|Year : 2022 | Volume
| Issue : 2 | Page : 473-474
Commentary: Clinical significance of vertical hyper-reflective track in optical coherence tomography of the fovea
Srikanta K Padhy1, Koushik Tripathy2
1 Department of Vitreo Retinal Diseases, Uveitis and Ocular Immunology, LV Prasad Eye Institute, Mithu Tulsi Chanrai Campus Patia, Bhubaneswar, Odisha, India
2 Department of Vitreoretina and Cataract Surgery, ASG Eye Hospital, Kolkata, West Bengal, India
|Date of Web Publication||13-Apr-2022|
Department of Vitreoretina and Cataract Surgery, ASG Eye Hospital, 149 BT Road, Kolkata - 700 058, West Bengal
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Padhy SK, Tripathy K. Commentary: Clinical significance of vertical hyper-reflective track in optical coherence tomography of the fovea. Indian J Ophthalmol Case Rep 2022;2:473-4
|How to cite this URL:|
Padhy SK, Tripathy K. Commentary: Clinical significance of vertical hyper-reflective track in optical coherence tomography of the fovea. Indian J Ophthalmol Case Rep [serial online] 2022 [cited 2022 May 27];2:473-4. Available from: https://www.ijoreports.in/text.asp?2022/2/2/473/342999
The article “Hyper-reflective track as an imaging biomarker for clinical improvement in photic retinopathy” in the current issue of the Indian Journal of Ophthalmology highlights a novel optical coherence tomography (OCT) prognostic marker for clinical improvement in cases of photic retinopathy. The authors describe a vertical hyper-reflective track (VHRT) extending from outer to inner retina along with or without ellipsoid zone (EZ) disruption tomographically in acute cases of photic retinopathy that resolved on follow-up correlating with the symptomatic improvement.
Photic retinopathy is an umbrella term that integrates retinal damage from the light of varying sources and wavelengths via different mechanisms, including photothermal, photomechanical, and photochemical damage. The most common form of photic retinopathy is solar retinopathy and the visual prognosis in such cases is usually favorable, perhaps due to the resistance of foveal cones to photochemical damage, with most cases showing partial recovery with or without treatment.
Generally, acute cases of photic retinopathy present with a typical history of sun/ultraviolet light exposure and are easy to diagnose, but chronic cases are challenging. Spectral domain OCT (SDOCT) of acute photic retinopathy shows changes in the retinal pigment epithelium (RPE) and outer photoreceptor segment, and some cases show VHRT as seen in this case. However, chronic changes show a vertical band of hypo-reflectivity (tissue loss) at the foveolar EZ along with differential RPE disruption, possibly indicating an RPE recovery following acute injury. Tomographically, solar retinopathy can sometimes mimic pathologies such as ocular trauma, the initial stages of an idiopathic macular hole, persistent retinal defects following successful macular hole surgery, whiplash injuries, idiopathic parafoveal telangiectasis, foveomacular retinitis, and occult macular dystrophy.
Ishibashi et al. retrospectively noted a novel OCT sign, the “foveal crack sign” (FCS; VHRT at umbo with a deformation of the fovea) in 13 eyes (2.5%), which preceded full-thickness macular hole (FTMH) formation after vitreoretinal surgery (VRSx) for rhegmatogenous retinal detachment (RRD). All such cases were associated with parafoveal epiretinal membrane (ERM) and none of these eyes had ERM over the foveola. Ten eyes developed FTMH with time. The mean intervals (±standard deviation) from VRSx to the development of FCS and from FCS detection to the formation of FTMH were 255 (±217) days and 232 (±171) days, respectively. The foveal crack started at the inner retina and eventually involved the entire neurosensory retina. The authors postulated tangential traction from the parafoveal ERM on disruption of the Müller cell cone (MSC) to be crucial for the development of FCS. The MSC is an inverted cone-shaped structure that might play an important role in stabilizing the central foveola by acting as a glue.
Scharf et al. demonstrated the presence of a central vertically oriented hyperreflective stress line in the fovea on SDOCT preceding FTMH and in approximately 50% of the cases after resolution of FTMH following vitrectomy and in almost one-fourth of the cases of lamellar macular hole. They attributed this to be a sign of central foveal dehiscence secondary to the disruption of the MSC. Similarly, Furashova and Matthe described the FCS as a predictive biomarker for the development of FTMH in fellow eyes of patients with FTMH. They also noted that the presence of vitreofoveal adhesion (vertical traction) was crucial for the development of FTMH and the risk of FTMH was not “substantial” in cases that did not have vitreofoveal adhesion (e.g., in the vitreous detachment group). VHRT as a precursor to FTMH (related to mechanical traction) appears to start at the inner retina at the base of the MSC, whereas in photic retinopathy, the damage is more severe at the EZ and RPE (where the light focuses).
Similar VHRT at the fovea may also be noted due to RPE plumes (especially, the thread or vitelliform variants) in age-related macular degeneration, though these are usually oblique, located away from the umbo, arise from RPE, and may not reach the internal limiting membrane. VHRT at the foveola may also be noted in multiple evanescent white dot syndrome (MEWDS) and after resolution of foveal hemorrhage. VHRT at areas other than foveola may be noted after macular laser or panretinal photocoagulation, acute posterior multifocal placoid pigment epitheliopathy (APMPPE), and self-inflicted laser burns.
Outer retinal hole/tissue defect in the setting of Stargardt disease sometimes mimics chronic photic retinopathy tomographically; however, it is progressive with round edges, contrary to the stationary sharply defined square-edged defects of the latter. Similarly, early vitreomacular traction and tamoxifen maculopathy can show a similar kind of rectangular outer retinal cysts.
The major limitation of this study is the smaller sample size. As VHRT is a very subtle structural change and is dependent on subjective assessment, its incidence might be underestimated on the SDOCT images captured with insufficient resolution and density of the scans or with interobserver variabilities. We feel a prospective study with larger sample size and longer follow-up would help address the issue, as the authors have already stated.
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