AN AVERAGING METHOD FOR THE INTERPRETATION OF THE FARNSWORTH-MUNSELL 100-HUE TEST—I. CONGENITAL COLOUR VISION DEFECTS

A method is described for identifying polarity in Farnsworth-Munsell 100-Hue test data. The method is facilitated by the use of a micro-computer and involves the plotting of "averaged" scores for each cap of the test. Results are presented for 30 protanopes, 30 deuteranopes, 1 tritanope and 2 typical rod monochromats. Analysis of the results shows that the proposed technique is compatible with standard methods of interpreting 100-Hue plots and is suitable to use when error scores are high and when polarity is difficult to interpret.     

THE OCULAR AND PERIOCULAR FEATURES OF MULTICENTRIC RETICU-LOHISTIOCYTOSIS WITH PARAPROTEINEMIA A report of two cases

Two patients with atypical multicentric reticulohistiocytosis are reported. Skin rigidity with mobile rubbery nodules, and telangiectases, are typical of this disease and occurred around the eyes and elsewhere. One patient also had subconjunctival nodules and corneal crystal formation probably due to her paraproteinaemia.
Some literature on this disease and on the occurrence of corneal crystal deposition in dysproteinaemia is reviewed.     

THE TREATMENT OF BETA IRRADIATION NECROSIS OF THE SCLERA

Although complications after using beta irradiation with pterygium excision are rather rare, they are serious. Methods of dealing with avascularity of the limbal area, and moderate and severe scleral necrosis are presented.     

CLINICAL FEATURES OF DEGENERATIVE RETINOSCHISIS

To elucidate clinical characteristics, typical and reticular degenerative retinoschisis are characterized histopathologically in a series of 2319 autopsy eyes, and clinically in a series of 77 eyes in 43 patients. In the autopsy series, typical degenerative retinoschisis was seen in 1.02% of the cases and 0.69% of the eyes; and reticular degenerative retinoschisis was seen in 1.62% of the cases and 0.95% of the eyes. Histopathology was correlated with clinical observations in adult patients with typical and reticular degenerative retinoschisis. On the basis of these observations, consideration was given to the clinical manifestations and management of typical and reticular degenerative retinoschisis.     

THE WAIT OF THE WORLD

In our modem world, avoidable blindness is as unacceptable as starvation. Frameworks exist for both preventative and curative ophthalmology, but these are under-staffed. In developing countries, the emphasis must shift to the people themselves to take responsibility for their own eye health, an aim which may be achieved by simple teaching at grassroots level.     

THE ALGEBRA OF SPHERO-CYLINDERS

Sphero-cylinders are shown to be representable by formal vectors. An algebra applicable to sphero-cylinders is stated and mathematically consistent operations are defined. Examples of practical applications of some operations are given.     

MODELLING THE RESULTS OF THE ORTHOPTIC TREATMENT OF DIVERGENCE EXCESS

Using data compiled from an earlier study of the results of the orthoptic treatment of divergence excess [Daum, K. M. Ophthal. Physiol. Opt. 4, 15-24 (1984)], a model has been presented regarding the results of the treatment. Provided the calibration sample is representative, the model may be used after an initial examination to predict the class of success a given subject will eventually be placed in as a result of orthoptic treatment. After treatment with a standard orthoptic regimen, the subjects were classified as being either totally successful (no objective or subjective visual difficulties) or partially/not successful. Stepwise discriminate analysis of 15 independent variables for the dependent variable success was used in order to choose the model with the highest coefficient of determination (r2) and the best statistical significance. The three variables chosen for the model were the angle of deviation at near and the blur and break values of the negative vergences at near. Using these variables, discriminant analysis was performed on the calibration sample of nine subjects. Each was classified correctly. The use and limitations of the model are briefly discussed.     

160例眼球后段磁性异物临床分析

本文分析了160例眼球后段磁性异物病人的治疗情况.结果发现:眼球后段磁性异物多数比较小,<2mm的占61.2%;异物接近球壁的占73.7%(<2mm).20例病人同时联合玻璃体切割术,110例做了单纯摘除异物.疗效的好坏取决于眼球损伤的程度、异物定位的准确性以及有无发生手术并发症.异物进入眼球的创口在角膜或角巩缘的占77.6%,这是术后影响病人视力的重要原因之一.     

THE LATERAL CHROMATIC ABERRATION OF THE EYE

Abstract Although the longitudinal chromatic aberration of the eye has been extensively studied, little data has been published on its lateral chromatic aberration. Using a reduced eye, this has been calculated for different eccentricities and wavelengths, and data are presented. The lateral chromatic aberration of the eye will cause the perceived direction of an off-axis object or light in vary with its wavelength.     

RELIABILITY OF THE WETTING VALUE OF TEARS

The wetting value is the length of a Schirmer strip wetted in millimetres for a 5 min test period plus the length of time in seconds for dry spots to appear and has been suggested as a better prognostic test than its components in isolation (Fanti and Holly, 1980). Parameters of these procedures are examined and important shortcomings in the derivation of wetting value discussed. Reliability figures are presented for the Schirmer, tear break-up and wetting value tests. The norms obtained for the tear break-up test are substantially different from those usually assumed and we recommend that practitioners should therefore rely on their own norms rather than published values.     

AN APPRECIATION OF THE PROPOSED MECHANISMS INVOLVED IN THE PHYSIOLOGY OF COLOUR PERCEPTION

The variable factors involved in the process of colour appreciation are introduced and discussed in detail according to their relative importance. The human retina, tract and cortex, together with the perceptual mechanisms arise as the most significant and complex factors. The duplex mechanism is discussed in the light of results of modern investigations and found to be still basically sound. The physiology of colour vision reveals further results pregnant with the potential of founding a new explanation of the process. When the accepted colour vision theories are reviewed it is obvious that none provides a complete explanation. The complexity of the process is thus established and the revelations conclude with a probable approach for further investigation.     

THE PRESENTATION OF ACUTE GLAUCOMA IN PSEUDOEXFOLIATION OF THE LENS CAPSULE

Up to 25% of patients with pseudoexfoliation of the tens capsule (PXF) and glaucoma may present with an acute rise in intraocular pressure (IOP) but the majority of these are not due to angle closure glaucoma. A series of 139 cases with acute presentation of PXF is described; this comprised 86 cases of acute open angle PXF glaucoma (9 bilateral), 18 cases of acute angle closure glaucoma with PXF, 21 cases of neovascular glaucoma with PXF and 14 cases of absolute PXF glaucoma. Males suffered acute open-angle PXF glaucoma and absolute PXF glaucoma significantly more frequently than females. The anterior chamber depth was 2.2 mm or less in all eyes having acute angle closure glaucoma with PXF but few cases with acute open-angle PXF glaucoma had a shallow anterior chamber, this difference being highly statistically significant (P < 0.001). The response to medical treatment was poor in most cases, while surgical treatment was successful in lowering IOP in the majority of cases. Argon laser trabeculoplasty was less successful with a risk of late high rise in IOP.     

THE EFFECT OF RESTRICTED VIEWING TIME ON THE PERFORMANCE OF COLOUR DEFECTIVES USING THE CITY UNIVERSITY COLOUR VISION TEST

The effect of restricting viewing time to 3.75 ms on the performance of seven red/green colour defectives is studied using the City University Colour Vision Test. One further subject who was screened as colour-defective but not classified on the City plates was studied in the same way and results for this subject are presented separately. The results are compared to those for normal observers who exhibit a tritan-classified defect when viewing time is restricted to 3.75 ms.