Retinal surface imaging provided by Cirrus high-definition optical coherence tomography prominently visualizes a dissociated optic nerve fiber layer appearance after macular hole surgery

Abstract

To investigate whether retinal surface imaging by Cirrus high-definition optical coherence tomography (HD-OCT) clearly depicts the development process of a dissociated optic nerve fiber layer (DONFL) appearance after macular hole (MH) surgery. We reviewed the medical records of the patients who underwent MH surgery with internal limiting membrane peeling. The cases were then selected using three principal criteria: (1) surgeries performed by the same surgeon (S. K.), (2) pre- and postoperative Cirrus HD-OCT imaging, and (3) minimal follow-up of 3 months. All cases received a complete ophthalmologic examination. The presence/absence of a DONFL appearance was determined using a retinal surface image provided by Cirrus HD-OCT. Color fundus photographs were also used for determination if available. Fifteen cases met the criteria. A DONFL appearance was identified in 11 (73%) cases during the postoperative course by retinal surface imaging. A DONFL appearance was not detected in any OCT retinal surface image within the first postoperative month, gradually became distinct between 1 and 3 months after surgery, and remained detectable thereafter in all cases but one whose DONFL appearance became less detectable at 12 months. Indentations of the innermost retinal layer became apparent on cross-sectional OCT images as a DONFL appearance developed on OCT retinal surface images. There were two cases in which the DONFL appearance was not observed on color fundus photographs but detected on OCT retinal surface images. Retinal surface imaging provided by Cirrus HD-OCT appeared to be a promising option in evaluating a DONFL appearance after MH surgery.

Evaluating Dissociated Optic Nerve Fiber Layer Appearance Using En Face Layer Imaging Produced by Optical Coherence Tomography

“…According to the previous reports, the incidence of an apparent DONFL ranges from 50 to 100% after MH surgery with ILM peeling [8,10,12,13,14,15,18,19], and the incidence in our study (76.5%) was in this range. However, although the reported postoperative incidence of an apparent DONFL in ILM-peeled non-MH eyes was 56-67% in ERM eyes [18,19] and 20% in BRVO eyes [19], the incidence of an apparent DONFL in our study was 11.1% in the ERM group and 5.9% in the RVO group (7.7% in BRVO eyes).…”

“…In the latest version of Cirrus high-definition OCT (HD-OCT; Carl Zeiss Meditec, Dublin, Calif., USA), the built-in software can create a tissue layer image of interest, including retinal pigment epithelium layer, photoreceptor layer, and internal limiting membrane (ILM) layer [5,6,7]. We have been interested in the retinal surface microstructure after PPV and carried out an OCT imaging study investigating the postoperative changes in the retinal surface, the results of which suggest the usefulness of this imaging modality for the assessment of retinal surface morphology [8]. …”

“…Previous studies documented that this characteristic DONFL appearance can be clearly visualized by SD-OCT retinal surface imaging after macular hole (MH) surgery [8,10,11,12]. Morphologically, a DONFL appearance is thought to reflect a true retinal nerve fiber layer defect, a retinal nerve fiber layer dehiscence, or a deep inner retinal damage secondary to ILM peeling [9,13,14,15], but there is no clear consensus about its pathology.…”

“…Although the incidence of a DONFL appearance ranges from 20 to 100% in ILM-peeled eyes, the majority of DONFL cases were reported after MH surgery [8,9,10,12,13,14,15,18,19]. This suggests that a DONFL appearance can be detected more predominantly in MH eyes.…”

Morphological Change of Inner Retinal Layer on Spectral-Domain Optical Coherence Tomography following Macular Hole Surgery

“…SD-OCT imaging of the DONFL appearance in our study provided different cross-sectional images. The defects of the innermost retinal layer were more deepened toward the outer retinal layer than postoperative focal RNFL defects reported in previous studies [20,21] (fig. 2).…”