TIAR

Description

Returns the toric IOL axis re-alignment (TIAR) values for an eye with given postoperative subjective refraction and knowledge on the implanted toric IOL (cylinder power and axis).

The TIAR components consist of the axis position of toric IOL with minimal residual astigmatism (RA), the amount of rotation required (re-alignment) to get the IOL to the ideal position (+ values = anti-clockwise rotation), the projected current corneal astigmatism, and the lowest RA achievable by re-alignment. By comparing the lowest possible RA and the current manifest cylinder the question 'Is it worth doing?' can be addressed.

Background
For every one degree of error in a toric IOL's rotational alignment, there is a 3.3 percent decrease in the correction of astigmatism. Re-alignment of misaligned toric IOLs reduces residual refractive errors and improves unaided visual acuity. Especially for high cylinder power IOLs, better refractive outcome can be seen when performing a 'back calculation' before realignment. Re-alignment should be done early, ideally 2-4 weeks after surgery. Once the capsule has shrunk alternative options include laser ablation, corneal incisions or contact lenses. Re-alignment does not always reduce the RA significantly enough and the intervention, with all associated risks, might not be worth doing.

URL

POST https://www.zubisoft.com/api/tiar

Permission

Standard authentication with public key, hashed private key and user key is required.

Parameters

Field	Description
refractive_cyl	1.5 (postop manifest cylinder power)
refractive_cyl_ax	90 (postop manifest cylinder axis)
iol_cyl	3 (cylinder power of toric IOL)
iol_cyl_ax	80 (postop axis of toric IOL)


    {
        "refractive_cyl": 1.5,
        "refractive_cyl_ax": 90,
        "iol_cyl": 3,
        "iol_cyl_ax": 80
    }


    curl --location --request POST 'https://www.zubisoft.com/api/tiar' \
    --header 'Content-Type: application/json' \
    --header 'X-Public-Key: yourPublicKey' \
    --header 'X-User-Key: yourUserKey' \
    --header 'X-Private-Key: hashOfYourPrivateKey' \
    --data-raw '{
        "refractive_cyl": 1.5,
        "refractive_cyl_ax": 85,
        "iol_cyl": 3,
        "iol_cyl_ax": 80
    }'

Response

The response includes the following values:

Table
JSON

Name	Format [Unit]	Example	Comment
ideal_axis_position	Float [degree]	83.3	Axis position of the toric IOL with lowest RA
rotation	Float [degree]	3.3	Rotation required (plus value = anti-clockwise)
projected_corneal_astigmatism	Float [diopter]	4.44	Projected corneal astigmatism
lowest_achievable_astigmatism	Float [diopter]	1.44	Lowest residual astigmatism achievable


{
    "ideal_axis_position": 83.3,
    "rotation": 3.3,
    "projected_corneal_astigmatism": 4.44,
    "lowest_achievable_astigmatism": 1.44
}