Vascular Changes of the Choroid and Their Correlations With Visual Acuity in Pathological Myopia.

Purpose: Photoreceptor loss plays a role in visual impairment in pathological myopia. As the nutrition and oxygen demands of photoreceptors are mainly supported by the choroidal vessels, we aimed to investigate changes in the choroidal vasculature and their correlations with visual acuity in pathological myopia. Methods: The cohort was composed of 136 eyes from 80 participants, including 42 eyes from 21 participants with emmetropia/low myopia, 48 eyes from 26 participants with simple high myopia, and 46 eyes from 33 participants with pathological myopia. Swept-source optical coherence tomography (OCT) was used to image the eyes with a 12-mm radial line scan protocol. The parameters for 6-mm diameters of macula area centered on the fovea were analyzed. A custom deep learning algorithm based on a modified residual U-Net architecture was used to segment the choroidal boundaries. Then, the distance between the two boundaries was determined and choroidal thickness (CT), luminal area (LA), and stromal area (SA) were demarcated based on Niblack's auto-local threshold algorithm after binarization of the OCT images. Finally, the ratio of LA and total choroidal area was defined as the choroidal vascularity index (CVI). The choroidal parameters in three groups were compared, and correlations of the choroidal parameters with age, gender, axial length, and best-corrected visual acuity (BCVA) were analyzed. Results: The CVI, CT, LA, and SA values were lower in pathological myopia than in emmetropia/low myopia and simple high myopia (P < 0.05). The CT, LA, and SA values were lower in simple high myopia than in emmetropia/low myopia (P < 0.05), whereas there was no difference between the CVIs in the emmetropia/low myopia and high myopia groups (P > 0.05). The CVI was nonlinear with increases in axial length (AL), and there was a critical AL flexion point, approximately 27.26 mm; however, the CT, LA, and SA were negatively correlated with AL. Further analysis showed that only younger subjects (40 years old or less) showed significant AL flexion points. Simple and multiple regression models showed that the CVI was correlated with BCVA (P < 0.05). Conclusions: Choroidal vascular alterations, especially decreased CVI, occurred in patients with pathological myopia. The CVI decreased with axial elongation beyond the flexion point and was correlated with visual impairment, indicating that the CVI might be a reliable imaging biomarker to monitor the progression of pathological myopia.

Biomechanical Considerations of Patching Material for Posterior Scleral Reinforcement Surgery.

Purpose: To characterize biomechanical properties of genipin-crosslinked human dura mater as reinforcing material for posterior scleral reinforcement (PSR) and to compare it with crosslinked human sclera. Methods: Donor dura mater and sclera were crosslinked in the same optimized genipin solution. Resistance to enzyme degradation for both materials were investigated by exposing the materials to accelerated enzyme degrading. Elastic modulus and tensile strength were measured by biomechanics testing equipment. Crosslinked human dura mater was used as reinforcing patch in PSR on 57 adult pathologic myopic eyes. The patients were followed up for an average 3 years. The main outcome was eye globe axial length change and safety profile of the reinforcing material. Results: Crosslinked dura mater demonstrated similar percentage weight loss to crosslinked sclera when exposed to enzymatic solution. Dura mater has higher density than sclera. The retaining elastic modulus after enzyme exposure was 72.02 MPa for crosslinked dura mater while 53.88 MPa for crosslinked sclera, 34% greater for crosslinked dura mater, P = 0.0186). At the end of 3 years follow-up, the mean globe axis of the surgery eyes was reduced by 1.29 mm (from 30.81 to 29.51 mm, P < 0.0001, paired t-test). Visual acuity (BCVA logMar) improved by 0.10 logMar unit which is an improvement of five letters (P = 0.0184, paired t-test). No material specific complication was noted. Conclusion: Crosslinked human dura mater may be superior to crosslinked human sclera as reinforcing material for PSR to manage progression of high myopia. This material was well tolerated on human eye.

Posterior scleral reinforcement for the treatment of myopic traction maculopathy.

BACKGROUND: This study aimed to investigate the clinical effectiveness of posterior scleral reinforcement(PSR) for the treatment of myopic traction maculopathy (MTM). METHODS: This was a prospective study of 32 eyes from 20 patients with MTM treated with PSR using genipin-cross-linked donor sclera. The length of the scleral strip used for the surgery was designed to be 1.5-times the axial length of the eye, whereas its width was 0.4-times the axial length of the eye. The optical coherence tomography images, spherical equivalent of refractive error, axial length, best corrected visual acuity, electroretinogram findings, and intraocular pressure of the patients were assessed postoperatively. RESULTS: The mean duration of follow-up was 17.80 ± 8.74 months. The differences between the spherical equivalent of refractive error, best corrected visual acuity, axial length, and electroretinogram findings recorded preoperatively and those measured postoperatively were statistically significant (p < 0.05). The final reduction in axial length was 1.64 ± 0.85 mm. At the end of the follow-up, optical coherence tomography showed essential foveal reattachment in 30 eyes (93.75%), partial reattachment in two eyes (6.25%), and closure of macular holes in seven eyes (77.78%). No retinal detachment, vitreous haemorrhage, or other serious complications occurred following the surgery. CONCLUSIONS: Posterior scleral reinforcement with genipin-cross-linked sclera showed safe and effective outcomes for the treatment of MTM during a follow-up period of at least one year. TRIAL REGISTRATION: 11\12\2018, ChiCTR1800020012 .

Posterior scleral contraction to treat myopic traction maculopathy at different stages.

OBJECTIVE: We aimed to evaluate anatomical and functional outcomes and determine posterior scleral contraction (PSC) timing in treating myopic traction maculopathy (MTM). METHODS: This is a retrospective study of MTM patients undergoing PSC with genipin cross-linked strip at a single hospital site. Differences in demographic and clinical characteristics were compared among three groups defined by the MTM staging system. All patients were followed up for at least one year postoperatively. The best-corrected visual acuity (BCVA), macular hole diameter, axial length (AL), optical coherence tomography findings, and the complications were evaluated. Additionally, regression analyses were performed to account for confounders. RESULTS: Sixty-one MTM patients (24 eyes at stage 2, 22 eyes at stage 3, and 18 eyes at stage 4) were included. The macular holes were closed in 16 eyes (66.7%), 13 eyes (59.0%), and 11 eyes (61.1%) at stage 2, stage 3, and stage 4, respectively. PSC improved the BCVA in patients at each stage (all P < 0.05). Postoperative BCVA at stage 2 was significantly better than that at stage 4 (P = 0.0069). Preoperative BCVA was associated with postoperative BCVA (P < 0.001). Preoperative AL (OR 0.676, 95% CI 0.480 to 0.951, P = 0.025), AL shortening amount (OR 5.129, 95% CI 1.974 to 13.327, P = 0.001) and macular hole diameter (OR 1.003, 95% CI 1.000 to 1.006, P = 0.030) were associated with macular hole closure. CONCLUSIONS: PSC is safe and effective in treating MTM at different stages. Early PSC intervention will have more significant visual benefits.

Dysfunction of VIPR2 leads to myopia in humans and mice.

BACKGROUND: Myopia is the leading cause of refractive errors. As its pathogenesis is poorly understood, we determined if the retinal VIP-VIPR2 signalling pathway axis has a role in controlling signalling output that affects myopia development in mice. METHODS: Association analysis meta-study, single-cell transcriptome, bulk RNA sequencing, pharmacological manipulation and VIPR2 gene knockout studies were used to clarify if changes in the VIP-VIPR2 signalling pathway affect refractive development in mice. RESULTS: The SNP rs6979985 of the VIPR2 gene was associated with high myopia in a Chinese Han cohort (randomceffect model: p=0.013). After either 1 or 2 days' form deprivation (FD) retinal VIP mRNA expression was downregulated. Retinal single-cell transcriptome sequencing showed that VIPR2 was expressed mainly by bipolar cells. Furthermore, the cAMP signalling pathway axis was inhibited in some VIPR2+ clusters after 2 days of FD. The selective VIPR2 antagonist PG99-465 induced relative myopia, whereas the selective VIPR2 agonist Ro25-1553 inhibited this response. In Vipr2 knockout (Vipr2-KO) mice, refraction was significantly shifted towards myopia (p<0.05). The amplitudes of the bipolar cell derived b-waves in 7-week-old Vipr2-KO mice were significantly larger than those in their WT littermates (p<0.05). CONCLUSIONS: Loss of VIPR2 function likely compromises bipolar cell function based on presumed changes in signal transduction due to altered signature electrical wave activity output in these mice. As these effects correspond with increases in form deprivation myopia (FDM), the VIP-VIPR2 signalling pathway axis is a viable novel target to control the development of this condition.

EVALUATION OF THE EFFICACY OF POSTERIOR SCLERAL CONTRACTION IN THE TREATMENT OF MACULAR HOLE WITH RETINAL DETACHMENT IN HIGH MYOPIA.

PURPOSE: To evaluate efficacy of posterior scleral contraction for macular hole with retinal detachment in high myopia. METHODS: Seventy-three macular hole with retinal detachment eyes were treated with posterior scleral contraction. A strip was sent across inferior-temporal scleral surface to posterior pole, then two ends were led out from nasal-inferior to temporal-superior areas. It was tightened to contract posterior sclera with designed axial length shortening ([10% of preoperative axial length-0.5] mm) after aqueous humor was drained from anterior chamber. Recovery was classified as type I (retinal reattachment with MH bridged) and II (retinal reattachment without MH bridged). Follow-up duration was 25.3 ± 18.0 months. RESULTS: Axial length was 30.01 ± 2.27 mm at preoperation and shortened by 2.57 ± 0.82 mm intraoperatively. At final postoperation, maintained axial length shortening was 1.87 ± 0.92 mm. Forty-six eyes (63.0%) recovered as type I, 26 eyes (35.6%) as type II, and 1 eye (1.4%) unrecovered. Postoperative best-corrected visual acuity (logarithm of minimal angle of resolution) was better than preoperative one (0.85 ± 0.50 [Snellen 20/125] vs. 1.11 ± 0.56 [Snellen 20/250], P < 0.001) with correlation (r = 0.662, P < 0.001) and consistency (Kappa = 0.34, P < 0.001) between two. Best-corrected visual acuity improvement did not differ between recovery types (P = 0.206). CONCLUSION: Macular hole with retinal detachment was successfully recovered by posterior scleral contraction with axial length shortening. Visual improvement was achieved, correlated, and consistent with preoperative best-corrected visual acuity while independent of recovery types.

PDE4B Proposed as a High Myopia Susceptibility Gene in Chinese Population.

Myopia is the most common cause of refractive error worldwide. High myopia is a severe type of myopia, which usually accompanies pathological changes in the fundus. To identify high myopia susceptibility genes, DNA-pooling based genome-wide association analysis was used to search for a correlation between single nucleotide polymorphisms and high myopia in a Han Chinese cohort (cases vs. controls in discovery stage: 507 vs. 294; replication stage 1: 991 vs. 1,025; replication stage 2: 1,021 vs. 52,708). Three variants (rs10889602T/G, rs2193015T/C, rs9676191A/C) were identified as being significantly associated with high myopia in the discovery, and replication stage. rs10889602T/G is located at the third intron of phosphodiesterase 4B (PDE4B), whose functional assays were performed by comparing the effects of rs10889602T/T deletion of this risk allele on PDE4B and COL1A1 gene and protein expression levels in the rs10889602T/Tdel/del, rs10889602T/Tdel/wt, and normal control A549 cell lines. The declines in the PDE4B and COL1A1 gene expression levels were larger in the rs10889602T/T deleted A549 cells than in the normal control A549 cells (one-way ANOVA, p < 0.001). The knockdown of PDE4B by siRNA in human scleral fibroblasts led to downregulation of COL1A1. This correspondence between the declines in rs10889602 of the PDE4B gene, PDE4B knockdown, and COL1A1 protein expression levels suggest that PDE4B may be a novel high myopia susceptibility gene, which regulates myopia progression through controlling scleral collagen I expression levels. More studies are needed to determine if there is a correlation between PDE4B and high myopia in other larger sample sized cohorts.

POSTERIOR SCLERAL CONTRACTION TO TREAT MYOPIC FOVEOSCHISIS IN HIGHLY MYOPIC EYES.

PURPOSE: To evaluate the efficacy of posterior scleral contraction to treat myopic foveoschisis (MF). METHODS: The records of MF patients treated with posterior scleral contraction were reviewed. During posterior scleral contraction, a cross-linked fusiform strip from allogeneic sclera was used and designed axial length (AL) shortening amount was around 2.0∼3.0 mm based on preoperative AL. The middle part of the strip was placed at the posterior pole of the eye. After few aqueous humors were released, the strip was tightened to contract posterior sclera and shorten AL. Clinical data were collected at pre-operation (op) and post-op follow-ups for 12 months. RESULTS: Twenty-four eyes were collected. The AL at pre-op, post-op 1-week, 3-month, 6-month, and 12-month were 29.84 ± 1.24, 27.39 ± 1.32, 27.73 ± 1.23, 27.86 ± 1.26, and 27.91 ± 1.29 mm. There was no AL difference between post-op 6-month and 12-month (P = 0.242). The accumulated MF reattachment rate at post-op 1-week, 3-month, 6-month, and 12-month were 8.3%, 16.7%, 50.5%, and 95.8%. The best-corrected visual acuity at post-op 6-month and 12-month were 0.71 ± 0.39 (Snellen acuity 20/80) and 0.64 ± 0.37 (Snellen acuity 20/63), improving significantly compared with pre-op (P = 0.006 and <0.001). CONCLUSION: The posterior scleral contraction was effective to treat MF. The AL stabilized after post-op 6-month and MF reattached gradually with improved visual acuity up to post-op 12-month.

Scleral HIF-1α is a prominent regulatory candidate for genetic and environmental interactions in human myopia pathogenesis.

BACKGROUND: Myopia is a good model for understanding the interaction between genetics and environmental stimuli. Here we dissect the biological processes affecting myopia progression. METHODS: Human Genetic Analyses: (1) gene set analysis (GSA) of new genome wide association study (GWAS) data for 593 individuals with high myopia (refraction ≤ -6 diopters [D]); (2) over-representation analysis (ORA) of 196 genes with de novo mutations, identified by whole genome sequencing of 45 high-myopia trio families, and (3) ORA of 284 previously reported myopia risk genes. Contributions of the enriched signaling pathways in mediating the genetic and environmental interactions during myopia development were investigated in vivo and in vitro. RESULTS: All three genetic analyses showed significant enrichment of four KEGG signaling pathways, including amphetamine addiction, extracellular matrix (ECM) receptor interaction, neuroactive ligand-receptor interaction, and regulation of actin cytoskeleton pathways. In individuals with extremely high myopia (refraction ≤ -10 D), the GSA of GWAS data revealed significant enrichment of the HIF-1α signaling pathway. Using human scleral fibroblasts, silencing the key nodal genes within protein-protein interaction networks for the enriched pathways antagonized the hypoxia-induced increase in myofibroblast transdifferentiation. In mice, scleral HIF-1α downregulation led to hyperopia, whereas upregulation resulted in myopia. In human subjects, near work, a risk factor for myopia, significantly decreased choroidal blood perfusion, which might cause scleral hypoxia. INTERPRETATION: Our study implicated the HIF-1α signaling pathway in promoting human myopia through mediating interactions between genetic and environmental factors. FUNDING: National Natural Science Foundation of China grants; Natural Science Foundation of Zhejiang Province.

Deep Retinal Capillary Plexus Decreasing Correlated With the Outer Retinal Layer Alteration and Visual Acuity Impairment in Pathological Myopia.

Purpose: The purpose of this study was to measure alterations of inner retinal microvascular density and outer retinal sublayer thicknesses in pathological myopia, and to correlate the measured parameters with best corrected visual acuity (BCVA). Methods: Optical coherence tomography (OCT) and OCT angiography (OCTA) images of 21 control, 48 simple high myopia, and 22 pathological myopia eyes were analyzed to quantify the thicknesses of the outer retinal sublayers and the density of the inner retinal microvascular network that includes the superficial retinal capillary plexus (SRCP) and deep retinal capillary plexus (DRCP). Retinal sublayer thicknesses and microvascular densities were compared among the three groups, and correlations of sublayer thicknesses and microvascular densities with BCVA were determined. Results: In pathological myopia, density of the DRCP, thicknesses of myoid and ellipsoid zone (MEZ), interdigitation zone and retinal pigment epithelium/Bruch complex (IZ + RPE), and choroid were lower than in simple high myopia (P < 0.05). The decreased DRCP density was correlated with thinner MEZ and IZ+RPE in pathological myopia (P < 0.05), but not in simple high myopia (P > 0.05). Simple linear regression showed that axial length, female, thicknesses of outer plexiform layer (OPL), MEZ, IZ + RPE, choroid, and density of the SRCP and DRCP were correlated with BCVA. In multiple regression analysis, worse BCVA was associated only with thinner MEZ, thinner choroid, and decreased DRCP (P < 0.05). Conclusions: Alteration of inner retinal microvascular density and outer retinal sublayer thicknesses occurred in pathological myopia, especially decreased DRCP and thinner MEZ, which were significantly associated with worse BCVA.

Changes in macular ultrastructural morphology in unilateral anisometropic amblyopia.

It is controversial that retina and photoreceptors are involved in amblyopic development. Lack of imaging devices for quantitative assessment of photoreceptors in vivo impedes further investigation. In this study we investigated the differences of macular thickness, outer nuclear layer (ONL) thickness and cone density among eyes with unilateral anisometropic amblyopia, amblyopic fellow eyes, and normal control eyes using high-definition spectral-domain optical coherence tomography and adaptive optics imaging system. Thicker fovea and parafovea with characteristic quantitative retinal changes in unilateral amblyopic patients indicated that the amblyopic process might involve the retina. Cones tended to be homogeneously distributed at 1.5° from the foveal center in all participants. However, we did not detect any significant differences in cone density and ONL thickness at 1.5° from the foveal center in patients with unilateral amblyopia when compared with the fellow eyes and the normal control eyes. This is the first study to explore whether photoreceptors are involved in amblyopic development in vivo that would help for understanding the underlying mechanisms of amblyopia. Whether macular changes relate to cone photoreceptors migration of the amblyopic eyes remains to be determined.

Photoreceptor Degeneration is Correlated With the Deterioration of Macular Retinal Sensitivity in High Myopia.

Purpose: To investigate structural changes in the retinal outer layers and choroid using adaptive optics (AO) and optical coherence tomography (OCT) in eyes with myopia, and to correlate the changes with decreased macular light sensitivity (MLS). Methods: This prospective study included 27 subjects with emmetropia and low myopia (EM/LM), 25 with moderate myopia (MM), and 25 with high myopia (HM). Microperimetry was used to quantify MLS in each subject, while AO and OCT images of fundus were analyzed to quantify cone density and regularity and thickness of outer retinal sublayers and choroid. Differences of MLS, cone distribution, and chorioretinal thicknesses were compared among the three groups, and the associations among photoreceptor morphological alterations, MLS, and other parameters were analyzed. Results: In HM, the MLS, cone density and regularity, and thicknesses of the myoid and ellipsoid zone (MEZ), Henle fiber layer and outer nuclear layer, interdigitation zone and RPE/Bruch complex, and choroid were lower than in EM/LM. Decreased MLS was correlated with lower cone density and regularity, and thinner MEZ and choroid in the inner region, and with lower cone density, thinner MEZ and choroid, and longer axial length in the outer region. Multivariate regression showed that better MLS was correlated with thicker MEZ in the inner region and with higher cone density in the outer region. Conclusions: Altered cone distribution and outer retinal thickness, especially cone density and MEZ thickness, were significantly correlated with decline of MLS in HM, which may help to evaluate and monitor visual impairment in HM.

POSTERIOR SCLERAL CONTRACTION TO TREAT RECURRENT OR PERSISTENT MACULAR DETACHMENT AFTER PREVIOUS VITRECTOMY IN HIGHLY MYOPIC EYES.

PURPOSE: To determine the efficacy of posterior scleral contraction (PSC) to treat recurrent or persistent macular detachment after previous vitrectomy in highly myopic eyes. METHODS: We reviewed the medical records of patients with high myopia and recurrent or persistent macular detachment after previous vitrectomy treated with PSC at our hospital between April 2013 and March 2017. Fourteen eyes (14 patients; mean age, 58.93 ± 11.08 years) were included. Sclera cross-linked with genipin was used for PSC. The desired axial length decrease was 0.1-fold. The reattachment rate, best-corrected visual acuity, and axial length changes were evaluated. RESULTS: The macular reattachment rate was 100%. In seven eyes with a silicone oil tamponade, the oil was successfully removed 2 weeks to 4 months after surgery. The best-corrected visual acuity improved significantly postoperatively (Snellen acuity improved from 20/1,000-20/400) (1.75 ± 0.90 vs. 1.34 ± 0.58 logarithm of the minimal angle of resolution; P < 0.05). Eight eyes (57.14%) improved; six eyes (43.86%) remained stable. The axial length decreased significantly postoperatively (31.32 ± 3.04 vs. 29.08 ± 3.05 mm; P < 0.05). CONCLUSION: Posterior scleral contraction is safe and effective for recurrent and persistent macular detachment after previous vitrectomy in highly myopic eyes. The silicone oil is removed after PSC, and vision can be preserved in these refractory cases.

Genipin-Crosslinked Donor Sclera for Posterior Scleral Contraction/Reinforcement to Fight Progressive Myopia.

Purpose: Myopia has become a global public health problem, particularly in East Asia where myopic retinopathy has become one of the leading causes of blindness and visual impairment in the elderly population. The purpose of this study was to evaluate the efficacy of posterior scleral contraction/reinforcement (PSCR) surgery on controlling the progressive elongation of axial length of highly myopic eyes in young patients. Methods: This is a prospective self-controlled interventional case series. Forty young patients (<18-years old) with progressive high myopia received PSCR with a genipin-crosslinked donor scleral strip for one eye and the fellow eye served as concurrent control without surgery. The main outcome measurement was the change of axial length over 2 to 3 years of follow-up. Results: Immediately after the surgery, axial length was shortened and subsequently increased by 0.32 mm over the follow-up period. In contrast, axial length of the fellow eyes increased by 0.82 mm over the same period (P < 0.001, paired t-test). PSCR delayed axial elongation in eyes with or without staphyloma. No significant change of visual acuity, cornea refractive power, or retina thickness was noted between the surgery and fellow eyes. None of the patients lost visual acuity compared with the baseline. The procedure was well tolerated with only temporary corneal refractive axis shifts that recovered by the 6-month postsurgical visit. Conclusions: PSCR with genipin-crosslinked sclera is safe and effective to restrain eye globe elongation in young patients within a 2- to 3-year follow-up period.

Posterior scleral reinforcement using genipin-cross-linked sclera for macular hole retinal detachment in highly myopic eyes.

BACKGROUND/AIMS: To investigate the surgical outcomes of posterior scleral reinforcement (PSR) using genipin-cross-linked sclera to treat macular hole retinal detachment (MHRD) in highly myopic eyes. METHODS: Nineteen patients with high myopia (19 eyes) with MHRD were treated sequentially with genipin-cross-linked PSR and were followed at least for 1 year after the surgery. The best corrected visual acuity (BCVA), axial length (AL), optical coherence tomography (OCT) outcomes and the complications were evaluated. RESULTS: Macular hole was closed in 73.7% of the eyes, foveal reattachment rate was 100%. The mean logMAR BCVA improved from 1.27±0.55 preoperatively to 0.88±0.55 postoperatively. The preoperative AL (29.88±1.97 mm) was decreased (27.73±1.84 mm) after the operation (p<0.001). CONCLUSIONS: For at least a 1-year period of follow-up, PSR with genipin-cross-linked sclera should be considered as a preferred surgical approach to treat MHRD in highly myopic eyes, especially when foveal retinoschisis is also documented.

The efficacy of posterior scleral contraction in controlling high myopia in young people.

OBJECTIVE: To investigate the clinical effectiveness and safety of posterior scleral contraction (PSC) surgery in controlling high myopia in young people. METHODS: Twenty patients with high myopia (30 eyes) were treated with PSC. The average age for the patients was 11.45 ± 5.17 years old (range 3-22). A genipin cross-linked sclera was implanted to the posterior sclera in PSC surgery. Axial length and myopia progression rates were measured at least two years before and after PSC surgery. RESULTS: Prior to surgery, the mean AL progression was 0.73 ± 0.33 mm, compared to -0.08 ± 0.31 mm (P=0.00) post-surgery; the degree of myopia increased was -1.40 ± 0.95 D, compared to 0.18 ± 1.10 D post-surgery (P=0.00). The best corrected visual acuity (BCVA, in LogMAR) improved from 0.21 ± 0.16 preoperatively to 0.13 ± 0.13 two years after PSC (P=0.014). CONCLUSIONS: PSC can restrict AL extension and safely control high myopia progression in young people.

Clinical Investigation of the Posterior scleral contraction to Treat Macular Traction Maculopathy in Highly Myopic Eyes.

Myopic traction maculopathy (MTM) can cause vision disabilities in highly myopic eyes. This retrospective case series investigated the clinical outcomes of posterior scleral contraction (PSC) using genipin-cross-linked sclera as the material to treat MTM in highly myopic eyes. In total, 32 eyes from 29 highly myopic patients who underwent PSC for MTM were recruited. The changes in best-corrected visual acuity (BCVA) and axial length were evaluated, macular reattachment and macular hole (MH) closure was assessed by optical coherence tomography, and complications were evaluated. At the final follow-up, the retina was completely reattached in 25 eyes (78.1%), essentially reattached in 4 eyes (12.5%), and partially reattached in 3 eyes (9.4%). The logMAR BCVA improved significantly from 1.18 ± 0.45 preoperatively to 0.87 ± 0.45 postoperatively (P < 0.001). The 32 eyes were further divided into the MH group (16 eyes) and the non-MH group (16 eyes) for comparison. The MH was closed in 9 eyes (56.3%). The retinal reattachment rate was 75.0% in the MH group and 81.25% in the non-MH group, and the logMAR BCVA improved significantly in both groups. The PSC using genipin-cross-linked sclera as the material can effectively treat MTM in highly myopic eyes, and significant visual improvement can be achieved with minimal complications.

Myopic Macular Retinoschisis in Teenagers: Clinical Characteristics and Spectral Domain Optical Coherence Tomography Findings.

To investigate the morphological characteristics of myopic macular retinoschisis (MRS) in teenagers with high myopia, six male (9 eyes) and 3 female (4 eyes) teenagers with typical MRS identified from chart review were evaluated. All cases underwent complete ophthalmic examinations including best corrected visual acuity (BCVA), indirect ophthalmoscopy, colour fundus photography, B-type ultrasonography, axial length measurement, and spectral-domain optical coherence tomography (SD-OCT). The average age was 17.8 ± 1.5 years, average refractive error was -17.04 ± 3.04D, average BCVA was 0.43 ± 0.61, and average axial length was 30.42 ± 1.71 mm. Myopic macular degenerative changes (MDC) by colour fundus photographs revealed Ohno-Matsui Category 1 in 4 eyes, and Category 2 in 9 eyes. Posterior staphyloma was found in 9 eyes. SD-OCT showed outer MRS in all 13 eyes, internal limiting membrane detachment in 7 eyes, vascular microfolds in 2 eyes, and inner MRS in 1 eye. No premacular structures such as macular epiretinal membrane or partially detached posterior hyaloids were found. Our results showed that MRS rarely occurred in highly myopic teenagers, and was not accompanied by premacular structures, severe MDC, or even obvious posterior staphyloma. This finding indicates that posterior scleral expansion is probably the main cause of MRS.

The efficacy and safety of posterior scleral reinforcement using genipin cross-linked sclera for macular detachment and retinoschisis in highly myopic eyes.

BACKGROUND/AIMS: To evaluate the efficacy and safety of posterior scleral reinforcement (PSR) using genipin cross-linked sclera as the material to treat macular detachment and retinoschisis, both without macular hole, in highly myopic eyes. METHODS: Twenty-one patients with highly myopic eyes (24 eyes) with macular detachment and retinoschisis were treated sequentially with genipin cross-linked PSR and were followed for at least 1 year after surgery. The best-corrected visual acuity (BCVA), spherical equivalent (SE) power, axial length (AL), optical coherence tomography, and the complications were evaluated. RESULTS: The mean SE decreased from -13.81±4.67 D preoperatively to -9.64±4.86 D postoperatively, while the improvement in the logMAR BCVA values was from 1.24±0.57 before surgery to 1.03±0.57 after surgery. The preoperative AL (29.73±2.31 mm) was decreased (28.08±2.08 mm) after the operation. The retina in 21 eyes (87.5%) was successful reattached and the macular detachment was significantly decreased in two eyes; a macular hole occurred in one eye. CONCLUSIONS: For at least a 1 year period of follow-up, PSR with genipin cross-linked sclera was safe and effective to treat macular detachment and retinoschisis in high myopia when a macular hole was not present. The reinforcement effect tended to be stabilised and maintained for 6 months after treatment.

[Effects of posterior chamber phakic intraocular lens on axial length measurements].

OBJECTIVE: To study the effects of posterior chamber phakic intraocular lens (IOL) on axial length (AL) measurements and whether a correction factor for later IOL power calculation before cataract surgery is necessary. METHODS: Twenty-two high myopic patients (39 eyes) with mean spherical equivalent -19.00 +/- 4.03 D received phakic refractive lens (PRL) implantation, and 24 patients (40 eyes) with mean spherical equivalent (-13.10 +/- 2.53) D received implantable Collamer lens (ICL) implantation. Pre-and postoperative AL measurements with the IOLMaster were compared. Results The pre-and postoperative ALs were (30.87 +/- 2.18) mm and (30.94 +/- 2.16) mm, respectively (t = -2.635, P = 0.012) in the PRL group, and (28.35 +/- 1.20) mm and (28.45 +/- 1.22) mm, respectively ( t = -3.97, P < 0.001) in the ICL group. Linear regression analysis showed: in the PRL group, preoperative AL = 1.01 x postoperative AL-0.24 (R2 = 0.99, P < 0.001), or postoperative AL--preoperative AL = 0.24-0.0055 x postoperative AL; in the ICL group, preoperative AL = 0.96 x postoperative AL +1.17 (R2 = 0.99, P < 0.001), or postoperative AL--preoperative AL = 0.0154 x postoperative AL -0.3763. The mean differences between pre-and postoperative ALs in the PRL and, ICL groups were 0.075 mm and 0.054 mm, respectively. CONCLUSIONS: Based on the SRK formula, a < 0.1 mm AL difference would result in a <0.25 D change in the calculated IOL power, possibly a < 0.20 D change in manifest refraction. Furthermore, for PRL, the longer the AL, the smaller the difference between pre-and postoperative ALs. These differences are so small that it is unnecessary to correct IOL power calculation.