|Year : 1991 | Volume
| Issue : 3 | Page : 85-86
Scleral rigidity in glaucoma, before and during topical antiglaucoma drug therapy
KK Agrawal, DP Sharma, Ganesh Bhargava, DK Sanadhya
Department of Ophthalmology, R.N.T. Medical College, General Hospital, Udaipur, Rajasthan, India
K K Agrawal
Department of Ophthalmology, R.N.T. Medical College, General Hospital, Udaipur, Rajasthan-313 001
Source of Support: None, Conflict of Interest: None
A study of 30 subjects (10 normal and 20 having glaucoma) was done to find out the scleral rigidity in glaucoma cases as compared to normal. The effect of miotics, timolol (0.25%) and pilocarpine (2%) eye drops on the scleral rigidity in cases of glaucoma was observed.
|How to cite this article:|
Agrawal K K, Sharma D P, Bhargava G, Sanadhya D K. Scleral rigidity in glaucoma, before and during topical antiglaucoma drug therapy. Indian J Ophthalmol 1991;39:85-6
The scleral rigidity was measured for each subject by the technique of differential tonometry using paired weights 5.5 gm. and 7.5 gm. on the Schiotz tonometer. Friedenwald pressure rigidity table for each paired weight reading was used to calculate the scleral rigidity.
In the study, the scleral rigidity was found to be reduced in the presence of glaucoma. It is concluded that it gradually increases during treatment with topical antiglaucoma drugs as the treatment progresses. Only a small percentage shows that the antiglaucoma drugs reduces the scleral rigidity in glaucomatous eyes.
| Introduction|| |
Blindness is a global problem and glaucoma shares a major part in creating an irreversible loss of sight. Such visual losses could be prevented if this dreadful disease is diagnosed in time and treated effectively. Tonometry is done routinely in the ophthalmic outdoor to diagnose or rule out glaucoma. The greatest error in such readings arise from variation in the scleral rigidity. If scleral rigidity is high, the intraocular pressure is over estimated and the tension recorded is less, if the scleral rigidity is lower than normal.
Scleral rigidity depends upon many factors. Topical antiglaucoma drug therapy is one of them. So a study was planned by us to find out the scleral rigidity in proved cases of glaucoma before and during the drug therapy, which will prove to be a guide in evaluating the control of this blinding disease.
| Material and methods|| |
Thirty patients were selected for the study and were divided into two groups. The first group comprised 10 normal individuals of different ages and the second group comprised 20 proved cases of chronic simple glaucoma, out of their 10 were treated with timolol maleate ( 0.25% ) and the other 10 were treated with pilocarpine (2% ) for 3 weeks.
The scleral rigidity was measured for each patient by the technique of differential tonometry using paired weights, 5.5 gm. and 7.5 gm. on Schiotz tonometer. Friedenwald pressure rigidity table for each paired weight reading was used to calculate the scleral rigidity. In all cases of glaucoma the scleral rigidity was recorded initially and then after every week. of drug treatment upto 3 weeks.
| Observations and discussions|| |
As per [Table - 1] the normal scleral rigidity in healthy individuals was found to range from 0.0180 to 0.0246 with a mean of 0.0217 irrespective of age and sex. The above findings mimic the results published in literature by Friedenwald (1937)  0.0215, Drance 0.0217 (1960)  and Goldmann 0.0200 (1957) .
[Table - 2] shows mean scleral rigidity to be 0.0143 in g iucomatous eyes which is much below the normal value 0.0217 as shown in [Table - 1]. A constant rise in scleral rigidity is seen after treatment of the case after 3 weeks with timolol ( 0.25% ). The scleral rigidity rose from 0.0143 to 0.0174, 0.0210 and 0.0214 after first, second and third weeks of treatment respectively. Thus the scleral rigidity rose to almost normal value. The observation confirms the findings of Drance (1960)  who also found an increase in scleral rigidity in 80 per cent of his cases having glaucoma after treatment with miotics.
[Table - 3] shows mean scleral rigidity to be 0.0115 in 10 glaucoma cases, who were treated with pilocarpine ( 2% ) for 3 weeks. It is ohserved that the mean scleral rigidity of this group rose to 0.0158 after the first week, to 0.0179 after the second week and to 0.0185 after the third week of treatment with pilocarpine 2% eye drops. Victor (1959)  commented that the scleral rigidity is lower in cases of glaucoma and when :topical antiglaucoma drugs are given, the scleral rigidity improves.
| References|| |
Friedenwald J.S. : Contribution of the theory and practice of tonometry. Amer. J. Ophth. 20 : 985, 1937.
Drance S.M. : The coefficient of scleral rigidity in normal and glaucomatous eyes. A.M.A. Arch. Ophth. 63 : 673, 1960.
Goldmann H. and Schmidt, T : Der Rigiditats coefficient ophthalmologica. 133 : 330, 1957.
Victor Goodside Ocular rigidity. Am. Arch. 62 : 839, 1959.
[Table - 1], [Table - 2], [Table - 3]