy | 3 |
| Diabetic papillopathy | 1 |
| Nerve palsy | 2 |
| Toxic neuropathy | 1 |
| Glaucoma | 3 |
| Macular scar | 1 |
Results of automated perimetry in each eye
Table 3
| Automated perimetry results | OD | OS |
| Defective with suggestive pattern | 18
(46.15%) |
14
(35.89%) |
| Depressed | 7
(17.94%) |
5
(12.82%) |
| Unreliable | 9
(23.07%) |
9
(23.07%) |
| Normal | 5
(12.82%) |
11
(28.20%) |
Results of starlight test
Table no. 4
| Starlight results | ||
| Defects suggestive of pattern | 29 | 74.35% |
| Normal | 5 | 12.82% |
| Inconclusive results | 5 | 12.82% |
Table no 5
| Perimetry defects present YES | Perimetry defects
NO |
|
| Starlight defect YES | 21 (53.84%) | 8( 20.51%) |
| Starlight defects NO | 5 (12.82%) | 5 (12.82%) |
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