Optical coherence tomography impacts the evaluation of visual pathway tumors

Bi-nasal sectors of ganglion cells complex and visual evoked potential amplitudes as biomarkers in pituitary macroadenoma management

The study aimed to evaluate the retinal ganglion cell structure using optical coherence tomography and the visual pathway function employing visual evoked potentials in the diagnosis and monitoring of patients with pituitary macroadenoma. A descriptive, cross-sectional, and longitudinal study (3 and 12 months follow-up) was conducted on forty-two patients. Thirty-five age-matched healthy controls were used in the cross-sectional one. Full neuro-ophthalmological evaluation (structural and functional) was carried out including global and segmented retinal nerve fiber layer/ganglion cell complex analysis and amplitude and latency of P100 component in the electrophysiology. Statistical data analysis was conducted with R version 3.6.3 and Python version 3.8. Associations were evaluated using Spearman's correlations. Amplitude sensitivities were 0.999, and bi-nasal sectors of ganglion cell complex thickness specificities were 0.999. This structural parameter had the highest diagnostic value (area under curve = 0.923). Significant associations were found between bi-nasal sectors with amplitude at 12' (rho > 0.7, p < 0.01) and median deviation of the visual field (rho > 0.5, p < 0.01) at 3 months. Pre-surgical values of bi-nasal sectors and amplitude can predict post-surgically median deviation and amplitude (Oz, 12') at 3 months with r ² > 0.5. Bi-nasal sectors of ganglion cell complex and visual evoked potentials P100 amplitude are efficient biomarkers of visual pathway damage for pituitary macroadenoma patients' management. Pre-surgical values of the bi-nasal sector and visual evoked potentials' amplitude could help to predict the restoration of parvocellular pathway traffic after decompression.

Retinal Microvascular Alterations Detected by Optical Coherence Tomography Angiography in Nonfunctioning Pituitary Adenomas

Purpose

Visual impairment assessment plays a significant role in diagnosis and clinical decisions in nonfunctioning pituitary adenoma (NFPA). Retinal microvascular alterations may potentially reflect the visual impairment. The purpose of this study was to evaluate fundus microvascular alterations in patients with NFPA.

Methods

Comparisons of visual field, retinal structure, and microcirculation were conducted between patients with NFPA and age- and sex-matched healthy controls. Multivariate regression modeling was used to assess the relationship between symptom duration, sellar mass size, and fundus vessel density (VD) of patients. Receiver operating characteristic (ROC) curves were depicted to determine the diagnostic performance of significant parameters to discriminate eyes with NFPA from healthy eyes.

Results

Forty eyes of patients and 40 eyes of healthy individuals were enrolled. Compared to healthy controls, patients with NFPA had a larger foveal avascular zone area and thinner ganglion cell complex thickness. The VDs of patients presented an obvious decrease in radial peripapillary capillary (RPC) and an increase in the deep capillary plexus segment of the perifoveal area. The peripapillary VDs of patients were significantly related to sellar mass size. The area under the ROC curve of VD in the RPC segment of the temporo-inferior sector was the largest (0.801; 95% confidence interval, 0.70–0.90; P < 0.001).

Conclusions

The fundus of patients with NFPA demonstrated significant and characteristic microvascular impairments. The VDs were also significantly associated with sellar mass size.

Translational Relevance

Retinal microvascular alterations detected by optical coherence tomography angiography are characteristic and related to sellar mass size, which may provide information that facilitates the diagnosis of NFPA.

The Value of Macular Optical Coherence Tomography in Watchful Waiting of Suprasellar Masses: A 2-Year Observational Study

BACKGROUND

A possible benefit of optical coherence tomography (OCT) in the approach to tumors involving the optic chiasm may be the ability to foresee visual deterioration. This study investigated the value of OCT in watchful waiting for compressive optic neuropathy as the primary management of suprasellar masses.

METHODS

The research was conducted as a 2-year observational study of a patient cohort with conservatively managed mass lesions involving the optic chiasm on MRI. Threshold perimetry and macular OCT were performed at baseline and each follow-up examination. Univariate Cox regression was used to determine the effect of baseline and longitudinal covariates upon development of visual field (VF) loss compatible with chiasmal dysfunction.

RESULTS

Nineteen eyes of 19 patients were included. The optic chiasm-tumor relationship on baseline MRI was abutment in 6 cases and compression in 13 cases. Seven eyes developed VF loss. None of the baseline covariates were predictors of VF loss. The longitudinal decrease in mean macular ganglion cell complex (mGCC) thickness on OCT was 2.5 μm/yr for eyes that developed VF loss and 0.2 μm/yr for eyes that did not develop VF loss (P = 0.02). The hazard ratio for VF loss per 1-μm/yr decrease in mGCC thickness was 1.30 (95% confidence interval [CI] 1.04-1.62; P = 0.02) for the inferior nasal quadrant and 1.45 (95% CI 1.02-2.07; P = 0.04) for the inferior temporal quadrant.

CONCLUSIONS

OCT offers a valuable complement to perimetry in monitoring for compressive optic neuropathy. Longitudinal mGCC thinning can anticipate VF loss.

Functional Prognostic value of optical coherence tomography in optic chiasmal decompression: A preliminary study

PURPOSE

To assess the predictive value for functional recovery of Ganglion Cell Complex Layer (GCC) and Retinal Nerve Fiber Layer (RNFL) measurements obtained by Optical Coherence Tomography (OCT) in patients undergoing chiasmal decompression and to define potential OCT thresholds for visual recovery.

METHODS

We measured preoperative GCC and RNFL thickness in patients with a sellar and/or perisellar tumor compressing the optic chiasm. Visual recovery was defined as recovery of mean deviation (MD) and pattern standard deviation (PSD) using Humphrey visual field testing after 12 successful decompressions (24 eyes). Receiver operating characteristic curve (ROC) analysis was used to identify the best thresholds.

RESULTS

Robust global and focal OCT thresholds were found. Superior GCC≥63μm had the best functional prognostic value (AUC=1) for visual improvement. Mean GCC ≥ 67μm and mean RNFL≥75μm also had excellent predictive values (AUC>0.9).

CONCLUSION

In this preliminary study, significant preoperative OCT thresholds for early visual recovery after chiasmal decompression were identified, mainly regarding GCC measurements. Further studies on larger cohorts with closely scheduled follow-up could refine our results.

Visual functions in children with craniopharyngioma at diagnosis: A systematic review

Childhood craniopharyngioma is a rare and slow growing brain tumour, often located in the sellar and suprasellar region. It commonly manifests with visual impairment, increased intracranial pressure and hypothalamic and/or pituitary deficiencies. Visual impairment in childhood adversely affects a child’s daily functioning and quality of life. We systematically reviewed the literature to provide an extensive overview of the visual function in children with craniopharyngioma at diagnosis in order to estimate the diversity, magnitude and relevance of the problem of visual impairment. Of the 543 potentially relevant articles, 84 studies met our inclusion criteria. Visual impairment at diagnosis was reported in 1041 of 2071 children (50.3%), decreased visual acuity was reported in 546 of 1321 children (41.3%) and visual field defects were reported in 426 of 1111 children (38.3%). Other ophthalmological findings described were fundoscopic (32.5%) and orthoptic abnormalities (12.5%). Variations in ophthalmological testing methods and ophthalmological definitions precluded a meta-analysis. The results of this review confirm the importance of ophthalmological examination in children with craniopharyngioma at diagnosis in order to detect visual impairment and provide adequate support. Future studies should focus on long-term visual follow-up of childhood craniopharyngioma in response to different treatment strategies to provide insight in risks and ways to prevent further loss of vision.

Retinal microvasculature in pituitary adenoma patients: is optical coherence tomography angiography useful?

PURPOSE

To examine retinal vascular changes in the peripapillary and macular areas in patients with pituitary adenoma (PA) using optical coherence tomography angiography (OCTA).

METHODS

Cross-sectional, retrospective study of 17 consecutive PA patients and 16 healthy subjects. All patients underwent a neuro-ophthalmological examination to assess the presence of optic neuropathy (ON). Static automated perimetry (SAP), macular and optic disc structural OCT [retinal nerve fibre layer (RNFL) and ganglion cell complex (GCC) thicknesses] and OCTA were performed. Pituitary adenoma (PA) patients with ON were compared to those without ON and to healthy subjects.

RESULTS

Optic neuropathy (ON) was found in 16 eyes of nine PA patients. Peripapillary vessel density (ppVD) and macular vessel density (VD) in the superficial vascular plexus were significantly decreased in PA eyes with ON, compared to healthy eyes (45.21 ± 5.69 versus 50.52 ± 2.14% and 43.79 ± 5.03% versus 48.96 ± 2.94%, respectively). No significant difference in VD was observed in the macular deep vascular complex (DVC) between groups. Pituitary adenoma (PA) patients with ON had a mean ppVD reduction by 10.51% compared to healthy subjects. RNFL and GCC thicknesses were significantly reduced in PA eyes with ON compared to the other groups. Peripapillary VD (ppVD) significantly correlated with RNFL thickness and SAP mean deviation.

CONCLUSIONS

Optical coherence tomography angiography showed a significant decrease in ppVD and superficial macular VD in PA eyes with ON compared to healthy eyes, according to RNFL and GCC thinning. Together with the absence of DVC alterations, it may provide further insights into neurovascular coupling.

Clinical Efficacy of Optical Coherence Tomography to Predict the Visual Outcome After Endoscopic Endonasal Surgery for Suprasellar Tumors

BACKGROUND

Prediction of visual outcome after endoscopic endonasal tumor resection still remains a challenge. We investigated the prognostic value of the preoperative peripapillary retinal nerve fiber layer (pRNFL) using optical coherence tomography for visual outcome after endoscopic endonasal surgery (EES) for suprasellar tumors.

METHODS

We retrospectively analyzed 122 patients who underwent EES for sellar and suprasellar tumors between January 2016 and January 2018. We retrospectively analyzed the pre- and postoperative relationship between pRNFL thickness and visual outcome based on visual acuity (visual acuity score) and visual field (mean deviation [MD]).

RESULTS

Preoperatively, 216 eyes (mean global pRNFL thickness, 94.3 ± 12.4 μm; 88.5%) were included in the normal pRNFL group (≥70 μm) and 28 eyes (mean global pRNFL thickness, 54.3 ± 11.0 μm; 11.5%) were included in the thin pRNFL group (<70 μm). There was a very strong correlation between pre- and postoperative pRNFL thickness (r = 0.930). The thin pRNFL group showed a stronger correlation between pre- and postoperative MDs than the normal pRNFL group (r = 0.619 and r = 0.420, respectively; P < 0.01). Multivariate analyses identified pRNFL thickness as the only significant predictor of postoperative visual acuity (odds ratio [OR], 25.02; 95% confidence interval [CI], 7.68-81.50; P < 0.01) and visual field (OR, 39.46; 95% CI, 10.39-149.83; P < 0.01).

CONCLUSIONS

Preoperative pRNFL thickness plays a prognostic value in postoperative visual outcome after EES for sellar and suprasellar tumors. Patients with pRNFL thickness ≥70 μm before surgery are more likely to improve visual outcome than those with thickness <70 μm.

Retinal Alteration Associated with an Arachnoid Cyst of the Pineal Region

BACKGROUND

Retinal optical coherence tomography (OCT) is a noninvasive high-resolution imaging technique, which is considered a biomarker of neurodegeneration. Several intracranial lesions can induce retrograde neurodegeneration which can be assessed using OCT. The cysts of the pineal region are usually asymptomatic and most often are an incidental radiologic finding.

CASE DESCRIPTION

We describe the case of a 50-year-old woman with an arachnoid cyst of the pineal region who complained of visual symptoms for 3 months. Bilateral macular thinning was demonstrated by OCT both on the preoperative and postoperative examinations, without any other clinical findings that could explain the results.

CONCLUSIONS

We suggest that the retinal alteration is caused by retrograde neurodegeneration secondary to the pineal region mass.

Optical coherence tomography for precision brain imaging, neurosurgical guidance and minimally invasive theranostics

This review focuses on optical coherence tomography (OCT)-based neurosurgical application for imaging and treatment of brain tumors. OCT has emerged as one of the most innovative and successful translational biomedical-diagnostic techniques. It is a useful imaging tool for noninvasive, in vivo, in situ and real-time imaging in soft biological tissues, such as brain tumor imaging. OCT can detect the structure of biological tissue in a micrometer scale, and functional OCT has some clinical researches and applications, such as nerve fiber tracts and neurovascular imaging. OCT is able to identify tumor margins, and it gives intraoperative precision identification and resection guidance. OCT-based theranostics is introduced into preclinical neurosurgical resection, such as the integration of OCT and laser ablation. We discuss the challenges and opportunities of OCT-based system in the field of combination of intraoperative structural and functional imaging, neurosurgical guidance and minimally invasive theranostics. We point out that OCT and laser ablation-based theranostics can give more precision and intelligence for intraoperative diagnosis and therapeutics in clinical applications. The theranostics can precisely locate, or specifically target cancerous tissues, and then as much as possiblly eliminate them.