Evaluation of the retinal nerve fibre layer and ganglion cell complex thickness in pituitary macroadenomas without optic chiasmal compression

Retinal vascular and structural recovery analysis by optical coherence tomography angiography after endoscopic decompression in sellar/parasellar tumors

We assessed the potential retinal microcirculation alterations for postoperative visual recovery in sellar/paraseller tumor patients with Optical Coherence Tomography Angiography (OCT-A). Two hundred ten eyes with sellar/parasellar tumor for which preoperative and postoperative (3 months) MRI Scans, Visual Acuity Test, Optical Coherence Tomography (OCT), OCT-A and, Visual Field Test data were available, besides 92 healthy eyes were evaluated. In the preoperative phase, significant reductions were observed in retinal vascular densities in various regions, including the Superficial Retinal Capillary Plexus (SRCP) (whole: p < 0.001, fovea: p = 0.025, parafovea: p < 0.001), Deep Retinal Capillary Plexus (DRCP) (whole: p < 0.001, fovea: p = 0.003, parafovea: p < 0.001), Peripapillary Vascular Density (PVD) (whole: p = 0.045, peripapillary: p < 0.001, nasal: p < 0.001, inferior: p < 0.001, temporal: p < 0.001), and Retinal Nerve Fiber Layer (RNFL) (nasal: p = 0.024, inferior: p < 0.001, temporal: p < 0.001, superior: p < 0.001) compared to the healthy control group. After surgery, the postoperative data of patients without chiasmal distortion were compared to their preoperative data. In the postoperative evaluation, significant increases were observed in vascular densities in patients without chiasmal distortion in the SRCP (whole: p < 0.001, parafovea: p = 0.045), DRCP (whole: p = 0.007, fovea: p = 0.006, parafovea: p = 0.040), PVD (peripapillary: p = 0.010, inferior: p < 0.001, temporal: p < 0.001, superior: p < 0.001), and RNFL (nasal: p = 0.011, inferior: p = 0.034, temporal: p = 0.046, superior: p = 0.011). Furthermore, significant associations were observed in the ROC analysis between the postoperative Visual Field Mean Deviation (VFMD) and SRCP (whole AUC = 0.793, p < 0.001, cut-off = 51.45, parafovea AUC = 0.820, p < 0.001, cut-off = 53.95), DRCP (whole AUC = 0.818, p < 0.001, cut-off = 55.95, parafovea AUC = 0.820, p < 0.001, cut-off = 59.05), PVD (temporal AUC = 0.692, p < 0.001, cut-off = 55.10), and RNFL (whole AUC = 0.690, p = 0.001, cut-off = 119.5, inferior AUC = 0.712, p < 0.001, cut-off = 144.75). These findings indicate a potential role of pre and post-operative OCT-A measurements in the assessment of surgical timing and postoperative visual recovery in patients with or without optic chiasm distortion.

Symptoms at presentation in conservatively managed patients with non-functioning pituitary adenomas

PURPOSE

Hypopituitarism and tumor growth are rare in patients with non-functioning pituitary microadenomas (NFPmA). However, patients often present with non-specific symptoms. The aim of this brief report is to examine presenting symptomatology in patients with NFPmA compared to patients with non-functioning pituitary macroadenomas (NFPMA).

METHODS

We performed a retrospective review of 400 patients (347 NFPmA and 53 NFPMA) who were conservatively managed; no patients had indications for urgent surgical intervention.

RESULTS

Average tumor size was 4.5 ± 1.9 and 15.5 ± 5.5 mm for NFPmA and NFPMA, respectively (p < 0.001). At least one pituitary deficiency was present in 7.5% of patients with NFPmA and 25% of patients with NFPMA. Patients with NFPmA were younger (41.6 ± 15.3 vs. 54.4 ± 22.3 years, p < 0.001) and more commonly female (64.6 vs. 49.1%, p = 0.028). There was no significant difference reported for similarly high rates of fatigue (78.4% and 73.6%), headache (70% and 67.9%), and blurry vision (46.7% and 39.6%). There were no significant differences in comorbidities.

CONCLUSION

Despite smaller size and lower rate of hypopituitarism, patients with NFPmA presented with a high prevalence of headache, fatigue, and visual symptoms. This was not significantly different from patients with NFPMA who were conservatively managed. We conclude that symptoms of NFPmA cannot fully be attributed to pituitary dysfunction or mass effect.

Retinal nerve fiber layer thickness and its correlation with visual symptoms and radiological features in pituitary macroadenoma

Objective

The aim of the study was to evaluate the association of the thickness of retinal nerve fiber layer (RNFL) with (i) visual symptoms and (ii) suprasellar extension defined by magnetic resonance imaging (MRI) in patients with pituitary macroadenoma.

Materials and Methods

RNFL thickness of 50 consecutive patients operated for pituitary macroadenoma between July 2019 and April 2021 were compared with standard visual examination findings and MRI measurements such as optic chiasm height, distance between the optic chiasm and adenoma, suprasellar extension, and chiasmal lift.

Results

The study group included 100 eyes of 50 patients operated for pituitary adenomas with suprasellar extension. RNFL thinning predominantly involved the nasal (84.26 ± 16.43 μm) and temporal quadrants (70.72 ± 14.80 μm) and correlated well with the visual field deficit (P < 0.001). Patients with moderate-to-severe deficit in visual acuity had a mean RNFL thickness <85 μm and patients with severe disc pallor had extremely thin RNFLs (<70 μm). Suprasellar extension defined as Wilsons Grade C, D, and E and Fujimotos Grades 3 and 4 were significantly associated with thin RNFLs <85 μm (P < 0.01). Chiasmal lift more than 1 cm and tumor chiasm distance of <0.5 mm were associated with thin RNFL (P < 0.002).

Conclusion

RNFL thinning correlates directly with the severity of visual deficits in patients with pituitary adenoma. Wilsons Grade D and E, Fujimoto Grade 3 and 4, chiasmal lift more than 1 cm, and chiasm tumor distance <0.5 mm are strong predictors of RNFL thinning and poor vision. Pituitary macro adenoma and other suprasellar tumors need to be excluded in patients with preserved vision but having obvious RNFL thinning.

Ocular Optical Coherence Tomography in the Evaluation of Sellar and Parasellar Masses: A Review

Compression of the anterior visual pathways by sellar and parasellar masses can produce irreversible and devastating visual loss. Optical coherence tomography (OCT) is a noninvasive high-resolution ocular imaging modality routinely used in ophthalmology clinics for qualitative and quantitative analysis of optic nerve and retinal structures, including the retinal ganglion cells. By demonstrating structural loss of the retinal ganglion cells whose axons form the optic nerve before decussating in the optic chiasm, OCT imaging of the optic nerve and retina provides an excellent tool for detection and monitoring of compressive optic neuropathies and chiasmopathies due to sellar and parasellar masses. Recent studies have highlighted the role of OCT imaging in the diagnosis, follow-up, and prognostication of the visual outcomes in patients with chiasmal compression. OCT parameters of optic nerve and macular scans such as peripapillary retinal nerve fiber layer thickness and macular ganglion cell thickness are correlated with the degree of visual loss; additionally, OCT can detect clinically significant optic nerve and chiasmal compression before visual field loss is revealed on automated perimetry. Preoperative values of OCT optic nerve and macular parameters represent a prognostic tool for postoperative visual outcome. This review provides a qualitative analysis of the current applications of OCT imaging of the retina and optic nerve in patients with anterior visual pathway compression from sellar and parasellar masses. We also review the role of new technologies such as OCT-angiography, which could improve the prognostic ability of OCT to predict postoperative visual function.

The Role of Optical Coherence Tomography in Early Detection of Retinal Nerve Fiber Layer Damage in Pituitary Adenoma

Background and objectives:This study aimed to evaluate the ability of optical coherence tomography (OCT) to differentiate eyes without obvious visual disturbances following pituitary adenomas (PAs) from normal eyes, in order to identify factors that could predict early diagnosis and timely treatment and prevent structural damage of visual pathway in patients with saddle area tumors. Material and methods:The present study was carried out between 2014-2018. Participants were divided into three groups: 23 subjects (44 eyes) in the PAs with visual field involvement (VFI) group, 10 (20 eyes) in the PAs with normal visual field (NVF) group and 22 subjects (44 eyes) in the control group. All patients received diagnostic magnetic resonance imaging (MRI), automated perimetry, visual acuity, OCT and ophthalmological assessments. Also, the degree of visual field (VF) deficit and thickness of peripapillary retinal nerve fiber layer (pRNFL) were measured by OCT and then considered for statistical analysis as predictors of early diagnostic visual involvement in the PAs. Results:All patients in the NVF and control groups (a total of 64 eyes) had normal VF. In the VFI group there were 16 eyes with complete hemianopia. Bitemporal hemianopia occurred in 20 eyes and eight eyes with concentric VF narrowing. Assessment of pRNFL thickness with OCT demonstrated the average and all quadrants of pRNFL thickness in the VFI group were significantly thinner than the pRNFL thickness in the other groups (P<0.001). The pRNFL thickness in the inferior and nasal quadrants and the average value in the NVF group were significantly thinner than the control group (P<0.05). Conclusion:If a patient has band atrophy, there is an irreversible damage and the main goal is to diagnose a nerve damage using OCT before band atrophy.

Early Retinal Microcirculation in Nonfunctioning Pituitary Adenomas Without Visual Field Defects Using Optical Coherence Tomography Angiography

BACKGROUND

For patients with nonfunctioning pituitary adenoma (NFPA) without manifesting visual acuity impairment or visual field defect (VFD), more sensitive and objective assessment methods will allow earlier detection before irreversible damage to the visual system. This study aimed to evaluate retinal vessel densities (VDs) alterations in these patients using optical coherence tomography angiography and to determine its diagnostic abilities.

METHODS

Between patients with NFPA without VFDs and age-matched, sex-matched healthy control individuals, comparisons of visual field metrics, retinal structural thickness, and microcirculation were conducted after adjusting for axial length (AL) and signal index of scans. Receiver operating characteristic (ROC) curves were further depicted to assess the diagnostic performance of significant parameters. To explore the impact of symptom duration, tumor size, and axial length on the significant parameters, multivariate regression analysis was conducted.

RESULTS

This cross-sectional study reviewed 107 patients with NFPA. Twenty-seven eyes of patients with NFPA without VFDs and 27 eyes of healthy controls were enrolled. Compared with healthy controls, patients with NFPA without VFDs had similar foveal avascular zone areas and perimeters, macular ganglion cell complex (mGCC) and peripapillary retinal nerve fiber layer thicknesses, and macular VDs. Only the VD in the radial peripapillary capillary (RPC) segment of the inferior temporal (IT) sector was much lower in the patient group. The 2 largest area under the ROC curves were the focal loss volume (FLV) of the mGCC and the VD in the RPC of the IT sector, both of which were significantly related to symptom duration and tumor size.

CONCLUSIONS

At the early stage of NFPA before VFD and retinal thickness thinning, fundus microcirculation impairments may occur initially in the microvascular density of the RPC segment of the IT sector. The FLV and the VD of RPC at the IT sector may provide a basis for the early diagnosis of NFPA without VFD in clinical practice.

Optical coherence tomography angiography characteristics of the retinal and optic disc morphology in prolactinoma

PURPOSE

To investigate changes in the retinal and optic disc (OD) morphology in prolactinoma patients without optical chiasmal compression and/or visual field defects using optical coherence tomography angiography (OCTA).

METHODS

In this cross-sectional imaging study, 16 consecutive prolactinoma patients (group 1, 32 eyes) and 15 age- and gender-matched healthy subjects (group 2, 30 eyes) underwent a thorough neuro-ophthalmological examination, which included testing for the presence of any intracranial compressive lesion that could cause optic neuropathy. Retinal morphological parameters, outer retinal and choriocapillaris flow areas, as well as OD vessel density (VD) and retinal nerve fiber layer (RNFL) thickness in for quadrants were then measured using OCTA.

RESULTS

Mean age (p = 0.537) and gender (p = 0.385) of participants in groups 1 and 2 did not differ significantly. The mean BCVA for both groups was 0.00 ± 0.00 logMAR. Microadenomas made up the majority of prolactinomas (87.1 %). All retinal morphological parameters in deep capillary plexus (excluding foveal VD) differed significantly between groups 1 and 2 (whole: p < 0.001, parafoveal: p = 0.021, and perifoveal: p < 0.001). Peripapillary RNFL thickness in temporal (p < 0.001), nasal (p = 0.010), and inferior (p = 0.007) quadrants also differed significantly between the two groups. Foveal deep (r = -0.304, p = 0.035) and choriocapillaris flow (r = -0.511, p = 0.008) were negatively correlated with tumor size at diagnosis.

CONCLUSIONS

Significant microvascular morphological changes, particularly in the deep retinal layer, as well as in the peripapillary RNFL thickness, were observed in prolactinoma patients. OCTA appears to be capable of detecting non-manifest circumpapillary and even intra-retinal microvascular changes even when there are no obvious signs of prolactinoma-related ocular complications caused by chiasmal compression.

Predictive value of macular ganglion cell-inner plexiform layer thickness in visual field defect of pituitary adenoma patients: a case-control study

OBJECTIVE

The present study explored the association between preoperative macular ganglion cell-inner plexiform layer thickness (GCIPL) and retinal nerve fiber layer thickness (RNFL) measured by optical coherence tomography (OCT) and the recovery of visual field (VF) defect after surgery in pituitary adenoma patients.

METHODS

This case-control study included patients with pituitary adenoma in the Neurosurgery Department of Shanxi Provincial People's Hospital between October 2019 and June 2021. Cranial MRI examination, three-dimensional OCT, and VF testing (Humphrey Field Analyzer II750) were performed before and at 6months after the surgery.

RESULTS

Fifty-three pituitary adenoma patients (81 eyes) were enrolled; 15 patients (23 eyes) were in the visual field did not recover group (VFNR), and 38 patients (58 eyes) were in the visual field recovered group (VFR). The temporal RNFL (P = 0.002) and average RNFL (P = 0.009) in the VFNR group were significantly lower than in the VFR group. The superior nasal GCIPL (P = 0.001), inferior nasal GCIPL (P = 0.001) and average GCIPL (P = 0.01) were significantly lower in the VFNR group than in the VFR group (all P < 0.01).The multivariable logistic regression analysis showed that nasal inferior GCIPL was an independent risk factor for VF recovery (odds ratio (OR) = 1.376,95% confidence interval (CI):1.089-1.739,P = 0.007). In the received operating characteristics (ROC) analysis, the area under the ROC curve (AUROCs) was the highest for nasal inferior GCIPL (AUROC = 0.739).

CONCLUSIONS

In patients who underwent resection of pituitary adenoma, nasal inferior GCIPL was an independent risk factor of visual field defect recover after surgery.

Predictive value of retinal nerve fibre layer thickness for postoperative visual improvement in patients with pituitary macroadenoma

Objective

To determine the usefulness of retinal nerve fibre layer (RNFL) thickness and a reliable cut-off value that can predict postoperative visual function improvement in patients with pituitary macroadenoma.

Methods and Analysis

This was a prospective observational study. Preoperative optical coherence tomography of the RNFL was performed in patients with pituitary macroadenoma. Postoperative visual function changes (acuity and visual fields) were identified using predefined criteria. Receiver operating characteristic curves were constructed for RNFL values to define the ideal cut-off value that predicted improvement. Other variables including preoperative visual acuity, mean deviation, visual field index and tumour volume were also analysed.

Results

Twenty-nine eligible subjects (58 eyes) were recruited. The mean (±SD) age was 43.9 (±12.85) years and 65.5% were male. The mean (±SE) follow-up duration was 20.8 (±6.42) months. RNFL thickness was significantly thinner in eyes with visual dysfunction and optic disc pallor. Better preoperative logarithmic minimum angle of resolution (logMAR) visual acuity, higher RNFL thickness and smaller tumour volume were associated with postoperative visual field improvement on univariate analysis; however, only mean RNFL thickness had significant association on multivariate analysis. None of the preoperative variables showed significant association with improvement in visual acuity. The best cut-off of mean RNFL thickness for visual field improvement was estimated at 81 μm with 73.1% sensitivity and 62.5% specificity.

Conclusion

Preoperative RNFL thickness can be an objective predictor of visual field outcomes in patients undergoing surgery for pituitary macroadenomas, with moderate sensitivity and specificity. It is, however, not a good predictor of visual acuity outcome.

The use of optical coherence tomography angiography in patients with chiasmal compression (literature review)

Optical coherence tomography (OCT) is currently the leading method for the observation and evaluation of microstructural changes in the retina in vivo. In recent years, OCT has been used in clinical practice to monitor the progression of compressive optic neuropathy in patients with chiasmal-sellar region neoplasms. The results obtained in the course of the studies opened up new opportunities for studying the pathogenesis of the development of compressive optic neuropathy in patients of this group. The advent of OCT-angiography (OCTA), developed on the basis of OCT, made it possible to study changes in the blood flow of the radial peripapillary capillary network, superficial and deep capillary plexuses, which opens up many opportunities for further research into the pathogenesis of visual impairment in this group of patients, prognosis of the development of the disease, and selection optimal terms of treatment. The literature review presents and analyzes the currently available results of the use of OCTA in patients with chiasmal compression.

Diagnostic and Prognostic Utility of Optical Coherence Tomography in Patients with Sellar/Suprasellar Lesions with Chiasm Impingement: A Systematic Review/ Meta-Analyses

BACKGROUND

In this review, we appraised the current literature on the utility of optical coherence tomography (OCT) as a diagnostic and predictive factor for postoperative visual function outcomes in patients with sellar/suprasellar lesions with chiasmal impingement.

METHODS

A systematic search of PubMed, CINAHL, Scopus, and Cochrane Library was conducted following PRISMA guidelines. Included studies described diagnostic or prognostic utility of OCT in patients with sellar/suprasellar lesions with chiasmal impingement. Meta-analysis was represented with mean difference (MD) with 95% confidence intervals. Meta-regression was performed to determine predictive factors of visual outcomes.

RESULTS

Forty-eight articles were identified for final pooled analysis, representing a total of 2,435 patients with compressive sellar/suprasellar lesions and 952 healthy controls. Mean age was 43.3(11.4) years, with 1,494(48.8%) male and 1,566(51.2%) female patients. Mean retinal nerve fiber layer(RNFL) was significantly different in the study population compared to healthy controls(75.8μ[13.2] vs 91.4μ[10.8], p<0.00001). The nasal segment of RNFL had the largest mean difference (MD -9.76[-12.39, -7.13], p<0.0001). Visual acuity, visual field mean deviation (VF-MD), and visual field pattern standard deviation, all showed significant differences between the study population and healthy controls as well(p<0.0001). Meta-regressions showed significant predictive capability of preoperative RNFL in determining visual function outcome (p<0.05).

CONCLUSION

Our findings provide promising support for the growing evidence that OCT parameters can be utilized as both a diagnostic and prognostic tool for patients with compression of the optic apparatus. There is a need for further studies to gain a better understanding of OCTs and to improve patient outcomes.

Optical coherence tomography and visual evoked potentials in evaluation of optic chiasm decompression

Chiasmal compression is a known cause of visual impairment, often leading to surgical decompression of the optic chiasm (OC). A prospective study was held at University Hospital in Hradec Králové to explore sensitivity of optical coherence tomography (OCT) and visual evoked potentials (VEPs) to OC compression and eventual changes after a decompression. 16 patients with OC compression, caused by different sellar pathologies, were included. The main inclusion criterion was the indication for decompressive surgery. Visual acuity (VA), visual field (VF), retinal nerve fibre layer (RNFL) and ganglion cell layer (GCL) thickness, and peak time and amplitude of pattern-reversal (P-VEPs) and motion-onset VEPs (M-VEPs) were measured pre- and postoperatively. The degree of OC compression was determined on preoperative magnetic resonance imaging. For M-VEPs, there was a significant postoperative shortening of the peak time (N160) (p < 0.05). P100 peak time and its amplitude did not change significantly. The M-VEPs N160 amplitude showed a close relationship to the VF improvement. Thinner preoperative RNFL does not present a statistically important limiting factor for better functional outcomes. The morphological status of the sellar region should be taken into consideration when one evaluates the chiasmal syndrome. M-VEPs enable detection of functional changes in the visual pathway better than P-VEPs.

Predictive value of OCT and MRI for postoperative visual recovery in patients with chiasmal compressive lesions

PURPOSE

We aimed to investigate the predictive value of retinal thickness measured by optical coherence tomography (OCT) and mass biometrics measured using magnetic resonance image (MRI) for visual recovery after surgery for removal of a mass compressing the optic chiasm.

METHODS

Consecutive patients who showed typical temporal visual field defect (VFD) with respect to the vertical meridian due to a chiasmal compressive mass and who underwent mass removal surgery were recruited. Ophthalmic examination was performed preoperatively and postoperatively. Retinal thickness was measured by the Cirrus OCT. The height and size of the mass and suprasellar extension (SSE) in both the sagittal and coronal planes were evaluated. Patients were divided into two groups based on the improvement in VFD (mean deviation [MD] change ≥ 5 dB: group R; others: group NR) and clinical characteristics were compared.

RESULTS

Fifteen patients were included in the study. Eight (53.3%) patients were allocated into group R and others (7 patients, 46.7%) into group NR. Age, sex, initial visual acuity, initial MD was not different between the two groups. The retinal thicknesses were not different while tumor height, volume, and both sagittal and coronal SSE were significantly different between the two groups. (p = 0.029, 0.014, <0.001, and <0.001, respectively) All MRI parameters showed significant predictive value for the degree of MD recovery.

CONCLUSION

MRI showed better predictive value than OCT in predicting postoperative VFD recovery in patients with temporal VFDs due to chiasmal compressive disorder.

Evaluation of Peripapillary Microcirculation in Patients with Acromegaly

OBJECTIVES

The aim of this study was to evaluate the radial peripapillary capillary (RPC) and the optic nerve head (ONH) perfusion of patients with acromegaly using optical coherence tomography angiography (OCTA).

METHODS

Twenty-four eyes of 24 acromegaly patients comprised the study group and 24 eyes of 24 healthy individuals were used as a control group. The ONH and RPC vascular density (VD) was measured for each patient using OCTA. The insulin-like growth factor 1 (IGF-1) levels were also recorded and compared.

RESULTS

The VD of the inferior nasal ONH and nasal RPC was significantly lower in the acromegaly group than in the control group (p=0.047 and p=0.001, respectively). There was a significant negative correlation between the VD of the superior nasal ONH and the IGF-1 level (r=-0.283, p=0.038).

CONCLUSION

The ONH and RPC VD values measured using OCTA were segmentally different in the acromegaly group compared with those of the control group. This method of non-invasive quantitative analysis of retinal perfusion using OCTA may be useful for future studies involving patients with acromegaly.

The Radiologic Characteristics and Retinal Thickness Are Correlated With Visual Field Defect in Patients With a Pituitary Mass

BACKGROUND

Investigation of visual field defects (VFDs) is important to decide the treatment and to predict the prognosis in patients with a pituitary mass. The aim of this study was to evaluate the correlation among 2 diagnostic modalities-MRI and optical coherence tomography (OCT)-and VFDs.

METHODS

Consecutive patients who showed the presence of a pituitary mass on MRI and in whom ophthalmic examinations were performed were recruited. Height and volume of the mass, sagittal and coronal displacement of optic chiasm, and the direction of mass expansion were measured. Patients were divided into 2 groups according to the presence (VFD group) or absence of VFDs (no VFDs group [NVFD]). The correlation among MRI parameters, OCT parameters, and VFDs were examined, and the diagnostic values of MRI and OCT and the combined value of the 2 modalities were analyzed.

RESULTS

Forty-one patients were included. The greatest coefficients of determination were observed between the sagittal displacement and pattern standard deviation (PSD) (R2 = 0.3661, P < 0.001) and between the inferonasal ganglion cell-inner plexiform layer (GCIPL) and PSD (R2 = 0.4079, P < 0.001). The height and the size of the mass in the VFD group were significantly greater as 57% and 148%, respectively, and the VFD group had more severe chiasmal displacement both in the sagittal (165%) and in the coronal (178%) plane (large effect in all). All macular GCIPLs were thinner in the NVFD group (range 9%-26%, large effect), whereas only temporal (25%) and average (11%) values were among peripapillary retinal nerve fiber layers.

CONCLUSIONS

The highest correlations with the degree of the VFD were seen in the sagittal displacement of optic chiasm and the inferonasal GCIPL, and these parameters were correlated concurrently. Both modalities showed a good diagnostic value for discriminating VFDs.

Parapapillary atrophy in optic neuropathies: Histology and clinical relevance

Parapapillary atrophy is one of the parameters of the optic nerve head area which are assessed during the ophthalmoscopic examination particularly useful to characterize glaucomatous optic neuropathy. Optical coherence tomography evaluation provides high-resolution images of the optic nerve head and surrounding area, and can be used to study parapapillary atrophy. Different parapapillary atrophy zones were described depending on their histological features and research has been conducted to investigate the possible association between the presence and/ or size of parapapillary atrophy zones and several optic nerve disorders. In this review we discuss the histology and the clinical findings related to parapapillary atrophy in patients with glaucomatous optic neuropathy, non-glaucomatous optic neuropathies (e.g. arteritic and non-arteritic anterior ischemic optic neuropathies; suprasellar and parasellar tumors), and other ocular conditions (e.g. high myopia; age-related macular degeneration). Two different histologic classifications were identified. Parapapillary atrophy was demonstrated in glaucoma and glaucoma-like neuropathies, but not in other types of optic nerve disorders.

How do intracranial tumors associated with visual pathways affect quadrant and sectoral based optical coherence tomography measurements: The effect of intracranial tumors on RNFL and GC-IPL thickness

AIM

To investigate the quantitative sectoral and regional changes of retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL) thickness in different types of intracranial tumors associated with visual pathways.

METHODS

This comparative retrospective study included 58 eyes of 30 patients with intracranial tumors and the data of 62 eyes of 31 healthy subjects. The RNFL and GCIPL thicknesses were analyzed using spectral-domain optical coherence tomography (OCT). The tumors were classified into ones that affect pre-geniculate and post-geniculate pathway.

RESULTS

The mean RNFL thickness in temporal quadrant was significantly thinner in eyes with intracranial tumors affecting the pre-geniculate optic pathway compared to controls (p = 0.04). In contrast, the mean superior quadrant RNFL thickness was significantly thicker in eyes with brain tumors associated with post-geniculate optic pathway (p = 0.01). The mean GC-IPL thicknesses of the inner ring superotemporal, superonasal, inferotemporal and inferionasal sectors and outer ring superonasal and inferonasal sectors were significantly thinner in eyes with intracranial tumors affecting the pre-geniculate optic pathway compared to control eyes (p = 0.02, p = 0.001, p = 0.02, p = 0.003, p = 0.008 and p = 0.03 respectively).

CONCLUSION

The results of this study showed that significant changes can be seen in the different RNFL quadrants and GC-IPL sectors in eyes with intracranial tumors affecting pre-geniculate or post-geniculate optic pathway. OCT is a very useful imaging technique to quantify these structural changes which take place during the neurodegeneration process of visual pathways in intracranial tumors.

Long term predictive ability of preoperative retinal nerve fiber layer thickness in visual prognosis after chiasmal decompression surgery

OBJECTIVE

To investigate the relationship between preoperative retinal nerve fiber layer (RNFL) thickness and the recovery of visual field (VF) and visual acuity (VA) 1 year after surgery in chiasmal compression patients presenting with visual impairment.

PATIENTS AND METHODS

Twenty-nine eyes of 16 patients with chiasmal compression and 14 eyes of 14 control subjects were enrolled. All patients undergoing chiasmal decompression surgery via a transsphenoidal approach were prospectively evaluated before and 1 year after surgery with best corrected visual acuity (BCVA, logMAR), mean deviation (MD) value with standard automated perimetry (SAP) and RNFL thickness with optical coherence tomography. Eyes with chiasmal compression were divided into two groups according to the mean preoperative RNFL thickness: ≥ 100 µm (Group 1) and < 100 µm (Group 2). The relationship between the mean preoperative RNFL thickness and visual prognosis parameters (VF, VA) was analyzed.

RESULTS

The mean preoperative RNFL thickness was 115.92 ± 8.97 µm, 84.0 ± 8.85 µm, and 114.21 ± 7.75 µm in Group 1 (n = 15 eyes), Group 2 (n = 14 eyes) and the control group (n = 14 eyes), respectively. The mean preoperative BCVA was 0.15 ± 0.3 in Group 1, and 0.41 ± 0.39 in Group 2. The mean BCVA increased to 0.03 ± 0.1 in Group 1 in the postoperative period but did not change in Group 2. MD value was - 6.10 ± 5.54 in the preoperative period and - 2.59 ± 2.23 in the postoperative period for Group 1 (p = 0.014), while it was - 18.97 ± 4.14 in the preoperative period and - 18.57 ± 4.51 in the postoperative period in Group 2 (p = 0.24).

CONCLUSIONS

This study suggests that lower mean preoperative RNFL thickness was associated with poorer long-term visual prognosis. Preoperative RNFL thickness measurements may be helpful in predicting the recovery of VF and VA after decompression surgery in patients with chiasmal lesion presenting with visual impairment.

Clinical efficacy of optical coherence tomography in sellar mass lesions: a meta-analysis

PURPOSE

Although optical coherence tomography (OCT) of the eyes has been studied to detect and monitor sellar masses, there is no recommendation for selecting the most effective measurement of OCT in clinical practice. Thus, we conducted a meta-analysis to examine the efficacy of OCT in sellar mass lesions.

METHODS

We conducted a literature search in PubMed and EMBASE through April 26, 2020. The primary outcomes were the thickness of the peripapillary retinal nerve fiber layer (pRNFL) and the macular ganglion cell complex (mGCC). The secondary outcomes included the thickness of the macular ganglion cell and inner plexiform layer (mGCIPL) and macular thickness. Random-effects models were used in all meta-analyses. Additionally, we conducted meta-regressions and subgroup analyses.

RESULTS

We included 22 studies, involving 1347 eyes of patients and 1198 eyes of controls. When compared with the control group, the reductions in pRNFL, mGCC and macular thickness in the patient group were significantly different, whereas significant thinning of the mGCIPL was restricted to the nasal hemiretina. Furthermore, we found that before visual field (VF) defects occurred, significant thinning of the pRNFL and mGCC thickness could be detected by OCT. The change in OCT parameters also showed different patterns in different types of pituitary adenomas.

CONCLUSIONS

Sellar mass lesions were associated with the changes in OCT measurements. The characteristic patterns of the OCT parameters may refine the diagnostic accuracy. Moreover, the alterations of OCT metrics before VF defects indicate the efficacy of OCT in early detection. Different types of pituitary adenomas may vary in OCT measurements, and their specific features warrant further research efforts.

[Chiasmatic syndrome]

The optic chiasm is an essential anatomical structure in neuro-ophthalmology. The systematization of the visual pathways results from the arrangement of the retinal ganglion cell fibers. It explains the signs of chiasmal syndrome. A good knowledge of the anatomy permits to correlate visual field defects with imaging results. It is now possible to map the organization of the ganglion cell fibers within the chiasm. Their hemidecussation allows for stereoscopic vision in humans. The causes of chiasmal syndrome are multiple, but tumors and compressive causes predominate. The proximity of the pituitary region to the chiasm accounts for the frequency of chiasmal syndrome, which involves ophthalmologists not only through dysfunction of the visual pathway, which may be the presenting sign, but also through possible complications throughout the course of the disease. This review aims to synthesize the embryology, anatomy and principles of work-up for chiasmal syndrome as well as its many possible causes.

SD-OCT parameters and visual field defect in chiasmal compression and the diagnostic value of neural network model

PURPOSE

To evaluate the peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) measurements using spectral domain optical coherence tomography (SD-OCT) in patients with chiasmal compression and analyze the diagnostic value of a neural network model.

METHODS

Forty-seven patients with chiasmal compressive disorder were recruited and divided into two groups depending on the visual field defect (perimetric; group 1 and preperimetric; group 2). Fifty-seven normal subjects were also recruited (group 3). Peripapillary RNFL and macular GCIPL were analyzed in each group. A multilayer perceptron was trained using a training dataset and derived a neural network model. The diagnostic performances were compared using the area under the receiver operating curve (AUROC) between each parameters and neural network model.

RESULTS

All macular GCIPL parameters, except inferotemporal GCIPL thickness, were thinner in group 1 than in group 2 and group 3, with barely any difference between group 2 and group 3 parameter values. The diagnostic power of the neural network model, minimum GCIPL, and inferonasal GCIPL were superior when compared with other parameters; the diagnostic values of these three parameters are not significantly different in discriminating the patients and normal control. However, the neural network exhibited the best diagnostic power in distinguishing group 2 and group 3.

CONCLUSION

Macular GCIPL was reduced in chiasmal compression patients with visual field defect which was not evident in the preperimetric state. Neural network model showed superior diagnostic value in discriminating the preperimetric patients from normal control. The results suggest that neural networks may be helpful in the early diagnosis of chiasmal compression.

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.

Assessment of inner retina layers thickness values in eyes with pituitary tumours before visual field defects occur

BACKGROUND

The purpose of this study was to evaluate macula, retinal nerve layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL) and macular nerve fibre layer (mNFL) thickness in patients with pituitary tumours who has normal visual field (VF).

METHODS

Thirty-five eyes of 35 patients with pituitary tumours with normal VF and 41 eyes of 41-healthy subjects were underwent a complete ophthalmic examination. The spectral domain- optical coherence tomography (OCT) was used to measure macular and optic disc parameters. Layer-by-layer segmentation was done automatically by using the new software. Data analyses were performed by using SPSS for Windows, version 22.0.

RESULTS

Average of total macula thickness inner temporal (p: 0.006), outer temporal (p < 0.001), inner nasal (p: 0.03), outer nasal (<0.001) were significantly lower in pituitary tumour group than normal group. Average of RNFL (p:0.009), temporal (p: 0.001), superiotemporal (p:0.004) and inferiotemporal (p: 0.01) were significantly lower in pituitary tumour group than normal group. Average of central GCL (p: 0.01) and central NFL (p: 0.03) were significantly lower in pituitary tumour group than normal group. There was no statistically significant difference between the two groups in IPL averages.

CONCLUSIONS

Pituitary tumour patients with normal VF had reduced nasal and temporal section of the total macula, temporal RNFL, central mGCL and mNFL thicknesses, reflecting the corresponding to the anatomical substrate of the underlying pathology of chiasmal compression. This indicates that the presence of retinal thinning may be a sign of early detection of anterior visual pathway injury before VF loss becomes apparent.

The Effect of Timing of Surgery in Pituitary Apoplexy on Continuously Valued Visual Acuity

Background  Pituitary apoplexy is often treated urgently, but this is based on studies which assess vision categorically and dichotomizes the time interval between symptom onset and surgery which may introduce bias in measuring an association between the two. Objective  This study was aimed to assess for a relationship between continuously valued surgery delay and visual acuity recovery after pituitary apoplexy. Methods  In this retrospective study, all patients presenting with symptomatic pituitary apoplexy between 2004 and 2016 were identified from an institutional database. The primary endpoint was visual acuity improvement, measured as the difference in acuity from the pre- to postoperative period, and measured in Logarithm of the Minimal Angle of Resolution (LogMAR) units. Analysis was performed using continuous values of time delay and visual acuity to assess for an underlying association. Results  Thirty-two pituitary apoplexy patients were identified. Visual acuity deficits were reported in 81%. The median visual acuity was 0.35 LogMAR (Snellen's fraction 20/40) preoperatively, and 0.1 (20/25) postoperatively ( p  < 0.01). The time between symptom onset and surgery was not associated with improvement in visual acuity ( p  = 0.46). When the time delay and visual outcome were intentionally dichotomized, patients undergoing surgery within 2 days of symptom onset had 0.21 times the odds of a good visual outcome (95% confidence interval [CI]: 0.04-1.05). Conclusion  When assessed as continuously valued measures, the time from symptom onset to surgical intervention and the improvement in visual acuity are not associated, although intentional dichotomization of data produced conflicting results.

Predicting the early visual outcomes in sellar-suprasellar lesions compressing the chiasm: the role of SD-OCT series of 20 patients operated via endoscopic endonasal approach

BACKGROUND

Tumors involving the sellar area often cause visual disorders due to optic nerves/chiasm compression, so that surgery is required. However the likelihood of visual improvement/restoration is variable. Optical coherence tomography (OCT) is a valid diagnostic tool for defining pathological conditions of the optic apparatus. We herein investigated the role of the SD-OCT and the best corrected visual acuity in predicting postoperative visual recovery, in patients complaining of chiasm compression due to sellar-suprasellar lesions.

MATERIALS AND METHODS

We retrospectively analyzed 20 patients (7 females and 13 males; mean age 50,8 ± 17,87 years, range 11-83), with optic chiasm/nerve compression that underwent endoscopic endonasal approach at the Division of Neurosurgery of the Università degli Studi di Napoli "Federico II", Naples - Italy, between June 2014 and February 2015. Pre-operative ophthalmological assessment focused on BCVA Snellen charts, Standard Automated Perimetry test and SD-OCT. Test were repeated at two weeks, one and three months after surgery.

RESULTS

A significant thickness reduction in all the patients, as compared to the control group was noted: GCC thickness reduction remained mostly unchanged postoperatively. 42.9% of the patients had altered visual acuity (VA), while the Perimetry revealed 90% of altered preoperative MD values (MD> -2.00): perimetry improvement was noted in 93% of cases and visual acuity in 91.3% of cases. A direct correlation between preoperative retinal status and functional recovery was identified considering the values of pRNFL and GCC.

CONCLUSIONS

OCT provides valuable information in regards to the entity of compression also in patients without any visual field defects. Although several factors should be taken into consideration, we retain that preoperative RNFL and GCC thickness values can be claimed as a reliable predictors of visual recovery in those patients presenting chiasm compression.

Optical Coherence Tomography of the Retinal Ganglion Cell Complex in Leber's Hereditary Optic Neuropathy and Dominant Optic Atrophy

Background: Mitochondrial optic neuropathies such as Leber's Hereditary Optic Neuropathy (LHON) and Dominant Optic Atrophy (DOA) have been shown to produce an optic neuropathy secondary to retinal ganglion cell loss with thinning of the retinal ganglion cell complex (RGCC). Methods: We performed a retrospective analysis assessing the thicknesses of the peripapillary retinal nerve fiber layer (pRNFL) along with the macular retinal ganglion cell-inner plexiform layer (RGC-IPL) using optical coherence tomography (OCT). We compared these changes among acute and chronic LHON, DOA, and normal healthy control patients. Results: Patients with chronic LHON exhibited statistically significant thinning of the RNFL in the superior, nasal, and inferior quadrants of the retina. In acute LHON, the RNFL was relatively thicker in all but the temporal quadrant when compared with respective quadrants in normal eyes; however, statistical significance was not achieved. In DOA, the RNFL was thinnest in the superior and inferior quadrants of the retina, measuring between acute and chronic LHON thickness values. In chronic LHON and DOA, both the pRNFL and RGC-IPL were significantly thinner in all four retinal quadrants relative to controls. Conclusions: This article represents the first comparative study of the RGCC between LHON and DOA. Our findings demonstrated significant thickness reductions in pRNFL and macular RGC-IPL in patients with LHON and DOA, with different specific patterns consistent with the general patterns of thinning classically observed. This study suggests the usefulness of the RGCC as a potential in vivo biomarker for assessing disease in patients with LHON and DOA.

The importance of the electrophysiological tests in the early diagnosis of ganglion cells and/or optic nerve dysfunction coexisting with pituitary adenoma: an overview

BACKGROUND AND METHODS

Based on the available literature, it is suggested, in the clinical evaluation of the chiasmal tumors, that the following electrophysiological tests: visual evoked potentials to pattern-reversal stimulation, multifocal visual evoked potentials (mfVEPs), and pattern electroretinogram (PERG) play an important role in the diagnosis of the optic nerve and retinal dysfunction in the course of pituitary tumors.

RESULTS

Macroadenomas and also microadenomas may cause dysfunction of retinal ganglion cells (RGCs) and their axons, even in the absence of changes in the routine ophthalmological examination, retinal sensitivity in standard automated perimetry, and retinal nerve fiber layer thickness in optical coherent tomography. The most frequently observed changes in electrophysiological tests were as follows: in PVEPs-the crossed/uncrossed asymmetry distribution, altered waveform, increase in P100-wave peak time, and/or reduction in amplitude; in mfVEPs-the peak time prolongation and/or amplitude reduction in C1-wave; in PERG-the reduction in N95-wave amplitude and decreased N95:P50 amplitude ratio. Hemifield PVEPs were more often abnormal than full-field PVEPs. Multi-channel recording is recommended for the assessment of the anterior visual pathway. The use of mfVEP offers the possibility to register localized disturbances of the optic nerve and ganglion cells. Additionally, an amplitude of N95-wave reduction in PERG correlated with a lack of postoperative visual acuity recovery. The postoperative improvement in the visual field was found to be associated with a normal N95:P50 amplitude ratio. The RGCs dysfunction manifested by decrease in PhNR/b-wave amplitude ratio was associated with the worse visual fields outcome. A review of the literature summarizing the electrophysiological testing in the pituitary adenoma is discussed.

CONCLUSION

In patients with pituitary tumor, detection of the early dysfunction of the visual pathway may lead to modification of the medical treatment regimen and reduce the incidence of irreversible optic nerve damage.

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.

Utility of optical coherence tomography in the evaluation of sellar and parasellar mass lesions

PURPOSE OF REVIEW

Anterior visual pathway compression is a common feature of sellar region masses. We review the visual pathway neuroanatomy pertaining to sellar and parasellar lesions and describe recent advances in optical coherence tomography (OCT) imaging that have provided a novel quantitative perspective in the evaluation and management of such patients.

RECENT FINDINGS

Ultrastructural measurements of optic nerve integrity using OCT, namely peripapillary retinal nerve fiber layer (pRNFL) and the ganglion cell and inner plexiform layer (GCIPL) thicknesses, have been shown to correlate with visual acuity and visual field deficits on perimetry in patients with compressive sellar region masses. In some cases, OCT can visualize early signs of anterior visual pathway involvement in the absence of clinically evident visual field loss or optic disc pallor. OCT is particularly useful when assessing patients who demonstrate less reliable visual field testing. Furthermore, there is growing awareness that pRNFL and GCIPL thinning preoperatively correlate with worse visual recovery following chiasmal decompression, highlighting the prognostic utility of OCT in this patient population.

SUMMARY

OCT provides a complimentary, yet critical, role in quantitatively assessing ultrastructural retinal injury in patients with sellar and parasellar lesions compressing the anterior visual pathway and should be incorporated into routine evaluation.

Ganglion cell layer complex measurements in compressive optic neuropathy

PURPOSE OF REVIEW

Neuroophthalmologists and neurosurgeons are often asked by their patients what their visual prognosis will be after decompression of an optic chiasm lesion. Previous methods have been studied but have not provided consistent guidance. However, a recent algorithm which allows for retinal ganglion cell analysis from optical coherence tomography (OCT) may be more helpful.

RECENT FINDINGS

Recent studies have shown that ganglion cell layer complex (GCC) measurements from OCT strongly correlate with the visual field loss associated with compressive optic neuropathies. For example, GCC measurements show corresponding binasal thinning with bitemporal hemianopia. Some investigators have also shown that more preserved GCC thickness is preoperatively associated with better postsurgical outcome. Interestingly, some patients experience almost complete recovery of visual fields despite considerable GCC thinning, and others may have GCC loss before they develop demonstrable visual field defects.

SUMMARY

GCC measurements on OCT strongly correlate with visual field defects from optic chiasm compressive lesions and may help with regard to prognosis following treatment. However, considerable visual recovery is possible despite persistent GCC loss.

Retina ganglion cell/inner plexiform layer and peripapillary nerve fiber layer thickness in patients with acromegaly

Increased secretion of growth hormone and insulin-like growth factor-1 in acromegaly has various effects on multiple organs. However, the ocular effects of acromegaly have yet to be investigated in detail. The aim of the present study was to compare retina ganglion cell/inner plexiform layer (GCIPL) and peripapillary nerve fiber layer thickness (pRNFL) between patients with acromegaly and healthy control subjects using spectral domain optical coherence tomography (SD-OCT). This cross-sectional, comparative study included 18 patients with acromegaly and 20 control subjects. All participants underwent SD-OCT to measure pRNFL (in the seven peripapillary areas), GCIPL (in the nine ETDRS areas), and central macular thickness (CMT). Visual field (VF) examinations were performed using a Humphrey field analyzer in acromegalic patients. Measurements were compared between patients with acromegaly and control subjects. A total of 33 eyes of 18 patients with acromegaly and 40 eyes of 20 control subjects met the inclusion criteria of the present study. The overall calculated average pRNFL thickness was significantly lower in patients with acromegaly than in control subjects (P = 0.01), with pRNFL thickness significantly lower in the temporal superior and temporal inferior quadrants. Contrary to our expectations, pRNFL thickness in the nasal quadrant was similar between acromegalic and control subjects. The mean overall pRNFL thickness and superonasal, nasal, inferonasal, and inferotemporal quadrant pRNFL thicknesses were found to correlate with the mean deviation (MD) according to Spearman's correlation. However, other quadrants were not correlated with VF sensitivity. No significant difference in CMT values was observed (P = 0.6). GCIPL thickness was significantly lower in all quadrants of the inner and outer macula, except for central and inferior outer quadrants, in the acromegaly group than that in the control group (P < 0.05). GCIPL thicknesses of the inferior inner and outer macula quadrants were found to correlate with MD, whereas no correlation was observed between other quadrants and VF sensitivity. We demonstrated that GCIPL thickness decreased in patients with acromegaly compared with that in control subjects. However, the nasal quadrant pRNFL thickness was similar in acromegaly, in contrast to our expectations. SD-OCT may have utility in the assessment of the effects of acromegaly on retinal structures.

Optical coherence tomography impacts the evaluation of visual pathway tumors

The objective of this systematic literature review is to assess the role of retinal optical coherence tomography (OCT) in the evaluation of patients with tumors of the visual pathway. We performed a PubMed database search according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The search was restricted to articles published in English between 2000 and 2016, with at least 10 human adult participants enrolled. Twenty-seven articles met the eligibility criteria. All studies investigated tumors of the anterior visual pathway. Both time-domain and spectral-domain OCT technologies were used and the role of OCT as diagnostic and/or prognostic tool was studied. Retinal OCT provides structural information about ganglion cell axon integrity and is complementary to visual function examination. OCT is a prognostic factor for post-operative visual outcome.

Interocular Symmetry of Macular Ganglion Cell Complex Thickness in Young Chinese Subjects

Purpose

To report interocular differences in macular ganglion cell complex (mGCC) thickness in young Chinese subjects using RTVue-100 optical coherence tomography (OCT).

Methods

This was an observational, cross-sectional study. The mGCC thickness was measured in 158young Chinese subjects using RTVue-100 OCT. The normal ranges of the interocular differences were determined as falling between the 2.5th and 97.5th percentiles. Right and left eyes were compared using a paired t test. Pearson correlation analysis was performed to assess the relationships between mGCC thickness and other potential factors. The relationships between the interocular difference in the average mGCC thickness and the potential factors were evaluated by univariate and multivariate linear regression analysis.

Results

The mean interocular difference in the average, superior, and inferior mGCC thickness were 0.19 ± 2.69 μm, 0.22 ±3.14 μm, and 0.25±3.34 μm, respectively, which were not statistically significant. The 2.5th and 97.5th percentiles of interocular difference for mean average mGCC thickness were -4.82μm and 4.38μm, for superior mGCC thickness, -6.67 μm and 7.04 μm, and for inferior mGCC thickness, -6.75 μm and 6.27 μm. There was a strong correlation between the right and left eyes for all the studied parameters, including spherical equivalent (SE) and axial length (AL). Interocular difference in SE (p = 0.007) were independently correlated with the interocular difference in average mGCC thickness.

Conclusions

There was no significant relative interocular difference in mGCC thickness in young Chinese subjects. Interocular difference exceeding the normal limits should be considered significantly asymmetrical, and suggestive of pathology.

Analysis of Retinal Layer Thicknesses and Their Clinical Correlation in Patients with Traumatic Optic Neuropathy

The aims of this study were 1) To evaluate retinal nerve fiber layer (fRNFL) thickness and ganglion cell layer plus inner plexiform layer (GCIPL) thickness at the fovea in eyes affected with traumatic optic neuropathy (TON) compared with contralateral normal eyes, 2) to further evaluate these thicknesses within 3 weeks following trauma (defined as “early TON”), and 3) to investigate the relationship between these retinal layer thicknesses and visual function in TON eyes. Twenty-nine patients with unilateral TON were included. Horizontal and vertical spectral-domain optical coherence tomography (SD-OCT) scans of the fovea were taken in patients with unilateral TON. The main outcome measure was thickness of the entire retina, fRNFL, and GCIPL in eight areas. Thickness of each retinal layer was compared between affected and unaffected eyes. The correlation between the thickness of each retinal layer and visual function parameters, including best corrected visual acuity, color vision, P100 latency, and P100 amplitude in visual evoked potential (VEP), mean deviation (MD) and visual field index (VFI) in Humphrey visual field analysis in TON eyes was analyzed. Thicknesses of the entire retina, fRNFL, and GCIPL in SD-OCT were significantly thinner (3–36%) in all measurement areas of TON eyes compared to those in healthy eyes (all p<0.05). Whereas, only GCIPL in the outer nasal, superior, and inferior areas was significantly thinner (5–10%) in the early TON eyes than that in the control eyes (all p<0.01). A significant correlation was detected between retinal layer thicknesses and visual function parameters including color vision, P100 latency and P100 amplitude in VEP, MD, and VFI (particularly P100 latency, MD, and VFI) (r = -0.70 to 0.84). Among the retinal layers analyzed in this study, GCIPL (particularly in the superior and inferior areas) was most correlated with these five visual function parameters (r = -0.70 to 0.71). Therefore, evaluation of morphological change of each retinal layer using SD-OCT can help in understanding TON pathophysiology and indirectly assessing visual function. Moreover, evaluation of the morphological change of the GCIPL in TON eyes may be useful to assess visual function in patients with early TON.