|Year : 1989 | Volume
| Issue : 2 | Page : 91-93
Myopia and plasma cortisol
RK Ojha, R Singh, OPS Maurya, JK Agrawal
C-7, New Medical Enclave, Naria, Banaras Hindu University, Varanasi - 221005, India
C-7, New Medical Enclave, Naria, Banaras Hindu University, Varanasi - 221005
Source of Support: None, Conflict of Interest: None
Estimation of plasma cortisol by flurometric technique desorbed by Maltingly's was carried out in 56 cases, including 38 cases of myopia (19 cases of simple myopia and 19 cases of degenerative myopia) and 18 normal individuals.Urinary 17-keto steroids/24 hours was also estimated by Zimmermann technique in 12 out of the 56 cases, which include 8 cases of myopia (4 cases of simple myopia and 4 cases of degenerative myopia) and 4 normal individuals as control.Plasma cortisol level is lower in simple and degenerative myopia than in normal subjects, but on statistcial analysis the difference was not of much significance. Patients with simple myopia with positive family history showed lower value of plasma cortisol than patients with simple myopia with negative family history, the difference was also statistically insignificant (P-0.1). In degenerative myopia patients, with and without family history, there was very little difference in plasma cortisol level and statistically highly insignificant (P-0.8). Urinary 17 keto steroid/24 hour values are lower in simple and degenerative myopia than in normal subjects.
|How to cite this article:|
Ojha R K, Singh R, Maurya O, Agrawal J K. Myopia and plasma cortisol. Indian J Ophthalmol 1989;37:91-3
| Introduction|| |
The hypothalamus secretes C.R.F. (Cortico trophin releasing factor) which brings about the release of A.C.T.H. from the anterior pituitary. ACTH in turn stimulates the adrenal cortex to produce and release cortisol, increased plasma level of cortisols inhibit further release of C.R.F. by the feedback mechanism.
Recent studies showed that imbalance of steroid hormone increaed (increase of growth hormone and cortisol, decrease of testosterone and modified incretion of 17 beta estradiol)  , which is intimately connected with and provoked by an insuffcient light signal from the myopic eye to the diencephalohypophysial centres  acts on the genetically conditioned target organ (the eyeball), encouraging and causing over the years a progressive lengthening of the antero-posterior axis, thus producing the deveopment of refractive defects along with all morphofunctional deterioration of the myopic eye.
Balacco-Gabrieli et al. (1978) reported relatively low excretion of 17-ketosteroid in 90 percent of patients suffering from degenerative myopia  . But relationship between plasma cortisol or 17-ketosteroid and myopia is still not unveiled satisfactorily. Keeping this in mind the present project has been undertaken to assess the relationship between plasma cortisol and urinary 17- ketosteroid with myopia.
| Material and Methods|| |
Estimation of plasma cortisol was carried out in 56 cases, which included 38 cases of myopia and 18 normal subjects as control. Out of 38 cased of myopia 19 cases were of simple myopia and the other 19 were of degenerative myopia. In this study urinary 17- ketosteroid/24 hour was also estimated in 12 cases, out of these 12 cases, 4 cases were normal subjects (control), 4 of simple myopia and 4 cases were of degenerative myopia. Cases of both sexes were included with age varying from 14 to 34 years. The cases in this series were divided into three groups.
Group A Controls : These were 18 patients who attended the Bhuwalka Eye Hospital with complaints of headache, watering and eye strain. There was no ocular infection and inflammation. History of taking steroid or any stressful situation and any endocrinal disorder was negative. On ophthalmoscopic examination their fundus findings were within normal limit and on retinoscopy there was no refractive error.
Group B Simple Myopia : This group included 19 patients who were cases of simple myopia with complaints of difficulty in vision for distance, watering and eye strain etc. There was no ocular infection or inflammation. On ophthalmoscopic examination their fundus picture was normal and retinoscopy showed a refractive error ranging from -0.5 to - 6.0 dioptres. History of taking steroid or any stressful situation and any endocrinal disorder was negative.
Group C Degenerative Myopia This group included 19 patients which were the cases of degenerative myopia with complaints of severe impairment of visual acuity of gradual onset, black spots moving in front of the eye, and eye strain. On ophthalmoscopy their fundus revealed extensive degenerative changes of varying degrees. Few of them had myopic temporal cresent, annular crescent, and chorio-retinal degenerative patches at various places. On retinoscopy these patients were found to be suffering from refractive error ranging from -6.0 to 18.00 dioptre. History of taking steroid or facing any stressful situation or of any endocrinal disorder was negative.
Before proceeding further for estimation of plasma cortisol and urinary 17-ketosteroid, all patients were tested for visual acuity with and with out glasses, intraocular pressure was taken with a Schiotz tonometer-detailed ophthalmoscopic and biomicroscopic (slit-lamp) examination, general examination to rule out inflammatory lesions and laboratory investigation including TC,DC, ESR, and Haemoglobin. Estimation of plasma cortisol by Flurometric technique (Mattingly's 1962) and urinary 17- keto steroid by Zimmermann technique were done in the endocrinology section of the Department of Medicine.
| Observations|| |
Group A (Control cases) Highest and lowest value of plasma cortisol in this group were 18ug/100ml and 8ug/100ml respectively.The mean (+ -S.E.) was 12.08+ - 0.75ug/100 ml [Table - 1]).
Group B (Simple myopia)Highest and lowest value of plasma cortisol were 19 ug/100 ml and 6ug/ 100 ml respectively. The Mean (+ -S.E.) was 10-78 + - o.84 ug/100 ml [Table - 1]
Group C (Degenerative Myopia) Highest and lowest values of plasma cortisol in this group were 18.2 ug/100ml [Table - 1].
Among the simple myopes (Group B), 15 patients had no family history and 4 patients had negative family history of myopia Corresponding mean plasma cortisol levee + -S.E.) was 11.38 + - 1.01 ug/IOOmi and 8.55 + - 0.48 ug/100ml respectively [Table - 2].
Among the degenerative myoopes (group C) 12 patients had no family history and 7 patients had positve history of myopia. Corresponding mean (± - S.E) plasma cortisol level was 11.69 + - 1.01 ug/ 100m1 and 11.96+ - 1.17ug/ IOOml respectively [Table - 3].
In our series of investigation we also estimated urinary 17ketosteroid/24 hours in 12 patients for each group. Mean values of urinary 17 ketosteroid/24 hours for group A (Control) was 11.97ug/24 hours, for group B( simple myopia) was 10.95 mg/ 24 hours and for group C (degenerative myopia) was 10.32mg/24 hours [Table - 4].
| Discussions|| |
Although very scanty information is available regarding relationship between plasma cortisol, urinary 17-ketosteroids and myopia. Balacco-Gabrieli et al. (1978) reported a low level of urinary 17-ketosteroid in most patients having degenerative muopia. Balacco-Gabrieli, Tundo, (1980) reported a slightly high level of plasma cortisol in degenerative muopic cases  .
In the present study, our observations shows a lower level of mean plasma cortisol in simple myopia and degenerative myopia than in control cases [Table - 1]. These findings are not in conformity with Balacco-Gabrielic, Tundo (1980) observation. This contradiction with Balacco-Gabbrieli, Tundo (1980) observation can be explained by the fact that in Balacco- Gabrieli, Tudo studies all the cases were of-10D myopia and the plasma cortisol may not be the same for myopia of - lOD and myopia ranging from -0.5 to -18.00 Dioptre which is the range of refractive error for our patients.
On statistical anaalysis the difference observed in mean plasma cortisol values of group A (control), group B (simple myopia) and group C (degenerative myopia) were found to be insignificant (A vs B-0.2,A vs C-0.7 and B vs C-0.3.
In the present series we also compared plasma cortisol level in cases of simple myopia and degenerative myopia with and without family history.
The patients of simple myoopia with positive family history showed lower value of mean plasma cortisol than patients of simple myopia with no family history, which is statistically insignificant (P-0. 1)
In degenerative myopia patients, with and without family history there was very little difference in mean plasma cortisol level. On statistical analysis the difference was insignificant (P-0.8).
As the correlation between plasma cortisol level and various aspect of myopia (degree of myopia - simple and degenerative family history in myopia) is found to be statistically insignificant. Probably plasma cortisol levels are little related to myopia.
In the present series of investigation mean value urinary 17detosteroid/24 hours in lower in simple and degenerative myopia than in the control. The mean values of urinary 17ketosteroid/24 hours was 11.97 mg/24 hours, 10.95 mg/24 hours and 10.32 mg/24 hour in group A (control) group B (simply myopia) and in group C (degenerative myopia) respectively [Table - 4]
These findings are in complete agreement with Balacco Gabrieli et al. (1978) observations. Urinary 17-ketosteroid values indicate a lowering of levels with increasing degrees of myopia.
| References|| |
Balacco-Gabrieli, Santoro, G; Santoro, M. et al.: Plasmatic and urinary steroids in high myopia: Note 22 cortisol, 17-OH, 17- ks(males). Boll Soc ital Biol Sper, 54, 978-980,1978.
Balacco-Gabrieli, C.; Tundo, R.: Plasmatic and urinary steroids in high muopia, presented at the Third International Conference on myopia, Copenhagen, 1980.
Mattingly. D.: J. Clin. Path. 5,374, 1962.
Raviola, E.; Wiesel, T.N.: Increase in axial length of the macaque monkey eye after corneal opocification. Invest Ophthalmol Vis sci., 18, 1232,1979.
Trachman, J.; Turkel, J.; Walman,J; Extreme myopia produced by modest change in early visual experience. Science, 201, 1249,1979.
[Table - 1], [Table - 2], [Table - 3], [Table - 4]