RA

Description

Returns the resuidual astigmatism (RA) for an eye with given post-incision corneal astigmatism (PICA magnitude) and chosen toric IOL model and cylinder power aligned correctly (PICA axis).

If the IOL model is deteremined by providing an IOL ID, the resource will automatically recognise the toric IOL family and will return a RA value for each IOL cylinder version.
If the IOL model is not determined (no ID provided), then the resource will calculate and return RAs for a standard range of possible IOL cylinder versions (from 0.5 to 6.0 in 0.25D steps).
The response 'recommended' is set 'true' for the IOL cylinder version that achieves a RA that is closest to 0, but remains on the 'plus' side, avoiding over-correction and shift of axis (e.g. RA=0.06)

Background
Residual astigmatism (RA) is the unwanted remaining astigmatism after lens surgery, usually reducing postoperative uncorrected visual acuity and causing unhappy patients. There are several organic causes that can lead to RA, including ocular surface disease, anterior basement membrane dystrophy, irregular corneal astigmatism, posterior corneal astigmatism, and extreme axial length and IOL prediction errors. However, the most common reason for RA in elective toric IOL surgery (excluding patients with organic problems) is misalignment of the toric intraocular lens (IOL), or incorrect selection of the toric IOL's cylinder power. The RA can be reduced by determining the post-incision corneal astigmatism, which will support cylinder power selection and toric IOL positioning. As most standard toric IOLs come in specific cylinder ranges (steps of 0.5-0.75 D) the RA usually cannot be completely flattened.

URL

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

Permission

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

Parameters

Field Description
corneal_astigmatism_power 2.63
corneal_astigmatism_axis 6
iol id of an IOL (optional)
Leave the complete field away if the ID is not provided. A list of IDs for all available IOL models can be called by the 'devices' resource. 

{
    "corneal_astigmatism_power": 2.63,
    "corneal_astigmatism_axis": 6,
    "iol": 109
}


    

curl --location --request POST 'https://www.zubisoft.com/api/ra' \
--header 'Content-Type: application/json' \
--header 'X-Public-Key: yourPublicKey' \
--header 'X-User-Key: yourUserKey' \
--header 'X-Private-Key: hashOfYourPrivateKey' \
--data-raw '{
    "corneal_astigmatism_power": 2.63,
    "corneal_astigmatism_axis": 6,
    "iol": 109
}'

Response

The response is an array with one or more of the following objects:

Name Format [Unit] Example Comment
id Integer 109 ID of the IOL. Only returned if an IOL ID was submitted with the request.
cyl_power Float [diopter] 3 Without IOL mode ID the range is from 0.5D to 6.0D.
model String "Lentis Tplus LS-313 T3" IOL model. Only returned if an IOL ID was submitted with the request.
residual_astigmatism_power Float [diopter] 0.57
residual_astigmatism_axis Integer [degree] 6
recommended Boolean false Points to the IOL version closest to RA of zero. 

[
    {
        "id": 514,
        "cyl_power": 0.75,
        "model": "Lentis Tplus LS-313 T0",
        "residual_astigmatism_power": 2.12,
        "residual_astigmatism_axis": 6,
        "recommended": false
    },
    {
        "id": 107,
        "cyl_power": 1.5,
        "model": "Lentis Tplus LS-313 T1",
        "residual_astigmatism_power": 1.6,
        "residual_astigmatism_axis": 6,
        "recommended": false
    },
    {
        "id": 108,
        "cyl_power": 2.25,
        "model": "Lentis Tplus LS-313 T2",
        "residual_astigmatism_power": 1.09,
        "residual_astigmatism_axis": 6,
        "recommended": false
    },
    {
        "id": 109,
        "cyl_power": 3,
        "model": "Lentis Tplus LS-313 T3",
        "residual_astigmatism_power": 0.57,
        "residual_astigmatism_axis": 6,
        "recommended": true
    },
    {
        "id": 110,
        "cyl_power": 3.75,
        "model": "Lentis Tplus LS-313 T4",
        "residual_astigmatism_power": 0.06,
        "residual_astigmatism_axis": 6,
        "recommended": false
    },
    {
        "id": 111,
        "cyl_power": 4.5,
        "model": "Lentis Tplus LS-313 T5",
        "residual_astigmatism_power": -0.45,
        "residual_astigmatism_axis": 6,
        "recommended": false
    },
    {
        "id": 112,
        "cyl_power": 5.25,
        "model": "Lentis Tplus LS-313 T6",
        "residual_astigmatism_power": -0.97,
        "residual_astigmatism_axis": 6,
        "recommended": false
    }
]




[
    {
        "cyl_power": 0.5,
        "residual_astigmatism_power": 2.29,
        "residual_astigmatism_axis": 6,
        "recommended": false
    },
    {
        "cyl_power": 0.75,
        "residual_astigmatism_power": 2.12,
        "residual_astigmatism_axis": 6,
        "recommended": false
    },
    {
        "cyl_power": 1,
        "residual_astigmatism_power": 1.94,
        "residual_astigmatism_axis": 6,
        "recommended": false
    },
    {
        "cyl_power": 1.25,
        "residual_astigmatism_power": 1.77,
        "residual_astigmatism_axis": 6,
        "recommended": false
    },
    {
        "cyl_power": 1.5,
        "residual_astigmatism_power": 1.6,
        "residual_astigmatism_axis": 6,
        "recommended": false
    },
    
    .... continue up to "cyl_power": 6
    
]