|Year : 1983 | Volume
| Issue : 1 | Page : 5-8
Medical therapy of cataract (evaluation of catalin)
SK Angra, Madan Mohan, JS Saini
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, A.I.I.M.S., New Delhi, India
S K Angra
Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, New Delhi- 110 029
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Angra S K, Mohan M, Saini J S. Medical therapy of cataract (evaluation of catalin). Indian J Ophthalmol 1983;31:5-8
|How to cite this URL:|
Angra S K, Mohan M, Saini J S. Medical therapy of cataract (evaluation of catalin). Indian J Ophthalmol [serial online] 1983 [cited 2021 May 11];31:5-8. Available from: https://www.ijo.in/text.asp?1983/31/1/5/27421
Catalin, a pyridophenoxazine compound resembling xanthommatin, an eye pigment of the insects was introduced in Japan in 1958. Several authors have claimed that it arrests or even reverses development of senile cataract.,, However, these studies were open and have number of fallacies. In one controlled double blind study, catalin was found to be ineffective in prevention or arrest of senile cataract  but the number of cases and follow up period was of short duration.
An attempt has been made in this prospective randomized double blind study to evaluate the effect of Catalin on senile and congenital cataract, using Catalin in one eye and place bo in other eye of same patient.
| Materials and methods|| |
1. Senile cataracts
Patients with sentic cataract having almost equal extent of cataract in each eye were the subjects of this study, who could be followed. The drop out of this study were 14 subjects. Topographic documentation supported by photographic records estimating the amount of cataract was made. Patients were categorised on the basis of the extent of cataract i.e. less than 10% (14 cases)-10% to 30% (25 cases), 30% to 50% (51 cases). The cases having cataract extent more than 50% were excluded from this study. Besides the morphololical diagnosis was also made. Patients were liven coded drugs (Catalin and Placebo) for instillation 6 times a day (not less than 5 times a day) on random basis in the right and left eye of same patient. The visual acuity and changes in refraction were noted before, during and after the study was over. Patients were then observed at intervals over a period of 2 years (24 months). Drug codes were then decoded and results compared.
II. 25 Bilateral congenital cataracts, (complete cataracts-8, nuclear cataracts-17) cases were taken in this study between age group of 2-8 weeks. Coded drops of Catalin and Placebo were put in right eye and left eye after randomisation. The drug instillation was made six times a day. The progress was noted on topographic charts upto 16 weeks in each case. Blood sugar was tested before the institution of therapy and in the middle of therapy. The code was broken at the end of the study,
| Observations|| |
Comparison of progression of cataract in the Catalin treated and placebo treated eye is similar without any significant difference. Worsening of cataract was in 62.5% eyes while on Catalin and on placebo it was 65.0% There was no statistically significant effect between the two [Table - 1]. In the group where amount of pre-treatment cataract was upto 10%, 7 out of 14 eyes worsened while on Catalin drops while 6 out of 14 eyes worsened while on placebo, Similarly almost parallel progression of cataract is seen in two eyes in other groups of 10-30%, 30%-50% extent of cataract. No correlation could be achieved on correlating the progress of cataract with amount of cataract before treatment and type of treotment instituted [Table - 2]. However, the cataract progressed more in one eye than other in 7.5% cases. The visual loss and progress of cataract did not run parallel to each other [Table - 3].
In congenital cataracts, no effect on the progress of the opacity was noted in all these patients. All these petients were then put for surgical procedure or mydiatric therapy. No difference was noted in pre treatment and mid treatment blood sugar levels.
| Discussion|| |
Several substances including pyridophenoxa zine, debenal, sodium thiosulfate and parolin, have been tested to prevent or ratard the formation or dissolve of cataract. However of these only pyridophenoxazine (Catalin) has undergone both clinical,, and experimental trials extensively. But the results were encouraging in some studies and not in others.
It has been observed in our study that the changes in the progress of cataract and visual acuity (maximally improved) are almost similar in the drug treated and placebo treated eyes [Table - 1][Table - 3] indicating that Catalin when instilled locally does not have any beneficial effect in checking the progress of senile and congenital cataract irrespective of the stage of its development. The natural course of progression of cataract is no way changed. It is evident from the progress of the cataracts in our study that in 2 years 65% of patients got progression of cataractous changes while 35% had almost same changes. The difference in progression btween two eyes was to the tune of 7.5%. Otherwise both eyes behaved equally as the two eyes had already equal cataract in the beginning of study.
Ochiai got 36.7% + 8.7% improvement in vision after use of 1 year and 32.4% ± 7.9% after the use of 2 years of Catalin. While Albal et a1 could get visual improvement in 8.33%, prevented visual deterioration in 58 33% and deterioration of V.A. in 33.3% inspite on Catalin therapy. Both the studies and others evaluating catalin have inherent defects like comparison of drug treated patient and placebo treated patients etc. The individual variations in the natural history of progress of a cataract and other variable factors e.g. constitutional, environmental, dietary etc. are difficult to assess, control or match. These can vitiate the results.
In our double blind randomised study, we have done right and left eye comparisons of same individual after due selection of cases, which obviates the above cited lacunae to a major extent. Standardised documentation and methodology has helped observation to be made on very precise and uniform basis.
The majority of exponents of Catalin believe that it is only useful when used in early stages of cataract. We have tried this drug in congenital cataract and early cataracts, that is the lens is affected not more than 50% of its extent. But the results are not good The age factor as related to therapy, is of no significance as the persons picked up in cuneaform and cuppuliform cataract were young (40-50 years) while those corticonuclear cataract were between 45 and 60 years. But hardly there is any difference in treated and untreated eye. Similar are the observations with congenital cataracts.
Our study is also not only taken into consideration of visual acuity but also the morpho logical progress of the opacity thus make the observations more precise as V.A. can be affected by the location of lenticular opacity and other various factors in that age group. [Table - 2].
However, it is not intended to imply that search for medical treatment is not likely to be fruitful. Such more and more researches and evaluations should be undertaken to achieve the target of getting a good anti cataractogenic agent.
| Summary|| |
Catalin has been evaluated in a double blind randomised study in medical therapy of congenital and senile cataracts and found that it has neither curative effect nor has effect on the progress of cataract.
| Acknowledgement|| |
We acknowledge with thanks M/S Biddle Sawyer India Ltd. for generous supply of Catalin.
| References|| |
Ogino, S., 1958, Jap. J. Clin. Ophthalmol. 12:591.
Asayama, R., Shirakani, T., and Amatsu, M., 1960, Jap. J. Clin. Ophthalmol. 14:789.
Ochiai, T., 1966, Jap. Rev. Clin. Ophthalmol. 60 : 641.
Albal, M.V., Chandorkar, A.G. and Jain, P.K,. 1976, Aeta 6th Afro-Asian Cong. Ophthalmol. 195.
Angra, S.K., 1976, Acta, 6th Afro-Asian Cong. Ophthalmol. 200.
Angra, S.K. and Mohan M., 1979, Ind. J. ophthalmol. 27 : 37.
Duke Elder, S., 1969, System of Ophthalmology Henary Kimpton London 11 : 244
[Table - 1], [Table - 2], [Table - 3]