Retinal nerve fiber layer and ganglion cell complex thickness as a diagnostic tool in early stage dysthyroid optic neuropathy

Purpose To compare the diagnostic accuracy of peripapillary retinal nerve fiber layer with macular ganglion cell complex thickness as an auxiliary tool for the early diagnosis of dysthyroid optic neuropathy and help assess the effectiveness of the treatment. Methods In this retrospective case–control study, a total of 58 thyroid-associated opthalmopathy patients and 58 healthy participants were enrolled in the study. Thyroid-associated opthalmopathy patients were divided according to the European Group Graves’ Orbitopathy severity classification. The thicknesses of peripapillary nerve fiber layer and macular ganglion cell complex were measured using optical coherence tomography and their correlation with the severity of the disease as well as the effect of the treatment was investigated. Results No statistically significant differences were found between the mild thyroid-associated opthalmopathy group and the control group in both peripapillary nerve fiber layer and macular ganglion cell complex thickness. In the moderate-to-severe thyroid-associated opthalmopathy group, however, Temporal and Nasal peripapillary nerve fiber layer thicknesses were lower compared to the control group ( p = 0.041, p = 0.012), whereas in the sight-threatening thyroid-associated opthalmopathy group Temporal Inferior, Nasal Superior, and mean (G) peripapillary nerve fiber layer thicknesses were larger ( p = 0.000, p = 0.004, p = 0.000). No significant differences were observed in the macular ganglion cell complex thickness among the different severity groups and the control groups ( p > 0.05). After treatment, the mean peripapillary nerve fiber layer thickness decreased whereas mean macular ganglion cell complex thickness showed no significant change in the sight-threatening group. A correlation was established between exophthalmos, best corrected visual acuity, clinical activity score, disease course, and the mean peripapillary nerve fiber layer thickness. The area under curve analysis indicated that mean peripapillary nerve fiber layer thickness can be used as a powerful diagnostic tool in early stage dysthyroid optic neuropathy in thyroid-associated opthalmopathy patients. Conclusion Our study indicates that peripapillary nerve fiber layer act as an auxiliary tool for the early diagnosis of dysthyroid optic neuropathy and helps assess the effectiveness of the treatment.

Therapeutic difference between orbital decompression and glucocorticoids administration as the first-line treatment for dysthyroid optic neuropathy: a systematic review

To assess all available data to compare the efficacy of glucocorticoids treatment and orbital decompression for dysthyroid optic neuropathy (DON). PubMed, EMBASE, the Cochrane Library databases as well as other sources were searched by two independent reviewers followed by extensive hand-searching for the identification of relevant studies. The primary outcomes were the improvement in visual acuity and responder rate. Secondary outcomes were the proptosis reduction, change in diplopia, and clinical activity score (CAS). One randomized controlled trial, three retrospective case series and one prospective case series met the inclusion criteria. They were divided into intravenous high-dose glucocorticoids (ivGC) group and orbital decompression (OD) group. Both groups demonstrated improvement in visual acuity. In addition, the proportion of patients with improved vision in OD group was higher than that in ivGC group (P<0.001). Post-treatment proptosis reduction was also reported in both groups. Overall, weighted mean in proptosis reduction estimated at 1.64 and 5.45 mm in patients treated with ivGC and OD respectively. This study also presented results regarding pre-existing and new-onset diplopia. Apart from diplopia, a wide variety of minor and major complications were noted in 5 included studies. The most common complication in ivGC group and OD group was Cushing’s syndrome and epistaxis respectively. The present systematic review shows that both glucocorticoids treatment and OD are effective in treating DON and OD may work better in improving visual acuity and reducing proptosis. However, high-quality, large-sample, controlled studies need to be performed in the future.

Impact of additional intravenous methylprednisolone pulse therapy on the quality of life in patients with dysthyroid optic neuropathy

Introduction. Dysthyroid optic neuropathy (DON) is a severe complication of Graves’ orbitopathy (GO). Treatment of DON should involve immediate administration of intravenous methylprednisolone (ivMP) in very high doses. It is recommended to include additional 12 pulses of ivMP according to a weekly schedule as a further step of the treatment process. The purpose of this study was to evaluate the influence of a 12-week ivMP treatment on the quality of life (QoL) in DON patients. Material and Methods. A retrospective study was conducted on 6 patients (the tests involved 8 individual eyes) with DON and treated with ivMP in very high doses, followed by orbital decompression in one patient. All patients were qualified for additional treatment with ivMP in a 12-week protocol and completed the Polish version of the GOQoL questionnaire before and after the therapy. Visual acuity (VA) and diplopia were examined prior to the administration of ivMP pulses for DON, as well as before and after the additional ivMP treatment. Results. A minimal clinically important difference in QoL was observed in four patients at the end of the additional ivMP therapy. A significant increase in VA was observed following additional pulses of ivMP compared to the evaluation at the time of the DON diagnosis (p=0.04). Conclusions. Applying additional 12 pulses of ivMP following DON therapy may impact QoL. Performing QoL assessment throughout the entire therapy in patients with DON is particularly important in the clinical practice. Final evaluation of QoL should be performed after completing the entire therapeutic process, which involves surgical treatment to correct diplopia.

A pathological indicator for dysthyroid optic neuropathy: tritan color vision deficiency

Purpose To investigate the sensitivity of the color vision test by Arden in patients with dysthyroid optic neuropathy (DON) to improve diagnosis. Methods In this observational, retrospective study, we included the medical records of 92 eyes (48 patients) with diagnosis of DON between 2008 and 2019 in order to evaluate the full spectrum of findings from the color vision test by Arden, and to determine potential importance of this test. Thirty-five patients were female, and 13 patients were male. The mean age was 58.0 years (range: 34–79) at the time of the DON diagnosis. Results Forty-one eyes displayed relatively good BCVA with ≤ 0.2 LogMAR. We found a protan value exceeding the threshold of ≥ 8% in 57 eyes (30 patients) at the time of the diagnosis. The sensitivity of protan was 61.9% (95% CI 51.2–71.8%), while that of tritan was a striking 98.9% (95% CI 94.1–99.9%). We discovered one pathological sign, tritan deficiency (based on a threshold of ≥ 8%) consistently in all eyes but one at the time of the diagnosis, regardless of the visual field defects or any changes in best-corrected visual acuity (BCVA). Conclusion We found blue-yellow (tritan) deficiency, to be a sensitive and reliable indicator of dysthyroid optic neuropathy. We conclude that, in cases with suspected DON, a color vision test that can detect tritan deficiency is an essential tool for the adequate assessment, diagnosis, and treatment of DON.

Combination Model of Thyrotrophin Receptor Antibody and Volumetric Orbital Apex Crowding Index as an Indicator of Dysthyroid Optic Neuropathy

Background. Dysthyroid optic neuropathy (DON) is one of the most serious vision-threatening complications of thyroid eye disease (TED); however, accurate and established diagnostic tools for DON are yet lacking. The present study was aimed at identifying new diagnostic factors for the accurate diagnosis of DON. Methods. This retrospective cross-sectional study included 25 TED patients (50 eyes) with enlarged extraocular muscles, no previous anti-inflammatory therapy, and the absence of other vision-affecting diseases between May 2017 and August 2019. Baseline data, such as gender, age, ophthalmological history, thyroid disease and management, TED history including clinical features, management, and long-term results, ophthalmological examinations, serology examinations, and single-photon emission computed tomography/computed tomography (SPECT/CT) results, were extracted. The diagnostic criteria were as follows: (1) best-corrected visual acuity (BCVA) loss coexisting with either of the following—increased latency or reduction of amplitude on visual evoked potential (VEP), impaired color vision, visual field defects, contrast sensitivity impairment, and optic disk swelling—and (2) Barret t ’ s index ≥ 60 % in CT. Univariate and multivariate logistic regression analyses assessed the differences in age, gender, eyes, medical history, clinical activity, thyroid hormone and antibodies, uptake ratio (UR) of extraocular muscles in SPECT/CT, and volumetric orbital apex crowding index (VACI) using the generalized estimation equation. Consequently, the receiver operating characteristic curve (ROC) of the significant factors was constructed. Results. Univariate analysis revealed significant differences in the clinical activity, free triiodothyronine (FT3), free thyroxine (FT4), thyrotrophin receptor antibody (TRAb) levels, the UR of superior and medial rectus, and VACI between DON and TED (without DON) groups. Multivariate regression analysis revealed that TRAb and VACI were significantly different. ROC analysis showed that the univariate models of TRAb or VACI and the multivariate model were effective indicators of DON, while the multivariate model had the highest area under the ROC curve. Conclusion. A combination of TRAb and VACI is an effective indicator for DON.