Reduced contrast sensitivity function correlated with superficial retinal capillary plexus impairment in early stage of dysthyroid optic neuropathy

Central and peripheral contrast sensitivity in thyroid eye disease

PURPOSE

Assessment of central and peripheral contrast sensitivity (CS) in thyroid eye disease (TED) with and without dysthyroid optic neuropathy (DON).

METHODS

This cross-sectional study enrolled 33 eyes of 18 treatment-naïve TED patients and 18 age- and sex-matched healthy controls for comparative analysis. A detailed ophthalmic examination included visual acuity (VA), intraocular pressure measurement, slit-lamp biomicroscopy, and CS testing (central and four peripheral regions) using Spaeth-Richman Contrast Sensitivity test was done.

RESULTS

The average age of TED patients was 47.17 ± 13.99 years and a female preponderance was noted (66.66%, n = 12). Twenty-five eyes (75.8%) were diagnosed as TED without DON, while eight eyes (24.2%) had DON. Nine eyes (27.2%) were in the active stage of disease and 29 eyes (87.8%) had proptosis. The difference in mean logMAR visual acuities between TED patients and controls was statistically insignificant ( P = 0.189), but a significant difference was noted in central and total CS score ( P < 0.001, Wilcoxon-Mann-Whitney test). On CS comparison between DON and non-DON eyes, a significant difference in average scores was noted in central and all peripheral areas ( P < 0.05, Wilcoxon-Mann-Whitney test). With increasing clinical activity score, a statistically significant reduction was noted in CS in three out of four peripheral regions (Spearman correlation, P < 0.05).

CONCLUSION

Visual function compromise can be detected in TED in the presence of intact VA, by testing CS. Peripheral CS deteriorates with increasing inflammation and in DON. Serial monitoring of both central and peripheral CS may help in diagnosing DON early.

Contrast Sensitivity Better Reflects Wide-Field Swept-Source Optical Coherence Tomography Angiography Vascular Metrics Among Healthy Eyes Compared to Visual Acuity

BACKGROUND AND OBJECTIVE

To evaluate the association between widefield swept-source optical coherence tomography angiography (WF SS-OCTA) and visual function in healthy eyes.

PATIENTS AND METHODS

Fifty-seven eyes of 45 patients were evaluated with visual acuity (VA), contrast sensitivity (CS), and WF SS-OCTA (3 × 3, 6 × 6, and 12 × 12 mm images) on the same day. Mixed-effects multivariable regression analyses were performed.

RESULTS

Contrast sensitivity metrics, including CS between 6 to 18 cycles per degree (cpd) and area under the logarithm CS function, were significantly associated with vessel density (VD) and vessel skeletonized density (VSD), whereas VA was not. The largest effect size was between CS at 18 cpd and VD (β = 0.41, P = 0.007) and VSD (β = 0.42, P = 0.006) on 12 × 12 mm images.

CONCLUSIONS

Reduced VSD and VD on WF SSOCTA was significantly associated with decreased CS, whereas VA was not. These results suggest CS could serve as a screening tool for early stage retinal and neurologic disorders. [Ophthalmic Surg Lasers Imaging Retina 2024;55:494-502.].

Optical coherence tomography angiography in thyroid associated ophthalmopathy: a systematic review

PURPOSE

To evaluate the evidence for alterations of blood flow, vascular and perfusion densities in the choroid, macula, peripapillary region, and the area surrounding the optic nerve head (ONH) in patients with thyroid-associated ophthalmopathy (TAO) based on changes of OCTA parameters.

METHODS

A systematic review of Pubmed, Google Scholar, Scopus, WOS, Cochrane, and Embase databases, including quality assessment of published studies, investigating the alterations of OCTA parameters in TAO patients was conducted. The outcomes of interest comprised changes of perfusion and vascular densities in radial peripapillary capillary (RPC), ONH, superficial and deep retinal layers (SRL and DRL), choriocapillaris (CC) flow, and the extent of the foveal avascular zone (FAZ).

RESULTS

From the total of 1253 articles obtained from the databases, the pool of papers was narrowed down to studies published until March 20th, 2024. Lastly, 42 studies were taken into consideration which contained the data regarding the alterations of OCTA parameters including choriocapillary vascular flow, vascular and perfusion densities of retinal microvasculature, SRL, and DRL, changes in macular all grid sessions, changes of foveal, perifoveal and parafoveal densities, macular whole image vessel density (m-wiVD) and FAZ, in addition to alterations of ONH and RPC whole image vessel densities (onh-wiVD and rpc-wiVD) among TAO patients. The correlation of these parameters with visual field-associated parameters, such as Best-corrected visual acuity (BCVA), Visual field mean defect (VF-MD), axial length (AL), P100 amplitude, and latency, was also evaluated among TAO patients.

CONCLUSION

The application of OCTA has proven helpful in distinguishing active and inactive TAO patients, as well as differentiation of patients with or without DON, indicating the potential promising role of some OCTA measures for early detection of TAO with high sensitivity and specificity in addition to preventing the irreversible outcomes of TAO. OCTA assessments have also been applied to evaluate the effectiveness of TAO treatment approaches, including systemic corticosteroid therapy and surgical decompression.

Macular blood flow changes in dysthyroid optic neuropathy after high-dose intravenous pulse methylprednisolone (IVMP)

OBJECTIVE

To investigate the changes in macular vessel density (VD) of the superficial layer of retina (SLR) and deep layer of retina (DLR) in dysthyroid optic neuropathy (DON) after high-dose intravenous pulse methylprednisolone (IVMP).

MATERIALS AND METHODS

Eighteen DON patients (29 eyes) who completed high-dose IVMP and 16 healthy individuals (32 eyes) were enrolled in this study. Optical coherence tomography angiography (OCTA) image analysis and comprehensive ophthalmic examinations were performed, including the SLR macular whole-image VD (SLR-mwiVD) and DLR-mwiVD, best-corrected visual acuity (BCVA), the mean deviation of visual field (VF-MD), pattern standard deviation of visual field (VF-PSD) and the other parameters.

RESULTS

The SLR-mwiVD (41.39 ± 4.71 vs. 48.13 ± 3.68, p < 0.001) and DLR-mwiVD (40.77 ± 5.85 vs. 49.14 ± 7.02, p < 0.001) were decreased in DON compared to control eyes. After IVMP, visual function parameters were improved, and SLR-mwiVD (49.41 ± 3.18, p < 0.001) and DLR-mwiVD (50.41 ± 4.04, p < 0.001) were increased in the DON group compared to pretreatment. The increased SLR-mwiVD and DLR-mwiVD were significantly correlated with improvements in BCVA (Log MAR: from 0.62 ± 0.49 to -0.01 ± 0.03, p < 0.001), VF-MD (from - 6.89 ± 2.89 dB to - 1.75 ± 1.29 dB, p < 0.001) and VF-PSD (from 4.38 ± 2.52 dB to 2.32 ± 1.64 dB, p < 0.001).

CONCLUSION

The increase in macular VD was significantly correlated with the improvement in visual function in DON after IVMP. Macular VD changes on OCTA may be a useful indicator for the response in DON after IVMP.

OCT and OCTA in dysthyroid optic neuropathy: a systematic review and meta-analysis

PURPOSE

To explore the current research about the role of optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) in dysthyroid optic neuropathy (DON).

METHODS

Studies in the literature that focused on OCT, OCTA and DON were retrieved by searching PubMed, EMBASE, Cochrane databases and Clinical Trial before 20 June 2023. The methodological quality was assessed using the Newcastle-Ottawa scale. The quantitative calculation was performed using Review Manager V.5.3.

RESULTS

Twelve studies met the eligibility criteria and were included. DON group presented lower macular ganglion cell complex in the overall, superior and inferior hemifields compared with the non-DON group. Furthermore, the ganglion cell layer and inner plexiform layer in DON group was thinner in contrast to the non-DON group. The optic nerve head vessel density was lower in the DON group than that in the non-DON group. A reduction of radial peripapillary capillary vessel density could be seen in the DON group than the non-DON group in overall, inside disc, peripapillary, superior-hemifield, temporal and nasal. Besides, the macular superficial retinal capillary layer of non-DON and DON is lower than the healthy control group.

CONCLUSIONS

This study supported the potential value of OCT and OCTA metrics as novel biomarkers of DON. Ophthalmologists should comprehensively consider the retinal structure and microvasculature in dealing with DON.

ETHICS AND DISSEMINATION

This systematic review included data from published literature and was exempt from ethics approval. Results would be disseminated through peer-reviewed publication and presented at academic conferences engaging clinicians.

PROSPERO REGISTRATION NUMBER

CRD42023414907.

Acute Optic Neuritis: An Update on Approach and Management

This review discusses the physical examination and diagnostic tests necessary to diagnose optic neuritis (ON) and provides an update on the approach and management of acute ON. A comprehensive search of the PubMed database was conducted, limited to English-language journals and recent publications. A total of 160 articles were initially screened by title, of which 73 articles were included in the narrative synthesis. ON is an inflammation of the optic nerve that can be caused by different systemic and neurological disorders. It is commonly presented as a subacute unilateral painful vision loss, and based on its clinical manifestation, it can be classified as typical or atypical. Atypical ON is bilateral with visual acuity of worse than 20/200 or has an atypical demographic presentation for demyelination, such as a non-Caucasian male with optic disc swelling, for which neuromyelitis optica spectrum disorder (NMOSD), myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD), or other etiologies should be considered. Steroids and immunosuppressants are the main treatment options for ON, and timely treatment initiation is critical to preventing irreversible vision loss, especially in atypical cases.