|Year : 1971 | Volume
| Issue : 3 | Page : 102-107
Macular illumination tests in various refractive states of the eye
SD Paul, Kapalmit Singh
Department of Ophthalmology, Postgraduate Institute of Medical Education & Research, Chandigarh, India
S D Paul
Department of Ophthalmology, Postgraduate Institute of Medical Education & Research, Chandigarh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Paul S D, Singh K. Macular illumination tests in various refractive states of the eye. Indian J Ophthalmol 1971;19:102-7
|How to cite this URL:|
Paul S D, Singh K. Macular illumination tests in various refractive states of the eye. Indian J Ophthalmol [serial online] 1971 [cited 2021 Mar 3];19:102-7. Available from: https://www.ijo.in/text.asp?1971/19/3/102/34982
In previously communicated studies on macular illumination tests ,,, . it has been pointed out that these tests are very useful in assessing macular pathology. As the refractive errors are very common, this communication aims at analysing macular function tests in various refractive states of the eye with special emphasis on amblyopia cases encountered in this group.
| Methods and Material|| |
220 cases of various refractive errors were studied from the outpatient department of the Postgraduate Institute of Medical Education and Research, Chandigarh.
The patients were divided as follows:
In each case the macular illumination tests were done as described earlier. 
| Observations|| |
In high myopes with full vision and normal fundus [Table - 1] it can be appreciated that recovery time was almost within normal limits.
In the group ranging from 610D and 11-15D myopics [Table - 2] the recovery was delayed with green and red filter. It was more delayed with green filter as compared to the red one. The recovery without filter was normal in 6-10 D group, while it was delayed in the 11-15D group.
In the third group there were cases of bilateral myopia with anisometropia with one eye amblyopia. There was almost normal recovery in macular illumination tests [Table - 3].
Group iv was of high myopes with bilateral amblyopia macular illumination tests showed a normal response with red and green filter. The recovery was delayed in the case of without filter illumination. [Table - 4].
In the 5th group there were unilateral myopes with difference of 3D on either side. The macular illumination tests [Table - 5] showed normal recovery time.
The 6th group constituted of simple myopes having full vision and normal fundus. The macular illumination tests showed normal values [Table - 6].
In the 7th group of simple myopes with bilateral amblyopia (without anisometropia). The recovery without filter was normal but with red and green filters it was delayed. The delay was more with green than with red filter [Table - 7].
In hypermetropes having full vision and normal fundus the macular illumination test showed normal response [Table - 7].
In hypermetropes with bilateral amblyopia the macular illumination tests were normal [Table - 9].
So considering the averages [Table - 10] one can appreciate that in high myopes with degenerative changes recovery is delayed with green filter more than with the red filter. In cases with very high myopic error the recovery time is delayed without filter as well.
If individual groups are analysed [Table - 11] separately then it can be appreciated that considerable percentage of cases in each group show delayed recovery, when compared with the normal figures.
| Discussion|| |
It is common experience that quite a number of cases of various refractive errors do not improve fully inspite of the fact that their fundus is normal and there is no anisometropia. To ascribe any one factor responsible for this pecularity is not feasible.
By the available clinical methods it is not possible to ascertain if these cases were primary or secondary amblyopes. It has not been possible so far to explain the production of this amblyopia or to pin point the site of lesion.
Rendermann (1966) observed that considerable number of myopic (65%) amblyopes show abnormal ERG. In his series of 720 cases he found abnormal ERG in 65% of the cases. In myopic anisometropes (bilateral amblyopes) 73% showed abnormal ERG. In amblyopic hypermetropes this abnormality was 33%. In myopic anisometropes this abnormality was seen in 56% of the cases. As ERG is known to reveal generalised functional changes, this study indicates a considerable functional loss in amblyopes with refractive errors.
It has been pointed out earlier ,, that with the help of macular illumination tests (differential) it was possible to differentiate between angiospastic maculopathy and macular degenerations. The same criteria were applied to analyse the present series. It is apparant in the present study that when the averages in various groups are considered then the delay in recovery is observed in the following groups:
(a) High myopes not recovering to 6/6,
(b) Simple myopes with bilateral amblyopia.
In the above groups the recovery was delayed more with green than with the red filter. It may be pointed out here that in group II of high myopia (above 10D) the delay was observed even without any filter. The inference therefore would be to classify group II in the broad group of macular degenerations.
In bilateral myopes with unilateral amblyopia (anisometropics) and in "High myopes with bilateral amblyopia and normal fundus", delay was observed without filter only. The recovery time recorded with filters was within normal limits. This indicates general depression of macular function.
Considering the various groups individually it was observed that high myopes with full vision and normal fundus (Group 1) showed delayed recovery with green filter in 20% of the cases. Even the simple myopes having full vision and normal fundus (Group VI) showed this delayed response in 12.5% (out of which 60% showed delayed recovery with green filter while 40% showed delay more with green than with red filter). This delay with green filter indicates involvement of recipient elements as has been envisaged earlier. It is, therefore, possible that these two groups which are apparently non-degenerative are likely to undergo myopic degeneration later.
In the group of simple myopes (bilateral amblyopes) (Group VII) 20% of the cases showed delayed recovery. Considering the fundus to be normal and that myopia was of less than 10D with full vision, the authors feel that the 20% that showed delayed response should be reclassified as the suspect group, the implication being that the delay was comparable to pathological changes reported earlier.
In high myopes (6-10D) with retinal degeneration (Group II) the abnormal response was seen in 51 % of the cases while in the group of over 10D this figure was 59.50%. In these two groups even those cases who showed normal response the readings were towards higher side of the normals.
In degenerative group (6 to 10D) the delay more with red filter was seen in 10% cases while the delay with green filter more than with red filter was in 50% of the cases. In the group of over 10D of myopia, the delay more with red filter than green filter was seen in 50% of the cases. This indicates that with increase in the degeneration the process that was at the recipient level first probably passed on to the synaptic level later. In still later cases the delay was observed even without filter, thus indicating a generalised depression.
Considerable number (10%) of hypermetropes who do not show full improvement in vision revel a subclinical macular pathology as judged by these tests.
Von Noorden (1967) while reclassifying amblyopias has described "Ametropic amblyopia" as a separate entity. Author points out that these cases improve with use of glasses. It is worth noting; here that amongst total amblyopes (primary) about 20% showed abnormal macular recovery following macular function tests, obviously indicating some macular pathology. It is, therefore, stressed that with the help of these tests primary and secondary amblyopes can be differentiated and these tests must be used wherever possible before giving a therapeutic trial.
| Summary|| |
Macular illumination tests in 220 cases of various refractive errors have been reported. It has been pointed out that the average values of recovery time show delay in high myopes (not recovering to 6/6) and in simple myopes (with bilateral amblyopia). The responses obtained with these tests indicated the presence of subclinical macular degeneration in these groups. 20% of the nonamblyopic and non-degenerative high myopes showed delay with green filter only. Even 12.5% of the simple myopes showed delayed recovery. It is possible that these cases are likely to undergo myopic degeneration later. The response obtained in cases below 10D of degenerative myopia indicated the involvement of recipient elements while in cases over 10D of this group the response was such that indicated involvement of conductional elements as well. 10% of the hypermetropes who did not improve to full vision showed delay in recovery time and hence some macular pathology. It has been pointed out that before labelling a case as `ametropic' or 'anisometropic' primary amblyopia the macular illumination tests should be done to rule out macular pathology.
| References|| |
PAUL, S. D., BATRA, D. V.: Macular illumination tests in Central serous retinopathy. Amer. J. Ophth. 63: 146: 1967.
PAUL, S. D., BATRA, D. V.: Macular illumination tests., Amer. J. Ophth. 61: 99: 1966.
PAUL, S. D., SINGH K. M.: Macular illumination tests in macular degeneration (in press).
PAUL, S. D., SINGH K. M.: Macular illumination tests in macular burns (in press).
PAUL, S. D., SINGH K. M.: Macular illumination tests in retinitis pigmentosa (in press).
REUDEMANN, A. D.: E.R.G. in amblyopia. Tr. Am. Ophth. Soc. 64: 163. 1966.
VON NOORDEN, G. K.: Classification of amblyopia. Amer.. J. Ophth. 63: 238. 1967.
[Table - 1], [Table - 2], [Table - 3], [Table - 4], [Table - 5], [Table - 6], [Table - 7], [Table - 8], [Table - 9], [Table - 10], [Table - 11]