High Myopic Eyes Research Articles

Relationship Between Posterior Vitreous Detachment and Macular Dimensions in Myopic Eyes.

BackgroundPosterior vitreous detachment (PVD) can result in serious pathologic events at the vitreoretinal interface. This study aims to assess the relationship between PVD, macular thickness (MT), and the foveal avascular zone (FAZ) in myopic eyes.MethodsThis retrospective study evaluated 63 myopic subjects’ data who were examined between January 1 and June 30, 2019. The myopes were grouped on a severity scale, namely mild, moderate, high, and very high using their spherical equivalent (SE). The PVD classification was based on OCT images. The status of the PVD and MT were evaluated with the Macular Cube 200×200 images, the FAZ with an OCTA Angioplex, and the dimensions were calculated using a customized algorithm.ResultsThe study population (114 eyes) had a median (range) age was 26.00 (22.00–28.00) years and the females constituted 62.3% of the dataset. In this population, 10 eyes had no PVD in any quadrant, and 73 eyes had incomplete PVD in all four quadrants. The inferior quadrant had the maximum rate of PVD occurrences and the nasal quadrant had the least number of occurrences. High myopic eyes exhibited significantly increased low foveal volume (p = <0.01). The inferior part of the para- and perimacular area showed a significant thinning in very high myopic eyes (p = <0.050). The very high myopic eyes showed a significant alteration of FAZ’s circularity index (p = 0.002).ConclusionIn high and very high myopic eyes, an increasing trend of partial PVD is seen, most commonly in the inferior quadrant. A significant alteration in foveal volume and circularity index of the FAZ is seen in high and very high myopic eyes.

Comparison of Visual Outcomes and Quality of Life in Patients with High Myopic Cataract after Implantation of AT LISA Tri 839MP and LS-313 MF30 Intraocular Lenses.

Purpose To investigate the benefits of multifocal lens in patients with high myopic cataract and compare the clinical effects between AT LISA tri 839MP and MPlus LS-313 MF30 intraocular lenses (IOLs) in high myopic eyes. Methods This retrospective cohort study analyzed 60 eyes with axial length >26 mm in 40 patients. Thirty eyes were implanted with MF30, and the remaining 30 eyes were implanted with 839MP. Postoperative uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (BCDVA), uncorrected intermediate visual acuity (UIVA) and uncorrected near visual acuity (UNVA), defocus curve, modulation transfer function (MTF) curve, Strehl ratio (SR), and complications were compared between the two groups. Results All vision outcomes were significantly improved in both groups (p < 0.05). There was no significant between-group difference in UDVA at 1 and 3 months postoperatively (p > 0.05). However, UIVA and UNVA were significantly better in the 839MP group (p < 0.05). The VF-14 score, especially for near vision quality, was significantly higher in the MF30 group (2.2 ± 0.9 vs. 0.8 ± 0.7; p ≤ 0.001). The SR of both groups significantly increased postoperatively (p < 0.05). All the 3-month MTF curve values (MTF 10 total, MTF 10 internal, MTF 30 total, and MTF 30 internal) were significantly better in the 839MP group (p < 0.05). Meanwhile, all the high-order aberration values (coma, spherical aberration, and trefoil) were significantly greater in the MF30 group (p < 0.05). Conclusion Multifocal IOL implantation achieves good quality of distance, intermediate, and near vision in patients with high myopia, improving their quality of life. Both 839MP and MF30 IOLs can provide good distance vision, but 839MP performs better in near and intermediate vision. However, for some patients with an extra-long optic axis, MF30 may be a good choice because of its wider range of degrees.

Application of Artificial Intelligence and Deep Learning for Choroid Segmentation in Myopia.

PurposeTo investigate the correlation between choroidal thickness and myopia progression using a deep learning method.MethodsTwo data sets, data set A and data set B, comprising of 123 optical coherence tomography (OCT) volumes, were collected to establish the model and verify its clinical utility. The proposed mask region-based convolutional neural network (R-CNN) model, trained with the pretrained weights from the Common Objects in Context database as well as the manually labeled OCT images from data set A, was used to automatically segment the choroid. To verify its clinical utility, the mask R-CNN model was tested with data set B, and the choroidal thickness estimated by the model was also used to explore its relationship with myopia.ResultsCompared with the result of manual segmentation in data set B, the error of the automatic choroidal inner and outer boundary segmentation was 6.72 ± 2.12 and 13.75 ± 7.57 µm, respectively. The mean dice coefficient between the region segmented by automatic and manual methods was 93.87% ± 2.89%. The mean difference in choroidal thickness over the Early Treatment Diabetic Retinopathy Study zone between the two methods was 10.52 µm. Additionally, the choroidal thickness estimated using the proposed model was thinner in high-myopic eyes, and axial length was the most significant predictor.ConclusionsThe mask R-CNN model has excellent performance in choroidal segmentation and quantification. In addition, the choroid of high myopia is significantly thinner than that of nonhigh myopia.Translational RelevanceThis work lays the foundations for mask R-CNN models that could aid in the evaluation of more intricate changes occurring in chorioretinal diseases.

Three-Dimensional Choroidal Vascularity Index in High Myopia Using Swept-Source Optical Coherence Tomography

ABSTRACTPurposeTo characterize the choroidal vasculature in high myopic eyes by three-dimensional choroidal vascularity index (CVI) using swept-source optical coherence tomography (SS-OCT).Subjects and MethodsA cross-sectional observational study of 98 right eyes from 98 consecutive nonpathological myopic patients, including 46 high myopes (HM) and 52 low to moderate myopes (LMM). OCT and OCT angiography covering an area of 6 × 6 mm2 centered on the fovea was conducted with a commercially available SS-OCT device. Three-dimensional CVI was defined as the ratio of choroidal vessel volume (CVV) to total choroidal volume. With the built-in automated quantification software, we assessed choroidal vascular and stromal features: three-dimensional CVI; CVV; choriocapillaris flow density and choroidal stroma volume (CSV) apart from choroidal thickness (CT).ResultsCompared to LMM, there was a significant reduction in three-dimensional CVI, CVV and CSV along with choroidal thinning in HM at both subfoveal and macular regions (all P < .01). The nasal quadrant had both the lowest CVI and the thinnest choroid. The greatest CVI was at the subfovea, while the choroid at the subfovea was thinner than that at the superior, temporal, and inferior quadrants. Multiple linear regression indicated that choroidal characteristics (CVI, CVV, CSV, CT) were mainly negatively correlated with axial length (all P < .01) instead of myopic spherical equivalent (all P > .05).ConclusionsBesides two-dimensional choroidal thinning, we also found the axial length-related reduction of three-dimensional choroidal vessel and stroma components in high myopic eyes without myopic maculopathy. The quadrantal distribution characteristics of three-dimensional CVI indicate the subfovea and the nasal quadrant to be the essential quadrants for monitoring the choroidal vasculature alteration in the progression of myopia. The novel quantitative analyses of the choroidal vasculature by three-dimensional CVI may help to characterize the underlying pathophysiology of nonpathological high myopia.

Choroidal vascularity index in leptochoroid: A comparative analysis between reticular pseudodrusen and high myopia.

To investigate the choroidal vascularity index (CVI) in patients affected by leptochoroid. Three distinct age-matched cohorts were collected: patients with reticular pseudodrusen (RPD) secondary to age-related macular degeneration, patients with high-myopia, and healthy controls. CVI was calculated in the subfoveal 6000 μm diameter area. 54 eyes (54 patients) were included (18 eyes in each cohort). No statistical differences were disclosed in terms of age between controls, RPD patients (p = 0.062), and myopic patients (p = 0.070). Total choroidal area showed a different distribution among the 3 cohorts (p < 0.001), due to the reduction of luminal and stromal choroidal area in both RPD and myopic groups in comparison to controls (p < 0.001). Interestingly, CVI showed a different distribution between the 3 cohorts (p < 0.001). In detail, RPD group showed no changes in CVI in comparison to controls (p = 1.000), whereas the myopic group showed a higher CVI in comparison to both RPD group and controls (p < 0.001 in both analyses). Different changes of the choroidal vascular and stromal components characterize the leptochoroid secondary to RPD eyes and high-myopic eyes. The relative greater impairment of the vascular area in RPD eyes in comparison to myopic eyes could be at the basis of the lower development of RPD in patients with high myopia.

Multimodal Imaging-Based Phenotyping of a Singaporean Hospital-Based Cohort of High Myopia Patients

Purpose: To assess the effect of axial length (AL) on the prevalence of pathologic myopia (PM) and associated myopic features in a Singaporean hospital-based cohort of patient with high myopia (HM).Methods: In total, 923 HM eyes from 495 individuals were recruited from the Myopic and Pathologic Eyes in Singapore (MyoPES) cohort and underwent ocular biometry, fundus photography, fundus autofluorescence, and swept-source optical coherence tomography (SS-OCT). Images were analyzed for the presence of myopic macular degeneration (MMD), myopic choroidal neovascularization (mCNV), myopic traction maculopathy (MTM), peripapillary atrophy (PPA), myopic tilted disc, posterior staphyloma (PS), dome-shaped macula (DSM), vitremacular adhesions (VMA), and the epiretinal membrane (ERM). Eyes were stratified into quartiles based on ALs to determine cut-off values to perform comparisons between shorter-length and longer-length groups. A χ2-test was done to determine the difference in the prevalence of pathologies between groups.Results: Overall, mean AL was 29.2 ± 2.2 mm (range 25.0–36.7 mm). Myopic macular degeneration, PPA, myopic tilted disc, and ERM have AL threshold of ≥27.5 mm, whereas MTM has an AL threshold of ≥29.0 mm. We found that there was a significantly higher prevalence of MMD (88.2 vs. 49.4%; p < 0.001), PPA (98.1 vs. 80.1%; p < 0.001), myopic tilted disc (72.7 vs. 50.2%; p < 0.001), and ERM (81.4 vs. 17.3%; p = 0.003) in eyes with AL ≥ 27.5 mm vs. eyes without AL <27.5 mm. Prevalence of MTM (34.7 vs. 32.1%; p < 0.001), mCNV (17.4 vs. 12.1%; p = 0.03), PS (43.4 vs. 34.7%; p = 0.012), DSM (21.3 vs. 13.2%; p = 0.002), and VMA (5.9 vs. 2.6%; p = 0.014) in eyes with AL ≥ 29.0 mm compared with AL < 29.0 mm.Conclusion: Our study describes the overall prevalence of PM and related pathologies among patients with HM in our hospital-based cohort. Longer eyes even among HM eyes had a significantly higher prevalence of PM-associated pathologies studied. This supports the premise that eyes with longer AL, even among HM eyes may be at greater risk of vision-threatening changes and therefore merit regular follow-up.

A Comparative Study on Accuracy of SRK-T And Haigis Formulas in IOL Power Calculation in Axial Myopes Undergoing Cataract Surgery.

Background and Objective:It has been a significant challenge since the advent of intraocular lens to give the best postoperative visual acuity and prevent refractive surprises due to biometry error. Among myopic eyes, it has been a debate among the various formulas introduced and their efficacy to prevent postoperative refractive surprises. Hence, the need for an accurate formula in high myopic eyes is obligatory.Objectives of the Study:To compare the accuracy of SRK-T and Haigis formulas in IOL power calculation in axial myopic eyes undergoing cataract surgery.Methods:A total of 50 cases with axial length >24 mm were taken up for the study and were examined in detail and error between both formulas were assessed.Results:The mean age of the subjects in the study was 53.50 ± 16.12 years; 27 were males, and 23 were females. The majority of patients had PSC + NS II. Seven out of 50 cases had posterior staphyloma. Most of the patients had average K value in the 44–46-D range. AL of most of the patients (66%) was between 24 and 26 mm. The majority of patients had IOL power >15 D, and 82% (41 eyes) were found to have no post-op complications. Four eyes had severe iritis, and five eyes had striate keratopathy. At the follow-up at 6th week postoperatively, 82% were found to have 6/6–6/9 vision on Snellen's chart. Four eyes had 6/12–6/24 post-op vision, mainly attributed to primary PCO. Five eyes (10%) had <6/24 post op vision at the end of 1 week due to the presence of posterior staphyloma. A higher percentage of eyes in the SRK/T group had a mean error >0.5 D. Upon comparing the mean error between the two groups, P was 0.005; hence, the results are statistically very significant, showing that Haigis formula is better than SRK/T formula in achieving target refraction (−1) in myopic eyes undergoing phacoemulsification.Interpretation and Conclusion:Our study shows that Haigis formula was better than SRK/T formula for achieving the target postoperative refraction in high axial myopes.

Visual outcome after Femtolasik vs. ICL for correction of high myopia

ObjectivesTo compare visual outcomes between femtosecond Lasik and implantable collamer lens (ICL) in patients with high myopia.BackgroundEven though the parameters for optical quality as well as intraocular scattering are valuable for the subsequent satisfaction and postoperative visual performance in myopia, the comparison between patients with Femtolasik (FS-Lasik) and ICL implantation of these parameters is still unclear.Materials and methodsThis study involved 50 high myopic eyes ≥−6.0 D recruited for FS-Lasik (group 1) and another 50 high myopic eyes recruited for ICL (group 2). Both age and sex were matched in the two groups.ResultsVisual acuities (VA) showed significant improvement in FS-Lasik group than ICL group 1 day postoperatively, whereas after 1 week, they had no difference (P > 0.05), but in the third and sixth months postoperatively, there was a statistically significant increase in VA in ICL group than FS-Lasik group. It was observed that there is a stability of VA after FS-Lasik and ICL groups, which indicated that eyes with FS-Lasik group tend to regress by time, whereas in ICL group, the line tends to be more stable. However, both groups showed highly significant improvement in VA (P < 0.001).ConclusionICL implantation is a better first choice especially in young adults who had high myopia and need the near vision. ICL seems to be better than FS-Lasik in the long-lasting correction of vision, and also, it has a better durability.

Macular and submacular choroidal microvasculature in patients with primary open-angle glaucoma and high myopia

AimsTo characterise the influence of primary open-angle glaucoma (POAG) and high myopia (HM) on the macular and choroidal capillary density (CD).MethodsTwo hundred and seven eyes were enrolled, including 80 POAG...

Group-wise context selection network for choroid segmentation in optical coherence tomography

Choroid thickness measured from optical coherence tomography (OCT) images has emerged as a vital metric in the management of retinal diseases such as high myopia. In this paper, we propose a novel group-wise context selection network (referred to as GCS-Net) to segment the choroid of either normal or high myopia eyes. To deal with the diverse choroid thickness and the variable shape of the pathological retina, GCS-Net adopts the group-wise channel dilation (GCD) module and the group-wise spatial dilation module, which can automatically select group-wise multi-scale information under the guidance of channel attention or spatial attention, and enhance the consistency between the receptive field and the target area. Furthermore, a boundary optimization network with a new edge loss is incorporated to improve the resulting choroid boundary by deep supervision. Experimental results evaluated on a dataset composed of 1650 clinically obtained OCT B-scans show that the proposed GCS-Net can achieve a Dice similarity coefficient of 95.97 ± 0.54%, which outperforms some state-of-the-art segmentation networks.

Twelve-Month Outcomes of the Wavefront-Optimized Photorefractive Keratectomy for High Myopic Correction Compared with Low-to-Moderate Myopia.

PurposeTo evaluate the 12-months outcomes of photorefractive keratectomy (PRK) in patients with high myopia (≥ 6.0 diopters, D) compared with low-to-moderate myopia (< 6.0 D).Patients and MethodsRecords of 46 patients (69 eyes) who underwent PRK for myopic and astigmatic correction between October 2015 and December 2018 were reviewed. High myopic eyes (29 eyes) were compared with low-to-moderate myopic eyes (40 eyes). All surgeries were adjunct with 0.02% mitomycin C intraoperatively. Measured outcomes included postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent, corneal haze rate, and any complications.ResultsAt 12 months post-PRK, 26 eyes (89.7%) in the high myopia and 39 eyes (97.5%) in the low-to-moderate myopia group had UDVA ≥ 20/20, (p=0.30). Average postoperative logMAR UDVA at 12 months was −0.04 (20/18) and −0.11 (20/15) for the high myopia and low-to-moderate myopia groups, respectively. No eyes in either group had residual refractive errors >1 D. No eyes in both groups developed significant corneal haze at month 12. No eyes had a loss of greater than two Snellen lines of CDVA at 12 months post-surgery. The efficacy and safety indices at 12 months post-surgery were not significantly different between groups (1.06±0.26 vs.1.14±0.27, p =0.25 and 1.14±0.27 vs 1.17±0.26, p=0.60 for low-to-moderate myopia vs high myopia groups, respectively).ConclusionPRK with high myopic correction provides excellent refractive outcomes and is safe, compared to those of low-to-moderate myopic correction.

Wide-field swept source optical coherence tomography evaluation of posterior segment changes in highly myopic eyes.

To investigate the features in the posterior pole of highly myopic (HM) eyes using a wide-field high-resolution swept source optical coherence tomography (SS OCT). This observational cross-sectional study involved 262 eyes of 139 patients, who were diagnosed as HM and had consecutively been examined by SS OCT in the Ophthalmology Department of the Peking Union Medical College Hospital between March 2019 and December 2019. The characteristics of OCT images were documented and analyzed. In our study, SS OCT could demonstrate the entire layer of the choroid and detect the sclera in all eyes. The mean subfoveal retinal/choroidal/scleral thickness were 204.84 ± 119.86 μm, 92.80 ± 75.78 μm and 394.734 ± 123.09 μm, respectively. 138 eyes (52.67%) had posterior precortical vitreous pocket. Myopic foveoschisis was detected in 110 eyes (41.98%), and significantly associated with the presence of posterior staphyloma. 36 eyes (13.74%) had DSM in our study, of which 8 eyes (22.22%) showed a round dome, 16 (44.44%) were horizontal oval-shaped, 9 (25%) were vertical oval-shaped and 3 (8.34%) were oblique oval-shaped. Both SFCT and SFST were inversely and significantly associated with age and refractive errors. Macular neovascularization was significantly correlated with intrascleral vessels. Different deformation of the sclera and posterior staphyloma were vividly identified on SS OCT images. This study provided a relatively comprehensive picture of posterior pole in HM eyes. Such good visualization of ocular fundus provided by wide-field SS OCT could be useful for the therapy option, disease condition monitoring and pathogenesis investigation.

High myopia and macular vascular density: an optical coherence tomography angiography study

ObjectiveTo investigate whether there are differences inmacular vascular density (VD) between patients with high-myopia (HM) and those with non-high myopia (NHM) using Optical Coherence Tomography Angiography (OCTA).MethodOCTA was performed on 35 eyes with HM with spherical equivalence (SE) > − 6.00D and 35 eyes with NHM with SE ≤ -6.00D. Vascular densities of the macula (overall macula, fovea, parafovea, superior hemi and inferior hemi) were measured in each of the superficial, deep and choriocapillaris layers of the retina.ResultsIn the superficial retinal layer, overall macular VFD was significantly higher in the NHM compared to the HM group (51.27 ± 3.74 vs. 48.07 ± 5.69, p < 0.05). There were significant differences between the NHM and HM in parafovea (52.58 ± 5.78 vs. 49.4 ± 6.43, p < 0.05), superior-hemi (53.38 ± 4.03 vs 49.78 ± 6.84, p < 0.05) and inferior-hemi regions (53.49 ± 4.61 vs 49.05 ± 6.41, p < 0.05), but not in the fovea region. Similarly, in the deep retinal layer, overall macular VFD was significantly higher in the NHM group compared to the HM group (58.69 ± 2.46 vs. 56.90 ± 4.08, p < 0.05). There was significant differences between the HM and NHM in superior-hemi region (61.97 ± 2.68 vs. 60.08 ± 3.98, p < 0.05), but not in the fovea, parafovea, and inferior-hemi region. In the choriocapillaris, there was no difference in the overall macular VFD, nor any of the individual sectors between the HM and the NHM groups.ConclusionVFD in the superficial and deep retinal layers of the macula are significantly increased in the NHM compared to HM eyes. This is not the case in the choroidal capillary layers of the retina.

Combined wide-field optical coherence tomography angiography density map for high myopic glaucoma detection

The present study aimed to evaluate the diagnostic ability of wide-field optical coherence tomography angiography (OCTA) density map for detection of glaucomatous damage in high myopic (HM) eyes and to further compare the diagnostic ability of OCTA with that of conventional imaging approaches including red-free photography and swept-source OCT (SS-OCT) wide-field maps. A total of 77 healthy HM eyes and 72 HM eyes with open angle glaucoma (OAG) participated in this retrospective observational study. Patients underwent a comprehensive ocular examination, including wide-field SS-OCT scan and peripapillary area and macular OCTA scans. An integrated OCTA density map thereafter was merged by vascular landmark-guided superimposition of peripapillary and macular superficial vascular density maps onto the red-free photography (resulting in the OCTA-PanoMap). Glaucoma specialists then determined the presence of glaucomatous damage in HM eyes by reading the OCTA-PanoMap and compared its sensitivity and specificity with those of conventional images. Sensitivity and specificity of OCTA-PanoMap for HM-OAG diagnosis was 94.4% and 96.1%, respectively. Compared with other imaging methods, the sensitivity of OCTA-PanoMap was significantly higher than that of red-free photography (P = 0.022) and comparable to that of wide-field SS-OCT maps. Specificity of OCTA-PanoMap was significantly higher than those of other conventional imaging methods (except for wide-field thickness map). The OCTA-PanoMap showed good diagnostic ability for discrimination of HM-OAG eyes from healthy HM eyes. As a complementary method of an alternative imaging modality, OCTA-PanoMap can be a useful tool for detection of HM-OAG.

Novel Corneal Protein Biomarker Candidates Reveal Iron Metabolic Disturbance in High Myopia Eyes.

Myopia is a major public health concern with increasing global prevalence and is the leading cause of vision loss and complications. The potential role of the cornea, a substantial component of refractive power and the protective fortress of the eye, has been underestimated in the development of myopia. Our study acquired corneal stroma tissues from myopic patients undergoing femtosecond laser-assisted small incision lenticule extraction (SMILE) surgery and investigated the differential expression of circulating proteins between subjects with low and high myopia by means of high-throughput proteomic approaches—the quantitative tandem mass tag (TMT) labeling method and parallel reaction monitoring (PRM) validation. Across all corneal stroma tissue samples, a total of 2,455 proteins were identified qualitatively and quantitatively, 103 of which were differentially expressed between those with low and high myopia. The differentially abundant proteins (DAPs) between the groups of stroma samples mostly demonstrated catalytic activity and molecular function regulator and transporter activity and participated in metabolic processes, biological regulation, response to stimulus, and so forth. Pathway enrichment showed that mineral absorption, ferroptosis, and HIF-1 signaling pathways were activated in the human myopic cornea. Furthermore, TMT analysis and PRM validation revealed that the expression of ferritin light chain (FTL, P02792) and ferritin heavy chain (FTH1, P02794) was negatively associated with myopia development, while the expression of serotransferrin (TF, P02787) was positively related to myopia status. Overall, our results indicated that subjects with low and high myopia could have different proteomic profiles or signatures in the cornea. These findings revealed disturbances in iron metabolism and corneal oxidative stress in the more myopic eyes. Iron metabolic proteins could serve as an essential modulator in the pathogenesis of myopia.

Automated in vivo detection and localization of posterior staphyloma in ultrasound b-modes

In high and pathologic myopia eyes, staphyloma, an outpouching of the eyewall, is associated with risks of permanent vision loss. Automated detection of staphyloma in ultrasound B-modes could assist clinicians in quickly identifying patients at risk. In this study, an algorithm to detect the presence of staphyloma and locate the staphyloma apex was developed. A 10 MHz ultrasound probe was used to acquire 127 B-modes, from 82 eyes and 52 patients. Sixty-one of the B-modes included staphyloma, as determined by an experienced ophthalmologist who also marked the staphyloma apex in each image where present. In each B-mode, the vitreoretinal boundary was automatically detected by a thresholding method. The local radius of curvature (K) was computed, and the ability of the standard deviation of K to detect staphyloma was evaluated by receiver-operating characteristic analysis. The staphyloma apex was automatically detected as the point on the vitreoretinal boundary furthest from the center of the transducer. The area under the curve using standard deviation of K for staphyloma detection was 0.927. The average error in detected staphyloma apex location was 1.34 ± 1.36 mm. These results demonstrate the potential of automated staphyloma detection and localization from ultrasound, which could assist in quick diagnosis of staphyloma.

Posterior vitreous detachment and paravascular retinoschisis in highly myopic young patients detected by ultra-widefield OCT

The purpose of this study was to determine the relationship between a posterior vitreous detachment (PVD) and retinoschisis (RS) in 73 highly myopic (HM) young patients age 16.4 ± 6.9 years and 24 non-HM children age 8.4 ± 1.5 years. The presence of the paravascular retinal abnormalities was determined in the images obtained by a ultra-widefield OCT (UWF OCT) instrument with an image field of 23 × 20 mm. The results showed that a partial PVD was detected in 15 (21%) of the HM patients, and the number increased significantly with increasing age (P = 0.02). PVDs of any type were not found in the non-HM eyes. The number of microvascular folds also increased with age in the HM patients (P = 0.03). Medium-reflective columnar tissues were present between the detached vitreous and inner retinal surface in 4 (5%) eyes of the HM patients. Myopic RS was found in 3 (4%) HM patients in the paravascular area but not in the macular area. These results suggest that early partial PVD may play a role in pathological and proliferative vitreous changes of HM eyes. An intense vitreoretinal traction with bridging tissues may cause the various paravascular retinal abnormalities. In HM eyes, paravascular RS is already present at an early age which may progress to macular RS with aging.

Comparison of the optical quality after SMILE and FS-LASIK for high myopia by OQAS and iTrace analyzer: a one-year retrospective study

BackgroundTo compare the correction effect and optical quality after small-incision lenticule extraction (SMILE) and femtosecond laser assisted laser in situ keratomileusis (FS-LASIK) for high myopia.Methods51 high myopia eyes after SMILE and 49 high myopia eyes after FS-LASIK were enrolled and divided into two groups retrospectively. The OQAS and iTrace analyzer were used for optical quality inspection. Between the two groups the spherical equivalent (SE), astigmatism, uncorrected distant visual acuity (UDVA), strehl ratio (SR), modulation transfer function cutoff frequency (MTF cutoff), objective scatter index (OSI) and wavefront aberrations were analyzed and compared before surgery and at 1, 6 and 12 months after surgery.ResultsAfter the operation: (1) SE and astigmatism declined and UDVA increased significantly in both groups, and UDVA was better after SMILE than FS-LASIK. (2) SR and MTF cutoff reduced and OSI increased significantly after SMILE and FS-LASIK. SR and MTF cutoff were significantly higher after SMILE than FS-LASIK. OSI was significantly lower after SMILE than FS-LASIK. (3) The total wavefront aberration, total low-order wavefront aberration, defocus and astigmatism aberration as well as trefoil aberration reduced significantly in both groups. The total high-order wavefront aberration increased significantly after FS-LASIK. The spherical and coma aberration increased significantly in both groups. The total high-order wavefront aberration and coma aberration at 1 month were higher after FS-LASIK than SMILE.ConclusionThe optical quality descended after SMILE and FS-LASIK. SMILE was superior to FS-LASIK at the correction effect and optical quality for high myopia. The combination of OQAS and iTrace analyzer is a valuable complementary measurement in evaluating the optical quality after the refractive surgery.Trial registrationThis is a retrospective study. This research was approved by the ethics committee of Xiangya Hospital and the IRB approval number is 201612074.

Evaluation of Barrett Universal II, SRK-T, and Haigis formulae for intraocular lens power calculation in myopes using optical biometry

Objective To assess the precision of Barrett Universal II, SRK-T, and Haigis formulas in high myopic eyes for the estimation of intraocular lens power, using optical biometry. Patients and methods This is an interventional prospective study that included 34 eyes with an axial length more than or equal to 26 mm, who underwent uneventful phacoemulsification. One month after the surgery, we recorded the postoperative refraction. Refractive prediction error (RPE), median absolute error (Med AE), and proportion of eyes with postoperative myopic and hyperopic outcomes were compared. Results The lowest mean RPE (−0.11±0.90 D), Med AE (0.15 D), and proportion of eyes with hyperopic outcomes (44.1%) were reported with the Barrett Universal II formula. They were all statistically lower than the results of SKR/T and Haigis formulas (mean RPE 0.16±0.99 and 0.31±0.98 D, respectively; Med AE 0.47 and 0.40 D, respectively; and percentage of hyperopic outcome 70.6 and 76.5%, respectively). Conclusion We concluded that the lowest mean RPE, median AE, and the lowest percentage of hyperopic outcome were reported with the Barrett Universal II formula.

Effect of orthokeratology on anisometropia control: A meta-analysis

The effectiveness of orthokeratology in retarding anisometropic progression has been investigated in several small-sample studies. This quantitative analysis aimed to elucidate the efficacy of orthokeratology for anisometropia control. We searched PubMed, Embase, and Cochrane databases for relevant studies through September 2020. Axial length (AL) data at baseline and final follow-up were extracted, and AL elongation and difference were calculated. Methodological quality was evaluated using the risk of bias in non-randomized studies of interventions (ROBINS-I) tool. Meta-analyses were performed using a fixed-effect model based on the heterogeneity. A total of 10 cohort studies (nine retrospective studies; one prospective study) were included. The pooled results for the unilateral myopia group showed that the mean AL elongation difference between myopic and emmetropic eyes was -0.27mm (95% CI, -0.31 to -0.22; p<0.01) at the one-year follow-up (four studies) and -0.17mm (95% CI, -0.33 to -0.02; p=0.03) at the two-year follow-up (two studies). In the bilateral anisomyopic group, mean AL elongation difference between high and low myopic eyes was -0.06mm (95% CI, -0.09 to -0.04; p<0.01) at the one-year follow-up (seven studies) and -0.13mm (95% CI, -0.21 to -0.06; p<0.01) at the two-year followup (three studies). This study demonstrated that orthokeratology can effectively retard myopic progression and reduce anisomyopic values. However, additional wellstructured randomized controlled trials or prospective studies with longer follow-up periods are warranted to address this topic in more detail.