Spectral domain optical coherence tomography in the diagnosis and monitoring of dengue maculopathy.

Abstract

A 23-year-old female presented with sudden onset of diminution of vision in the right eye (RE) associated with a central blurring of vision. She had been diagnosed to have dengue fever based on a NS1 Antigen Test 10 days before.[1] Her corrected distance visual acuity (CDVA) in the RE was 20/200 and the left eye (LE) was 20/20. Fundus evaluation revealed a yellow orange lesion at the fovea in the RE and a normal fundus in the LE [Fig. 1]. Fundus fluorescein angiogram showed early hyperfluorescence at the fovea, which persisted in the late phase with mild perifoveal capillary leakage in the RE [Fig. 2]. The RE macular (9 mm radial) spectral domain optical coherence tomography (SD OCT) scan suggested a normal contoured foveal dip with normal inner retinal layers [Fig. 3]. In the outer retina, there was a focal discontinuity of the inner segment-outer segment layer (IS-OS) or ellipsoid zone (EZ) subfoveally, with an irregular and elevated hyper reflective lesion extending from the broken EZ into and filling the outer nuclear layer (ONL) through a disrupted external limiting membrane (ELM). The foveal tent was absent and there was disruption of the outer segment retinal pigment epithelium (OS RPE) layer or the cone outer segment tips (COST) layer due to the central lesion. The RPE was relatively unaffected and appeared to be uniform throughout the scan.[2] A diagnosis of Dengue Foveolitis was made. The patient was started on treatment with oral steroids. Two weeks later the SD OCT scan through the foveal center showed resolution of the lesion [Fig. 4]. There was a focal, linear hyper reflective residual lesion (red arrow) in the outer nuclear layer just underlying the outer plexiform layer. The ELM was now more linear but still remained discontinuous under the subfovea but continuous on either side of this disruption. The EZ appeared to have regained continuity except in the subfoveal region. The foveal tent still remained absent and the RPE was normal as before. The CDVA had improved to 20/60 and funduscopy showed resolution of the foveal lesion. At 12 weeks after treatment, the SD OCT scan showed further resolution of the lesion [Fig. 5]. The ONL was now free of the lesion. The ELM was continuous throughout the scan. The EZ had now gained continuity and the foveal tent had re-appeared. The OS RPE or COST layer underlying the foveal tent could be appreciated in the temporal section of the scan (red arrow) and appeared deficient in the nasal section of the scan corresponding to the papillo-macular bundle. The CDVA had improved to 20/20. Open in a separate window Figure 1 Right eye fundus shows a yellow orange lesion at the fovea (black arrow) with a normal left eye fundus