Incidence and quantitative analysis of dissociated optic nerve fiber layer appearance: real loss of retinal nerve fiber layer?

Purpose: To assess the association between appearance of dissociated optic nerve fiber layer (DONFL) after internal limiting membrane (ILM) peeling and changes in the macular nerve fiber layer (NFL) area by spectral-domain optical coherence tomography (SD-OCT). Methods: This study included 132 consecutive patients who had successfully undergone vitrectomy with ILM peeling for idiopathic epiretinal membrane or macular holes and had been followed up for ≥6 months. Two examiners evaluated macular 5-line raster horizontal SD-OCT images and categorized the patients on the basis of presence (group I) or absence (group II) of DONFL. The average macular NFL areas in both groups were measured using ImageJ at baseline and 1, 3, and 6 months after surgery. Results: Among the 132 eyes of 132 patients, DONFL was noted in 42 (31.8%), 104 (78.8%), 106 (80.3%), and 106 (80.3%) eyes at 1, 3, and 6 months and at the last visit (12.8 ± 6.5 months) after surgery. These layers appeared most commonly between 1 and 3 months after ILM peeling. There was no significant difference in average macular NFL area between groups I and II (3453.4 ± 125.3 and 3513.0 ± 100.2 pixels, respectively) at 6 months after surgery (p = 0.56). Conclusions: Appearance of DONFL increased between postoperative months 1 and 3. Moreover, there was no significant difference in average NFL in terms of DONFL. Thus, appearance of DONFL might represent macular NFL rearrangement and reorganization rather than true mechanical damage to the NFL after ILM peeling.

Download Full-text

Involvement of Anoikis in Dissociated Optic Nerve Fiber Layer Appearance

International Journal of Molecular Sciences ◽

10.3390/ijms22041724 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1724

Author(s):

Tsunehiko Ikeda ◽

Kimitoshi Nakamura ◽

Takaki Sato ◽

Teruyo Kida ◽

Hidehiro Oku

Keyword(s):

Optic Nerve ◽

Nerve Fiber ◽

Retinal Ganglion Cells ◽

Ganglion Cells ◽

Internal Limiting Membrane ◽

Retinal Ganglion ◽

Ilm Peeling ◽

Fiber Layer ◽

Nerve Fiber Layer ◽

Optic Nerve Fiber

Dissociated optic nerve fiber layer (DONFL) appearance is characterized by dimpling of the fundus when observed after vitrectomy with the internal limiting membrane (ILM) peeling in macular diseases. However, the cause of DONFL remains largely unknown. Optical coherence tomography (OCT) findings have indicated that the nerve fiber layer (NFL) and ganglion cells are likely to have been damaged in patients with DONFL appearance. Since DONFL appearance occurs at a certain postoperative period, it is unlikely to be retinal damage directly caused by ILM peeling because apoptosis occurs at a certain period after tissue damage and/or injury. However, it may be due to ILM peeling-induced apoptosis in the retinal tissue. Anoikis is a type of apoptosis that occurs in anchorage-dependent cells upon detachment of those cells from the surrounding extracellular matrix (i.e., the loss of cell anchorage). The anoikis-related proteins βA3/A1 crystallin and E-cadherin are reportedly expressed in retinal ganglion cells. Thus, we theorize that one possible cause of DONFL appearance is ILM peeling-induced anoikis in retinal ganglion cells.

Download Full-text

Leukocoria in a 2-Year-Old Patient With Atypical Optic Nerve Fiber Layer Myelination

Journal of Pediatric Ophthalmology & Strabismus ◽

10.3928/01913913-20200527-02 ◽

2020 ◽

Author(s):

Dhariana Acón ◽

Sophia El Hamichi ◽

Audina Berrocal ◽

Timothy G. Murray

Keyword(s):

Optic Nerve ◽

Nerve Fiber ◽

Fiber Layer ◽

Nerve Fiber Layer ◽

Optic Nerve Fiber

Download Full-text

Age-Related Physiologic Thinning Rate of the Retinal Nerve Fiber Layer in Different Levels of Myopia

Journal of Ophthalmology ◽

10.1155/2020/1873581 ◽

2020 ◽

Vol 2020 ◽

pp. 1-6

Author(s):

Daun Jeong ◽

Kyung Rim Sung ◽

Youn Hye Jo ◽

Sung-cheol Yun

Keyword(s):

Nerve Fiber ◽

Retinal Nerve Fiber Layer ◽

Refractive Error ◽

Fiber Layer ◽

Nerve Fiber Layer ◽

Rnfl Thickness ◽

Significant Difference ◽

Thinning Rate ◽

Sd Oct ◽

Retinal Nerve Fiber

Purpose. To investigate the effect of refractive error on the physiologic thinning rate of the retinal nerve fiber layer (RNFL) in healthy eyes. Materials and Methods. This study analyzed 223 eyes of 141 healthy subjects followed for more than 5 years and underwent at least five serial spectral domain optical coherence tomography (SD-OCT) examinations. Longitudinal RNFL measurements were analyzed by linear mixed models incorporating follow-up duration, baseline RNFL thickness, spherical equivalent (SE), age, intraocular pressure, and visual field mean deviation. Thinning rates were classified according to SE into three groups: nonmyopic (NM; >0 D), mild-to-moderately myopic (MM; >–6 D and ≤0 D), and highly myopic (HM; ≤–6 D). Results. The overall slopes of change in RNFL thickness over time in the NM, MM, and HM groups were −0.305 ± 0.128, −0.294 ± 0.068, and −0.208 ± 0.097 μm/yr, respectively. Slopes of RNFL thickness changes in these groups were −0.514 ± 0.248, −0.520 ± 0.133, and −0.528 ± 0.188 μm/yr, in the superior quadrant; −0.084 ± 0.145, 0.107 ± 0.082, and −0.161 ± 0.112 μm/yr, in the temporal quadrant; −0.807 ± 0.242, −0.794 ± 0.130, and −0.727 ± 0.183 μm/yr, in the inferior quadrant; and 0.160 ± 0.157, 0.118 ± 0.084, and 0.429 ± 0.119 μm/yr, in the nasal quadrant. Overall and in all four quadrants, there was no significant difference in the rate of RNFL thickness change among the three groups. Conclusions. Refractive error did not affect the physiologic thinning rate of RNFL when assessed by SD OCT.

Download Full-text