|Year : 1969 | Volume
| Issue : 2 | Page : 52-54
Human aqueous electrolytes
BN Consul, JP Taunk, GB Mathur
Department of Ophthalmology, Sawai Man Singh Medical College and Hospital, Jaipur, India
|Date of Web Publication||8-Jan-2008|
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, Taunk J P, Mathur G B. Human aqueous electrolytes. Indian J Ophthalmol 1969;17:52-4
Aqueous humour termed rightly as ocular lymph by Adler is the main source of nourishment of the avascular structures of the eye, specially of the lens. Although the biochemistry of the normal and cataractous human lenses has been investigated by a number of workers (Salit, Adler, Consul and Sharma), the aqueous humor has been analysed mostly in animals - (Kinsey, Kinsey and Redely) and no comprehensive data on the electrolytes of this fluid are available so far in human subjects. In view of the changes recorded in the sodium and potassium ratio in the various regions of the human lenses following senile cataract – Salit, Consul and Sharma, it would be of interest to analyse also the aqueous for the corresponding changes in these electrolytes.
With these objectives in view it was planned to study first the three important electrolytes of the human aqueous humour-sodium, potassium and chloride, in normal and cataractous states.
| Material and method|| |
The estimation of sodium, potassium and chloride in aqueous humor was done in 5 normal and 28 senile cataractous patients. The cases were selected from the Ophthalmic wards and out-door of S. M. S. Hospital, Jaipur. Detailed relevant history and thorough general examination including blood pressure recording and urine examination was done to rule out any systemic disease. Local examination of the eve was done to rule out any evidence of ocular disease. A thorough slit-lamp examination was clone to know the type of cataract and tension was recorded to exclude glaucoma.
After local anaesthesia by instilling 1% anethaine drops into the conjunctival sac, a 26 gauge needle attached to a tuberculin syringe was introduced into the anterior chamber through the corneal side of the limbus under perfect aseptic conditions. An appropriate amount of aqueous was transferred into a sterile dry glass vial and analysed within 24 hours for its electrolyte contents.
The sodium and potassium estimation was carried out by using the E.E.L. flame photometer and chloride was estimated by the method of King.
| Observations|| |
We have not encountered any complications while aspirating aqueous humor from the anterior chamber, except in one case where the lens capsule got punctured, and in another where the iris got punctured. These two cases were excluded from the present study. The results obtained in normal and senile cataractous cases are recorded (see [Table - 1])
It may thus he observed from the above table that the mean levels of aqueous sodium, potassium and chloride of the cataractous eyes were on the lower side of the normal. However the difference in electrolyte levels in the aqueous humour in normal and cataractous subjects was not statistically significant.
| Discussion|| |
After a thorough search in the available literature for data covering the electrolyte composition of normal human aqueous humour, it was observed that very few studies have been conducted or reported so far on the subject. In the present study 5 samples of aqueous humour from normal subjects were analysed for electrolytes (sodium, potassium and chloride). The average electrolyte content was found to be 147, 4.4, 127 m Eq/Lit. for sodium, potassium and chloride respectively.
A comparison of sodium and potassium contents of the lens with their ratio in normal and senile cataractous subjects as observed in a previous study is shown in [Table - 2] (Consul and Sharma).
It can be seen from the above table that during cataract formation there is a loss of the normal potassium which is replaced by sodium so that the Na ; K ratio changes from 1:3.4 to 1 : 0.235. It may be stated here that the normal sodium, potassium ratio considered by Salit et al to be an index of tissue vitality is 1.65 in the cortex and 1.34 in the nucleus of the lens. According to Adler in cataract this seems to fall to 0.41 in the cortex and 0.32 in the nucleus.
Burdan put forward the hypothesis that in human cataractous aqueous humour there is a fall in the potassium level to about 25% of the normal level. This investigator concluded that this observation probably proved that the supply of potassium to the lens is deficient in cataractous conditions. This we are unable to confirm because in our series the average drop in aqueous potassium level was only marginal when a cataract matured. The slight fall of potassium in the aqueous humor in cases with senile cataract could not be correlated with the lenticular changes.
Aqueous humour chloride in these 28 patients with senile cataract varied from 117 to 136 m Eq/Lit. the mean being 125.4 m Eq/Lit. + 6.0 (S.D.) which is slightly lower than the level present in cases with normal lens. Carigali and Bonaccorsi reported a slight diminution of the chloride level in eyes with senile cataract. In our study this slightly low level of chloride in aqueous humour with senile cataract was also found but it could not be correlated with lenticular opacification, as again the drop was not significant (from 127 to 125.4).
| Summary and conclusion|| |
1. Estimation of electrolytes (sodium, potassium and chloride) level of human aqueous humour in 5 normal and 28 senile cataractous subjects have been done.
2. Levels of the electrolytes in human aqueous humour in normal and cataractous cases have been compared.
3. It has been found that there is a slight decrease in aqueous humour electrolytes (sodium, potassium and chloride) levels, comparatively more marked in patients with senile cataract which is neither marked nor found to be statisticaly significant when compared with normal figures. They are not related to alterations in Na:K ratio that take place in the lens during cataract formation.
It is, therefore, suggested that this slightly diminished values of electrolytes in aqueous humor of cataractous subjects cannot be correlated with their cataractous changes and may be just another manifestation of senility.
| References|| |
ADLER, F. H.: The `Aqueous humor' in physiology of the eye, Clinical application. 4th Ed. p. 96-143 C. V, Mosby & Co.; St. Louis (1965).
BURDAN-COOPER, J.: A report on the spectroscopic examination of the mineral constituents of the human cataractous lens and that of healthy animal lenses. Traus. Ophthal. Soc. U.K. 48, 340-346 (1928).
CONSUL, B. N. and SHARMA, R. G.: A study of sodium and potassium in human senile cataractous cases. To be published in the proceedings of the All India Ophthal. Conference, Calcutta, Jan. 1967.
CARIGALI, F. and BONACCORSI, A. B.: Chemical cataract. Cited in Ophthal. Literature. 28, 33-44 Abs. No. 4767 (1959).
KING, E, J.: Microanalysis in Medical biochemistry. 2nd Ed. p. 99. J. and A. Churchill Ltd., London (1951).
KINSEY, V. E.: Comparative chemistry of aqueous humour in posterior and anterior chamber of rabbit eye. Arch. Ophth. (Chicago) 50, 401 (1953).
KINSEY, V. E. and REDELY, D.: Transport of amino-acids into the posterior chamber of rabbit eye. Invest. Ophth. 1, 355 (1962).
SALIT, P.W.; SWAN, K. C. and PAUL, W. D.: Changes in mineral composition of rat lenses with galactose cataract. Am. J. of Ophth. 25: 1482-1486 (1942).
SALIT, P. W.: Mineral constituents of sclerosed human lenses. Arch. Ophth. (Chicago) 30, 255 (1943).
[Table - 1], [Table - 2]