Indian Journal of Ophthalmology

ARTICLES
Year
: 1971  |  Volume : 19  |  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

Correspondence Address:
S D Paul
Department of Ophthalmology, Postgraduate Institute of Medical Education & Research, Chandigarh
India




How to cite this article:
Paul S D, Singh K. Macular illumination tests in various refractive states of the eye.Indian J Ophthalmol 1971;19:102-107


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 2024 Mar 29 ];19:102-107
Available from: https://journals.lww.com/ijo/pages/default.aspx/text.asp?1971/19/3/102/34982


Full Text

In previously communicated studies on macular illumination tests [1],[2],[3],[4] . it has been pointed out that these tests are very useful in assessing macular pathology. As the refractive errors are very com�mon, this communication aims at analysing macular function tests in various refractive states of the eye with special emphasis on am�blyopia cases encountered in this group.

 Methods and Material



220 cases of various refractive errors were studied from the out�patient department of the Post�graduate Institute of Medical Edu�cation and Research, Chandigarh.

The patients were divided as follows:

In each case the macular illumi�nation tests were done as describ�ed earlier. [1]

 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 6�10D and 11-15D myopics [Table 2] the recovery was delayed with green and red filter. It was more delayed with green filter as com�pared 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 am�blyopia. 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 nor�mal response with red and green filter. The recovery was delayed in the case of without filter illu�mination. [Table 4].

In the 5th group there were uni�lateral myopes with difference of 3D on either side. The macular illumination tests [Table 5] show�ed 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 re�covery 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 illumina�tion 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 analys�ed [Table 11] separately then it can be appreciated that consider�able 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 pecu�larity is not feasible.

By the available clinical methods it is not possible to as�certain if these cases were primary or secondary amblyopes. It has not been possible so far to explain the production of this am�blyopia or to pin point the site of lesion.

Rendermann (1966) observed that considerable number of myo�pic (65%) amblyopes show ab�normal ERG. In his series of 720 cases he found abnormal ERG in 65% of the cases. In myopic ani�sometropes (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 generalis�ed functional changes, this study indicates a considerable functional loss in amblyopes with refractive errors.

It has been pointed out earlier [3],[4],[5] that with the help of macular illumination tests (differential) it was possible to differentiate bet�ween 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 re�covery 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 uni�lateral amblyopia (anisometropics) and in "High myopes with bilate�ral amblyopia and normal fundus", delay was observed with�out 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 indi�cates 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 degene�ration 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 to�wards 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 proba�bly 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 re�classifying amblyopias has des�cribed "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 ab�normal macular recovery follow�ing macular function tests, ob�viously indicating some macular pathology. It is, therefore, stres�sed that with the help of these tests primary and secondary am�blyopes can be differentiated and these tests must be used wherever possible before giving a therapeu�tic trial.

 Summary



Macular illumination tests in 220 cases of various refractive er�rors have been reported. It has been pointed out that the average values of recovery time show de�lay in high myopes (not recover�ing 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 non�amblyopic and non-degenerative high myopes showed delay with green filter only. Even 12.5% of the simple myopes showed de�layed recovery. It is possible that these cases are likely to undergo myopic degeneration later. The response obtained in cases below 10D of degenerative myopia indi�cated 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 patho�logy. It has been pointed out that before labelling a case as `ametropic' or 'anisometropic' primary amblyopia the macular illumina�tion tests should be done to rule out macular pathology[7].

References

1PAUL, S. D., BATRA, D. V.: Macu�lar illumination tests in Central serous retinopathy. Amer. J. Ophth. 63: 146: 1967.
2PAUL, S. D., BATRA, D. V.: Macu�lar illumination tests., Amer. J. Ophth. 61: 99: 1966.
3PAUL, S. D., SINGH K. M.: Macu�lar illumination tests in macular degeneration (in press).
4PAUL, S. D., SINGH K. M.: Macu�lar illumination tests in macular burns (in press).
5PAUL, S. D., SINGH K. M.: Macu�lar illumination tests in retinitis pigmentosa (in press).
6REUDEMANN, A. D.: E.R.G. in amblyopia. Tr. Am. Ophth. Soc. 64: 163. 1966.
7VON NOORDEN, G. K.: Classifica�tion of amblyopia. Amer.. J. Ophth. 63: 238. 1967.