The Farnsworth-Munsell

Measurements of pupiliary reactivity and size were recorded using neutral density filters and infrared pupiliometry (IRP) in a prospective masked study of acute central retinal vein occlusion (CRVO) to quantify the two methods of measurement and to compare their value in the prediction of rubeosis. Thirty two patients were examined within 45 days of disease onset. The mean relative afferent pupillary defect (RAPD) with filters was significantly greater in patients who developed rubeosis than in those who did not (0.9 vs 03 log units; p=0-012). Using IRP, the pupiliary diameters in the dark (maximum) and in the. light (minimum) were significantly greater, the rate of pupillary constriction was significantly lower, and the latency ofconstriction was significantly greater in affected eyes than in unaffected eyes. The differences between affected and unaffected eyes in the IRP parameters of latency, rate, maximum, and minimum pupillary diameters were significantly greater in patients who developed rubeosis than in those who did not. Discriminant analysis of the IRP parameters correctly and statistically significantly identified rubeotic patients with 83% sensitivity and 95% specificity. An RAPD of .-06 log units was 83% sensitive and 70% specific in this regard. It is concluded that pupillary reactions are abnormal in many patients with acute CRVO, as measured by both pupiliometric methods. The degree of these abnormalities has a relationship to the development of rubeosis, and might prove useful in planning the follow up of these patients or in deciding whether to apply panretinal photocoagulation. The neutral density filter test is readily available but subjective. IRP is more specific, objective, and suited to further development, but requires sophisticated equipment. (BrJ Ophthalmol 1993; 77: 75-80) Bristol Eye Hospital P A Bloom D Papakostopoulos S Papakostopoulos RH B Grey

The Electrodiagnostic Neurophysiological Automated Analysis (ENAA) telematic system was developed in the EU EUREKA project. To validate the system 2500 electrodiagnostic tests were administered in a standardized manner during a three-year period. The tests were performed on 70 normal subjects and 500 patients in five laboratories in three European countries. The data were transmitted to the Bristol Telematic Electrodiagnostic Centre in the Bristol Eye Hospital. Data from normal subjects were not significantly different between laboratories. Data from patients were reported upon and the conclusions transmitted to the place of origin. The system provided the remote consultant with multimedia data, including medical images such as colour fundus photography and angiography, video and sound.

The pattern-reversal visual evoked potential (PR VEP) is an electrodiagnostic test which uses an alternating checkerboard pattern as the visual stimulus. To validate the performance of an automated testing system, the equipment was installed in five locations in three countries (the UK, Greece and Cyprus). PR VEPs require accurate control of stimulus size, luminance, contrast, timing, multichannel recordings and various modes of signal processing. Recordings were obtained from 70 subjects, 18-34 years old (seven male and seven female in each laboratory). The data were transmitted by telephone line to the central station in Bristol. Only in Bristol were the operators experienced. There were no significant differences between laboratories in latency or amplitude of the N70 and P100 components. There were no significant differences between eyes. There were significant differences between the sexes but this was related to head size. Decreased square size used in stimulation produced an increased latency in both components. The amplitude of the N70 component increased while that of the P100 decreased with reduced square size. The results confirmed the ability of the automated system to produce standardized PR VEP recordings comparable to those obtainable in advanced laboratories. The system performed well in different locations using inexperienced operators. The system is suitable for multicentre research studies and telemedicine.

The results of an electrodiagnostic test, the electro-oculogram, recorded under standardized conditions, were compared. Recordings were obtained from 70 normal subjects in three European countries and 28 subjects in an Asian country. All subjects were 18-34 years old. Equal numbers of male and female patients were tested in each of six laboratories. There were no significant differences between the results of the European laboratories. There were, however, significant differences between the results of the European and the Asian laboratories, and between the results from the male and female subjects in all laboratories. This suggests the need for considering the possibility of male/female as well as local variations in normal control values when telemedicine is applied on a global scale.