Optical coherence tomography analysis of inner and outer retinal layers in eyes with chiasmal compression caused by suprasellar tumours

Role of Optical Coherence Tomography in Predicting Visual Outcome after Surgery for Sellar and Supra-Sellar Tumors

BACKGROUND

Almost one-fifth of patients undergoing surgery for sellar/supra-sellar tumors do not gain a significant improvement in their vision. Various methods have been described to predict prospective visual outcomes in them, although they lack uniformity.

OBJECTIVE

The study was conducted to predict visual outcomes following surgery for sellar and supra-sellar tumors compressing the anterior optic pathway based on pre-operative optical coherence tomography (OCT) parameters.

METHODS AND MATERIALS

This was a record-based observational descriptive longitudinal study done in a tertiary care center in India. Thirty-seven patients (74 eyes) diagnosed with sellar supra-sellar lesions were included in the study. Patients' ophthalmic evaluations, done pre-operatively and 3 months post-operatively, were reviewed. Spectral-domain OCT and segmentation were done using the automated segmentation technology of Spectralis software. The thickness of the respective layers was measured.

RESULTS AND CONCLUSIONS

The mean age of the study population was 42.68 years. Eyes with a pre-operative visual acuity component of VIS (visual impairment score) ≤61, pre-operative ganglion cell layer thickness ≥26.31 um, a pre-operative inner plexiform layer thickness of ≥25.69 um, a pre-operative ganglion cell inner plexiform layer thickness of 52.00 um, pre-operative ganglion cell complex thickness ≥84.47 μm, and a pre-operative inner retinal layer thickness of ≥205.25 μm were more likely to have an improved visual outcome. Eyes with a pre-operative duration of visual symptoms of ≥15 months, VIS ≥126.50, a pre-operative decimal visual acuity of <0.035, a pre-operative visual field index of ≤8%, a pre-operative macular thickness of ≤287.06 um, a pre-operative macular RNFL (retinal nerve fiber layer) thickness ≤66.00 μm, and a pre-operative peri-papillary RNFL thickness ≤64.62 μm were unlikely to have visual improvement.

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.

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.

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.

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.

Microarray-based gene expression analysis combined with laser capture microdissection is beneficial in investigating the modes of action of ocular toxicity

The retina consists of several layers, and drugs can affect the retina and choroid separately. Therefore, investigating the target layers of toxicity can provide useful information pertaining to its modes of action. Herein, we compared gene expression profiles obtained via microarray analyses using samples of target layers collected via laser capture microdissection and samples of the whole globe of the eye of rats treated with N-methyl-N-nitrosourea. Pathway analyses suggested changes in the different pathways between the laser capture microdissection samples and the whole globe samples. Consistent with the histological distribution of glial cells, upregulation of several inflammation-related pathways was noted only in the whole globe samples. Individual gene expression analyses revealed several gene expression changes in the laser capture microdissection samples, such as caspase- and glycolysis-related gene expression changes, which is similar to previous reports regarding N-methyl-N-nitrosourea-treated animals; however, caspase- and glycolysis-related gene expressions did not change or changed unexpectedly in the whole globe samples. Analyses of the laser capture microdissection samples revealed new potential candidate genes involved in the modes of action of N-methyl-N-nitrosourea-induced retinal toxicity. Collectively, our results suggest that specific retinal layers, which may be targeted by specific toxins, are beneficial in identifying genes responsible for drug-induced ocular toxicity.

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.

Heritability of Inner Retinal Layer and Outer Retinal Layer Thickness: The Healthy Twin Study

The purpose of the study is to evaluate the heritability of inner retinal layer (IRL) and outer retinal layer (ORL) thicknesses in the healthy Korean population. This was a cross-sectional, twin and family study. We included 374 Korean adults with healthy eyes from 89 families. IRL thickness (from the internal limiting membrane to the external limiting membrane) and ORL thickness (from the external limiting membrane to the outer border of the retinal pigment epithelium layer) were measured in the nine macular subfields as defined by the Early Treatment of Diabetic Retinopathy Study using optical coherence tomography. The heritability on IRL and ORL thicknesses were investigated using a variance decomposition model. The heritability of IRL thickness was 0.87, 0.58, 0.85, 0.89, and 0.74 for the central, inner superior, inner inferior, inner temporal, inner nasal subfields, respectively; and 0.62, 0.83, 0.62, and 0.60 for the outer superior, outer inferior, outer temporal, outer nasal subfields, respectively. The heritability of ORL thickness was 0.56, 0.75, 0.66, 0.72, and 0.56 for the central, inner superior, inner inferior, inner temporal, inner nasal subfields, respectively; and 0.64, 0.63, 0.73, 0.54 for the outer superior, outer inferior, outer temporal, and outer nasal subfields, respectively. The heritability estimates of IRL thickness and ORL thickness ranged from moderate to high. The IRL thickness at the central, inner temporal, and inner inferior subfields had particularly high heritability.