|Year : 1983 | Volume
| Issue : 5 | Page : 612-614
Peripheral iridectomy in primary angle clusure glaucoma
Indira Mondal, P Mondal
Regional Institute of Ophthalmology, Calcutta, India
Regional Institute of Ophthalmology, Calcutta
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Mondal I, Mondal P. Peripheral iridectomy in primary angle clusure glaucoma. Indian J Ophthalmol 1983;31:612-4
|How to cite this URL:|
Mondal I, Mondal P. Peripheral iridectomy in primary angle clusure glaucoma. Indian J Ophthalmol [serial online] 1983 [cited 2019 Oct 19];31:612-4. Available from: http://www.ijo.in/text.asp?1983/31/5/612/36605
The purpose of this study was to evaluate the outcome of peripheral iridectomy in cases of angle closure glaucoma, in which the intraocular pressure had been medically controlled.
| Materials and Methods|| |
One hundred and thirty four eyes of 67 patients were followed up from 1971 until December, 1979 at the Regional Institute of Ophthalmology, Calcutta. The minimum follow up period was 6 months. 41 were female and 26 were male [Table - 1].
The peripheral iridectomy cases in this study were into four groups [Table - 2].
Twentyseven eyes did not have peripheral iridectomies for reason shown below [Table - 3].
The cases were recorded in a proforma, the presentation, course, examination of anterior and posterior segments and special investigations which include the field of vision and angle of anterior chamber. Eyes with raised intraocular pressure had prior medical control before assessment.
Grades of angle closure as determined before peripheral iridectomy is shown in [Table - 4].
On analysis it was found that 62% in group I, 63% in group II, 52% in group III and 7% in group IV had more than 70% angle closure.
Abexterno peripheral iridectomy was done through a tiny incision at the limbus on one side of the mid-line. There was no loss of aqueous and no suturing were required. Except in cases of group I where pre-operative medical treatment was required and cases with only eye, patients were not hospitalised. As no instrument was introduced in the eye and anterior chamber was never lost, the incidence of post-operative lens opacity was not in any way higher than the incidence of senile cataract in that age group.
Control was considered to have achieved if the intraocular pressure was 21 mm of Hg or less one month after operation, optic disc and field did not show any change during the follow up period.
| Observations|| |
On analysis it was found that out of 42 eyes with acute primary glaucoma 27 (64%) eyes being completely controlled with peripheral iridectomy alone. Pilocarpine therapy was required for the remaining 15 eyes (36%). Out of this 7 eyes (17%) were stabilised but in 8 eyes (19%) further operation was required. Of those requiring further surgery 4 had pressure more than 30 mm Hg after two operations and required medical control and cyclocryo. One eye became hypotonic. Six of the cases who had initial success with peripheral iridectomy required miotic therapy in the follow up period. [Figure 1].
In eight eyes of group II with subacute and creeping angle closure glaucoma 5 eyes had miotic treatment for over 6 months prior to peripheral iridectomy. In 4 eyes (50%) peripheral iridectomy was successful and 4 eyes (50%) required pilocarpine in addition. 2 eyes (25%) required further surgery. One case having bilateral creeping angle closure glaucoma who required in both eyes pilocarpine and acetazolamide before operation, after peripheral iridectomy non-operated eye required only pilocarpine of a weaker strength for control, indicating consenual effect of the operation on the fellow eye [Figure 2].
In group III of the 13 eyes having angle closure following mydriasis, 10 eyes (76%) were controlled by peripheral iridectomy 3 eyes (24%) required additional miotic therapy of which in one filtration operation had to be done.
In group IV peripheral iridectomy was done as a prophylactic measure in the asymptomatic fellow eye of patients who had angle closure in the other eye.
Out of the 44 eyes 39 eyes (89%) never had any trouble in the follow up period. Only 5 eyes (11%) miotic had to be used for episodic rise of pressure.
| Discussion|| |
This study deals with the efficacy of peripheral iridectomy in a wide group of angle closure glaucoma and eyes having critically narrow angles with high risk of angle closure.
Peripheral iridectomy should be the initial surgical procedure following the termination of an acute attack with medical means, and should be considered as a safe prophylaxis in asymptomatic fellow eye. This safe and simple operation, can be done as a day case, without any inconvenience to the patient. If required, it makes the use of miotic safer and does not stand in the way of further filtration operation.
It has been observed that gonioscopic examination is not to be taken as a guide to predict pre-operatively which patient would be left with residual raised pressure and need further medical and/or surgical therapy. Gonioscopic examination gives valuable information about the state of the angle but it does not help to differentiate the degree of appositional contact from synechial closure. The corneal indentation gonioscopy and operative gonioscopy is not equivocal or reliable.
In this study peripheral iridectomy has achieved success in 66% eyes even where 60% eyes had over 70% angle closure as determined by pre-operative gonioscopy. Addition of miotic therapy controlled half of the remaining 34% eyes while filtration operation was required in remaining 17% eyes.
Mapstone has pointed out some fallacy in the gonioscopic evaluation of narrow angle eyes. He showed that the intraocular pressure may not rise even when 80% of the angle is closed.
The higher success rate of peripheral iridectomy in this study which does not corelate with the gonioscopic state of the angle indicate that appositional contact predominate over organic closure. As there is no means to detect the relative proportion of the block, it is logical to do peripheral iridectomy as an initial procedure.
It is also found that after peripheral iridectomy careful and frequent follow up is required in all cases. A controlled case may behave otherwise as we are ignorant of the pathogenesis of episodic angle closure. A slight rise of intraocular pressure can produce loss of field rapidly after an acute attack.
As a choice of second operation trabeculectomy and Scheie operation were performed. Cyclocryotherapy have helped in selected cases.
| Acknowledgement|| |
I thank the Director of the Institute for allowing me to use the hospital materials in this study. I also thank all the staff of the Glaucoma clinic of the Institute for their kind help in the present study.
[Table - 1], [Table - 2], [Table - 3], [Table - 4], [Table - 5]