Distinct patterns of diabetic maculopathy seen on OCT

Optical coherence tomography (OCT) is valuable in managingdiabetic macular edema (DME), more so than fluoresceinangiography, in which the degree of leakage is not correlatedwith visual acuity and outcomes, according to Peter Kaiser, MD.In addition, angiography does not show vitreoretinalabnormalities that may require a different treatment.

OCT provides a retinal thickness map that correlates well withleakage clinically, fluorescein leakage, and more importantly,with decreased visual acuity. The maps can be used to trackprogression and treatment efficacy, according to Dr. Kaiser, ofthe Cole Eye Institute, Cleveland Clinic.

The OCT single scan tomograms identify specific patterns inpatients with DME.

"The patterns may have different prognoses and require differentmanagement," Dr. Kaiser said. "It is important to recognize thepatterns on OCT."

The sponge-like pattern is the one most commonly seen in whichthe inner layers of the retina appear to be compressed as theresult of fluid absorption. This pattern responds well to lasertreatment.

Cystoid macular edema is characterized by cysts that grow andcoalesce and are associated with worse visual acuity than withthe sponge-like pattern; this responds to steroids andanti-vascular endothelial growth factor drugs.

Serous retinal detachment without posterior hyaloidal tractionis characterized by serous fluid in the fovea not seen onophthalmoscopy; treatment and absorption of the fluid often leadsto the hard exudates deposits in the subretinal space.

Posterior hyaloidal traction leading to DME seems to be adistinct subgroup of patients. The traction is subtle but can beidentified by sheen on clinical examination.

Traction can cause a traction retinal detachment in a fewpatients. If there is traction that is more tangential resultingfrom the hyaloidal traction, it can be very subtle.

A retinal detachment can occur without traction; this does notrespond to laser or medical therapy but requiresvitrectomy.

"There are six morphologic patterns on OCT of DME that mayrepresent distinct entities that require different treatmentregimens," Dr. Kaiser said. "Identifying the patterns allows moreeffective management of these patients."