Indian Journal of Ophthalmology

: 1972  |  Volume : 20  |  Issue : 3  |  Page : 120--122

Comparative study of mannitol, diamox, and glycerol on intra-ocular pressure and post-operation shallow chamber

RR Shah 
 Sir Cowasjee Jehangir Ophthalmic Hospital, Bombay, India

Correspondence Address:
R R Shah
Sir Cowasjee Jehangir Ophthalmic Hospital, Bombay

How to cite this article:
Shah R R. Comparative study of mannitol, diamox, and glycerol on intra-ocular pressure and post-operation shallow chamber.Indian J Ophthalmol 1972;20:120-122

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Shah R R. Comparative study of mannitol, diamox, and glycerol on intra-ocular pressure and post-operation shallow chamber. Indian J Ophthalmol [serial online] 1972 [cited 2021 Jun 16 ];20:120-122
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Full Text

This trial was undertaken to study and compare the hypotensive effects of acetazolamide, glycerol and mannitol; and their effects on post-operative shallow anterior chamber, if any.

Earlier work done by DRANCE[3] sug­gested that glycerol was as effective as any intra-venous osmotic agent. KORNBLUETH, GOMBOS AND TRAUB [5] acame to the conclusion that mannitol was most effective, and between gly­cerol and Diamox, glycerol was more effective than Diamox. JAFFE AND LIGHT used oral glycerine in his pa­tients and came to the conclusion that average fall in ocular pressure was 5.4 mm. Hg. and the patients with rela­tively high intraocular pressure experi­ence a greater fall than those with lower pressure. VIRNo [6] noted an verage fall much larger, i.e. from 21.1 mm of Hg. to 9.1 mm of Hg. BENJUMEDA AND PINER0 [2] used gly­cerine and urea to lower intra-ocular pressure, and said that Diamox, anti­emetics and analgesics, if added, are helpful in lowering the tension. AWASTHI' also noted marked reduc­tion in intra-ocular tension following oral administration of glycerine.


At random 150 patients were taken, and were divided in four groups. The first three groups were of twenty five each, and the fourth group of seventy five. Group 1 received 20% mannitol, about 150 to 200 cc. intra-venously, on the day of the operation. Group II .received glycerine 40 to 50 cc orally, diluted with lime juice, on the day of operation. Group three patients were admitted three days before the day of operation and were given 250 mgm. of Diamox tablets, three times a day, and on the day of operation at 7 a.m. Group IV did not receive any hypo­tensive medication.

The intra-ocular pressure of all the patients was measured on the day of admission, prior to any hypotensive medication. For the mannitol group intra-ocular tension was measured at 1, 12, and 2 hours after finishing the I.V. drip. For glycerol group the intra­ocular tension was measured at the same time intervals after it adminis­tration. For the Diamox group, inter­ocular pressure was measured daily at the same time, and just prior to the operation. All intra-ocular tensions were taken on a Schiotz tonometer.

Pre-operatively all of them received Dial 50 mgm tablet on the previous night, and Pethidine and Phenergan Inj. I . M. about an hour before the operation. Pupil was dilated with homatropine 2% eye drops instilled at 6, 6-30, 7, 7-30 a.m. on the day of operation. Surgical technique remained almost the same in all the cases.


Mannitol Group

In this group the maximum drop in tension was after 2 hours, the average for the 2nd hour being 6 mm Hg. The maximum drop was 16.8 mm. (initial Tn 29 mm) and the minimum drop was 2.7 mm (initial Tn 17.3 mm).

In majority of cases maximum fall in pressure took place at the end of 1½ to 2 hrs. A large drop in .tension occurs at the end of one hour, follow­ed by a slow fall over 1½ and 2 hours.

Average fall in tension was 6 mm. of Hg. (range 16.8 to 2.7 mm).

Of the 75 cases who received hypo­tensive agents shallow anterior cham­ber was found on second and third day of operation in 6 cases i.e. 8%. While of the twenty five cases who did not receive any hypotensive agents, shallow anterior chamber was found in three cases i.e. 4%.


Between Mannitol Diamox and gly­cerol, mannitol has the maximum hy­potensive effect. Hypotensive effect of Diamox is unpredictable in about 20% of the cases, and it needs to be given at least two days prior to the day of operation, to achieve significant hypo­tension in normotensive eyes. The hypotensive effect of glycerol is more than Diamox but less than that of mannitol, but it has au advantage that it can be easily administered, and has almost no systemic side effects.

The post-operative incidence of shallow anterior chamber appears to be more, almost double, in cases where hypotensive agents were used pre-operatively It is doubtful if this may be due to `rebound choroidal ede­ma' or `rebound vitreous swelling'.


150 cases were studied, and hypo­tensive effects of Diamox, Mannitol, and glycerol were compared. Mannitol has the maximum hypotensive effect. but glycerol is the safest hypotensive agent. An attempt was made to com­pare the incidence of post-operative shallow chamber, with and without hypotensive agents, where incidence was more in cases where hypotensive agents were used[7].


1Awasthi P.; Mathur S. P.; and Sri­vastava: Oral glycerine in Cataract Surgery: Brit. J. Ophth. 51: 130, (1967).
2Benjume.da S. A. and Pinero C. A.: Osmotic agents in the pre-operative care for Cataract extraction: Arch. Soc. oftal. hisp-am. 27: 142 (1967).
3Drance S. M.: Effect of oral gly­cerine on intea~ocular pressure in normal and Glaucomatous eyes: Arch. of Opht (Chicago 72: 491 (1964).
4Jaffe S. and Light S.: Oral glycerine in Cataract surgery. Arch. of Ophth. (Chicago) 73: 516 (1965).
5Kornblueth W. Gombos G. and Traub B.: The effects of Osmotic agents employed before Cataract extraction: Amer. J. Ophth. 62: 221 (1966).
6Virno: Oral glycerol in Ophthal­mology: Amer J. Ophth: 55: 1133 (1963).
7Benjumeda S. A. & Pinero, C. A.: Osmotic agents in the preoperative care for cat ext: Arch. Soc. Oftal, hisp.-am. 27: 142, Feb. 1967.