Evaluation ofIn VivoHuman Retinal Morphology and Function in Myopes

Biofeedback Training after Successful Inverted Internal Limiting Membrane (ILM)-Flap Technique for High Myopic Macular Hole

BACKGROUND

Microperimetric biofeedback training improved visual acuity and fixation stability in patients who previously underwent macular surgery. We aimed to compare the functional results of biofeedback training with the standard of care in patients who underwent successful inverted Internal Limiting Membrane (ILM)-flap technique for high myopic macular holes (hMMH).

METHODS

This was a retrospective, comparative, cohort study. Patients with hMMH after surgical hole closure underwent microperimetric biofeedback using structured light stimulus plus acoustic tone (n = 12; Biofeedback) or standard of care with scheduled visits (n = 11; Control). Best-corrected visual acuity, retinal sensitivity at central 12° (RS) and 4° (CRS) with a mean deviation at central 12° (MD), and fixation stability as bivariate contour ellipse area (BCEA 68%, 95%, and 99%) were assessed at baseline and month 1, 3, 6, and 12. The Mann-Whitney test was used to test the difference between the groups.

RESULTS

Baseline functional parameters were not significantly different among the groups. BCVA significantly improved in each group (Biofeedback, p = 0.002; Control, p ≤ 0.02) at all follow-up visits. CRS significantly improved at 6 (p = 0.03) and 12 (p = 0.01) months in the Biofeedback group and at month 12 (p = 0.01) in the Control group. RS (p = 0.001) and MD (p = 0.005) improved at the last follow-up only in the trained group. After training, BCEA 68% and 95% significantly improved (6 and 12 months, p < 0.05). The Biofeedback group had better results in RS (p ≤ 0.02), CRS (p ≤ 0.02), and BCEA 68%, 95%, and 99% (p ≤ 0.01) compared to the Control at all follow-ups. BCVA and MD were better in the Biofeedback group at month 3 (p = 0.01), and month 3 (p = 0.01) and 12 (p = 0.003), respectively.

CONCLUSIONS

Microperimetric biofeedback can increase retinal sensitivity and stabilize fixation better than the standard care over months after a successful inverted ILM-flap for hMMH.

Analysis of Microcirculation Changes in the Macular Area and Para-Optic Disk Region After Implantable Collamer Lens Implantation in Patients With High Myopia

Myopia has become an important public health problem to be solved urgently. Posterior chamber phakic implantable Collamer lens (ICL) implantation is one of the latest and safest products for myopia correction worldwide. This prospective cross-sectional case series aimed to observe changes in the macular retinal thickness, retinal nerve fiber layer (RNFL) thickness of para-optic disk region, and blood flow density after posterior ICL implantation in patients with high myopia using optical coherence tomography angiography (OCTA). A total of 67 eyes of 67 patients with high myopia, who underwent ICL implantation at The Affiliated Eye Hospital of Nanjing Medical University from January 2020 and December 2020, were included. The spherical equivalent (SE) of the operative eyes was &gt;−6.00 D. The changes in vision, intraocular pressure (IOP), SE, and vault were observed pre-operatively, and follow-up were performed 1 week, 1 month, and 3 months. OCTA was used to observe the changes in the CRT, retinal thickness of paracentral fovea, FAZ, superficial and deep retinal blood flow density in the macular area, RNFL thickness of para-optic disk region, and blood flow density before and after ICL implantation. The uncorrected distance visual acuity (UDVA) and best corrected distance visual acuity (CDVA) of the patients post-operation were significantly improved (P &lt; 0.001). The IOP increased in comparison with other time points at 1 week post-operation (P &lt; 0.05). There were no significant changes in CRT post-operation. The retinal thickness in the upper, lower, nasal, and temporal quadrants of the paracentral fovea increased significantly at 1 month and 3 months post-operation (P &lt; 0.05). The FAZ area at all postoperative time points were decreased (P &lt; 0.001). At 3 months post-operation, the blood flow density of the superficial and deep retinal layers in the upper, lower, and nasal macular area were significantly reduced (P &lt; 0.05). At 1 month post-operation, the RNFL thickness in the temporal para-optic disk region and blood flow density were significantly reduced (P = 0.001 and P &lt; 0.05, respectively). ICL implantation for highly myopic eyes led to an increase of the retinal thickness in the upper, lower, nasal, and temporal regions of the paracentral fovea; reduction of RNFL thickness in the temporal area of para-optic disk; decrease in FAZ area; and decrease in the blood flow density of some deep and superficial retinal layers as well as that of the temporal para-optic disk region.

The Relationship Between Choroidal and Photoreceptor Layer Thickness With Visual Acuity in Highly Myopic Eyes

Purpose

The aim of this study was to evaluate the choroidal and photoreceptor thickness in highly myopic eyes and its correlation with visual acuity.

Methods

This is a cross-sectional, observational study involving 57 eyes of 57 highly myopic subjects [spherical equivalent ≥ –6 diopters (D) or axial length ≥ 26 mm] seen in a tertiary institutional center. Eyes with any clinical evidence of maculopathy or amblyopia were excluded. All subjects underwent a refraction assessment, visual acuity, axial length measurement using the IOL Master, and full ocular assessment. Eyes were imaged using Spectralis Optical Coherence Tomography by one experienced operator. Two independent investigators manually measured subfoveal choroidal thickness (SFCT) and foveal photoreceptor thickness (FPT).

Results

The mean SFCT was 195.88 ± 87.63 μm (range: 32–373) and mean FPT was 96.68 ± 11.23 μm (range: 67–100), after correction for ocular magnification. The best corrected visual acuity (BCVA) in LogMAR was negatively correlated with SFCT (r = –0.510, p = 0.001) and FPT (r = –0.397, p = 0.002) and positively correlated with age (r = 0.418, p = 0.001) and axial length (r = 0.551, p = 0.001). Multiple linear regression analysis showed that age, axial length, and corrected FPT were significant risk factors for poorer BCVA (p = 0.021, &lt; 0.001, and 0.02, respectively).

Conclusion

FPT, age, and axial length are significant moderate predictive factors for poorer visual acuity in highly myopic eyes without myopic maculopathy. Thinner SFCT does not translate into poorer vision.

Design and Pilot data of the high myopia registration study: Shanghai Child and Adolescent Large-scale Eye Study (SCALE-HM)

PURPOSE

To describe the methodology and pilot data of the Shanghai Child and Adolescent Large-scale Eye Study (SCALE-HM).

METHODS

This is a population-based, prospective, examiner-masked study with annual follow-up. Patients are 4- to 18-year-olds with high myopia. The participants will fill out questionnaires and then undergo visual acuity, axial length (AL), intraocular pressure, ophthalmologist assessment, microperimetry, cycloplegic refraction, Pentacam, wavefront aberration, fundus, blood and saliva examinations. To describe the pilot data, intergroup differences were assessed with t-tests or analysis of variance and a logistic regression model was used to determine the independent factors associated with peripapillary atrophy (PPA).

RESULTS

Overall, 134 eyes of 79 participants met the pilot study recruitment criteria. The mean AL and spherical equivalent were 26.91 ± 1.07 mm and -9.40 ± 1.77 D, respectively. Peripapillary atrophy (PPA) (N = 112) and tessellated fundus (N = 67) were the most common fundus changes. The mean AL was significantly longer in PPA (27.08 ± 0.93 mm) than in non-PPA eyes (26.06 ± 1.31 mm; p < 0.001). Axial length (AL) (p = 0.041) was the only independent factor associated with PPA. Axial length (AL) was significantly longer in eyes with diffuse chorioretinal atrophy (N = 11; 28.02 ± 1.31 mm) than without myopic retinal lesions (N = 56; 26.48 ± 0.91 mm, p < 0.001) or with tessellated fundus (N = 67; 27.09 ± 0.97 mm, p = 0.012). The myopic degree was higher in eyes with diffuse chorioretinal atrophy than without myopic retinal lesions (-10.51 ± 2.76 D versus -9.06 ± 1.58 D, p = 0.039).

CONCLUSION

Peripapillary atrophy and tessellated fundus were common in children and adolescents with high myopia. Results from this prospective study will help to understand the mechanisms, development and prognosis of these changes and can guide early myopia screening.

Retinal pigment epithelium melanin distribution estimated by polarisation entropy and its association with retinal sensitivity in patients with high myopia

PURPOSE

To investigate retinal sensitivity of highly myopic eyes without choroidal neovascularisation (CNV) or patchy chorioretinal atrophy (PCA) and investigated its association with anatomical characteristics including melanin distribution at the retinal pigment epithelium (RPE), which was evaluated with polarisation-sensitive optical coherence tomography (PS-OCT).

DESIGN

Retrospective consecutive observational cohort study.

METHODS

We included highly myopic eyes (refractive error ≤-8.0 dioptres or axial length of ≥26.5 mm) from patients at the University of Tokyo Hospital. Retinal sensitivity was measured by microperimetry at 25 sectors within 6 degrees from the fovea. Depolarisation value, which reflected melanin pigmentation, was measured by a clinical prototype of PS-OCT and was parameterised as polarimetric entropy. Retinal sensitivity or entropy at the RPE in high myopia was compared with emmetropic control subjects. The association of retinal sensitivity with age, axial length, entropy, or choroidal thickness was assessed in per-eye and per-sector analysis.

RESULTS

Twenty-three highly myopic eyes (age, 66.6±12.3 years) were included. The average retinal sensitivity was 25.3±3.0 dB, which was significantly decreased compared with the control (p<0.0001). The average entropy at the RPE in the highly myopic eyes was significantly lower than in the control (p<0.0001). Univariate analysis followed by multivariate analysis showed that besides age, axial length or choroidal thickness, RPE entropy was independently associated with retinal sensitivity (β=4.4; 95% CI 0.5 to 8.3; p=0.03).

CONCLUSIONS

Decreased depolarisation at the RPE measured with PS-OCT, which reflected altered melanin pigmentation, was independently associated with reduced retinal sensitivity in patients with early stages of myopic maculopathy without CNV or PCA.

On the mechanics of myopia and its influence on retinal detachment

A mechanics-based mathematical model of retinal detachment due to the geometric changes of the eye associated with the evolution of myopia is developed. This includes deformation of the retina due to biological growth of the retina, as well as elastic deformation imposed on the retina by the myopic change in shape of the much stiffer choroid and sclera. The problem is formulated as a propagating boundary value problem in the calculus of variations, which yields self-consistent governing equations, boundary conditions, and transversality conditions that establish the location of the propagating boundaries that correspond to equilibrium configurations of the detaching ocular system. Axisymmetric conditions are considered, and exact, analytical solutions to the corresponding boundary value problem are obtained for detaching retinas with and without a tear. Based upon application of the model presented herein to the emmetropic retina, a value of the bond energy of the retina to retinal pigment epithelium interface is estimated using material properties found in the literature. Simulations based on the analytical solutions are performed for a detachment in the retina located at either the posterior or superior pole of the eye. The results support the clinical finding of an increased prevalence of retinal detachment in myopic eyes and provide insight into the potential causation for the increased prevalence.

Retinal Morphology and Sensitivity Are Primarily Impaired in Eyes with Neuromyelitis Optica Spectrum Disorder (NMOSD)

BACKGROUND

Previous studies of neuromyelitis optica spectrum disorder (NMOSD) using spectral domain optical coherence tomography (SD-OCT) showed that the outer nuclear layer (ONL) in eyes without a history of optic neuritis (ON) was thinner than that of healthy controls. It remains unclear whether the ONL thinning is caused by a direct attack on the retina by an autoantibody or a retrograde degeneration.

OBJECTIVE

To determine the mechanisms involved in the retinal damage in eyes with NMOSD without ON.

METHODS

SD-OCT was used to determine the thicknesses of the different retinal layers of 21 eyes of 12 NMOSD patients without prior ON and 19 eyes of 10 healthy controls. Eyes with peripapillary retinal nerve fiber layer (RNFL) thinning were excluded to eliminate the confounding effects of retrograde degeneration. Microperimetry was used to determine the central retinal sensitivity. The data of the two groups were compared using generalized estimated equation models to account for inter-eye dependencies.

RESULTS

The ganglion cell plus inner plexiform layer and the inner nuclear layer plus outer plexiform layer thicknesses of the NMOSD eyes were not significantly different from that of the control eyes (P = 0.28, P = 0.78). However, the ONL and average macular thickness (AMT) in the NMOSD eyes were significantly thinner than that of the control eyes (P = 0.022, P = 0.036). The retinal sensitivity in the central 10°, 10° to 2°, and 2° sectors were significantly lower in the NMOSD eyes than in the control eyes (P = 0.013, P = 0.022, P = 0.002).

CONCLUSIONS

The ONL thinning, AMT thinning, and reduced retinal sensitivity in eyes with NMOSD without significant peripapillary RNFL thinning are most likely due to direct retinal pathology.

Influence of macular choroidal thickness on visual function in highly myopic eyes

PURPOSE

To explore the retinal and choroidal thicknesses (RT, CT), as measured using enhanced depth imaging (EDI) optical coherence tomography (OCT, Spectralis) in highly myopic eyes and its relationship with visual function.

MATERIALS AND METHODS

Prospective, case-control, noninterventional clinical study. CT was measured by EDI-OCT in highly myopic eyes (≥6 dpt) without any macular diseases and age-matched control eyes. A complete ophthalmological examination, visual acuity assessment and MP1 microperimetry were obtained.

RESULTS

38 myopic (15 M/23 F, mean age 51 ± 8.9 years) and 21 control eyes (5 M/16 F, mean age 50 ± 5.4 years) were included. The myopic mean refractive error was -13.3 ± 4.9 dpt and axial length 29.2 ± 2.2 mm. The mean best-corrected visual acuity (BCVA) was lower in highly myopic than in control eyes (77.3 ± 9.25 vs. 84.8 ± 0.6 letters, p = 0.0001, respectively) as was the mean retinal sensitivity (MRS; 16.32 ± 2.6 vs. 19.9 ± 0.2 dB, p < 0.0001). While RT was similar between groups (291.5 ± 24.2 vs. 283.6 ± 13.9 µm, p = 0.06, respectively), subfoveal CT was thinner in highly myopic compared to control eyes (114.3 ± 78.5 vs. 272.6 ± 110.2 µm, p < 0.0001). A significant relationship was found between subfoveal CT and MRS (R(2) = 0.22; p = 0.003) and BCVA (R(2) = 0.13; p = 0.027).

CONCLUSIONS

Macular function is reduced in highly myopic eyes without any visible macular diseases compared to controls, and a significant proportion of the macular function variability seems to be related to a reduced CT.