Lp Agarwal

MYCOTIC CORNEAL ULCERS.

CORNEAL ulcers present one of the major ophthalmic problems of India. Mitsui and Hanabusa (1955), Ley (1956), and Ley and Sanders (1956) considered that antibiotic and/or corticosteroid therapy might convert non-pathogenic into pathogenic fungi. Seligmann (1953), Mankowski and Littleton (1954), and Vogel, Michael, and Timpe (1955) have reported the systemic dissemination of fungus infection after systemic cortisone therapy. Conant, Smith, Baker, Callaway, and Martin (1954) stated that mycotic keratitis was mainly due to potentially pathogenic fungi. Leber (1879), Berliner (1882), Schirmer (1896), Uhthoff (1897), Stern and Kulvin (1950), Thygeson, Hogan, and Kimura (1953), Pautler, Roberts, and Beamer (1955), Anderson, Roberts, Gonzalez, and Chick (1959), and Barsky (1959) have reported clinical cases of mycotic infection of the cornea, and Fazakas (1953), Ley (1956), Hirose, Yoshioka, Abe, Kanemitsu, and Kiya (1957), and Montana and Sery (1958) have produced mycotic keratitis experimentally. Some of our recent cases of corneal ulcer, in spite of suitable antibiotic and other therapy, progressed relentlessly and ended in blindness. We assumed that, besides bacteria, other pathogens were complicating these ulcers and we were able in a few to isolate fungi. We therefore attempted to produce experimental fungal keratitis in rabbits and to study the corneal ulcers thus obtained.

INTRALAMELLAR HETEROGRAFTS OF FROG CORNEA INTO RABBIT CORNEA.

THE idea of heterograft keratoplasty was first conceived by Himly (1813). Early experimental work (Reisinger, 1824; Bigger, 1837; Dieffenbach, 1831; Lesser, 1908) and clinical application (Bigger, 1837; Power, 1873; Sellerbeck, 1878; Fuchs 1894), however, both proved unsatisfactory and in some cases disastrous. Because of these failures and the success of homotransplants, heterogeneous corneal grafting was almost abandoned, until the work of Babel and Bourquin (1952) and Choyce (1952) revived interest in experimental heterografts. Basu and Ormsby (1957) found that the antibody-antigen reactions were less frequent with avian than with mammalian corneae and surmised that the farther apart in the scale the donor and recipient tissues were the less likelihood there was of antigen-antibody reaction. Tsutsui and Watanabe (1959) studied intralamellar fish heterografts in the rabbit with encouraging results, and this prompted our experiments with amphibian corneae.

RETINITIS PIGMENTOSA A NEW THERAPEUTIC APPROACH

THE aetiology of various types of retinal and macular degeneration is unsatisfactory and controversial, and little treatment can be given. Many authors have attributed these changes to disturbance of the choriocapillaris and local angiosclerosis of the choroid, and the retinal lesions have been regarded as secondary to these changes (Verhoeff and Grossman, 1937; Brown, 1940). Certain areas, i.e. the macular, equatorial, and peripheral regions, seem to be more prone to degeneration. An analysis of the vascular supply of these areas reveals that the macular region is supplied primarily from the choroid, and that the retinal vessels do not play an important role in its nourishment. Dartnail and Thomson (1949) showed histologically and subjectively that the macula does not have retinal blood vessels but that this is compensated for by the abundance of choriocapillaries. In the equatorial region there is an anastomosis between the posterior and anterior ciliary circulation and this is probably the least resistant part of the vascular system of the choroid. The peripheral region is poorly supplied by retinal blood vessels. The peripheral margin of the retinal vascular system is formed by wide-calibre capillary arches joining the termination of the arteries of the veins. The frequent occurrence of cystoid degeneration in this region is probably due to its relatively poor blood supply which leads to atrophic retinal changes. The many conditions have been attributed primarily to choroidal sclerosis, disciform degeneration of the macula, senile macular degeneration, myopic degeneration of the fundus, retinitis pigmentosa, and circinate retinopathy. The management of these conditions is often difficult. Vasodilators have been recommended but have given equivocal results. Filatov and Verbitska (1946) recommended tissue therapy for retinal pigmentosa. Campos (1956) recommended the implantation of strips of lateral and/or medial rectus close to the choroid after a lamellar scleral resection, aiming at the revascularization of the choroid. Burnside (1956) demonstrated experimentally on monkeys that a simple advancement of inferior oblique muscle strip over the macular area improved the vascular supply of the macula by establishing a collateral circulation with the choroid. Burnside (1958) advocated this method for the treatment of senile macular degeneration. Tamesis (1960) modified the technique of Burnside and implanted the muscle strip in the supra-choroidal space over the macula; he claimed good results in cases of