Guo et al reported a nomogram for predicting myopia in a school child. This can help to identify a child to follow more closely. The authors are from Wenzhou Medical University and the China National Research Center for Ocular Diseases.
Patient selection: Chinese schoolchild, with average age 7.8 years
Myopia onset was defined as SER <= -0.50 D in the right eye
Parameters:
(1) SER (spherical equivalent refraction) in D, from 5 to -0.5
(2) PRA (positive relative accommodation) in diopters, from -16 to 0
(3) AL (axial length) in mm, from 20.5 to 25
(4) CR (corneal refractive power) in D, from 39 to 49
(5) gender
points for SER =
= 84.82 - (16.96 * SER))
points for PRA =
= (0.83 * (PRA)) + 13.3
points for AL =
= (22.22 * (AL)) - 455.56
points for CR =
= (8.93 * (CE)) - 348.66
=
|
Gender
|
Points
|
|
male
|
0
|
|
female
|
9.2
|
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 305.2
value of X =
= (-0.001238 * ((score)^2)) + (0.3311 * (score)) - 19.24
probability of myopia in 4.5 years =
= 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve was 0.74 in the training and 0.86 in the validation cohorts.
