Table 1

Summary of the information collected for the predictor variables and how they were recorded

VariableHow it was scored
AgeRecorded in months at the time of treatment.
Anterior chamber cellsScored from 1 (no cells), 2 (cells +/−), 3 (+) and so on to 6 (++++ of cells).
Anterior chamber flareScored from 1 to 5. 1 was no flare, 2 was + and so on to 5 for ++++.
Anterior chamber invasionPresence of anterior chamber (AC) invasion scored 1 and no invasion scored 2.
IritisSummary variable constructed by the addition of the two variables anterior chamber cells and anterior chamber flare.
Largest tumour diameter (LTD)Largest tumour diameter as measured on ultrasonography in millimetres at presentation.
LipofuscinNo lipofuscin, or the presence of drusen, scored 1. Presence of lipofuscin scored 2 and the presence of a collar stud lesion scored 3.
Location 1Average of the shortest distance from edge of tumour to fovea and to the optic disc in millimetres. Overlap scored 0.
Location 2Refers to which area the tumour appeared centred on. It was scored in as posterior pole (1), equator (2), ora serrata (3) and ciliary body (4).
PigmentMelanotic tumours scored 1 and amelanotic tumours scored 2
PressureRecorded, in mm Hg, for presentation (IOP) and for 8 weeks (IOP − 8).
Retinal detachment Absence of subretinal fluid was scored as 0. The presence of subretinal fluid as determined by slit lamp biomicroscopy with a hand held 78 or 90 DS lens or by fluorescein angiography but not visible by indirect ophthalmoscopy with a 20 DS lens scored 1. Retinal detachment observed by indirect ophthalmoscopy involving less than 1 quadrant scored 2, involving one quadrant or more but less than two quadrants scored 3, more than two but less than 3 quadrants scored 4, more than 3 but less than total scored 4 and total retinal detachment scored 5.
SexDichotomous variable. Male scored as 1 and female as 2.
SideDichotomous variable. Right scored as 1 and left as 2.
Visual acuityThe best visual acuity recorded, with pinhole and refraction, for the tumour containing eye at presentation. 6/6 was coded as 1, 6/9 as 2, 6/12 as 3, 6/18 as 4, 6/24 as 5, 6/36 as 6, 6/60 as 7, 1/60 as 8, counting fingers as 9, hand movements as 10, perception of light as 11, and blind as 12.
Vitreous haemorrhagePresence of vitreous haemorrhage scored 1 and absence scored 2.