Direct demonstration of transsynaptic degeneration in the human visual system: a comparison of retrograde and anterograde changes

Transneuronal degeneration of retinal ganglion cells was directly demonstrated in a patient who had unilateral removal of the striate cortex forty years prior to necropsy. For comparison, another case is presented showing anterograde transneuronal atrophy forty years after enucleation of one eye.     

DRAINING PUS FROM THE CORNEA

Thirteen patients with varying grades of suppurative keratitis were studied with regard to their response to keratoplasty. In all patients there was a rapid improvement in symptoms and signs. In eight of the 13 there was restoration at least of previous function: one patient lost all vision due to secondary closed-angle glaucoma, because he refused further surgery. Corneal graft opacification occurred in three eyes; one other became partially opaque; whilst in a fourth, the lamellar graft remained clear while the original autograft failed. At last follow-up, all eyes were normotensive and free of symptoms. Keratoplasty should assume an important part of the management of suppurative keratitis, from both theoretical and practical considerations.     

OUTLINE FOR A COMPREHENSIVE CLASSIFICATION OF RETINAL DYSTROPHY AND ITS CONSEQUENCES

Classification of all relevant factors is a prerequisite to the formulation of specific objectives to attain goals of prevention of retinal dystrophy (RD) and effective provision of services. National and international agreement on a classification is sought. This outline stresses the importance of a sound conceptual basis. The root meaning of dystrophy (difficult nourishment), and the concepts given in the World Organization's International Classification of Impairments, Disabilities and Handicaps are emphasized. The proposed classification is designed to be statistical as well as assisting diagnosis and case management. The scheme for RD entities takes into account special features, in contrast to most treatable eye diseases. Genetics is stressed because of the importance of genetic counselling and rapid research advances.
Three appendices illustrate portions of a comprehensive classification already in operation at the Retinal Dystrophy Service of NSW.     

A REVIEW OF LEISKE STYLE SEMI-FLEXIBLE INTRAOCULAR LENSES 1981–1984

A consecutive series of 205 patients had 237 intracapsular cataract extractions performed with the insertion of a semi-flexible intraocular lens in the period 1981–1983. The average follow-up period was 17.8 months; 87.0% of cases obtained a visual acuity of 6/12 or better after operation, compared with 80.6% of cases whose preoperative visual acuity was 6/36 or worse. Twenty-six eyes (11 %) had clinical cystoid macular oedema at some stage after operation, and seven eyes (3%) had persistent cystoid macular oedema at final follow-up. Only one eye had a postoperative retinal detachment. Thirty eyes (14.1%) required treatment for elevated intraocular pressure at some time after operation.     

THE TRACHOMA STATUS AND BLINDNESS RATES OF SELECTED AREAS OF PAPUA NEW GUINEA IN 1979-80

A survey of 4 selected areas of Papua New Guinea was made during 1979-80 to establish the prevalence of trachoma and its complications, and blindness rates and causes, in those areas. Trachoma was found to be endemic in all the areas studied, but was of mild intensity and rarely caused visual deficit. It is suggested that the most practical step towards reducing the prevalence of trachoma in P.N.G., in the future, is not by a mass treatment campaign, but by basic education in simple hygiene. An overall blindness rate of 0.50% was found in this survey, indicating that blindness is not a big problem in P.N.G. today. However there is still a need tor improved Primary Eye Health Care, the training of national ophthalmologists, and provision for one institution for the training of the blind in P N G.     

RETINOBLASTOMA IN THE ANTERIOR CHAMBER OF THE EYE

An uncommon presentation of retinoblastoma in an eleven-year-old boy is discussed. There was no family history of retinoblastoma and the child had never complained of a sore eye. He was not aware that he could not see out of his right eye.     

THE USE OF ULTRASONOGRAPHY IN DETERMINING THE AMOUNT OF EXTRAOCULAR MUSCLE SURGERY IN STRABISMUS

In twenty strabismus patients using ultrasonography a measurement was taken from the apex of the orbit through the centre of rotation of the eye to the front of the eye along the oculomotor axis which is at an angle of approximately 10° to the anteroposterior axis of the eye. From this and from the diameter of the eye average values were derived for the distance from the equator of the medial rectus insertion of 6.27 mm (range 3. 96–8. 92 mm) the lateral rectus insertion 8. 77 mm, the length of the medial rectus 35.32 mm (range 32. 40–40.25 mm) and the lateral rectus 37.82 mm (range 34, 79–42. 75 mm). There are sources of error in these measurements but they are probably not great, though corneal diameter and muscle positions should be checked at operation. In addition a recession/muscle length ratio may be calculated and it is probably wise not to exceed a ratio of 0. 20 for the medial rectus and 0.25 for the lateral rectus with similar resection muscle length ratios suggested. The variability of the distance of the muscle insertions from the equator is greater than the muscle lengths and it seems important not to recess beyond the equator while alteration of muscle length may be less important This suggests maximal recession of the medial rectus may vary from 4 up to almost 9 mm and from 6.5 to almost 11.5 mm for the lateral rectus. The value of making these measurements pre-operatively seems obvious and the considerable variation is the amount of squint surgery is stressed, particularly for muscle recessions.