Conjunctival microvascular haemodynamics in sickle cell retinopathy

Area of Science:

• Ophthalmology
• Microvascular Medicine
• Hematology

Background:

• Sickle cell retinopathy (SCR) is a sight-threatening complication of sickle cell disease.
• Focal macular thinning (FMT) is a recognized feature in SCR, but its microvascular underpinnings are not fully understood.

Purpose of the Study:

• To investigate alterations in bulbar conjunctival microvascular hemodynamics in SCR patients with and without focal macular thinning (FMT).

Main Methods:

• Conjunctival microcirculation imaging and spectral domain optical coherence tomography (SD-OCT) were used in 22 SCR subjects.
• Eyes were grouped based on the presence or absence of FMT.
• Conjunctival venular diameter and axial blood velocity were measured and analyzed in relation to vessel size and FMT status.

Main Results:

• Eyes with FMT showed significantly reduced retinal thickness in temporal subfields.
• Focal macular thinning significantly affected axial blood velocity (p=0.04).
• Specifically, axial blood velocity in smaller venules (vessel size 1) was lower in eyes with FMT (p=0.03).

Conclusions:

• Conjunctival axial blood velocity in small venules is diminished in SCR subjects experiencing focal macular thinning.
• This suggests impaired microvascular function in the conjunctiva associated with macular changes in SCR.