|Year : 1984 | Volume
| Issue : 4 | Page : 209-211
Observations on the use of low temperature in the treatment of glaucoma
Kazimierz Gerkowicz, Jerzy Toczolowski
Clinic of Ophthalmology, Medical Academy in Lublin, Poland
Clinic of Ophthalmology. Chmielna 1, 20-079 Lublin
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Gerkowicz K, Toczolowski J. Observations on the use of low temperature in the treatment of glaucoma. Indian J Ophthalmol 1984;32:209-11
Bietti was the first to use low temperature for the treatment of glaucoma, but it was only in the '60s that this method gained wider application, thanks to the publication of a greater number of experimental and clinical studies,,. The general opinion is that cyclocryoapplication represents in many forms of glaucoma, an efficacious therapeutic method,,,. Although no uniform technique of this operation has been established so far with the result that the methods of applying low temperature and the reports on their efficacy show considerable differences. In the present work, two groups of patients are compared, in whom two different methods of performing cyclocryoapplication were applied in various clinical forms of glaucoma.
| Material and methods|| |
The patients were divided into two groups: group I consisted of 39, and group 2 of 44 patients. All operations were performed under topical anaesthesia. A cryoprohe with a ball shaped tip of a 2.5 mm diameter was refrigerated to about-74°C and applied in the region of the ciliary body, with a pressure which caused some indentation of the sclera. The operation consisted of 5-6 applications in the two upper or lower quadrants of the eyeball.
In patients of group 1, the cryo-probe was applied at a distance of about 0.5-1 mm from the limbus, for 30 sec. In patients of group 2, care was taken to maintain a 1 mm distance from the limbus in the lower quadrants, and a 1.5 mm distance in the upper ones, the duration of each application being 60 sec. [Figure - 1].
An increased intraocular pressure, which did not respond to conservative treatment, was found in all patients prior to the operation. Control examination and comparison of tonometric results were carried out 6 to 8 weeks after cryoapplication. The effects of the operation were classified as follows:no reduction of the intraocular pressure /0/; partial reduction, the pressure still remaining above 30 mmHg /+/; reduction of the pressure to normal limits /++/.
| Observations|| |
The results obtained in both groups of patients are presented in [Table - 1][Table - 2].
In group 1, normal intraocular pressure was found in 31% of patients, partial reduction in 26%, and in the remaining 43% cyclocryoapplication had no effect on the intra ocular pressure. The respective figures in patients of group 2 were 57%, 23% and 20%.
No case of hypotony was observed in both groups, either immediately after the operation or during the first post-operative days, the intraocular pressure never falling below 18-20 mmHg. As a complication during the early post-operative period, hemorrhage into the anterior chamber occurred in 3 patients of group 2; two of them had hemorrhagic glaucoma, and one had diabetic retinopathy. Blood was resorbed after instituting conservatrive treatment.
| Discussion|| |
Most authors perform cyclocryoapplication using temperatures ranging from-70 to -80°C. This preference is supported by experimental studies, which have demonstthat no therapeutic effect can be obtained with higher temperatures,, and that with too low temperatures the risk of phthiris bulbi presents itself,.
An essential element of the operation is the duration of the individual applications of the instrument. According to Faulborn and Birnbaum the intended effect of cyclocryoapplication, consisting in reducing the secretion of the aqueous in consequence of damaging the epithelium of the ciliary processes, is obtainable when temperatures between-60 and -80°C act for 60 sec. For this reason, we thought it indicated to extend the duration of each application from the 30 sec. used in group 1, to 60 sec.
It is known that the best effect of cyclocryoapplication is obtained when the ciliary processes are refrigerated from their base to the apex. The instrument should therefore be applied immediately over the pars plicata of the ciliary body. Measurements of human eyeballs demonstrate that the most reasonable method of performing cyclocryoapplication is to maintain the distance between the anterior contour of the cryoapplicator and the limbus at 1 mm in both lower quadrants, and at 1.5 mm in both upper ones.
The therapeutic results obtained in glaucomatous patients of group 2 seem to confirm the soundness of the cyclocryoapplication modification under discussion. In this group, comparable with group 1 as far as the diagnosed forms of glaucoma are concerned, normalization of the intraocular pressure was observed almonst twice as often. We think it therefore advisable to perform cyclocryoapplication by the method described for our group 2 of glaucomatous patients.
| Summary|| |
Comparison is made between the results of cyclocryoapplication obtained in 2 groups of
patients with similar clinical forms of glaucoma. With the same temperature of the instrument and the same diameter of its tip, in one group the cryoaplicatorwas applied at the distance of about 0.5-1 mm from the limbus: for 30 sec. In the other group, the distance of the instrument from the limbus was 1.5 mm in the upper quadrants of the eyeball, and I mm in the lower ones, and the duration of each application was 60 sec. Normalization of the intraocular pressure was distinctly more frequent in patients of the latter group.
| References|| |
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Haddad. R, 1981, Wien. Klin. Wochenschr. Suppl. 126 93:3.
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[Figure - 1]
[Table - 1], [Table - 2]