Indian Journal of Ophthalmology

: 1984  |  Volume : 32  |  Issue : 5  |  Page : 437--438

Prophylactic peripheral iridectomy with argon laser & abraham contact lens

K Rama Mohan Rao, PN Srinivasa Rao 
 O.E. U Institute of Ophthalmology, KMC Hospital, Manipal, India

Correspondence Address:
K Rama Mohan Rao
O.E.U, Institute of Ophthalmology, KM.C. Hospital, Manipal

How to cite this article:
Mohan Rao K R, Srinivasa Rao P N. Prophylactic peripheral iridectomy with argon laser & abraham contact lens.Indian J Ophthalmol 1984;32:437-438

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Mohan Rao K R, Srinivasa Rao P N. Prophylactic peripheral iridectomy with argon laser & abraham contact lens. Indian J Ophthalmol [serial online] 1984 [cited 2021 Sep 17 ];32:437-438
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Full Text

The need for management of the fellow eye in patients with narrow angle glaucoma is an accepted fact. Conventionally surgical peripheral iridectomy is done as pro­phylactic procedure.

Use of light energy of a Xenon arc was tried by Meyer Schwickerath as early as 1956 but did not seem to gain popularity as incidence of corneal and lenticular opacity was high and was advocated only for aphakic eyes.

Use of varieties of laser has been reported to achieve the same. [1],[2]

We are reporting our experience in pro­phylactic laser iridectomy in narrow angle glaucoma-using the Abraham Hump Technique, the Abraham Iridectomy contact lens and short exposure burns.


22 fellow eyes presented to us in the period between Jan. 1980-Jan. '83 were managed in the following way.

Peripheral Iridectomy-15

Laser iridectomy - 7 (One patient one eyed)

Peripheral iridectomy is done usually as a routine in this hospital, but in 7 cases who refused surgery-laser iridectomy was done.

Observations done in follow up of these cases (period of 1 Year-3 Years)


1. Pupil rendered miotic by 4% Pilocarpine instilled 4-5 times 1/2 hour prior to surgery.

2. Surface anaesthesia and sub conj. bleb at 1-2 O'clock position.

3. Abraham lens placed over cornea with methyl cellulose and iris focussed through the button of lens.

4. l st burn of 500 M with 0.5 sec. exposure and 0.5W at 1.30 or 2.30 position to raise hump on either side.

5. Penetrating burn of 50 M in 0.02 sec. and 0.5 W power at apex of the hump. Observe appearence of air bubble.

6. Topical steroids for 3-5 days.


Prophylactic iridectomy with laser seems to have gained popularity because of certain advantages. Abraham lens reduces chances of cornea burns due to the fact that laser beam diameter doubles over the cornea and halves over the iris resulting in power dec­rease by a factor of 4 over the cornea but increase by a factor of 4 over the iris. This shortens exposure time, reduces energy required for full thickness burns. The methylcellulose used absorbs heat to some extent.[3] The short burn technique has been reported to be better and as having less complications.[4]

It is safe procedure with minimum iritis lasting only about 3-4 days and easily con­trolled with steroids.

Indian patients with brown to light brown irides require minimal burns and are not resistant to short burns. In contradiction to reported resistance to burn in thick brown irides requiring longer burn and more exposure.[5],[6]


Laser iridectomy seems to be well accepted and ideal for Indian patients of light brown to brown Irides and also to apprehensive patients and when facilities are available. Surgical iridectomy can be justified only when laser cannot be used as in cloudy cor­neas, totally flat anterior chambers of extremely fibrotic irides or in rare occasions when laser fails. But more often-laser cures where surgery fails.


1Khuri, Amer. J. Ophthalmol. 76, 490, 73.
2Pollack and Patz, 1976. Ophthalmic Surgery. 7, 822, 1.
3Robert, R. Trans, Asia Pacific Acad. Of Ophthalmol. Vol. VIII.
4Tetsuya Y. 1982. Jap. J. Ophthalmol. 26: 4/387.
5Laser Iridectomy of Por. J. Hung-Trans. Asia Pacific Academy of Ophthalmol. Vol VIII.
6Quingley H.A.. 1981. Ophthalmology 88: 218.