High Axial Myopia Research Articles

Variability in Optic Nerve Head Morphology in High Axial Myopia and Its Association with Glaucoma

Purpose: To investigate optic disc morphology in high axial myopia and its associations with the deep-layer structure of the optic disc using optical coherence tomography and glaucoma.Methods: We retrospectively reviewed the medical records of 69 eyes (33 normal and 36 glaucomatous eyes) with an axial length of 26-27 mm. The eyes were categorized into two groups based on the optic disc tilt ratio (≥ 1.3 or < 1.3). Characteristics of optic disc morphology, including lamina cribrosa depth, peripapillary atrophy width, and Bruch’s membrane opening area, were compared between the two groups. Furthermore, factors related to mean deviation and global retinal nerve fiber layer (RNFL) thickness were analyzed.Results: The mean optic disc tilt ratio was 1.31 ± 0.23. Eyes with a tilt ratio ≥ 1.3 (30 eyes) had a higher likelihood of glaucoma (<i>p</i> = 0.035) and severe visual field (VF) defects (<i>p</i> < 0.001), a thinner global RNFL thickness (<i>p</i> = 0.046), and larger gamma peripapillary atrophy width (<i>p</i> < 0.001) compared to eyes with a tilt ratio < 1.3 (39 eyes). Linear regression analysis revealed that the optic disc tilt ratio was significantly associated with VF loss (<i>p</i> = 0.018) but not with global RNFL thinning (<i>p</i> = 0.203).Conclusions: Variations in optic disc morphology are observed in eyes with similar axial lengths, and a higher optic disc tilt ratio is associated with more severe VF defects. These findings suggest the potential influence of optic disc morphological changes due to axial elongation on the severity of glaucomatous damage.

Congenital microcoria deletion in mouse links Sox21 dysregulation to disease and suggests a role for TGFB2 in glaucoma and myopia

Congenital microcoria (MCOR) is a rare hereditary developmental defect of the iris dilator muscle frequently associated with high axial myopia and high intraocular pressure (IOP) glaucoma. The condition is caused by submicroscopic rearrangements of chromosome 13q32.1. However, the mechanisms underlying the failure of iris development and the origin of associated features remain elusive. Here, we present a 3D architecture model of the 13q32.1 region, demonstrating that MCOR-related deletions consistently disrupt the boundary between two topologically associating domains (TADs). Deleting the critical MCOR-causing region in mice reveals ectopic Sox21 expression precisely aligning with Dct, each located in one of the two neighbor TADs. This observation is consistent with the TADs' boundary alteration and adoption of Dct regulatory elements by the Sox21 promoter. Additionally, we identify Tgfb2 as a target gene of SOX21 and show TGFΒ2 accumulation in the aqueous humor of an MCOR-affected subject. Accumulation of TGFB2 is recognized for its role in glaucoma and potential impact on axial myopia. Our results highlight the importance of SOX21-TGFB2 signaling in iris development and control of eye growth and IOP. Insights from MCOR studies may provide therapeutic avenues for this condition but also for glaucoma and high myopia conditions, affecting millions of people.

Wide-Field Optical Coherence Tomography Imaging Improves Rate of Change Detection in Progressing Glaucomatous Eyes Compared With Standard-Field Imaging.

To compare rates of retinal nerve fiber layer change over time in healthy, eyes with nonprogressing glaucoma and eyes with progressing glaucoma using single wide-field (SWF) and optic nerve head (ONH) cube scan optical coherence tomography (OCT) images. Forty-five eyes of 25 healthy individuals and 263 eyes of 161 glaucoma patients from the Diagnostic Innovations in Glaucoma Study were included. All eyes underwent 24-2 visual field testing and OCT (Spectralis SD-OCT) ONH and macular imaging. SWF images (up to 43° × 28°) were created by stitching together ONH cube scans centered on the optic disc and macular cube scans centered on the fovea. Visual field progression was defined as guided progression analysis likely progression and/or a significant (P < 0.01) mean deviation slope of less than -1.0dB/year. Mixed effects models were used to compare rates of change. Highly myopic eyes were included. Thirty glaucomatous eyes were classified as progressing. In eyes with glaucoma, mean global rate of change was -1.22 µm/year (P < 0.001) using SWF images and -0.83 µm/year (P = 0.003) using ONH cube scans. Rate of change was significantly greater in eyes with progressing glaucoma compared with eyes with nonprogressing glaucoma (-1.51 µm/year vs. -1.24 µm/year; P = 0.002) using SWF images and was similar using ONH cube scans (P = 0.27). In this cohort that includes eyes with and without high axial myopia, the mean rate of retinal nerve fiber layer thinning measured using SWF images was faster in eyes with progressing glaucoma than in eyes with nonprogressing glaucoma. Wide-field OCT images including the ONH and macula can be effective for monitoring glaucomatous progression in patients with and without high myopia.

Optical coherence tomography angiography findings in high myopia

Background Optical coherence tomography angiography (OCTA) is a sophisticated ophthalmic imaging technique, enables us to obtain images of blood vessels and blood flow at different levels of the retina and choroid without the use of contrast. Therefore, its potential application could be useful in the early detection of retinal vascular and macular pathologies and to recognize the pathogenesis of various ophthalmic diseases. Aim In this study, OCTA was utilized to detect the macular changes in eyes with high myopia. Patients and methods This cross-sectional study was carried out at the Department of Ophthalmology of Menoufia University Hospital according to the Helsinki Declaration and the Code of Ethics for Human Research of the World Medical Association and after obtaining approval of the institutional review board (IRB) 10/2022 OPHT 32. A total of 152 eyes of the study participants were included in this study and were divided into group A, which includes 76 eyes of highly myopic participants (&gt;−6 D), and group B includes 76 eyes of nonmyopic (emmetropic) participants. Result In our study, there was a high statistically significant difference between the studied groups as regards axial length. In group A, it was 27.26±0.74 mm, while in group B, it was 23.14±0.73 mm (P&lt;0.001). Regarding the comparison between studied cases according to the superficial and deep vascular density (SVD and DVD), there was a statistically significant difference between the studied groups. As regards overall SVD in group A, it was 46.48±4.78 while in group B, it was 51.78±2.8 (P&lt;0.001). Meanwhile, the overall DVD in group A was 56.67±3.98, while in group B was 58.76±2.27 (P&lt;0.001). Conclusion In the light of our study, OCTA shows significantly reduced SVD and DVD in eyes with high axial myopia, which could be an important aspect of understanding the natural history and etiology of pathologic myopia.

Indications and Outcomes of Intraocular Lens Explantation in a Tertiary Eyecare Center in Hungary between 2006 and 2020.

Our study aimed to evaluate the indications and outcomes of intraocular lens (IOL) explantation surgeries in a tertiary eyecare center in Hungary. This retrospective study included all IOL explantation surgeries performed between 2006 and 2020 at the Department of Ophthalmology of Semmelweis University, Budapest, Hungary. There were no exclusion criteria for this study. For each patient, the demographics, clinical history, preoperative status, indications for IOL explantation, and operative and postoperative details were reviewed. Primary outcomes included explantation indications and the type of secondary implanted IOL. A total of 161 eyes from 153 patients were included (96 males; 62.7%); age at the time of the IOL explantation was 65.0 ± 17.4 years. The mean time between primary cataract surgery and IOL explantation was 8.5 ± 7.7 years. In total, 139 (86.3%) PCIOLs and 22 (13.7%) ACIOLs were explanted. The main indications for IOL explantation were dislocation (n = 133; 95.7%) and refractive cause (n = 2; 1.4%) in the PCIOL group. Among ACIOL explantations, the main reasons were pseudophakic bullous keratopathy (n = 14; 63.6%), dislocation (n = 4; 18.2%), and refractive cause (n = 2; 9.1%). In the PCIOL group, 115 (82.7%) primary IOLs were implanted in the capsular bag, 16 (11.5%) were sulcus fixated, and 8 (5.8%) were scleral fixated. The most frequent ocular comorbidities were previous vitrectomy (n = 50, 31.1%), previous ocular trauma (n = 45, 28.0%), glaucoma (n = 16, 9.9%), pseudoexfoliation syndrome (n = 15, 9.3%), and high axial myopia (n = 14, 8.7%). The most commonly used secondary IOL implant was the prepupillary iris-claw IOL (n = 115, 73.7%), followed by the retropupillary iris-claw IOL (n = 32, 20.5%). Uncorrected visual acuity (UCVA) was significantly better following IOL exchange in the entire sample (1.57 ± 0.61 (range: 2.40-0.05) vs. 0.77 ± 0.56 (range: 2.40-0.00); p < 0.001). Best-corrected visual acuity (BCVA) was maintained or improved in 80.7% of cases after IOL explantation. The most common indication for IOL explantation at a tertiary eyecare center in Hungary is IOL dislocation, followed by pseudophakic bullous keratopathy. Prepupillary and retropupillary iris-claw IOL are the most frequently used secondary implants and their use resulted in a significant UCVA improvement following IOL exchange.

Diagnostic Accuracy of Optic Nerve Head and Macula OCT Parameters for Detecting Glaucoma in Eyes With and Without High Axial Myopia

PurposeTo characterize structural differences and assess the diagnostic accuracy of optic nerve head (ONH) and macula optical coherence tomography (OCT) parameters to detect glaucoma in eyes with and without high axial myopia. DesignCross-sectional study Methods368 glaucoma and 411 healthy eyes with no axial myopia, 393 glaucoma and 271 healthy eyes with mild axial myopia and 124 glaucoma and 85 healthy eyes with high axial myopia were included. Global and sectoral peripapillary retinal nerve fiber layer thickness (pRNFLT), Bruch's membrane opening minimum rim width (BMO-MRW), ganglion cell inner plexiform layer thickness (GCIPLT), and macula RNFLT (mRNFLT) were compared and the diagnostic accuracy for glaucoma detection was evaluated using adjusted area under the receiver operating characteristic curve (AUC). ResultsDiagnostic accuracy for ONH and macula parameters to detect glaucoma was generally high and differed by myopia group. For ONH parameters the diagnostic accuracy was highest for global (AUC=0.95) and inferotemporal (AUC=0.91) pRNFLT for high myopes and global BMO-MRW for non-myopes (AUC=1.0) and mild myopes (AUC=0.97). For macula parameters, the diagnostic accuracy was higher in high myopes with 6 of the 11 GCIPLT global/sectors having adjusted AUCs > 0.90 compared to non-high myopes with no AUCs > 0.90. In all myopia groups, mRNFLT had lower AUCs than GCIPLT. ConclusionsThe diagnostic accuracy for pRNFL and GCIPL was high for high axial myopic eyes and shows promise for glaucoma detection in high myopes. Further analysis is needed to determine whether the high diagnostic accuracy can be confirmed in other populations.

Effectivity and safety of trifocal intraocular lenses and capsular tension rings implantation for cataract patients with axial high myopia.

To assess effectivity and safety of trifocal intraocular lenses (IOLs) and capsular tension rings in treating cataract patients with axial high myopia. A prospective nonrandomized controlled clinical trial was conducted. Totally 98 eyes (74 patients) who underwent femtosecond laser-assisted cataract surgery (FLACS) with trifocal IOLs were enrolled in the study and followed up for 2y after surgery: 46 eyes (33 patients) with capsular tension ring implantation in the long axial lengths (AL) group (26<AL<29 mm) and 52 eyes (41 patients) in the normal AL group (22<AL<24.5 mm). Postoperative outcomes about effectivity and safety, including the subjective and objective visual quality, and postoperative complications were assessed. Uncorrected distance visual acuity at 5 m and uncorrected intermediate visual acuity at 60 and 80 cm in the long AL group were significantly worse than those in the normal AL group at 3mo postoperatively (P<0.05). The differences in reading speed, spectacle independence and potential visual complaints between the two groups were not statistically significant (P>0.05). The dysfunctional lens index and total modulation transfer function (MTF) average height were similar between the two groups. The postoperative internal coma aberrations in the axial high myopia eyes were significantly higher than that in the normal AL group (P<0.05). The total satisfaction score in the long AL group (91.32±2.76) was slightly higher than that in the normal AL group (90.36±3.47), but there was no difference (P=0.136). A statistically negative correlation was found between corrected distance visual acuity (CDVA) and dysfunctional lens index (r=-0.382, P=0.009), and between CDVA and the total MTF average height (r=-0.374, P=0.01). But there was no significant correlation between CDVA and total satisfaction score (r=0.059, P=0.696). Postoperative complications mainly presented as posterior capsular opacity (PCO), retinal detachment and cystoid macular edema. There was no difference in the incidence of fundus disease (6.5% vs 3.8%, P=0.663) or PCO (17.4% vs 7.7%, P=0.217) between the two groups at two years. The utilization of trifocal IOL and capsular tension ring implantation is beneficial for cataract patients with axial high myopia undergoing FLACS. This approach not only ensures excellent subjective feelings and objective visual quality, but also does not increase the incidence of postoperative complications.

Systematic evaluation of machine learning-enhanced trifocal IOL power selection for axial myopia cataract patients

PurposeThis study aimed to evaluate and optimize intraocular lens (IOL) power selection for cataract patients with high axial myopia receiving trifocal IOLs. DesignA multi-center, retrospective observational case series was conducted. Patients having an axial length ≥26 mm and undergoing cataract surgery with trifocal IOL implanted were studied. MethodsPreoperative biometric and postoperative outcome data from 139 eyes were collected to train and test various machine learning (ML) models (support vector machine, linear regression, and stacking regressor) using five-fold cross-validation. The models' performance was further validated externally using data from 48 eyes enrolled from other hospitals. Performance of seven IOL calculation formulas (BUII, Kane, EVO, K6, DGS, Holladay I, and SRK/T) were examined with and without ML models. ResultsThe results of cross-validation revealed improvements across all IOL calculation formulas, especially for K6 and Holladay I. The model increased the percentage of eyes with a prediction error (PE) within ±0.50 D from 71.94% to 79.14% for K6, and from 35.25% to 51.80% for Holladay I. In external validation involving 48 patients from other centers, six out of seven formulas demonstrated a reduction in the mean absolute error (MAE). K6's PE within ±0.50 D improved from 62.50% to 77.08%, and Holladay I from 16.67% to 58.33%. ConclusionsIn this study, we conducted a comprehensive evaluation of seven IOL power calculation formulas in high axial myopia cases and explored the effectiveness of the Stacking Regressor model in augmenting their accuracy. Of these formulas, K6 and Holladay I exhibited the most significant improvements, suggesting that integrating ML may have varying levels of effectiveness across different formulas but holds substantial promise in improving the predictability of IOL power calculations in patients with long eyes.

Effect of capsular tension ring on the refractive outcomes of patients with extreme high axial myopia after phacoemulsification

PurposeThe aim of the study is to evaluate the effect of capsular tension ring (CTR) implantation following cataract surgery on the refractive outcomes of patients with extreme high axial myopia.MethodsSixty eyes (with an axial length of ≥26 mm) were retrospectively reviewed and classified into two groups: CTR group (n = 30), which underwent CTR implantation following phacoemulsification, and control group (n = 30), which did not undergo CTR implantation. Intraocular lens (IOL) calculation was performed using Barrett Universal II (UII), Haigis, and SRK/T formulas. The refractive prediction error (PE) was calculated by subtracting the postoperative refraction from predicted refraction. The mean PE (MPE), mean absolute error (MAE), and percentages of eyes that had a PE of ±0.25, ±0.50, ±1.00, or ±2.00 diopters (D) were calculated and compared.ResultsNo significant differences were observed in PE between the two groups. The Barrett UII formula revealed a lower AE in the CTR group than in the control group (p = 0.015) and a lower AE than the other two formulas (p = 0.0000) in both groups. The Barrett UII formula achieved the highest percentage of eyes with a PE of ±0.25 D (66.67%).ConclusionsThe refractive outcomes were more accurate in eyes with CTR implantation than in those with routine phacoemulsification based on the Barrett UII formula. The Barrett UII formula was recommended as the appropriate formula when planning CTR implantation in high myopia.

The optic nerve in glaucoma

Purpose: To describe particularities of the optic nerve head of axially highly myopic eyes.Methods: Measurements were obtained from enucleated globes and from population‐based studies.Results: Morphologic optic disc particularities in high axial myopia included enlarged disc size (secondary macrodisc), widening and temporal translocation of the papillary Bruch's membrane (BM) opening, parapapillary gamma and delta zone, elongation and thinning of lamina cribrosa and peripapillary scleral flange, steeper translamina cribrosa pressure gradient, decreased peripapillary choroid thickness, longer distance between peripapillary arterial circle and optic disc, optic cup flattening, presumably a stretching of the lamina cribrosa pores, and peripapillary intrachoroidal cavitations. These changes may be explained by growth of new BM in the retroequatorial region in the process of emmetropization or myopization as “overshooting” of the emmetropization process.Conclusions: The intrapapillary and parapapillary changes in the highly myopic optic nerve head may be reason for the increased susceptibility for glaucomatous optic nerve damage in high axial myopia. The widening of the papillary BM opening and the potential shift of the optic nerve head's 3 layer into temporal direction, both potentially leading to the development of parapapillary gamma zone may be of interest for elucidating the process of emmetropization/myopization.

Yokoyama procedure for cyclic strabismus with axial high myopia:a case report

BackgroundIt is a very rare form of ocular motility characterized by alternating strabismus and orthotropia. We report a patient with a 48-h cycle of esohypotropia associated with axial high myopia that resolved by Yokoyama procedure.Case presentationA 43-year-old female patient who underwent left medial rectus muscle recession and lateral rectus muscle resection elsewhere due to highly myopic strabismus 2 years ago. The patient experienced a recurrence of left esohypotropia 12 months after undergoing surgery, exhibiting a 48-hour cycle. The cycle is one full day of esohypotropia and one day of orthotropia. The patient exhibited a case of high myopia in the left eye, characterized by a diopter measurement of -24.00DS and an eye axis measurement of 28.43 mm. Orbital CT showed supertemporal dislocation of the posterior portion of the elongated globe out from the muscle cone. Based on these observations, we performed Yokoyama procedure by uniting the muscle bellies of the superior rectus(SR) and lateral rectus (LR) muscles to restoring the dislocated globe back into the muscle cone.ConclusionsWhen cyclic strabismus is combined with axial high myopia, the Yokoyama procedure was effective and cycles are successfully terminated without overcorrection on no squint days. The purpose of this procedure is to put the dislocated globe back into its muscle cone by uniting the muscle bellies of the superior rectus and lateral rectus.

Fluid Supplementation Through Weakened Zonules via Side-Port Incision to Maintain Intraocular Pressure in High Myopic Eyes.

During phacoemulsification, the infusion pressure can cause the liquefied vitreous fluid to escape through the ciliary fiber interspace in highly myopic eyes, leading to reduced vitreous cavity pressure similar to vitrectomized eyes. This study assessed the probability of low intraocular pressure (IOP) in high myopic eyes with different axial length (AL) group undergoing cataract surgery, as well as the impact of balanced salt solution (BSS) supplementation and the optimal IOP value for such supplementation. The control group consisted of cataract eyes with normal AL (group 1: 22mm ≤ AL < 24.5mm), while cataract eyes with high axial myopia were categorized into three groups (group 2: 26mm ≤ AL < 28mm, group 3: 28mm ≤ AL < 30mm, group 4: AL ≥ 30mm). IOP was measured using the iCare pro tonometer intraoperatively. BSS supplementation was performed to raise IOP in cases of low IOP, before intraocular lens (IOL) implantation and before the end of surgery. The probability of low IOP was calculated, and the IOP before and after supplementation were compared. Ninety-five eyes were included. The total probability of low IOP in groups 2, 3, and 4 was 56.52, 62.50, and 70.83%, respectively, significantly higher than that in group 1 (16.67%). Similarly, the probability of low IOP before IOL implantation was significantly higher in groups 2, 3, 4 (43.48, 41.67, and 62.50%) compared to group 1 (4.17%, P < 0.05). The IOP before and after the first BSS supplementation in three high myopia groups were statistically significant (P < 0.05), increasing from 12.10mmHg (range, 6.0-24.9mmHg) to 16.60mmHg (range, 10.2-34.4mmHg). After the second BSS supplementation before the end of surgery, the IOP of high myopia groups increased from 12.60mmHg (range, 7.0-25.3mmHg) to 14.60mmHg (range, 9.8-25.3mmHg). The condition of highly myopic eyes seems more likely to develop low IOP during cataract surgery. There is an observed correlation: as AL increases, the total probability of low IOP rises. In patients with IOP < 9.5mmHg intraoperatively, fluid supplementation via a side-port incision can effectively raise IOP to about 16mmHg before IOL implantation and about 14mmHg after incision sealing, facilitating smoother IOL implantation and reducing the risk of postoperative low IOP. NCT, NCT05201677. Registered 23 November 2021-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05201677 .

Retinal Artery Angles in High Axial Myopia and Its Relationship With Visual Function.

To evaluate the retinal artery angles in high axial myopia and assess the correlation with other morphometric and functional parameters. This cross-sectional study included 112 eyes of 112 patients with high axial myopia. Based on axial length (AL), the participants were divided into three groups: group 1 (26 ≤ AL < 28 mm), group 2 (28 ≤ AL < 31 mm), and group 3 (≥31 mm). Scanning laser ophthalmoscopy imaging was used to analyze the retinal artery angle (Yugami correlated angle [YCA]). Retinal vascular densities (VDs) in both superficial capillary plexuses (SCPs) and deep capillary plexuses were evaluated. Fixation behavior, including retinal mean sensitivity (MS), macular fovea 2°, 4° fixation rate (P1, P2), and 68.2% bivariate contour ellipse area, were analyzed by microperimetry. Finally, the correlation between YCAs and AL, VDs, best-corrected visual acuity (BCVA), and fixation behavior was assessed. The YCAs showed significant differences among the three groups (all P < 0.001, respectively). Compared to group 1, the YCA decreased in group 2 (P < 0.001) and continued to decrease in group 3 (P = 0.043). The correlation analysis revealed that smaller YCAs (YCA, YCA1/2, YCA1/4) were positively correlated with the longer AL (ρ = 0.580, 0.545, 0.448, P < 0.001) and lower VDs in any sector in SCPs (all P ≤ 0.05). Furthermore, smaller YCAs were positively correlated with decreased BCVA (ρ = 0.392, 0.387, 0.262; all P < 0.001) and reduced MS (ρ= 0.300, 0.269, 0.244; all P < 0.05). Smaller YCAs were correlated with longer AL, lower VD in SCP, decreased BCVA, and reduced MS. The YCAs might reflect vascular deformation caused by axial elongation and could potentially be useful in predicting visual function in high axial myopia. The quantitative analysis of YCAs in fundus photography holds potential clinical value in predicting visual function in high axial myopia.

The Genetic Determinants of Axial Length: From Microphthalmia to High Myopia in Childhood.

The axial length of the eye is critical for normal visual function by enabling light to precisely focus on the retina. The mean axial length of the adult human eye is 23.5 mm, but the molecular mechanisms regulating ocular axial length remain poorly understood. Underdevelopment can lead to microphthalmia (defined as a small eye with an axial length of less than 19 mm at 1 year of age or less than 21 mm in adulthood) within the first trimester of pregnancy. However, continued overgrowth can lead to axial high myopia (an enlarged eye with an axial length of 26.5 mm or more) at any age. Both conditions show high genetic and phenotypic heterogeneity associated with significant visual morbidity worldwide. More than 90 genes can contribute to microphthalmia, and several hundred genes are associated with myopia, yet diagnostic yields are low. Crucially, the genetic pathways underpinning the specification of eye size are only now being discovered, with evidence suggesting that shared molecular pathways regulate under- or overgrowth of the eye. Improving our mechanistic understanding of axial length determination will help better inform us of genotype-phenotype correlations in both microphthalmia and myopia, dissect gene-environment interactions in myopia, and develop postnatal therapies that may influence overall eye growth.

Accuracy of Different Intraocular Lens Calculation Formulas in Patients with High Axial Myopia

Background The two main problems encountered in calculation of intra ocular lens power are the measurement of the proper axial length (AL), and the lack of accuracy of the available formulas that calculate the power of the intra ocular lens in cases of eyes with high axial length. Aim of the Work To compare the accuracy of intraocular lens (IOL) calculation formulae (Holladay I, Haigis, SRK/T, Hoffer Q, Holladay II, and Barrett Universal II) in the prediction of postoperative refraction for eyes with AL 26.0 mm or more. Patients and Methods A prospective study was carried on forty-seven eyes of forty-seven patients. All the patients were managed at Ain Shams University Hospitals in cooperation with a specialized centre between April 2019 and March 2020. Results Mean absolute error (MAE) was calculated for each formula showed that the least MAE is for Barrett Universal II formula. SRK/T formula is the 2nd lower MAE followed by Haigis formula and the last is Holladay II formula. The scatter plots between AL and absolute error from each of the six calculations formulae was done and showed that Barrett universal II has negative correlation with AL. As for SRK/T and Haigis formulae there is a linear correlation. Numerical Predictive Error showed that SRK/T formula had the lowest mean numerical error followed by Haigis formula then Barrett Universal II and last came Holladay II formula. Conclusion for high axial myopic eyes, the Barrett Universal II formula is the best in this group of patients and provide the lowest mean absolute error, highest percentage of eyes within ≤ ± 0.50 D and the lowest risk of refractive surprise compared to other IOL power calculation formulae. Then comes Haigis and SRK/T formulae which performed similarly and provide a good predictable outcome then at last came Holladay II formula.

Multimodal Deep Learning Classifier for Primary Open-angle Glaucoma Diagnosis Using Wide-field Optic Nerve Head Cube Scans in Eyes With and Without High Myopia.

An OCT-based multimodal deep learning classification model including texture information is introduced that outperforms single-modal models and multimodal models without texture information for glaucoma diagnosis in eyes with and without high myopia. To evaluate the diagnostic accuracy of a multimodal deep learning (DL) classifier using wide optical coherence tomography (OCT) optic nerve head cube scans in eyes with and without axial high myopia. 371 primary open-angle glaucoma (POAG) eyes and 86 healthy eyes, all without axial high myopia (axial length AL≤26mm) and 92 POAG eyes and 44 healthy eyes, all with axial high myopia (AL>26mm) were included. The multimodal DL classifier combined features of 3 individual VGG-16 models: 1) texture-based en face image, 2) retinal nerve fiber layer (RNFL) thickness map image and 3) confocal scanning laser ophthalmoscope (cSLO) image. Age, AL, and disc area adjusted area under the receiver operating curves (AUROC) were used to compare model accuracy. Adjusted AUROC for the multimodal DL model was 0.91 (95% CI = 0.87, 0.95). This value was significantly higher than the values of individual models (0.83 [0.79, 0.86] for texture based en face image; 0.84 [0.81, 0.87] for RNFL thickness map; and 0.68 [0.61, 0.74] for cSLO image; all P≤0.05). Using only highly myopic eyes, the multimodal DL model showed significantly higher diagnostic accuracy (0.89 [0.86 , 0.92]) compared to texture en face image (0.83 [0.78 , 0.85]), RNFL (0.85 [0.81 , 0.86]) and cSLO image models (0.69 [0.63 , 0.76]) (all P≤0.05). Combining OCT-based RNFL thickness maps with texture based en face images showed better ability to discriminate between healthy and POAG than thickness maps alone, particularly in high axial myopic eyes.

Prevalence and Associations of Nonglaucomatous Optic Nerve Atrophy in High Myopia: The Ural Eye and Medical Study

To assess the prevalence of non-glaucomatous optic nerve atrophy (NGOA) and its associations in highly myopic individuals. Population-based study. The Ural Eye and Medical Study included 5899 (80.5%) out of 7328 eligible individuals. The participants underwent an ophthalmological and general examination. NGOA, graded into five arbitrary stages, was characterized by decreased visibility of the retinal nerve fiber layer (RNFL) on fundus photographs and on red-free fundus photographs, neuroretinal rim pallor, abnormally thin retinal arteriole diameter, and abnormally thin peripapillary RNFL as measured by optical coherence tomography. NGOA prevalence and degree. Out of 5709 (96.9%) participants with axial length measurements, 130 (2.3%) individuals were highly myopic, of which 116 (89.2%) participants (age:57.8±11.1 years; range:41.0-84.2 years; axial length:27.0±1.2mm; range:26.01-32.87mm) had available fundus photographs and OCT images and were included into the present study. NGOA prevalence was 34/116 (29.3%;95%CI:21.0,38.0), and mean NGOA degree in eyes with NGOA was 1.7±1.0 arbitrary units. Higher NGOA degree correlated (multivariable analysis; regression coefficient r2:0.59) with longer axial length (beta:0.22; B:0.18; 95%CI:0.05,0.31; P=0.007), wider temporal parapapillary gamma zone width (beta:0.50; B:0.45; 95%CI:0.30,0.59; P<0.001), higher prevalence of diabetes (beta:0.20; B:0.63; 95%CI:0.20,1.06; P=0.005), and higher systolic blood pressure (beta:0.15; B:0.01; 95%CI:0.001,0.02; P=0.03). Higher NGOA prevalence was associated with longer axial length (odds ratio (OR):7.45; 95%CI:2.15,25.7; P=0.002), wider temporal parapapillary gamma zone (OR:6.98; 95%CI:2.61,18.7; P<0.001), and higher systolic blood pressure (OR:1.05; 95%CI:1.01,1.10; P=0.02). In this ethnically mixed population from Russia with an age of 40+ years, high axial myopia showed a relatively high prevalence of NGOA, increasing with longer axial length and wider temporal parapapillary gamma zone. For each millimeter of axial elongation and widening of gamma zone, the odds for NGOA increased 7.45-fold and 6.98-fold, respectively. The axial elongation-associated and gamma zone-related increase in the distance between the retinal ganglion cells and the optic disc may lead to a lengthening and stretching of the retinal ganglion cell axons and may pathogenetically be of importance. In highly myopic eyes, NGOA may be a reason for visual field and central visual acuity loss, unexplainable by myopic macular pathologies.

Central visual field damage in glaucoma eyes with choroidal microvasculature dropout with and without high axial myopia

PurposeTo characterise the relationship between a deep-layer microvasculature dropout (MvD) and central visual field (VF) damage in primary open-angle glaucoma (POAG) patients with and without high axial myopia.DesignCross-sectional study.MethodsSeventy-one eyes...

Optical Biometry versus Ultrasonic Biometry in Intraocular Lens Power Calculations in High Axial Myopia

Background: IOL implantation is now seen as a type of refractive surgery rather than merely being used to improve visual rehabilitation. In this context, accurate pre-operative biometric measurement is a crucial requirement. Aim of the work: comparing the refractive predictability of optical biometry versus applanation ultrasonic biometry in high axial myopic eyes undergoing cataract surgery. Patients and Methods: A total of 50 eyes from 50 patients with axial lengths greater than 26.5 mm and just cataract were analyzed in this study. In this study, patients were randomly assigned to one of two groups. Twenty-five patients were split evenly between the two groups, with group 1 using optical biometry and group 2 using applanation ultrasound. Results: Group 1 mean age was 53.8 ± 8.9 years since it was 51.8 ± 10.8 years in group 2. There were 7 males (28%) and 18 females (72%) in group 1 while there were 11 males (44%) and 14 females (56%) in group 2. There was no statistically significant variation in axial length between groups (p-value = 0.101).Statistically significant increased K1 and K2 among group 1 when compared with group 2 (p-value =0.003 and 0.001 respectively). Statistically significant (p-value = 0.015) increased anterior chamber depth (ACD) in group 1 when compared with group 2. Significant differences in postoperative refraction were seen across the groups (p 0.001) (SE values). Conclusion: Optical biometry offers significantly more precise IOL power prediction and refractive outcomes in cataract surgery for high axial myopia than applanation ultrasound biometry.

Macula structural and vascular differences in glaucoma eyes with and without high axial myopia

AimsTo identify clinically relevant parameters for identifying glaucoma in highly myopic eyes, an investigation was conducted of the relationship between the thickness of various retinal layers and the superficial vessel...