|Year : 1968 | Volume
| Issue : 3 | Page : 105-108
Aqueous humor ascorbic acid in normal, cataractous and aphakic Indian subjects
BN Consul, GB Mathur, AS Mehrotra
Department of Ophthalmology, Sawai Man Singh Medical College and Hospital, Jaipur, India
|Date of Web Publication||24-Dec-2007|
B N Consul
Department of Ophthalmology, Sawai Man Singh Medical College and Hospital, Jaipur
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Consul B N, Mathur G B, Mehrotra A S. Aqueous humor ascorbic acid in normal, cataractous and aphakic Indian subjects. Indian J Ophthalmol 1968;16:105-8
|How to cite this URL:|
Consul B N, Mathur G B, Mehrotra A S. Aqueous humor ascorbic acid in normal, cataractous and aphakic Indian subjects. Indian J Ophthalmol [serial online] 1968 [cited 2020 Aug 6];16:105-8. Available from: http://www.ijo.in/text.asp?1968/16/3/105/37530
| Introduction|| |
Ascorbic acid is a well known body constituent reacting and changing during many metabolic and pathological processes in the human body. It plays an important role in metabolism of the crystalline lens in addition to metabolising large quantities of aromatic aminoacids, tyrosine, phenylaneline and is probably also anti-infective. Besides, it takes part in the tissue respiratory mechanism involving the glutathione system (SZENT-GYORGI,  )
Although some work had been done on the chemistry of intraocular fluids previously, it was not till 1927, that DUKE-ELDER  made a more complete analysis of their composition. The actual work of the estimation of ascorbic acid in aqueous humor and its relationship with lenticular changes started after the demonstration of its presence in lens and aqueous by BRICH AND DANN  in 1933, and also by HARRIS  in the same year.
It is now confirmed that the ascorbic acid concentration in aqueous humor is higher than in serum but the ratio between them, as reported by different workers - KINSEY  , CHATERJEE AND GHOSH,  NEMA and SHRIVASTAVA  and others, have been different. Indian figures given by the latter two workers are lower as compared to workers outside India [Table - 3].
With the great advance in the precision of medical instruments and use of devices such as spectro photometer and flame photometer, it has been possible to assess the details of the composition of intraocular fluid more accurately. This, coupled with - lack of reports on the aspects of the study of ascorbic acid content in aqueous humor of cataractous patients in our country, has made us undertake this study to establish normal values of ascorbic acid in aqueous humor of healthy persons in Rajasthan and to explore the significance of changes produced in its level in those suffering from various types of cataract.
| Material and method|| |
Estimation of ascorbic acid in aqueous humor was done for the present study in 80 cases, out of which 10 cases were having a normal lens, 25 cases were of immature cataract, 25 cases of mature cataract, 10 cases of hypermature cataract and 10 cases of aphakia. All these samples of aqueous were taken from the patients admitted in the wards of S. M. S. Hospital, Jaipur waiting for cataract operation. The cases with transparent healthy lenses were selected from those patients who came for extraocular operations and were admitted in the wards (Pterygium, chronic dacryocystitis etc.).
On admission of the patients, a brief clinical history was taken and detailed clinical examination was made, including blood pressure and urine examinations. Detailed local examination of the eye was done to rule out any evidence of general and local disease. In cases with cataract, an examination with a slitlamp was made to determine the type of cataract.
Using 1 per cent anethaine for surface anesthesia, about 0.2 cc of aqueous humor was aspirated from the anterior chamber by means of a tuberculin syringe with a 26 gauge needle attached to it, which was introduced into the anterior chamber through the limbus under perfect aseptic conditions fixing the eye ball at 6 O'clock position.
Ascorbic acid was estimated by NATELSON'S  technique spectrophotometrically.
| Observations|| |
The results obtained in normal, cataractous and aphakic cases are given in [Table - 1],[Table - 2].
Ascorbic acid level in aqueous humor has been found to diminish gradually from normal to cataractous to aphakic cases. Amongst cataractous cases though the drop in its level was not marked from immature to hypermature stage of cataract, still we found that ascorbic acid level in aqueous humor in immature cataractous cases was highest (4.92 mg percent) and it gradually diminished in mature and hypermature cataract cases where it was found to be 4.5 mg percent and 4.1 mg percent respectively.
Further, in the age group of 40 to 50 years, ascorbic acid level was studied in normal and cataractous cases. It was observed that in normal cases (5 cases) it was 5.48 mg percent, in immature cataract (8 cases) 5.37 mg and in mature cataracts (6 cases) 4.33 mg percent, thus confirming the above findings of gradual decrease of ascorbic acid level with maturing of cataract. The study of this level in hypermature and aphakic cases in this age group could not be done since such cases were not available.
| Discussion|| |
MULLER AND BUSCHKE  reported that ascorbic acid concentration decreases in patients with senile cataract. PURCELL, TERNER and KINSEY  and CHATERJEE and GHOSH  reported that there is no appreciable difference in aqueous serum ratio of ascorbic acid in normal, cataractous and aphakic subjects showing thereby that the lens is not responsible for higher concentration of ascorbic acid maintained in aqueous humor.
In order to derive practical information from this study with regards to the possible role of ascorbic acid content of aqueous in the formation of cataract, it would be interesting to compare the results of Indian workers on Indian subjects in whom the incidence of cataract is much higher, with those obtained by Western investigators on western subjects where cataract is a less frequent condition. Fortunately such figures are available for both normal and cataractous subjects [Table - 3].
It can be seen from [Table - 3] that much higher levels of ascorbic acid have been reported in aqueous of normal subjects by workers outside India, (first three) as compared to the values obtained by workers on Indian subjects (last three).
As regards Indian observers on Indian subjects it is observed in [Table - 3], that there is a slight fall from normal to cataractous lenses to aphakic cases. CHATERJEE and CHOSHS do not consider the drop significant (0.19), although in the discussion they mention about the retarding action of the pigmented ciliary epithelium on the formation of aqueous ascorbic acid. (see later). On the other hand NEMA et al  and in our study there is to be noticed a drop of 0.35 and 0.4 respectively. On the difference in the figures obtained from normal and cataractous patients there seems to be a wide disagreement even with western observers. On one hand KRONFIELD and BERARDINIS et al  find practically no difference between the two. On the other hand PURCELL et a1  find a big difference. It has also been mentioned by MULLER AND BUSCHKE,  BIETTI  and WILLIAMSON-NOBLE  that concentration of ascorbic acid becomes less in aphakic and cataractous patients.
The two facts that emerge from this discussion therefore are:
(a) A lower aqueous ascorbic acid figure prevails in Indian subjects, who have a higher incidence of cataract, than in western subjects,
(b) There occurs a drop, though not perhaps significant, in the aqueous ascorbic acid level from normal to cataractous (various stages) to aphakic eyes, the only two studies definitely against this finding being those of KRONFIELD and BERARDINIS et al. 
CHATERJEE AND GHOSHF have given the view that the pigment content of the ciliary epithelium in our patients exerts a retarding effect on the formation of ascorbic acid from the ciliary epithelium. In addition to the above view we want to add from our experience that the average ascorbic acid content of an Indian patient is poorer and as such deficiency of ascorbic acid may be one of the factors for early cataract formation.
| Summary and conclusion|| |
Estimation of ascorbic acid in aqueous humor of 80 cases, with normal, cataractous and aphakic eyes was done. Highest level was found in cases with normal lenses. It decreases with. maturing of cataract and is found to be least in aphakic cases.
There is a marked difference in the averages of ascorbic acid levels in human aqueous of Indian subjects, (in whom cataract is much more common) as worked out by three sets of Indian observers as compared with those of Western subjects, worked out by three different sets of Western observers.
The question arises, does the lower value of ascorbic acid in the aqueous of Indian subjects contribute to the higher incidence of cataract in Indian subjects. If so, is it because of a general low level of serum ascorbic acid or does the, heavy uveal pigment of the Indian uveal tissue impede higher concentration of ascorbic acid in the aqueous locally?
| References|| |
BERZELIUS, L. Quoted by Duke Elder in 6 (1932): Text Book of Ophthalmology. Vol. p. 426 Henry Kimpton, London.
BERARDINIS, E. D., TIERI, O., POLZELLA, A. and SUGLIA, N.: The chemical composition of aqueous humor in normal and pathological conditions. Exp. Eye. Res. IV, 179-186, (1965).
BIETTI, G. (1935): Quoted by Bellows, J. G. Cataract and anomalies of lens. p. 127 Henry Kimpton, London (1944).
BRICK T. W. and DANN, W. J. Estimation and distribution of ascorbic acid and glutathione in animal tissue. Nature, 131, 469, (1933).
CHATTERJEE, B. -
\4. AND GHOSH, B.P.: Total ascorbic acid in aqueous humor and serum in Indian patients with and without cataract A. M. A. Arch. Ophth. (Chicago) 56, 756-760, (1932).
DUKE-ELDER, S. W.: Text book of Ophthalmology Vol. ? p. 426. Henry Kimpton, London (1932).
HARRIS, L. J. (1933): Quoted by RADOS, A., Arch. Ophth. 34, 202, (1945).
KINSEY, V. E.: Comparative chemistry of aqueous humor in anterior and posterior chamber of rabbit eye. A. M. A. Arch. Ophth. (Chicago) 50, 401, (1950).
MULLER, H. K. and BUSCHKE, W. (1934): Quoted by Bellows, J. G.: Cataract and anomalies of lens p. 229 Henry Kimpton, London. (1944).
NEMA, H. V. and SHRIVASTAVA, S.P.: Ascorbic acid in aqueous humor and serum in normal and mature cataract on Indian subjects. J. All-Ind. Ophth. Sec., 11, 53-61, (1963).
NATELSON, S. (1961): Micro-technique of clinical chemistry course. C. p. 121 Thorn. Springfield. U.S.A. 2nd Edition.
PURCELL, E. F., TERNER, N. H. and KINSEY, V. E.: Ascorbic acid in aqueous humor and serum of patients with and without cataract. A. M. A. Arch. Ophth. (Chicago) 51: 5, (1954).
SZENT-GY ORGI, A.: Quoted by Best and Taylor, (1961): The physiological basis of medical practice. Williams and Wilkins Co. Baltimore. 7th Ed. (1957).
WILLIAMSON-NOBLE, F. A.: Role of Vitamins in Ophthalmology: Trans. Ophthal. Soc. of U.K., 62, 53, (1942).
[Table - 1], [Table - 2], [Table - 3]