Anterior Scleral Thickness and Anterior Segment Biometrics Measured with Swept Source Ocular Coherence Tomography in High Myopic Eyes with and without Glaucoma: A Comparative Study.

Background: To assess the anterior scleral thickness (AST), Schlemm's canal diameter (SCD), trabecular meshwork diameter (TMD) and conjunctiva tenon capsule thickness (CTT) in high myopic (HM) subjects and HM subjects with glaucoma (HMG) compared to control eyes. Methods: One hundred and twenty eyes were included, and AST at 0, 1, 2 and 3 mm from the scleral spur, SCD, TMD and CTT were measured. Results: Mean age was 64.2 ± 11.0 years, and the temporal SCD and temporal TMD were significantly longer in the HMG subjects compared to the controls (380.0 ± 62 µm vs. 316.7 ± 72 µm, p = 0.001) and (637.6 ± 113 µm vs. 512.1 ± 97 µm, p = 0.000), respectively. There were no significant differences between the HM and HMG subjects in SCD and TMD (all p > 0.025). Compared to the HM subjects, the temporal AST0 (432.5 ± 79 µm vs. 532.8 ± 99 µm, p = 0.000), temporal AST1 (383.9 ± 64 µm vs. 460.5 ± 80 µm, p = 0.000), temporal AST2 (404.0 ± 68 µm vs. 464.0 ± 88 µm, p = 0.006) and temporal AST3 (403.0 ± 80 µm vs. 458.1 ± 91 µm, p = 0.014) were significantly thinner in the HMG group. No differences were found between the CTT in the three groups (all p > 0.025). Conclusions: Our data indicate a thinner AST in HMG subjects and no differences in SCD and TMD between HM and HMG subjects.

Atrophic, Tractional, and Neovascular Grading System in a Dome-Shaped Macula and Ridge-Shaped Macula Highly Myopic Cohort.

INTRODUCTION: The aim of this study was to analyze the atrophic, tractional, and neovascular (ATN) components grading in highly myopic patients with dome-shaped macula (DSM) and ridge-shaped macula (RSM). METHODS: This was a cross-sectional, noninterventional study. 57 eyes of 38 different patients were included. They were classified as DSM or RSM based on the number of radial scans that showed an inward protrusion ≥50 µm in the swept-source optical coherence tomography (SS-OCT) (12 = DSM; <12 = RSM). All patients underwent a complete ophthalmological examination in addition to SS-OCT. They were graded using the ATN system for myopic maculopathy by 2 masked retina specialists that assessed the atrophic (A), tractional (T), and neovascular (N) components in order to analyze the differences between the groups. As complementary measurements, age, axial length, and best-corrected visual acuity were collected. Height and orientation of the macular bulge and the presence of Bruch's membrane defects, scleral perforating vessels, and staphyloma were recorded. RESULTS: Out of total 57 eyes, 13 eyes (22.8%) were classified as DSM. Regarding the atrophic component (A), there were statistically significant differences between groups, with DSM group showing a greater stage of atrophy (predominantly stage A3 in 69.2% of the sample) compared to the RSM group (predominantly stage A2 in 61.3% of the sample) (p < 0.05). For the T and N components, there were no significant differences between groups. The presence of Bruch's membrane defects was more frequently seen in DSM (p < 0.05). CONCLUSIONS: DSM group showed more Bruch's membrane defects and a greater stage of the atrophy component, based on the ATN grading system, compared with RSM group. As Bruch's membrane may have biomechanical properties in terms of strength, the defects found around the macula, added to the major atrophic component, may be a cause of a local relaxation that induce a central bulge forming the dome.

Pathologic myopia and severe pathologic myopia: correlation with axial length.

PURPOSE: This study had three aims: (1) correlate axial length (AL), age and best-corrected visual acuity in high myopic patients scored on the ATN grading system; (2) determine AL cut-off values to distinguish between pathologic myopia (PM) and severe PM; and (3) identify clinical differences between PM and severe PM. METHODS: This is a cross-sectional, non-interventional study. All patients underwent complete ophthalmologic examination, ATN grading and multimodal imaging (colour fundus photography, swept-source OCT, fundus autofluorescence, OCT angiography and fluorescein angiography). RESULTS: Six hundred forty-four eyes from 345 high myopic patients were included. The eyes were graded on the ATN system and classified as PM (≥ A2) or severe PM (≥ A3, ≥ T3 and/or N2). Significant between-group (PM vs. severe PM) differences (p < 0.05) were observed on the individual ATN components (atrophic [A], tractional [T] and neovascular [N]), age, BCVA and AL. AL was also linearly correlated with the A, T and N components (r = 0.53, p < 0.01; r = 0.24, p < 0.01; r = 0.20, p < 0.01; respectively). ROC curve analysis showed the optimal AL cut-off value to distinguish between PM at 28 mm (AUC ROC curve: 0.813, specificity: 75%, sensitivity: 75%) and severe PM at 29.50 mm (AUC ROC curve: 0.760, specificity: 75%, sensitivity: 70%). CONCLUSION: AL is the main variable associated with myopic maculopathy. Due to the clinical differences found between PM and severe PM, there is need to create an objective cut-off point to distinguish these two different entities being the optimal cut-off points for AL 28 mm and 29.5 mm, respectively. These objective AL cut-off values should be taken into account for determining a correct follow-up, ophthalmic management and treatment.

Dome-Shaped Macula versus Ridge-Shaped Macula Eyes in High Myopia Based on the 12-line Radial Optical Coherence Tomography Scan Pattern. Differences in Clinical Features.

PURPOSE: To study clinical features in patients with ridge-shaped macula (RSM) compared with those with dome-shaped macula (DSM) having been previously classified by the number of swept-source optical coherence tomography (SS-OCT) radial scans affected. METHODS: Retrospective observational study including 49 highly myopic eyes from 31 patients who underwent SS-OCT. DSM eyes were defined as those that showed a complete round inward convexity in all their axes, presenting an inward convexity ≥50 µm in the 12-line radial OCT scans. Eyes that did not meet this criterion and had at least one flat radial scan were grouped into the RSM group, defined as a macular inward convexity in some meridians across the fovea, whereas the opposite perpendicularly oriented meridians were flat. Age, spherical equivalent, axial length (AL), and best-corrected visual acuity (BCVA) were collected. Height of the bulge, scleral and choroidal thicknesses, Bruch´s membrane defects, and presence of perforating scleral vessels were recorded. RESULTS: Thirty-seven (75.5%) eyes were classified into the RSM group and 12 (24.5%) into the DSM group. Twenty-six (53.0%) eyes showed macular elevation only in the horizontal direction. Mean AL showed statistically significant differences (28.8 ± 2.7 vs. 30.5 ± 1.5 mm in the RMS vs. DSM group, respectively) and the presence of Bruch´s membrane defects was more frequently seen in DSM (p < 0.001). Mean age, spherical equivalent, BCVA, height of the inward convexity, retinal foveal thickness, foveal scleral thickness, subfoveal choroidal thickness, and the presence of perforating scleral vessels did not show significant differences between groups. CONCLUSION: This study shows the reliability of using the 12 equal radial OCT scans as an objective method to define and differentiate DSM versus RSM. Patients with RSM showed differences in AL compared with those with DSM, being longer in DSM, and regarding the presence of Bruch´s membrane defects, being more common in DSM. This may contribute to identifying those patients that, in daily clinical practice, have a higher risk of developing complications due to their myopia.