Opi
Calc
AMD Severity Scale
Astigmatism Assistant
Barrett / SRK-T Sim
Diabetic Retinopathy Risk
Glaucoma Progression
Glaucoma Risk (OHTS)
Graves CAS
HFA MD to VFI Converter
IOP Correction (CCT)
LogMAR <-> Snellen
MRD Assessment
ROP Risk (G-ROP)
SPEED Score (Dry Eye)
SUN Uveitis Grading
Vertex Distance
MRD Assessment
MRD-1 (Upper Lid)
mm
MRD-2 (Lower Lid)
mm
Clear Measurements
Guidelines & Evidence
Clinical Details
Section 1
Formula & Logic
Definitions
MRD-1: Distance from the upper eyelid margin to the corneal light reflex (Normal: 4-5 mm)
MRD-2: Distance from the corneal light reflex to the lower eyelid margin (Normal: 5 mm)
Palpebral Fissure (PF): MRD-1 + MRD-2
Clinical Interpretation
MRD-1 < 4mm typically defines ptosis. Low MRD-1 with a high MRD-2 may suggest eyelid retraction (e.g., in Graves disease).
Last Comprehensive Review: 2026
Related Ophthalmology Tools
AMD Severity Scale
Astigmatism Assistant
Barrett / SRK-T Sim
Diabetic Retinopathy Risk
Glaucoma Progression
Glaucoma Risk
Graves CAS
HFA MD to VFI Converter
IOP Correction
LogMAR <-> Snellen
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