Pre-Op Calculator

LASIK / PRK / ICL Treatment Planning
Recommendation
OD Awaiting inputs
OS Awaiting inputs
Patient
Dominant Eye: not set

Right Eye

Dominant OD
I-S Ratio (iDesign)
Keratometry
Manifest Refraction awaiting refraction
Ablation
μm
PTA — PRK / LASIK
%
Residual — PRK
μm
Residual — LASIK
μm
Post-Op K Tracker
D
Ablation, PTA & residual bed are myopia-calibrated planning estimates (|max-meridian| × 16 μm); actual depth varies by laser platform and optical zone. Verify against your nomogram.

Left Eye

Dominant OS
I-S Ratio (iDesign)
Keratometry
Manifest Refraction awaiting refraction
Ablation
μm
PTA — PRK / LASIK
%
Residual — PRK
μm
Residual — LASIK
μm
Post-Op K Tracker
D
Ablation, PTA & residual bed are myopia-calibrated planning estimates (|max-meridian| × 16 μm); actual depth varies by laser platform and optical zone. Verify against your nomogram.

Disparity Between Eyes

OU Comparison
K Diff OU
D
Axial Diff
mm
Axial → Diopters
D
Total Power Disparity
D
Status
Corneal vs. Refractive Cylinder Threshold: > 1.00 D suggests accommodation / internal astigmatism — possible early touch-up risk
Right Eye · OD
Corneal Cyl
Refractive Cyl
Δ Disparity
Left Eye · OS
Corneal Cyl
Refractive Cyl
Δ Disparity
K-Axis vs. Refractive-Axis Threshold: > 15° between corneal cyl axis and refractive cyl axis suggests irregular astigmatism, lenticular contribution, or measurement error
Right Eye · OD
K Axis
Refractive Axis
Δ Disparity
Left Eye · OS
K Axis
Refractive Axis
Δ Disparity

Pentacam / Belin-Ambrósio Risk Screen

Weighted BAD-D reasoning · age + RSB modulated
Patient advisory factors (informational, do not change verdict)
Right Eye · OD
Awaiting tomography inputs
Left Eye · OS
Awaiting tomography inputs

Randleman Ectasia Risk Score

Validated ERSS · LASIK ectasia risk
All other factors (RSB, age, corneal thickness, MRSE) auto-populate from the calculator. RSB uses the LASIK residual bed. Topography pattern is the one factor requiring clinical judgment from your topographer.
Right Eye · OD
ERSS Total
Awaiting inputs
Left Eye · OS
ERSS Total
Awaiting inputs
Randleman JB, Trattler WB, Stulting RD. Validation of the Ectasia Risk Score System for preoperative LASIK screening. Am J Ophthalmol. 2008;145(5):813-818. Risk: 0–2 low · 3 moderate · ≥4 high. Screening aid only — not a substitute for surgeon judgment.

Dysfunctional Lens Syndrome Screen

DLS Score — / 10
Awaiting inputs

ICL Eligibility Screen

SE ≤ −4.00 D · ACD ≥ 3.00 mm · AXL > 26 mm flag
Right Eye · OD
SE ≤ −4.00 D
ACD ≥ 3.00 mm
Axial Length > 26 mm
Awaiting inputs
Left Eye · OS
SE ≤ −4.00 D
ACD ≥ 3.00 mm
Axial Length > 26 mm
Awaiting inputs

Refractive Procedure Recommendation

Metrics-driven · LASIK / PRK / ICL
Right Eye · OD
Awaiting metric inputs
Left Eye · OS
Awaiting metric inputs
Screening guide only. This calculator is a clinical decision-support and triage aid. It does not diagnose, prescribe, or determine candidacy. The final surgical decision rests entirely with the operating surgeon, integrating full clinical examination, patient history, and professional judgment. Estimates are planning figures and must be verified against your own measurements and nomograms.

Ectasia Risk Screening

  • Randleman JB, Trattler WB, Stulting RD. Validation of the Ectasia Risk Score System for preoperative LASIK screening. Am J Ophthalmol. 2008;145(5):813-818. — basis for the ERSS panel point values and risk tiers.
  • Ambrósio R, Belin MW, et al. Enhanced ectasia detection / BAD-D analyses (Belin/Ambrósio Enhanced Ectasia Display). — basis for the weighted BAD-D reasoning and the 1.6 suspicious / ~2.6 abnormal cutoffs.
  • Guerra F, Luz A, Price FW, Price MO, Schallhorn S, Belin MW. Role of age and residual stromal bed with BAD-D in ectasia susceptibility. — basis for the age + RSB modulation of the Pentacam verdict.
  • Belin MW. ABCD progression display; posterior elevation and pachymetric progression as early subclinical markers. — basis for the Db / Dp escalators.

Corneal Treatment Planning

  • Santhiago MR, et al. Percent tissue altered (PTA) and ectasia risk. — basis for the PTA thresholds (35% / 40%) used in LASIK vs PRK logic.
  • Residual stromal bed convention: ≥300 µm minimum; max-meridian ablation (|steepest treated meridian| × ~16 µm) used for worst-case safety estimates.
  • Post-Op K floor conventions: <33 D hard ICL trigger; <34 D myopic; <35.50 D ICL favored to avoid over-flattening.

Dysfunctional Lens Syndrome

  • Waring GO IV, et al. Dysfunctional Lens Syndrome staging framework (Stage 1 presbyopia → Stage 3 early opacification). — basis for the DLS screen criteria and age thresholds.
  • HOA source guidance: iDesign total HO RMS at 6 mm pupil for lens-aberration signal; Pentacam measures corneal aberrations only.

Notes on Methodology

  • The composite BAD-D is the validated parameter; sub-index escalators and age/RSB modulation are a conservative, evidence-informed encoding — not a prospectively validated standalone algorithm.
  • Ablation, PTA, and residual-bed figures are myopia-calibrated planning estimates; actual values vary by laser platform and optical zone.
  • All thresholds are configured for screening sensitivity and should be reviewed against your practice's clinical experience and your medical director's guidance.
Patient Information
Notes / Auto-Ref & K's / Zones / Prep & Timeout