|Year : 1977 | Volume
| Issue : 2 | Page : 27-30
Intravenous glycerol-sodium ascorbate combination as osmotic agent to reduce intraocular pressure
Swapna Samant Ray, Anna Thomas
Christian Medical College, Vellore, India
Swapna Samant Ray
Department of Ophthalmology Christian Medical College Vellore-632001
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Ray SS, Thomas A. Intravenous glycerol-sodium ascorbate combination as osmotic agent to reduce intraocular pressure. Indian J Ophthalmol 1977;25:27-30
|How to cite this URL:|
Ray SS, Thomas A. Intravenous glycerol-sodium ascorbate combination as osmotic agent to reduce intraocular pressure. Indian J Ophthalmol [serial online] 1977 [cited 2022 Aug 19];25:27-30. Available from: https://www.ijo.in/text.asp?1977/25/2/27/31255
The effect of osmolar agents on intraocular pressure has been known for long. The osmotic effect in lowering intraocular pressure by oral glycerol was reported by Virno. Because of its effectiveness, at the oral glycerol is preferred in mostcases to the other osmotic agents like urea and manitol.
In view of the marked ocular hypotensive action of oral glycerol, it seems reasonable to assume that if intravenous administration of the drug could be made possible a much greater hypotony of the eye ball could be obtained.
Clinical studies revealed that intravenous administration of glycerol as 30% solution in saline produced haematuria both in experimental animals and man.
In later studies by Virno et al showed the haematuria and renal histological alterations can be eliminated by adding 20% solution of sodium ascorbate to the 30% glycerol and they claimed, this osmotic agent is highly eflective and safe to bring down the ocular hypertension.
The present investigation was aimed to study the efficacy of intravenous glycerol 30% with sodium ascorbate 20% as a tension lowering osmotic agent.
| Material and Methods|| |
Vitamin C (pure crystal of ascorbic acid) was dissolved in bidistilled water to make a 20% solution which was titrated to pH values of 7.2-7.4 with sodium bicarbonate.
To 30 ml. of pure glycerol were added 70 ml. of 20% Vitamin C solution, titrated to pH 7.2--7.4 with sodium carbonate, to make a 100 ml. solution.
Dose administered was 1.0-1.5 gm/kg. of body weight.
Tonometric readings were taken with Schiotz tonometer before treatment and at every 15 minutes intervals following administration. Each patient was questioned and observed regarding subjective feelings.
The effects of intravenous glycerol 30% with 20% sodium ascorbate were studied in 5 patients with glaucoma. The solution was administered at the rate of 60-80 drops per minute. Urine samples were collected from each patient at the end of infusion and examined for evidence of macroscopic and micro3copic haematuria.
| Results|| |
Of the ten eyes analysed, 3 were suffering from chronic congestive glaucoma, three were with glaucoma of open angle type and one of them had secondary lens induced glaucoma, three had normal intraocular pressure,
[Figure - 1] shows the response to glycerol sodium ascorbate administration of a patient with chronic congestive glaucoma of the left eye. The patient was a 60 year old woman, had recurrent attacks of pain with redness in her left eye. Pre treatment pressure was 17.3 mm Hg. right eye and 49.8 mm Hg in the left eye. Intravenous glycerol sodium ascorbate was administered at the rate of 60 drops per minute. Pressure was brought down to 8.5 mm Hg right and 24.4 mm left eye within 3 hours from the start of infusion. No side effects were noticed. Blood pressure was normal and microscopic examination of the urine did not reveal any haematuria.
[Figure - 2] shows the response of a patient with lens induced glaucoma of the left eye, within 2 hours of intravenous administration of glycerol-sodium ascorbate there was a reduction in pressure from 50.6 to 17.3 mm Hg left eye and from 12.2 to 8.5 mm Hg right eye. Blood pressure was normal but urine collected sample was red in colour and microscopic examinations revealed plenty of R.B.C. The haematuria cleared within 2-3 hours time and subsequent microscopic examination of urine was normal.
[Figure - 3] shows the ocular hypotensive effect obtained by intravenous administration of glycerol sodium ascorbate. The patient 47 year old man was having open angle glaucoma in both eyes. No medical, topical or general management had been used previously. Pre treatment pressure was 35.8 mm Hg. right eye and 42.1 mm Hg. left eye. Within 2 hours of treatment, tension came down to 14.6 and 17.3 mm Hg. respectively. The patient had nausea, vomiting and had severe chills. Symptoms subsided after one hour.
[Figure - 4] shows the reduction in pressure in an eye with pseudoexfoliative open angle glaucoma in the left eye. Pressure was brought down after the infusion from 42.1 to 20.6 within 2 hours time. Right eye pressure was lowered from 17.3 to 12.2 mm Hg. This patient developed chills and tremors of the extremities. Urine was normal.
[Figure - 5] shows effect of intravenous association of glycerol and sodium ascorbate in a 60 year old male patient having chronic congestive glaucoma in both eyes. The tension was effectively brought down from 30.4 mm Hg. in right eye to 14.6 mm Hg. and 30.4 mm Hg. in left eye to 12.2 mm Hg. within 2 hours time. At the end of the infusion this patient again developed nausea, vomiting and chills. He had mental confusion and headache. Patient came back to normal after one hour.
There was effective lowering of intraocular pressure in all the cases, but because of the side effects encountered in majority of the patients, subsequent trials with this drug was not possible.
| Discussion|| |
Glycerin is a trihydric alcohol with a molecular weight of 92. It is a viscid liquid chiefly familiar to the Ophthalmologists as an oral osmotic agent to reduce intraocular pressure and as a topical dehydrating agent for clearing oedematous corneas. Glycerol reduces the intraocular pressure by three possible ways:
(1) By increasing the serum osmolarity to a higher level which opposes the osmotic pull within the eye.
(2) The ciliary epithelium, retino-choroidal surface and iris providing a dehydrating interface for water transfer.
(3) By reducing the vitreous volume which correspondingly accompanies the weight loss shown in experimental animals. Intravenously administered glycerol probably acts in a similar manner as oral glycerol but in a more effective way as it is a direct administration to vascular volume whereas because of uncertain absorption, the hypotensive response to oral glycerol is quite variable. Sodium ascorbate by itself is an effective osmotic agent, hence addition of this agent potentiates the effect of glycerol administered intravenously.
The results obtained in our study with the intravenous administration of sodium ascorbate20% solution and glycerol 30% showed that this combination is quite effective in significant lowering of intraocular pressure. Maximum hypotensive effect was attained after 2 hours from the start of the infusion, going at the rate of 60-80 drops per minute.
Virno, considered the combination of these two drugs as a very effective and safe osmotic agent. Of 9- eyes analysed by them only 2 patients had headache. But in our serious most of the patients had severe headache, nausea, vomiting and chills. One of them had tremor of the extremities and mental confusion. one patient had micro and macroscopic haematuria as well which is reported not to be the usual side effect by Virno et al.
Headache in all these cases probably is due to sudden lowering of the inracranial pressures.
Haematuria occurs due to transient histopathological alterations in the kidney. It has been shown in experimenetal animals that following the administration of glycerol, there is vasoconstriction of the affarent glomerular arterioles evidenced by numerous areas of subcapsular ischaemia. A reflex vasodilatation follows. Intracapsular and interstitial haemorrhages are noted. The vasodilatation usually lasts for 5.8 hours. We presume the same process may be happening in human beings too. The addition of Vitamin C (sodium salt) had not proved useful in completely eliminating the haematuria.
| Conclusion|| |
The combined effect of 30% glycerol and 20% sodium ascorbate is additive and produces marked hypotensive effect but because of the side effects commonly met with as seen in our present study this combination may not be a very safe osmotic agent.
| References|| |
Cantonnet, A., 1904, Arch. Ophthal. 24, 1.
Dell Rocca et al, 1966, Gaz. Ind. Med, Chir., 71,
Virno, M. et al, 1963, Amer. Jour. Ophthal. 55,
Virno, M. et al, 1965, Policlinico (Sez Part) 72,
Virno, M. et al, 1966, Amer. Jour. Ophtha!. 62,
William H. Havener, 1970, Ocular Pharmacology, II ed. The C.V. Mosby Co., Saint Louis
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5]