This prospective study found that cystic morphological alterations in uveitis-associated cystoid macular edema (CME) were associated with specific retinal sensitivity decreases.
CME is a cause of significant visual morbidity in patients with ocular inflammation, although structural improvement on OCT does not always correlate with increased visual function. Patients who do not show marked visual improvement with aggressive treatment of uveitic CME are challenging to manage, and physicians often struggle with the question of retreatment.
The authors sought to define which morphological changes in uveitic CME have the greatest impact on central retinal sensitivity (CRS). These findings could help influence the management of patients with CME, including retreatment decisions and setting patient expectations.
They superimposed microperimetry maps on spectral domain OCT (SD-OCT) images of 20 patients with chronic recurrent uveitic CME. Morphological features on OCT were correlated point-to-point with CRS measured with microperimetry maps. The mean duration of CME was 34.5 months at enrollment.
Each patient underwent an initial injection of intravitreal triamcinolone acetonide (IVTA) and follow-up visits with a complete eye examination, mircoperimetry and SD-OCT at one day, one week, and one to three months after the injection. Epiretinal membrane was present in six eyes, and 14 eyes had serous retinal detachment.
They found that an increase in intraretinal cysts was associated with a significant decrease in retinal sensitivity. However, the proportion of diffuse macular edema had no effect on retinal sensitivity, and the presence of serous retinal detachment at baseline did not impact CRS.
This data suggest that aggressive treatment of cystic changes may result in continued visual improvement, particularly in those patients with healthy appearing photoreceptors and retinal pigment epithelium. On the other hand, decreased vision in the presence of diffuse macular edema or mild subretinal fluid has a more limited prognosis.