Macular features from spectral-domain optical coherence tomography as an adjunct to indirect ophthalmoscopy in retinopathy of prematurity

Abstract

Purpose: To compare vitreoretinal pathology imaged with portable handheld spectral-domain optical coherence tomography (SD-OCT) to conventional indirect ophthalmoscopic examination in neonates undergoing screening for retinopathy of prematurity.

Methods: Spectral-domain optical coherence tomography images were collected from 76 eyes of 38 neonates during 118 routine retinopathy of prematurity examinations. Imaging sessions in the Neonatal Intensive Care Unit were performed immediately after the subjects underwent a standard ophthalmic examination with indirect ophthalmoscopic by a pediatric ophthalmologist. Masked certified SD-OCT graders evaluated scans for preretinal and retinal findings including material in the vitreous, epiretinal membrane, intraretinal cystoid structures and deposits, optic nerve and vascular features, and severity and location of retinopathy of prematurity. The frequency of detection of these features by clinical examination and evaluation of SD-OCT images was compared to determine potential clinical advantages for each modality.

Results: Portable SD-OCT imaging characterized macular features of retinal cystoid structures in 39% of examinations and epiretinal membrane in 32% of examinations. Neither feature was visualized by indirect ophthalmoscopy in any cases. The clinician using indirect ophthalmoscopy detected stage of retinopathy of prematurity and the presence or absence of Plus or pre-Plus disease. These were not visualized with SD-OCT.

Conclusion: Spectral-domain optical coherence tomography provides new information about the premature infant retina that is of unknown importance relative to visual development and acuity. As used in this study, SD-OCT does not replace indirect ophthalmoscopy for evaluation of retinopathy of prematurity.

Figure 1

Color photograph showing a portable spectral domain optical coherence tomography (SD OCT) workstation connected to a handheld probe for imaging of infants in the neonatal intensive care unit.

Figure 2

Cross-sectional SD OCT image shows a laterally elongated preretinal structure with shadowing. As these preretinal structures were sometimes found adjacent to blood vessels, we hypothesize that they may represent early proliferative changes. In the sessions where preretinal tissue was seen on SDOCT (presumably within zone I) the ROP was staged as 3 or greater in 38% of sessions.

Figure 3

The cross-sectional SD OCT image on the left demonstrates a prominent epiretinal membrane deforming fovea. The cross-sectional SD OCT image on the right shows an epiretinal membrane adjacent to blood vessel. Neither case of epiretinal membrane was noted on clinical examination.

Figure 4

Cross-sectional SD OCT image shows hyaloidal remnant.

Figure 5

Cross-sectional SD OCT image on left with corresponding en-face retinal summed image on right.

Figure 6

Cross-sectional SD OCT image showing retinal cystoid structures or schisis present in the inner nuclear layer with associated thickening and deformation of the photoreceptor layer elevating the outer plexiform layer. This session had been graded by the clinical examiner as stage II ROP disease in zone 2, no cystoid structures.

Figure 7

Cross-sectional SD OCT image demonstrating single intraretinal cystic structure without complete loss of foveal depression. The optic nerve is visible to the right.

Figure 8

Cross-sectional SD OCT image showing a severe case of macular edema with gross elevation of the central fovea and vertically elongated hyporeflective structures alternating with thin strands of hyperreflectivity. This eye reached stage 2 disease in zone III and did not receive laser treatment.

Figure 9

Schematic diagram showing range of retinal imaging with the portable handheld SD OCT unit. This system is provides high magnification imaging within zone I and can only infrequently capture images at the anterior border of zone I.

Figure 10

Early retinal summed image on left showing motion artifact and incomplete view of optic nerve and vascular arcades. Example of a later retinal summed image on the right demonstrating improved image of optic nerve and vascular arcades.