Morphological analysis and quantitative evaluation of myopic maculopathy by three-dimensional magnetic resonance imaging

Visualized analysis of research on myopic traction maculopathy based on CiteSpace

AIM

To analyze the global scientific output concerning myopic traction maculopathy (MTM) and to summarize the research frontiers and hot topics of MTM related researches.

METHODS

Data were collected for bibliometric and visualization analyses from Web of Science (WOS) Core Collection. Exported records were analyzed for titles, publication years, research institutions, journal names, authors, keywords, and abstracts using CiteSpace software version 6.1.

RESULTS

A total of 839 related studies were analyzed, the publication volume increased annually, with Asia the most active region of MTM research. Optical coherence tomography angiography, optical coherence tomography, macular hole, high myopia, macular buckling were identified as the focus of the current research. Progression, association, classification and shape were identified as the major research frontiers.

CONCLUSION

MTM is a major cause of visual loss in pathological myopic eyes. During the preceding 17y, the number of annual publications in MTM research increased gradually. Studies on the progression nature of MTM, genome-wide association study and proper classification of MTM might still be the frontiers of MTM researches.

Analysis of morphological and quantitative changes in pathological myopia and perioperative changes in posterior scleral reinforcement using three-dimensional magnet resonance imaging

Objective: To compare the morphological and quantitative changes in pathological myopia (PM) and the perioperative changes in posterior scleral reinforcement (PSR) using three-dimensional magnetic resonance images (3D MRI). Methods: A total of 49 patients with high myopia (HM; 98 eyes), 15 with pathological myopia (PM; 19 eyes), and 10 without high myopia (NORM; 20 eyes) were recruited between September 2019 and July 2021. The patients underwent measurements of refractive error and axial length, as well as 3D MRI of the eyeball. Python was used to analyze the 3D MRI images, calculate the vitreous volume, establish a topography of the height of the eyeball posterior surface, and calculate the rate of change in height (H). For the PM group undergoing PSR, changes in vitreous volume and the highest point of the eyeball posterior surface in four quadrants (temporal, subtemporal, nasal, and subnasal) were compared before and after PSR. Results: The vitreous volume was smaller in the NORM group compared to the HM and PM groups (p < 0.01). The PM group had a larger volume than the HM group (p < 0.01). The H for the PM group was higher than that of the NORM and HM groups (p < 0.01). After PSR in the PM group, the total vitreous volume, as well as the volume in the subnasal and supratemporal quadrants, decreased (p < 0.05). Additionally, the highest point of the eyeball's posterior surface was generally shifted to the upper nasal side. Finally, the shape and position of the scleral band after PSR were plotted. Conclusion: 3D MRI is capable of a quantitative description of the eyeball morphology in PM and PSR. It allows for precise calculations of changes in vitreous volume and the H of the posterior surface. It also facilitates a meticulous analysis of the specific details of the scleral band following PSR.

Fully Automated Segmentation of Human Eyeball Using Three-Dimensional U-Net in T2 Magnetic Resonance Imaging

Purpose

To develop and validate a fully automated deep-learning-based tool for segmentation of the human eyeball using a three-dimensional (3D) U-Net, compare its performance to semiautomatic segmentation ground truth and a two-dimensional (2D) U-Net, and analyze age and sex differences in eyeball volume, as well as gaze-dependent volume consistency in normal subjects.

Methods

We retrospectively collected 474 magnetic resonance imaging (MRI) scans, including different gazing scans, from 119 patients. A 10-fold cross-validation was applied to separate the dataset into training, test, and validation sets for both the 3D U-Net and 2D U-Net. Performance accuracy was measured using four quantitative metrics compared to the ground truth, and Bland-Altman plot analysis was conducted. Age and sex differences in eyeball volume and variability in eyeball volume differences across gazing directions were analyzed.

Results

The 3D U-Net outperformed the 2D U-Net with mean accuracy scores >0.95, showing acceptable agreement in the Bland-Altman plot analysis despite a tendency for slight overestimation (mean difference = -0.172 cm³). Significant sex differences and age effects on eyeball volume were observed for both methods (P < 0.05). No significant volume differences were found between the segmentation methods or within each method for the different gazing directions. Significant differences in performance accuracy were identified among the five gazing directions, with the upward direction showing a notably lower performance.

Conclusions

Our study demonstrated the effectiveness of 3D U-Net human eyeball volume segmentation using T2-weighted MRI. The robustness and reliability of 3D U-Net across diverse populations and gaze directions support enhanced ophthalmic diagnosis and treatment strategies.

Translational Relevance

Our findings demonstrate the feasibility of using the proposed 3D U-Net model for the automatic segmentation of the human eyeball, with potential applications in various ophthalmic research fields that require the analysis of 3D geometric eye globe shapes or eye movement detection.

LONG-TERM EVOLUTION OF MYOPIC RETINOSCHISIS WITH A DOME-SHAPED MACULA AND PREDICTORS OF PROGRESSION AND VISUAL PROGNOSIS

PURPOSE

To study the long-term natural course of myopic retinoschisis (MRS) with a dome-shaped macula (DSM) and to identify the factors affecting its development and visual prognosis.

METHODS

In this retrospective case series study, we followed 25 MRS eyes with a DSM and 68 MRS eyes without a DSM for at least two years and observed changes in optical coherence tomography morphologic features and best-corrected visual acuity.

RESULTS

During the mean follow-up of 48.3 ± 13.24 months, the difference in the rate of MRS progression between the DSM and non-DSM groups was not significant ( P = 0.7462). In the DSM group, the patients whose MRS progressed were older and had a higher refractive error than those whose MRS was stable or improved ( P = 0.0301 and 0.0166, respectively). The patients whose DSM was located in the central fovea had a significantly higher progression rate than those whose DSM was located in the parafovea ( P = 0.0421). For all DSM eyes, BCVA did not decrease significantly in eyes with extrafoveal retinoschisis ( P = 0.2500), patients whose best-corrected visual acuity decreased more than two lines had a greater central foveal thickness initially than those whose best-corrected visual acuity decreased less than two lines during the follow-up period ( P = 0.0478).

CONCLUSION

A DSM did not delay the progression of MRS. The development of MRS in DSM eyes was associated with age, myopic degree, and DSM location. A higher schisis cavity predicted visual deterioration, and a DSM protected visual function in extrafoveal MRS eyes during the follow-up period.

Altered whole-brain gray matter volume in form-deprivation myopia rats based on voxel-based morphometry: A pilot study

Background

Myopia is one of the major public health problems worldwide. However, the exact pathogenesis of myopia remains unclear. This study proposes using voxel-based morphometry (VBM) to investigate potential morphological alterations in gray matter volume (GMV) in form-deprivation myopia (FDM) rats.

Methods

A total of 14 rats with FDM (FDM group) and 15 normal controls (NC group) underwent high-resolution magnetic resonance imaging (MRI). Original T2 brain images were analyzed using VBM method to identify group differences in GMV. Following MRI examination, all rats were perfused with formalin, and immunohistochemical analysis of NeuN and c-fos levels was performed on the visual cortex.

Results

In the FDM group, compared to the NC group, significantly decreased GMVs were found in the left primary visual cortex, left secondary visual cortex, right subiculum, right cornu ammonis, right entorhinal cortex and bilateral molecular layer of the cerebellum. Additionally, significantly increased GMVs were found in the right dentate gyrus, parasubiculum, and olfactory bulb.

Conclusions

Our study revealed a positive correlation between mGMV and the expression of c-fos and NeuN in the visual cortex, suggesting a molecular relationship between cortical activity and macroscopic measurement of visual cortex structural plasticity. These findings may help elucidate the potential neural pathogenesis of FDM and its relationship to changes in specific brain regions.

CHARACTERISTICS AND MANAGEMENT OF MYOPIC TRACTION MACULOPATHY IN MYOPIC EYES WITH AXIAL LENGTH LESS THAN 26.5 mm

To explore the characteristics and underlying mechanisms of myopic traction maculopathy (MTM) with axial length less than 26.5 mm and to assess the effectiveness of macular buckling for the treatment of MTM.

Progression Patterns of Myopic Traction Maculopathy in the Fellow Eye After Pars Plana Vitrectomy of the Primary Eye

Purpose

This retrospective study investigated the patterns and risk factors of progression of myopic traction maculopathy (MTM) of fellow eyes after pars plana vitrectomy (PPV) of primary eyes.

Methods

The study population comprised 153 patients with MTM in both myopic eyes who sequentially underwent PPV (2006–2021). Observation periods were from PPV of the primary eye (baseline) to PPV of the fellow (end). MTM was graded based on optical coherence tomography (OCT) images and the ATN (atrophy [A], traction [T], and neovascularization [N]) system. An increase in T grade was considered MTM progression.

Results

MTM progressed in 43.8% of fellow eyes during 34.57 ± 34.08 months. The progression of fellow eyes correlated with T grade of primary eyes (P < 0.001). Risk factors for the progression of MTM in fellow eyes were primary eyes in T4–T5, age at baseline <60 years, and fellow eyes with partial posterior vitreous detachment (PVD; P < 0.001, P = 0.042, and P = 0.002, respectively). Fellow eyes in T1/T2 at baseline progressed faster compared with those in T0 (P < 0.001); the annual rate of progression to T3–T5 of the T0 (T1–T2) groups was 9.98% (24.59%).

Conclusions

Risk factors for the progression of MTM in fellow eyes included PPV when relatively young, primary eye at high T grade, and partial PVD of the fellow eye. Personalized follow-up for fellow eyes should be based on the severity of MTM of both eyes.

Natural course of myopic traction maculopathy and factors influencing progression and visual acuity

Background

To describe the natural course of myopic traction maculopathy (MTM) and determine predictive factors for its progression and visual prognosis.

Methods

This retrospective observational study included 113 MTM patients (113 eyes). Best-corrected visual acuity (BCVA) measurements and optical coherence tomography findings were recorded.

Results

Over a mean follow-up of 38.2 ± 11.1 months, 49 of 113 eyes (43.4 %) progressed. The progression rate of outer schisis prominently located in the fovea or posterior staphyloma was significantly higher than that of outer schisis prominently located in paravascular areas (P = 0.0011). MTM with partial posterior vitreous detachment during the follow-up progressed more rapidly than MTM without (P = 0.0447). Patients with older age (> 65 years), without domed-shaped macula and with defects in the ellipsoid zone (EZ) had worse BCVA at the last visit (P = 0.0416, P = 0.0494and P = 0.0130). Multiple linear regression analysis showed that BCVA and defects in the EZ at baseline were significantly associated with the final BCVA (P < 0.0001 and P = < 0.0001, respectively).

Conclusions

MTM has a high possibility for progression. Outer schisis located predominantly in the fovea or posterior staphyloma or with partial posterior vitreous detachment exhibits rapid progression. The integrity of the EZ is related to visual prognosis.

CHANGES IN THE CHOROIDAL THICKNESS AFTER MACULAR BUCKLING IN HIGHLY MYOPIC EYES

PURPOSE

To assess changes in the choroidal thickness (CT) after macular buckling in eyes with high myopia.

METHODS

Highly myopic eyes that underwent macular buckling surgery were retrospectively analyzed. Data of swept-source optical coherence tomography scanning at baseline and at 1, 3, 6, 12, and 18 months after macular buckling were collected. Subfoveal CT and CT at 750 µm superior, inferior, nasal, and temporal to the fovea were measured. The total choroidal area, vascular area, and stromal area were measured by the binarization method. The choroidal vascularity index was calculated by dividing the vascular area by the total choroidal area.

RESULTS

Forty-one eyes were included in the final analysis. The subfoveal CT increased from 49.85 ± 31.23 µm preoperatively to 75.74 ± 37.89 µm 1 month after macular buckling (P < 0.001), then decreased over time, coinciding with the trends of parafoveal CT, total choroidal area, vascular area, and stromal area. The subfoveal CT was restored to the preoperative level six months postoperatively (P = 0.202) and remained stable until the end of follow-up. The choroidal vascularity index increased at 1 and 3 months postoperatively (P = 0.001 and 0.005, respectively).

CONCLUSION

The choroid thickened in the early postoperative period. The compression force of the buckle implant might disturb microcirculatory drainage and contribute to the thickening. The choroid spontaneously recovered to the preoperative level over time.

Differences in network centrality between high and low myopia: a voxel-level degree centrality study

BACKGROUND

Previous studies have linked high myopia (HM) to brain activity, and the difference between HM and low myopia (LM) can be assessed.

PURPOSE

To study the differences in functional networks of brain activity between HM and LM by the voxel-level degree centrality (DC) method.

MATERIAL AND METHODS

Twenty-eight patients with HM (10 men, 18 women), 18 patients with LM (4 men, 14 women), and 59 healthy controls (27 men, 32 women) were enrolled in this study. The voxel-level DC method was used to assess spontaneous brain activity. Correlation analysis was used to explore the change of average DC value in different brain regions, in order to analyze differences in brain activity between HM and LM.

RESULTS

DC values of the right cerebellum anterior lobe/brainstem, right parahippocampal gyrus, and left caudate in HM patients were significantly higher than those in LM patients (P < 0.05). In contrast, DC values of the left medial frontal gyrus, right inferior frontal gyrus, left middle frontal gyrus, and left inferior parietal lobule were significantly lower in patients with HM (P < 0.05). However, there was no correlation between behavior and average DC values in different brain regions (P < 0.05).

CONCLUSION

Different changes in brain regions between HM and LM may indicate differences in neural mechanisms between HM and LM. DC values could be useful as biomarkers for differences in brain activity between patients with HM and LM. This study provides a new method to assess differences in functional networks of brain activity between patients with HM and LM.