Myopia and the long-term incidence of cataract and cataract surgery: the Blue Mountains Eye Study

Accuracy of 14 intraocular lens power calculation formulas in extremely long eyes

PURPOSE

To compare the accuracy of 14 formulas in calculating intraocular lens (IOL) power in extremely long eyes with axial length (AL) over 30.0 mm.

METHODS

In this retrospective study, 211 eyes (211 patients) with ALs > 30.0 mm were successfully treated with cataract surgery without complications. Ocular biometric parameters were obtained from IOLMaster 700. Fourteen formulas were evaluated using the optimized A constants: Barrett Universal II (BUII), Kane, Emmetropia Verifying Optical (EVO) 2.0, PEARL-DGS, T2, SRK/T, Holladay 1, Holladay 2, Haigis and Wang-Koch AL adjusted formulas (SRK/Tmodified-W/K, Holladay 1modified-W/K, Holladay 1NP-modified-W/K, Holladay 2modified-W/K, Holladay 2NP-modified-W/K). The mean prediction error (PE) and standard deviation (SD), mean absolute errors (MAE), median absolute errors (MedAE), and the percentage of prediction errors (PEs) within ± 0.25 D, ± 0.50 D, ± 1.00 D were analyzed.

RESULTS

The Kane formula had the smallest MAE (0.43 D) and MedAE (0.34 D). The highest percentage of PE within ± 0.25 D was for EVO 2.0 (37.91%) and the Holladay 1NP-modified-W/K formulas (37.91%). The Kane formula had the highest percentage of PEs in the range of ± 0.50, ± 0.75, ± 1.00, and ± 2.00 D. There was no significant difference in PEs within ± 0.25, ± 0.50 ± 0.75 and ± 1.00 D between BUII, Kane, EVO 2.0 and Wang-Koch AL adjusted formulas (P > .05) by using Cochran's Q test. The Holladay 2modified-W/K formula has the lowest percentage of hyperopic outcomes (29.38%).

CONCLUSIONS

The BUII, Kane, EVO 2.0 and Wang-Koch AL adjusted formulas have comparable accuracy for IOL power calculation in eyes with ALs > 30.0 mm.

Comparison of macular changes and visual outcomes between femtosecond laser-assisted cataract surgery and conventional phacoemulsification surgery for high myopic cataract patients

BACKGROUND

To evaluate differences in log MAR best-corrected visual acuity (BCVA) improvement and postoperative central foveal thickness (CFT) and choroidal thickness (CT) changes between conventional phacoemulsification surgery (CPS) and femtosecond laser-assisted cataract surgery (FLACS) for high-myopia cataracts.

METHODS

This was a retrospective and observational study. One hundred and two eyes of 102 patients with high-myopia cataracts were examined. CPS was performed in 54 eyes, and FLACS was performed in 48 eyes. All eyes underwent logMAR BCVA, CFT and CT of three different sectors preoperatively and one week and six months postoperatively.

RESULTS

The logMAR BCVA improved significantly after surgery in both groups (both P < 0.001), but no difference was observed in BCVA improvement between the groups (P = 0.554). Moreover, no significant differences were reflected in the changes in CFT, nasal 1 mm CT or temporal 1 mm CT between the two groups, and only subfoveal choroidal thickness (SFCT) in the CPS group decreased significantly compared with that in the FLACS group at any postoperative time (P = 0.003 and 0.026). AL, preoperative logMAR BCVA, and CT of the three regions exhibited a notable correlation with postoperative BCVA (all P < 0.05) according to univariate logistic regression analysis. However, only the AL, preoperative logMAR BCVA and SFCT remained significant in the multivariate model. Postoperative logMAR BCVA revealed a positive correlation with AL and preoperative logMAR BCVA but a negative correlation with SFCT.

CONCLUSIONS

FLACS was not superior to CPS in improving BCVA but had less impact on SFCT in the treatment of high-myopia cataracts. Eyes with a longer AL, worse preoperative logMAR BCVA and thinner SFCT had a high risk of worse postoperative BCVA.

Refractive stability and timing of spectacle prescription following cataract surgery in myopic eyes

PURPOSE

To investigate the post-operative refractive stabilisation time and provide evidence for the optimal timing of a spectacle prescription in myopic post-cataract surgery patients.

METHODS

A total of 116 consecutive myopic cataract patients were recruited from the Zhongshan Ophthalmic Center in this prospective study. Post-operative subjective refraction was assessed after 1 week and 1 month (4-6 weeks), with the interval for the new spectacle acquisition being recorded. Visual Function Index-14 (VF-14) questionnaires were used to assess the vision-related quality of life.

RESULTS

There was no significant difference in spherical (p = 0.33), cylindrical (p = 0.65) or spherical equivalent refractions (p = 0.45) obtained 1 week and 1 month post-operatively, indicating that subjects achieved refractive stability within 1 week. In subgroups having differing age and axial lengths, there were also no significant differences between the 1 week and 1 month findings. The spherical equivalent refractive shift between 1 week and 1 month was significantly correlated with the post-operative prediction error (R = 0.35; p < 0.001). Only five (4.3%) out of 116 patients obtained new spectacles 1 week post-surgery. The VF-14 values improved from 85.77 ± 7.24 to 90.45 ± 5.39 after acquiring new spectacles (p < 0.01).

CONCLUSIONS

The stabilisation of subjective refraction occurred within 1 week in myopic cataract patients. Shortening the interval before prescribing a new spectacle prescription is recommended for myopic patients following cataract surgery to improve their vision-related quality of life.

Association Between Physical Indicators and Myopia in American Adolescents: National Health and Nutrition Examination Survey 1999-2008

PURPOSE

Myopia is the most prevalent refractive error, imposing a substantial economic burden. Physical indicators constitute significant influencing factors for myopia. The National Health and Nutrition Examination Survey (NHANES) investigates the health and nutritional status of both children and adults in the United States. This study leveraged NHANES to explore the association between physical indicators and myopia among American adolescents.

DESIGN

Retrospective case-control study.

METHODS

The final study cohort consisted of 9008 adolescents. Demographic data, physical indicators, and vision data were extracted. The association between myopia and demographic factors, as well as physical indicators, employed weighted methods. Regression models were utilized to identify the associations between physical indicators and myopia. Cumulative odds logistic regression analysis was employed to investigate the association between physical indicators and the degree of myopia. Restricted cubic spline analysis was employed to examine the potential nonlinear relationship between physical indicators and the risk of myopia.

RESULTS

The occurrence of myopia was significantly correlated with age (P < .001) and race (P = .019). Adolescents in the fourth percentile for weight (odds ratio [OR] 1.38, 95% confidence interval [CI] 1.13-1.70) and body mass index (BMI) (OR 1.26, 95% CI 1.05-1.51) exhibited an increased possibility of myopia. The highest risk of myopia was observed when the BMI approached 30. Height emerged as a risk factor for the degree of myopia (OR 1.02, 95% CI 1.01-1.03).

CONCLUSIONS

A certain association existed between physical indicators and myopia. Weight and BMI were related to the occurrence of myopia, while height and race were associated with the degree of myopia.

Cataract surgery following refractive surgery: Principles to achieve optical success and patient satisfaction

A growing number of patients with prior refractive surgery are now presenting for cataract surgery. Surgeons face a number of unique challenges in this patient population that tends to be highly motivated to retain or regain functional uncorrected acuity postoperatively. Primary challenges include recognition of the specific type of prior surgery, use of appropriate intraocular lens (IOL) power calculation formulas, matching IOL style with spherical aberration profile, the recognition of corneal imaging patterns that are and are not compatible with toric and/or presbyopia-correcting lens implantation, and surgical technique modifications, which are particularly relevant in eyes with prior radial keratotomy or phakic IOL implantation. Despite advancements in IOL power formulae, corneal imaging, and IOL options that have improved our ability to achieve targeted postoperative refractive outcomes, accuracy and predictability remain inferior to eyes that undergo cataract surgery without a history of corneal refractive surgery. Thus, preoperative evaluation of patients who will and will not be candidates for postoperative refractive surgical enhancements is also paramount. We provide an overview of the specific challenges in this population and offer evidence-based strategies and considerations for optimizing surgical outcomes.

Actual lens positions of three intraocular lenses in highly myopic eyes: an ultrasound biomicroscopy-based study

AIM

To evaluate the actual lens positions (ALPs) of three intraocular lenses (IOLs) in highly myopic eyes and to identify relevant factors using ultrasound biomicroscopy (UBM).

METHODS

Ninety-three highly myopic eyes (93 patients) that underwent uneventful cataract surgery were included: 36 eyes were implanted with Zeiss 409MP IOLs, 27 with Rayner 920H IOLs and 30 with HumanOptics MCX11 IOLs. The prediction error (PE), ALP determined by UBM and the factors associated with ALP at 3 months after surgery were evaluated.

RESULTS

The eyes in the MCX11 IOL group had a more hyperopic PE (0.67±0.45 diopters (D)) and greater ALP (4.86±0.39 mm) than those in the 409MP and 920H IOL groups at 3 months after surgery (PE: -0.25±0.54 and -0.16±0.65 D, respectively; ALP: 4.34±0.26 and 4.14±0.32 mm, respectively). The MCX11 IOLs showed more backward bending deformation after surgery than 409MP and 920H IOLs. The radius of curvature of the IOL was negatively correlated with ALP (r=-0.532, p=0.002) in the MCX11 IOL group, but not in the other two groups. Multivariate analysis showed that MCX11 IOLs were more prone to bending in highly myopic eyes with a smaller anterior capsular opening (β=0.236, p=0.023) and lower implanted power (β=0.542, p=0.001).

CONCLUSION

In highly myopic eyes, IOLs with good capsular support show less backward bending, which result in a more stable lens position and refractive status postoperatively. Severe capsular contraction and low implanted power are risk factors for bending of certain IOLs.

Effect of Segmented Optical Axial Length on the Performance of New-Generation Intraocular Lens Power Calculation Formulas in Extremely Long Eyes

PURPOSE

To evaluate the performance of traditional vergence formulas with segmented axial length (AL) compared to traditional composite AL in extremely long eyes, and to determine whether the segmented AL can be extended to the new-generation formulas, including the Barrett Universal II, Emmetropia Verifying Optical 2.0 (EVO2), Hill-RBF 3.0 (Hill3), Kane, and Ladas Super formula (LSF) formulas in extremely long eyes.

SETTING

National Hospital. Organization, Tokyo Medical Center, Japan.

DESIGN

Retrospective case series.

METHODS

Consecutive patients who underwent uncomplicated cataract surgery implanted with a three-piece intraocular lens between December 2015 and March 2021 were retrospectively reviewed. The composite AL was measured with a swept-source optical coherence tomography (SS-OCT) biometer using a mean refractive index. The segmented AL was calculated by summing the geometric lengths of the ocular segments (cornea, aqueous, lens, and vitreous) using multiple specific refractive indices based on the data obtained by the SS-OCT-based biometer. When refraction was measured at three months postoperatively, the median absolute errors (MedAEs) were calculated with two ALs for each formula.

RESULTS

The study included 31 eyes of 22 patients. The segmented AL (30.45 ± 1.23 mm) was significantly shorter than the composite AL (30.71 ± 1.28 mm, p < 0.001). The MedAEs were significantly reduced when using segmented AL for SRK/T, Haigis, Hill3, and LSF, compared to those obtained using composite AL (0.38 vs. 0.62, 0.48 vs. 0.79, 0.50 vs. 0.90, 0.34 vs. 0.61, p < 0.001 for all formulas, respectively). On the contrary, the MedAE obtained by Kane with segmented AL was significantly worse compared to the one with composite AL (0.35 vs. 0.27, p = 0.03).

CONCLUSION

In extremely high myopic eyes, the segmented AL improves the performance of SRK/T, Haigis, Hill3, and LSF formulas compared to the composite AL, while the segmented AL worsens the prediction accuracy of the Kane formula.

Challenges of refractive cataract surgery in the era of myopia epidemic: a mini-review

Myopia is the leading cause of visual impairment in the world. With ever-increasing prevalence in these years, it creates an alarming global epidemic. In addition to the difficulty in seeing distant objects, myopia also increases the risk of cataract and advances its onset, greatly affecting the productivity of myopes of working age. Cataract management in myopic eyes, especially highly myopic eyes is originally more complicated than that in normal eyes, whereas the growing population of cataract with myopia, increasing popularity of corneal and lens based refractive surgery, and rising demand for spectacle independence after cataract surgery all further pose unprecedented challenges to ophthalmologists. Previous history of corneal refractive surgery and existence of implantable collamer lens will both affect the accuracy of biometry including measurement of corneal curvature and axial length before cataract surgery, which may result in larger intraocular lens (IOL) power prediction errors and a compromise in the surgical outcome especially in a refractive cataract surgery. A prudent choice of formula for cataract patients with different characteristics is essential in improving this condition. Besides, the characteristics of myopic eyes might affect the long-term stability of IOL, which is important for the maintenance of visual outcomes especially after the implantation of premium IOLs, thus a proper selection of IOL accordingly is crucial. In this mini-review, we provide an overview of the impact of myopia epidemic on treatment for cataract and to discuss new challenges that surgeons may encounter in the foreseeable future when planning refractive cataract surgery for myopic patients.

We can't afford to turn a blind eye to myopia

BACKGROUND

Myopia is becoming increasingly prevalent throughout the world. It is an overlooked but leading cause of blindness, particularly among the working aged population. Myopia is often considered benign because it is easily corrected with glasses, contact lenses or refractive surgery. Traditionally myopia has been classified into physiological and pathological subtypes based on the degree of myopia present. Higher levels of myopia are associated with increased risk of pathological complications but it is important to note that there is no safe level of myopia. Even low levels of myopia increase the risk of retinal detachment and other ocular comorbidities which will be discussed in detail later. The most serious complication, myopic maculopathy, is the only leading cause of blindness without an established treatment and therefore leads to inevitable loss of vision in some myopes, even at a young age.

AIM

To highlight the current myopia epidemic and the sight threatening complications associated with it.

DESIGN

This is a commissioned review article. Data were gathered by performing a literature review, searching the PubMed database for recent articles regarding myopia.

CONCLUSIONS

Myopia is a potentially blinding disease. By identifying at risk individuals and intervening before they become myopic, eye care practitioners can prevent or delay spectacle use, reduce the risk of the myriad of myopic complications, thereby improve the patient's quality of life and positively impact its socio-economic effects.

Time trends and heterogeneity in the disease burden of visual impairment due to cataract, 1990–2019: A global analysis

Objectives

This study aimed to estimate the disease burden of cataract and evaluate the contributions of risk factors to cataract-associated disability-adjusted life years (DALYs).

Materials and methods

Prevalence and DALYs of visual impairment due to cataract were extracted from the Global Burden of Disease (GBD) study 2019 to explore time trends and annual changes. Regional and country-level socioeconomic indexes were obtained from open databases. The time trend of prevalence and DALYs was demonstrated. Stepwise multiple linear regression was used to evaluate associations between the age-standardized rate of DALYs of cataract and potential predictors.

Results

Global Prevalence rate of visual impairment due to cataract rose by 58.45% to 1,253.9 per 100,000 population (95% CI: 1,103.3 to 1,417.7 per 100,000 population) in 2019 and the DALYs rate rose by 32.18% from 65.3 per 100,000 population (95% CI: 46.4 to 88.2 per 100,000 population) in 1990 to 86.3 per 100,000 population (95% CI: 61.5 to 116.4 per 100,000 population) in 2019. Stepwise multiple linear regression model showed that higher refractive error prevalence (β = 0.036, 95% CI: 0.022, 0.050, P &lt; 0.001), lower number of physicians per 10,000 population (β = −0.959, 95% CI: −1.685, −0.233, P = 0.010), and lower level of HDI (β = −134.93, 95% CI: −209.84, −60.02, P = 0.001) were associated with a higher disease burden of cataract.

Conclusion

Substantial increases in the prevalence of visual impairment and DALYs of cataract were observed from 1990 to 2019. Successful global initiatives targeting improving cataract surgical rate and quality, especially in regions with lower socioeconomic status, is a prerequisite to combating this growing burden of cataract in the aging society.

[Post-SMILE-What myopes know about their secondary emmetropic eyes]

BACKGROUND

Small incision lenticule extraction (SMILE) is popular among young myopic adults for long-term correction of myopia; however, the excessive axial lengths of myopic eyes and the associated risks for more serious eye diseases later on remain with surgical correction of the refractive error. These risks are greater the higher the myopia is. Are patients well informed about this and to what extent does further eye growth occur even after SMILE?

MATERIAL AND METHODS

Myopic young adults who underwent binocular SMILE before 2019 were given the opportunity to have their eyes examined at a follow-up visit (biometry using IOL-Master 700 [Zeiss, Oberkochen, Germany], subjective refraction, examination of the anterior and posterior segments of the eye using the slit lamp) and to participate in a survey. Patients with a preoperative axial length ≥ 25.5 mm and a preoperative axial length < 25.5 mm (high myopia) were statistically evaluated separately.

RESULTS

A total of 44 patients (age 30.39 ± 2.39 years) appeared at the visit and the SMILE was 3.18 ± 0.82 years ago: The spherical equivalent at the follow-up visit was -0.05 ± 0.21 dpt in the weaker myopes and -0.18 ± 0.23 dpt in the high myopes. Of the respondents 27% estimated that SMILE would reduce the risk of retinal detachment and cataract, with 80% of high myopes underestimating the individual risk of retinal detachment. Also, 57% said they would not see an ophthalmologist until within 1 week if they had symptoms consistent with acute retinal detachment, and only 27% would go to an emergency room immediately. In general, 59% reported having normal health awareness and 41% reported going for annual ophthalmological check-ups.

CONCLUSION

The collected axial lengths and refractions show no relevant change in the eyes regarding progression of myopia; however, the patients' statements in the survey point out that most patients are not aware of the risk of serious eye diseases (retinal detachment, cataract). Therefore, repeated risk education and close postoperative care are needed, especially in preoperatively highly myopic patients.

The Differential Expression of Circular RNAs and the Role of circAFF1 in Lens Epithelial Cells of High-Myopic Cataract

High-myopic cataract (HMC) is a complex cataract with earlier onset and more rapid progress than age-related cataract (ARC). Circular RNAs (circRNAs) have been implicated in many diseases. However, their involvement in HMC remain largely unexplored. To investigate the role of dysregulated circRNAs in HMC, lens epithelium samples from 24 HMC and 24 ARC patients were used for whole transcriptome sequencing. Compared with ARC, HMC had 3687 uniquely expressed circRNAs and 1163 significantly differentially expressed circRNAs (DEcRs) (|log₂FC| > 1, p < 0.05). A putative circRNA-miRNA-mRNA network was constructed based on correlation analysis. We validated the differential expression of 3 DEcRs by quantitative polymerase chain reaction (qPCR) using different sets of samples. We further investigated the role of circAFF1 in cultured lens epithelial cells (LECs) and found that the overexpression of circAFF1 promoted cell proliferation, migration and inhibited apoptosis. We also showed that circAFF1 upregulated Tropomyosin 1 (TPM1) expression by sponging miR-760, which was consistent with the network prediction. Collectively, our study suggested the involvement of circRNAs in the pathogenesis of HMC and provide a resource for further study on this topic.

The Role of Multifocal Intraocular Lens Implantation in Extreme Axial Myopia: A Case Report and Literature Review

The prevalence of high myopia is rising globally. In addition to an increased risk of retinal detachment, high myopia is associated with earlier cataract formation. Patients with myopia are also often more motivated to become spectacle-independent after a lens procedure. However, the use of multifocal intraocular lens (MfIOL) remains controversial for patients with extreme myopia, which is classified as patients with an axial length >28 mm. Here, we present the case of a 64-year-old patient with visually significant cataract and extreme axial myopia >31 mm in both eyes who desired to be spectacle-independent. A preoperative workup revealed a normal macula with peripheral lattice degeneration. On optical coherence tomography, the macula had a normal fovea contour without the presence of a staphyloma. A thorough peripheral examination was performed by a retina specialist which required no prophylactic treatment. Pentacam analysis demonstrated a low spherical aberration and minimal ectasia risk. Cataract surgery was uneventful with a 5 mm laser capsulotomy centered over the visual axis with the placement of a trifocal intraocular lens. Two months after the cataract surgery, the remaining refractive error was corrected with a laser-assisted in situ keratomileusis enhancement. The patient achieved an uncorrected distance visual acuity of 20/15- and uncorrected near visual acuity of J1+ in both eyes. Overall, this case report and review aims to highlight important preoperative, intraoperative, and postoperative techniques to improve patient outcomes with MfIOL in patients with extreme myopia.

Comparison of visual outcomes of a diffractive trifocal intraocular lens and a refractive bifocal intraocular lens in eyes with axial myopia: a prospective cohort study

Background

To assess and compare the efficacy, safety, accuracy, predictability and visual quality of a diffractive trifocal intraocular lens (IOL) and a refractive rotationally asymmetric bifocal IOL in eyes with axial myopia.

Methods

This prospective cohort study enrolled patients with implantation of the diffractive trifocal IOL or the refractive bifocal IOL. Eyes were divided into four groups according to the IOL implanted and axial length. Manifest refraction, uncorrected and corrected visual acuity at far, intermediate and near distances, prediction error of spherical equivalent (SE), contrast sensitivity and aberrations were evaluated three months after surgery.

Results

In total, 80 eyes of 80 patients were included: 20 eyes in each group. Three months postoperatively, the corrected distance visual acuity of two trifocal groups were significantly better than the axial myopia bifocal group (P = 0.007 and 0.043). There was no significant difference of postoperative SE (P = 0.478), but the SE predictability of the trifocal IOL was better, whether in axial myopia groups (P = 0.015) or in control groups (P = 0.027). The contrast sensitivity was similar among four groups. The total aberration, higher order aberration and trefoil aberration of bifocal groups were significantly higher (all P < 0.001).

Conclusions

The diffractive trifocal IOL and the refractive bifocal IOL both provided good efficacy, accuracy, predictability and safety for eyes with axial myopia. By contrast, the trifocal IOL had a better performance in corrected distance visual acuity and visual quality.

Trial registration

The study was retrospectively registered and posted on clinicaltrials.gov at 12/02/2020 (NCT04265846).

Comparison of Iris-Claw Phakic Lens Implant versus Corneal Laser Techniques in High Myopia: A Five-Year Follow-Up Study

Background. This study aimed to compare the efficacy and safety of Femto-LASIK, PRK, and Artiflex/Artisan phakic lens implantation in the surgical correction of myopia at different moments of postoperative follow-up; to propose a linear predictive model of visual acuity without correction at five years of refractive procedures; and to evaluate its validity. Methods. A retrospective observational analysis was performed. Patients were clinically reviewed after three months, one year, two years, and five years. Univariate and bivariate analyses and a multivariate linear regression model were performed. Results. Six hundred seventy-nine eyes were analyzed: 18.9% Artiflex, 2.8% Artisan, 42.3% Femto-LASIK, and 36.1% PRK. There were significant differences in effectiveness and safety after five years when comparing Artiflex/Artisan versus PRK and Femto-LASIK (p < 0.01). The linear regression model explained 30.32% of the patients’ visual acuity variability after five years. Conclusions. PRK surgery, Femto-Lasik, and Artiflex/Artisan type phakic lens implantation are effective, safe, and predictable techniques with stable refractive results. Phakic lenses magnify myopic patients who improve their UCVA and BCVA. Concerning phakic lens implantation, corneal endothelial cells remain stable. The predictive model calculated that surgery with a phakic lens increased the UCVA result at five years, and surgery with PRK slightly decreased the long-term results.

Application of prechop technique in phacoemulsification for cataract patients with highly liquefied vitreous: a retrospective study

Background

Phacoemulsification using phaco-chop technique has many challenging features in cataract patients with highly liquefied vitreous. This study aimed to compare the intraoperative parameters and safety between prechop technique and traditional phaco-chop in phacoemulsification for these patients.

Methods

A total of 54 eyes of 54 patients with high myopia-related or post-vitrectomy cataract that underwent phacoemulsification combined with intraocular lens implantation were included in this retrospective study. Of them, 25 eyes that received manual prechop were included in the prechop group, and 29 eyes with best match of age, axial length and nuclear opalescence (NO) that received standardized phaco-chop were included as the control group. The intraoperative complications and surgery parameters were compared between groups.

Results

No surgical complications were observed in the prechop group, while 2 eyes with posterior capsular rupture and 1 eye with a broken ciliary zonule (10.3%) were found in the control group. There was no significant difference in phaco time, average energy, and cumulative dissipated energy (CDE) between groups (all P > 0.05), but for hard nuclear cataracts with NO grading ≥ 5, prechop group required less phaco time (P = 0.008) and CDE (P = 0.029). There were significant correlations between phaco time vs. NO (r = 0.762 vs. 0.581, both P < 0.005) and CDE vs. NO (r = 0.717 vs. 0.668, both P < 0.001) in the prechop group and control group, respectively.

Conclusions

The prechop technique which seemed to have less intraoperative complications, reduced phaco time and CDE compared to standardized phaco-chop might be a good alternative for cataract patients with highly liquefied or vitrectomized vitreous, especially those with hard nuclear cataracts.

Extended Depth of Focus Versus Monofocal IOLs in Patients With High Myopia: Objective and Subjective Visual Outcomes

PURPOSE

To compare the objective and subjective outcomes between the extended depth of focus (EDOF) Mini Well intraocular lens (IOL) and the aspheric monofocal Mini-4-Ready IOL (both SIFI S.p.A.) in patients with high myopia.

METHODS

In this prospective comparative study, 40 patients with high myopia (axial length ≥ 26 mm) were enrolled: 20 patients were bilaterally implanted with the EDOF Mini Well IOL (EDOF group) and 20 patients were bilaterally implanted with the Mini-4-Ready IOL (monofocal group). Three-month follow-up data included corrected and uncorrected distance visual acuity at 4 m and 80, 67, and 40 cm, defocus curves, subjective and objective contrast sensitivity, objective optical quality (calculated with Optical Quality Analysis System; Visiometrics SL), halometry, and reading performance. Subjective visual quality was evaluated with National Eye Institute Refractive Error Quality of Life Instrument 42 scores.

RESULTS

All visual acuities were significantly better in the EDOF group (P ⩽ .04) except monocular and binocular uncorrected and corrected distance visual acuities for distance (P ≥ .50). Defocus curves for myopic and hyperopic values were better in the EDOF group (P ⩽ .05), apart from +0.50 to -0.50 D (P ≥ .16). Contrast sensitivity curves was worse in the EDOF group in the mesopic-with-glare condition (P ⩽ .04). No differences were found in halometric values (P ≥ .15) and OQAS outcomes (P ≥ .47). National Eye Institute Refractive Error Quality of Life Instrument 42 subscale scores were better for expectation, near vision, activity limitations, and dependence on correction in the EDOF group (P ⩽ .04).

CONCLUSIONS

Intermediate and near visual acuities were better in the EDOF group than in the monofocal group, with a comparable visual quality index between groups. [J Refract Surg. 2022;38(3):158-166.].

Macular vascular density and visual function after phacoemulsification in cataract patients with non-pathological high myopia: a prospective observational cohort study

PURPOSES

This study aimed to evaluate changes in macular vascular density and macular function in patients with high myopia cataract (HMC) after phacoemulsification surgery, using optical coherence tomography angiography (OCTA) and multifocal electroretinography (mfERG).

METHODS

Patients with cataracts scheduled for phacoemulsification surgery were divided into a high myopia group (axial length > 26.5 mm) and a control group (22 mm < axial length ≤ 24.5 mm). OCTA examinations were performed before surgery and at 1 day, 1 week, 1 month, and 3-6 months post-surgery, while mfERG was conducted before surgery and at 3-6 months post-surgery.

RESULTS

A total of 38 patients were included, of whom 20 were HMC patients and 18 were control patients. The macular vascular density significantly increased after phacoemulsification surgery in both groups, while foveal avascular zone area decreased significantly (HMC group: all p < 0.01; control group: all p < 0.05). Mean changes in macular vascular density were significantly greater in HMC patients than in the control group at 1 day after surgery (all p < 0.05). The amplitude density and latency of P1 wave in all macular rings (Ring_1-5) did not differ significantly before or after surgery in either group (all p > 0.1).

CONCLUSION

Phacoemulsification may not affect HMC patients' macular mfERG responses within 3-6 months post-surgery, but it may influence macular microcirculation. HMC patients should be closely monitored after surgery, as their retinal vascular density may fluctuate substantially in the early postoperative period.

The Refractive Error and Vision Impairment Estimation with Spectacle Data Study

Purpose

To investigate whether spectacle lens sales data can be used to estimate the population distribution of refractive error among patients with ametropia and hence to estimate the current and future risk of vision impairment.

Design

Cross-sectional study.

Participants

A total of 141 547 436 spectacle lens sales records from an international European lens manufacturer between 1998 and 2016.

Methods

Anonymized patient spectacle lens sales data, including refractive error information, was provided by a major European spectacle lens manufacturer. Data from the Gutenberg Health Survey was digitized to allow comparison of a representative, population-based sample with the spectacle lens sales data. A bootstrap analysis was completed to assess the comparability of both datasets. The expected level of vision impairment resulting from myopia at 75 years of age was calculated for both datasets using a previously published risk estimation equation combined with a saturation function.

Main Outcome Measures

Comparability of spectacle lens sales data on refractive error with typical population surveys of refractive error and its potential usefulness to predict vision impairment resulting from refractive error.

Results

Equivalent estimates of the population distribution of spherical equivalent refraction can be provided from spectacle lens data within limits. For myopia, the population distribution was equivalent to the Gutenberg Health Survey (≤ 5% deviation) for levels of –2.0 diopters (D) or less, whereas for hyperopia, the distribution was equivalent (≤ 5% deviation) for levels of +3.0 D or more. The estimated rates of vision impairment resulting from myopia were not statistically significantly different (chi-square, 182; degrees of freedom, 169; P = 0.234) between the spectacle lens dataset and Gutenberg Health Survey dataset.

Conclusions

The distribution of refractive error and hence the risk of vision impairment resulting from refractive error within a population can be determined using spectacle lens sales data. Pooling this type of data from multiple industry sources could provide a cost-effective, timely, and globally representative mechanism for monitoring the evolving epidemiologic features of refractive error and associated vision impairment.

Associations between anterior segment biometry and high axial myopia in 3438 cataractous eyes in the Chinese population

Background

To investigate the associations between anterior segment biometry and high axial myopia in cataractous eyes in the Chinese population.

Methods

Data on 3438 eyes from 3438 subjects were analyzed in this cross-sectional study. Anterior segment biometry, axial length measurements, and intraocular pressure evaluation were implemented using an Oculus Pentacam HR, a Zeiss IOLMaster 500, and a Nidek TonoRef II, respectively. A multivariate-adjusted logistic model and a multivariate-adjusted linear model were used for statistical analysis.

Results

The mean age of the subjects was 62.2 ± 10.6 years, and 56.4% were female. There were 2665 subjects with high axial myopia (axial length, ≥26.50 mm) and 773 without (axial length, < 26.50 mm). The characteristics independently associated with high axial myopia included lower total corneal refractive power, a more negative Q value, greater total corneal astigmatism, greater white-to-white corneal diameter, greater anterior chamber depth, and higher intraocular pressure (all P <  0.05). In addition, greater axial length correlated with a thicker temporal cornea and a thinner nasal cornea (both P <  0.001).

Conclusions

For cataractous eyes, high axial myopia was associated with corneal flattening, increased total corneal astigmatism, anterior segment enlargement, and intraocular pressure elevation. The findings may inform the choice of intraocular lenses and the calculation of their power, help improve the surgical practice of refractive cataract procedures, and provide useful information on the centration and stability of intraocular lenses.

Change in the prevalence of myopia in Australian middle-aged adults across 20 years

BACKGROUND

The prevalence of myopia is increasing globally including in Europe and parts of Asia but Australian data are lacking. This study aim described the change in myopia prevalence in middle-aged Australian adults over approximately a 20-year period.

METHODS

Two contemporary Western Australian studies (conducted in mid-late 2010s): the coastal-regional Busselton Healthy Ageing Study (BHAS) and the urban Gen1 of the Raine Study (G1RS) were compared to two earlier studies (early-mid 1990s) in Australia: the urban Blue Mountains Eye Study (BMES) and urban/regional Melbourne Visual Impairment Project (MVIP). Refractive error was measured by autorefraction, vertometry, or subjective refraction. Participants (49-70 years) of European descent without self-reported/diagnosed cataract, corneal disease, or refractive or corneal surgery were included.

RESULTS

After exclusions, data were available from 2217, 1760, 700, 2987 and 756 participants from BMES, urban MVIP, regional MVIP, BHAS, and G1RS, respectively. The mean age ranged from 57.1 ± 4.6 years in the G1RS to 60.1 ± 6.0 years in the BMES; 44-48% of participants were male. When stratified by location, the contemporary urban G1RS cohort had a higher age-standardised myopia prevalence than the urban MVIP and BMES cohorts (29.2%, 16.4%, and 23.9%, p < 0.001). The contemporary coastal-regional BHAS had a higher age-standardised myopia prevalence than the regional MVIP cohort (19.4% vs. 13.8%, p = 0.001).

CONCLUSIONS

We report an increase in myopia prevalence in older adults in Australia born after World War ll compared to cohorts born before, accounting for urban/regional location. The prevalence of myopia remains relatively low in middle-aged Australian adults.

Effect of cataract surgery on vision-related quality of life among cataract patients with high myopia: a prospective, case-control observational study

OBJECTIVES

To evaluate the effect of cataract surgery on vision-related quality of life (VR-QOL) in cataract patients with high myopia (HM).

METHODS

In this prospective study, 90 patients with bilateral HM (HM group, mean [SD] age, 62.9 [9.7] years) and 90 age-matched patients with normal axial lengths (ALs) (control group) who underwent phacoemulsification surgery were consecutively included. The VR-QOL was evaluated using the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) preoperatively and 6 months postoperatively. During the same periods, the best-corrected visual acuity (BCVA) was recorded.

RESULTS

Postoperatively, the BCVA improved significantly in the HM group, with 78 patients (86.7%) achieving improvements ≥0.2 logMAR units, higher than that in the control group (61.1%, P < 0.001). Although the preoperative NEI-VFQ-25 composite score was lower in the HM group than in the control group (65.8 ± 4.7 [95% CI] versus 77.3 ± 3.8, P < 0.001), the postoperative composite score was not significantly different between the two groups (87.5 ± 2.6 versus 90.4 ± 1.6, P = 0.126); changes in composite score and scores of 7 subscales were greater in the HM group than in the control group (P < 0.05 for all). In the HM group, but not in the control group (r = -0.019, P = 0.860), patient age was negatively associated with the change in composite score (r = -0.235, P = 0.026). Preoperative BCVA (logMAR) was positively associated with changes in composite score for both groups (r = 0.796 and 0.714, respectively, P < 0.001 for both).

CONCLUSIONS

VR-QOL is significantly impaired in cataract patients with HM and is remarkably improved by cataract surgery. The improvement is greater than that in normal AL cases.

Quantitative Phosphoproteomic Comparison of Lens Proteins in Highly Myopic Cataract and Age-Related Cataract

Purpose

To investigate and compare the lens phosphoproteomes in patients with highly myopic cataract (HMC) or age-related cataract (ARC).

Methods

In this study, we undertook a comparative phosphoproteome analysis of the lenses from patients with HMC or ARC. Intact lenses from ARC and HMC patients were separated into the cortex and nucleus. After protein digestion, the phosphopeptides were quantitatively analyzed with TiO₂ enrichment and liquid chromatography-mass spectrometry. The potential functions of different phosphopeptides were assessed by Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis.

Results

In total, 522 phosphorylation sites in 164 phosphoproteins were identified. The number of phosphorylation sites was significantly higher in the cortex than in the nucleus, in both ARC and HMC lenses. The differentially phosphorylated peptides in the lens cortex and nucleus in HMC eyes were significantly involved in the glutathione metabolism pathway. The KEGG pathway enrichment analysis indicated that the differences in phosphosignaling mediators between the ARC and HMC lenses were associated with glycolysis and the level of phosphorylated phosphoglycerate kinase 1 was lower in HMC lenses than in ARC lenses.

Conclusions

We provide an overview of the differential phosphoproteomes of HMC and ARC lenses that can be used to clarify the molecular mechanisms underlying their different phenotypes.

Recurring themes during cataract assessment and surgery

The aim of this review was to discuss frequently encountered themes such as cataract surgery in presence of age-related macular degeneration (AMD), dementia, Immediate Sequential Bilateral Cataract Surgery (ISBCS), discussing non-standard intraocular lens (IOL) options during consultation in the National Health Services (NHS) and the choice of the biometric formulae based on axial length. Individual groups of authors worked independently on each topic. We found that cataract surgery does improve visual acuity in AMD patients but the need for cataract surgery should be individualised. In patients with dementia, cataract surgery should be considered 'sooner rather than later' as progression may prevent individuals presenting for surgery. This should be planned after discussion of patients' best interests with any carers; multifocal IOLs are not proven to be the best option in these patients. ISBCS gives comparable outcomes to delayed sequential surgeries with a low risk of bilateral endophthalmitis and it can be cost-saving and efficient. Patients are entitled to know all suitable IOL options that can improve their quality of life. Deliberately withholding this information or pressuring patients to choose a non-standard IOL is inappropriate. However, one should be mindful of the not spending inappropriate amounts of time discussing these in the NHS setting which may affect care of other NHS patients. Evidence suggests Hoffer Q, Haigis, Hill-RBF and Kane formulae for shorter eyes; Barrett Universal II (BU II), Holladay II, Haigis and Kane formulae for longer eyes and BU II, Hill-RBF and Kane formulae for medium axial length eyes.

IMI Impact of Myopia

The global burden of myopia is growing. Myopia affected nearly 30% of the world population in 2020 and this number is expected to rise to 50% by 2050. This review aims to analyze the impact of myopia on individuals and society; summarizing the evidence for recent research on the prevalence of myopia and high myopia, lifetime pathological manifestations of myopia, direct health expenditure, and indirect costs such as lost productivity and reduced quality of life (QOL). The principal trends are a rising prevalence of myopia and high myopia, with a disproportionately greater increase in the prevalence of high myopia. This forecasts a future increase in vision loss due to uncorrected myopia as well as high myopia-related complications such as myopic macular degeneration. QOL is affected for those with uncorrected myopia, high myopia, or complications of high myopia. Overall the current global cost estimates related to direct health expenditure and lost productivity are in the billions. Health expenditure is greater in adults, reflecting the added costs due to myopia-related complications. Unless the current trajectory for the rising prevalence of myopia and high myopia change, the costs will continue to grow. The past few decades have seen the emergence of several novel approaches to prevent and slow myopia. Further work is needed to understand the life-long impact of myopia on an individual and the cost-effectiveness of the various novel approaches in reducing the burden.

Middle- and long-term results after iris-fixated phakic intraocular lens implantation in myopic and hyperopic patients: a meta-analysis

The iris-fixated phakic intraocular lens (pIOL) has been available for over 25 years. To provide a clear picture of outcomes and risks, for this systematic review and meta-analysis, the literature was searched for reports on middle- and long-term effects. The iris-fixated phakic intraocular lens (pIOL) has been available for over 25 years. To provide a clear picture of outcomes and risks, for this systematic review and meta-analysis, the literature was searched for reports on middle- and long-term effects of iris-fixated pIOLs on myopic and hyperopic eyes with a follow-up of at least 2 to 4 years. Visual and refractive results after implantation for correction of myopia are positive and the complication rate is low. Endothelial cell loss appears to be at an acceptable rate, although the range of endothelial cell change is too wide to draw firm conclusions. Care should be taken when considering an iris-fixated pIOL for hyperopic eyes because complication rates, particularly pigment dispersion, might be higher than those in myopic eyes. More well-designed, long-term studies are needed, especially in hyperopic eyes. The authors advocate for standardized reporting of refractive surgery data. Initiatives proposed by journal authors and editors to achieve uniformity should be supported.

Accuracy Improvement of IOL Power Prediction for Highly Myopic Eyes With an XGBoost Machine Learning-Based Calculator

Purpose: To develop a machine learning-based calculator to improve the accuracy of IOL power predictions for highly myopic eyes.

Methods: Data of 1,450 highly myopic eyes from 1,450 patients who had cataract surgeries at our hospital were used as internal dataset (train and validate). Another 114 highly myopic eyes from other hospitals were used as external test dataset. A new calculator was developed using XGBoost regression model based on features including demographics, biometrics, IOL powers, A constants, and the predicted refractions by Barrett Universal II (BUII) formula. The accuracies were compared between our calculator and BUII formula, and axial length (AL) subgroup analysis (26.0–28.0, 28.0–30.0, or ≥30.0 mm) was further conducted.

Results: The median absolute errors (MedAEs) and median squared errors (MedSEs) were lower with the XGBoost calculator (internal: 0.25 D and 0.06 D²; external: 0.29 D and 0.09 D²) vs. the BUII formula (all P ≤ 0.001). The mean absolute errors and were 0.33 ± 0.28 vs. 0.45 ± 0.31 (internal), and 0.35 ± 0.24 vs. 0.43 ± 0.29 D (external). The mean squared errors were 0.19 ± 0.32 vs. 0.30 ± 0.36 (internal), and 0.18 ± 0.21 vs. 0.27 ± 0.29 D² (external). The percentages of eyes within ±0.25 D of the prediction errors were significantly greater with the XGBoost calculator (internal: 49.66 vs. 29.66%; external: 78.28 vs. 60.34%; both P < 0.05). The same trend was in MedAEs and MedSEs in all subgroups (internal) and in AL ≥30.0 mm subgroup (external) (all P < 0.001).

Conclusions: The new XGBoost calculator showed promising accuracy for highly or extremely myopic eyes.

Reducing the Global Burden of Myopia by Delaying the Onset of Myopia and Reducing Myopic Progression in Children: The Academy's Task Force on Myopia

In 2019, the American Academy of Ophthalmology (AAO) created the Task Force on Myopia in recognition of the substantial global increases in myopia prevalence and its associated complications. The Task Force, led by Richard L. Abbott, MD, and Donald Tan, MD, comprised recognized experts in myopia prevention and treatment, public health experts from around the world, and organization representatives from the American Academy of Family Physicians, American Academy of Optometry, and American Academy of Pediatrics. The Academy's Board of Trustees believes that myopia is a high-priority cause of visual impairment, warranting a timely evaluation and synthesis of the scientific literature and formulation of an action plan to address the issue from different perspectives. This includes education of physicians and other health care providers, patients and their families, schools, and local and national public health agencies; defining health policies to ameliorate patients' access to appropriate therapy and to promote effective public health interventions; and fostering promising avenues of research.

Efficacy in myopia control

There is rapidly expanding interest in interventions to slow myopia progression in children and teenagers, with the intent of reducing risk of myopia-associated complications later in life. Despite many publications dedicated to the topic, little attention has been devoted to understanding 'efficacy' in myopia control and its application. Treatment effect has been expressed in multiple ways, making comparison between therapies and prognosis for an individual patient difficult. Available efficacy data are generally limited to two to three years making long-term treatment effect uncertain. From an evidence-based perspective, efficacy projection should be conservative and not extend beyond that which has been empirically established. Using this principle, review of the literature, data from our own clinical studies, assessment of demonstrated myopia control treatments and allowance for the limitations and context of available data, we arrive at the following important interpretations: (i) axial elongation is the preferred endpoint for assessing myopic progression; (ii) there is insufficient evidence to suggest that faster progressors, or younger myopes, derive greater benefit from treatment; (iii) the initial rate of reduction of axial elongation by myopia control treatments is not sustained; (iv) consequently, using percentage reduction in progression as an index to describe treatment effect can be very misleading and (v) cumulative absolute reduction in axial elongation (CARE) emerges as a preferred efficacy metric; (vi) maximum CARE that has been measured for existing myopia control treatments is 0.44 mm (which equates to about 1 D); (vii) there is no apparent superior method of treatment, although commonly prescribed therapies such as 0.01% atropine and progressive addition spectacles lenses have not consistently provided clinically important effects; (viii) while different treatments have shown divergent efficacy in the first year, they have shown only small differences after this; (ix) rebound should be assumed until proven otherwise; (x) an illusion of inflated efficacy is created by measurement error in refraction, sample bias in only treating 'measured' fast progressors and regression to the mean; (xi) decision to treat should be based on age of onset (or refraction at a given age), not past progression; (xii) the decreased risk of complications later in life provided by even modest reductions in progression suggest treatment is advised for all young myopes and, because of limitations of available interventions, should be aggressive.

The Complications of Myopia: A Review and Meta-Analysis

Purpose

To determine the risk between degree of myopia and myopic macular degeneration (MMD), retinal detachment (RD), cataract, open angle glaucoma (OAG), and blindness.

Methods

A systematic review and meta-analyses of studies published before June 2019 on myopia complications. Odds ratios (OR) per complication and spherical equivalent (SER) degree (low myopia SER < -0.5 to > -3.00 diopter [D]; moderate myopia SER ≤ -3.00 to > -6.00 D; high myopia SER ≤ -6.00 D) were calculated using fixed and random effects models.

Results

Low, moderate, and high myopia were all associated with increased risks of MMD (OR, 13.57, 95% confidence interval [CI], 6.18-29.79; OR, 72.74, 95% CI, 33.18-159.48; OR, 845.08, 95% CI, 230.05-3104.34, respectively); RD (OR, 3.15, 95% CI, 1.92-5.17; OR, 8.74, 95% CI, 7.28-10.50; OR, 12.62, 95% CI, 6.65-23.94, respectively); posterior subcapsular cataract (OR, 1.56, 95% CI, 1.32-1.84; OR, 2.55, 95% CI, 1.98-3.28; OR, 4.55, 95% CI, 2.66-7.75, respectively); nuclear cataract (OR, 1.79, 95% CI, 1.08-2.97; OR, 2.39, 95% CI, 1.03-5.55; OR, 2.87, 95% CI, 1.43-5.73, respectively); and OAG (OR, 1.59, 95% CI, 1.33-1.91; OR, 2.92, 95% CI, 1.89-4.52 for low and moderate/high myopia, respectively). The risk of visual impairment was strongly related to longer axial length, higher myopia degree, and age older than 60 years (OR, 1.71, 95% CI, 1.07-2.74; OR, 5.54, 95% CI, 3.12-9.85; and OR, 87.63, 95% CI, 34.50-222.58 for low, moderate, and high myopia in participants aged >60 years, respectively).

Conclusions

Although high myopia carries the highest risk of complications and visual impairment, low and moderate myopia also have considerable risks. These estimates should alert policy makers and health care professionals to make myopia a priority for prevention and treatment.

Six-Year Changes in Myopic Macular Degeneration in Adults of the Singapore Epidemiology of Eye Diseases Study

Purpose

To examine the 6-year incidence, progression, associated risk factors, and impact of myopic macular degeneration (MMD) in a myopic population in Singapore.

Methods

We examined myopic (spherical equivalent ≤-0.5 diopters) adults (N = 2157 persons and 3661 eyes) who were phakic at baseline and participated in both baseline and 6-year follow-up visits of the Singapore Epidemiology of Eye Diseases study. Eye examinations, including visual acuity, subjective refraction and axial length (AL) measurements, were performed. MMD was graded from fundus photographs following the META-PM classification. Vision-related quality of life was assessed with Rasch-transformed scores from reading, mobility, and emotional domains of the Impact of Vision Impairment questionnaire.

Results

The 6-year eye-specific incidence of MMD among myopic eyes was 1.2% (95% CI, 0.9%-1.6%). Older age, worse spherical equivalent, and longer AL at baseline were associated with MMD incidence (all P < 0.001). The 6-year eye-specific progression of MMD in 288 eyes with baseline MMD was 17.0% (95% CI, 12.6%-21.4%). More severe MMD at baseline, worse spherical equivalent, and longer AL (all P < 0.05) were associated with MMD progression. Patients with Meta-PM categories 3 and 4 had worse best-corrected visual acuity and poorer vision-related quality of life outcomes than those without MMD (all P < 0.05).

Conclusions

Over a 6-year period, one in 80 myopic eyes developed MMD and one in six with existing MMD had MMD progression. Myopia severity and AL were strong predictors of MMD development and progression. Eyes with severe MMD were at higher risk of MMD progression than those with less severe MMD, and were associated with poorer visual acuity and vision-related quality of life.

Implantation of a Trifocal Intraocular Lens in High Myopic Eyes with Nasal-Inferior Staphyloma

Purpose

To assess visual outcomes in high myopic eyes with nasal-inferior staphyloma implanted with a pseudophakic trifocal intraocular lens (IOL).

Methods

We retrospectively analyzed the visual outcomes of 50 eyes of 45 patients who had cataract surgery after AT LISA trifocal IOL implantation. Twenty-five eyes diagnosed with posterior staphyloma (nasal-inferior, type IV and V), and 25 eyes as long eyes. Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) values were used to assess the efficacy and safety of the surgery. Refraction and defocus curves were also evaluated at 6 months.

Results

No intra- or post-operative problems occurred during the 6 months of follow-up. After the surgery, the mean Snellen decimal UDVA ranged from 0.50 to 1.00, and CDVA from 0.60 to 1.00 for both groups. CDVA was 0.91 and 0.74 for the long eye and nasal-inferior staphyloma groups, respectively. Efficacy and safety indexes were 1.22 and 1.32 for the long eye, and 1.26 and 1.43 for the nasal-inferior staphyloma group, respectively. All eyes of both groups showed a postoperative spherical equivalent within ±1.00D. The long eye group showed the highest percentage of spherical equivalent between −0.13D and +0.13D (56%) and the nasal-inferior staphyloma group was between −0.51D and −0.14D (40%).

Conclusion

The outcomes of the present study show that a trifocal IOL provides good visual acuity in high myopic eyes, being worse for nasal-inferior staphyloma eyes. The degree of tilt of the macular plane is related with the expected visual acuity.

The myopic shift associated with hyperbaric oxygen administration is reduced when using a mask delivery system compared to a hood - a randomised controlled trial

INTRODUCTION

A temporary myopic shift is a well-recognized complication of hyperbaric oxygen treatment (HBOT). Oxidation of proteins in the crystalline lens is the likely cause. Direct exposure of the eye to hyperbaric oxygen may exacerbate the effect. Our aim was to measure the magnitude of the myopic shift over a course of HBOT when using two different methods of oxygen delivery.

METHODS

We conducted a randomised trial of oxygen delivery via hood versus oronasal mask during a course of 20 and 30 HBOT sessions. Subjective refraction was performed at baseline and after 20 and 30 sessions. We repeated these measurements at four and 12 weeks after completion of the course in those available for assessment.

RESULTS

We enrolled 120 patients (mean age 57.6 (SD 11.2) years; 81% male). The myopic shift was significantly greater after both 20 and 30 sessions in those patients using the hood. At 20 treatments: refractory change was -0.92 D with hood versus -0.52 D with mask, difference 0.40 D (95% CI 0.22 to 0.57, P < 0.0001); at 30 treatments: -1.25 D with hood versus -0.63 with mask, difference 0.62 D (95% CI 0.39 to 0.84, P < 0.0001). Recovery was slower and less complete in the hood group at both four and 12 weeks.

CONCLUSIONS

Myopic shift is common following HBOT and more pronounced using a hood system than an oronasal mask. Recovery may be slower and less complete using a hood. Our data support the use of an oronasal mask in an air environment when possible.

Comparison of six methods for the intraocular lens power calculation in high myopic eyes

PURPOSE

The aim of this study was to compare the accuracy of Barrett Universal II and Hill-Radial Basis Function with other four popular formulas for the calculation of intraocular lens power in high myopic eyes.

METHODS

A total of 56 eyes with an axial length of more than 26.0 mm were retrospectively reviewed. Six intraocular lens power calculation methods, including Barrett Universal II, Hill-Radial Basis Function, SRK/T, Haigis, Holladay 2 and Holladay 1, were evaluated. The difference between the postoperative actual refraction and the refraction predicted by the six methods was evaluated as the prediction error. The absolute prediction error was also calculated.

RESULTS

The mean numerical prediction error ± standard deviation of the six intraocular lens power calculation methods, in order of lowest to highest, was Barrett Universal II (0.37 ± 0.54 D), Hill-Radial Basis Function (0.40 ± 0.56 D), SRK/T (0.44 ± 0.56 D), Haigis (0.53 ± 0.54 D), Holladay 2 (0.88 ± 0.62 D) and Holladay 1 (1.00 ± 0.60 D). The median absolute errors predicted by the Barrett (0.46 D), Hill-Radial Basis Function (0.47 D), SRK/T (0.53 D) and Haigis (0.58 D) were significantly lower than those of the Holladay 1 (0.90 D) and Holladay 2(1.10 D; all p < 0.001). There was no significant difference among the median absolute errors of Barrett, Hill-Radial Basis Function, SRK/T and Haigis (all p > 0.05).

CONCLUSION

The prediction errors differed for each method in the selection of intraocular lens power for the long eyes. In terms of overall accuracy, the Barrett Universal II formula provided the lowest prediction error. The Hill-Radial Basis Function method was comparable to the theoretical formulas, such as SRK/T and Haigis.

Profiling and Bioinformatic Analysis of Differentially Expressed Cytokines in Aqueous Humor of High Myopic Eyes - Clues for Anti-VEGF Injections

Purpose: To investigate the aqueous humor growth factor profile in high myopic eyes and analyze the interaction of differentially expressed cytokines.Methods: A case-control study including aqueous humor samples from 36 high myopic patients and 32 controls was conducted. Quantibody® Human Growth Factor Array was used to screen the presence of 40 growth factors in aqueous humor. Expressions of differential growth factors were validated by Bio-Plex Pro^TM multiplex bead-based immunoassay. Protein-protein interaction (PPI) and gene ontology (GO) analyses were performed.Results: Growth differentiation factor 15 (GDF-15), hepatocyte growth factor (HGF), and platelet-derived growth factor (PDGF)-AA were found to be significantly higher and vascular endothelial growth factor (VEGF) was detected to be lower in high myopic eyes (all P = .03). Multi-plex bead-based assay further validated the differential expressions of four growth factors and all of them were significantly correlated with axial length (P < .001). Twenty-six proteins were mapped into PPI network and positive regulation of cell migration, cellular component movement, and cell motility were the most enriched biological processes based on GO analysis.Conclusions: Differential expressed cytokines that indicates a distinctive intraocular microenvironment in high myopic eyes might provide clues for pathological changes within high myopic eyes after anti-VEGF injections.

Low 25-Hydroxyvitamin D Concentration Is Not Associated With Refractive Error in Middle-Aged and Older Western Australian Adults

Purpose

To investigate the association between serum 25-hydroxyvitamin D (25[OH]D) concentration and refractive error in a community-based cohort of adults aged 46 to 69 years.

Methods

Residents of the City of Busselton in Western Australia born between 1946 and 1964 were invited to participate. Participants underwent cycloplegic autorefraction and completed questionnaires on education, occupational sun exposure, and physical activity. Blood samples were collected and serum frozen at −80°C. Serum 25[OH]D concentration was measured by immunoassay. Data on 25[OH]D were deseasonalized and multivariate models built to analyze the association between 25[OH]D concentration and spherical equivalent and myopia, defined as spherical equivalent <−0.50 D.

Results

After exclusions, data were available for 4112 participants. Serum 25[OH]D concentration was not associated with spherical equivalent or myopia after adjustment for confounding factors (β = −0.01, 95% confidence interval [CI]: −0.03 to −0.008, P = 0.25, and odds ratio = 1.02, 95% CI: 0.99 to 1.05, P = 0.12, respectively). When participants were classified into 25[OH]D groups of lower (<50 nmol/L), medium (≥50 to <75 nmol/L), and upper (≥75 nmol/L), the upper group had slightly greater myopic refractive error than the medium group (P = 0.02) but not the lower group, after adjustment for confounders.

Conclusions

There was no substantial association between 25[OH]D levels and spherical equivalent or odds of myopia in this study. The association previously noted between low serum 25[OH]D level and myopia in younger Western Australians is not evident in later adulthood.

Translational Relevance

This study provides further evidence suggesting that vitamin D levels are unrelated to myopia risk in adults and thus not a suitable target for myopia intervention.

DNA hypermethylation-mediated downregulation of antioxidant genes contributes to the early onset of cataracts in highly myopic eyes

High myopia is recognized as a risk factor for earlier onset of nuclear cataracts. One possible explanation for this is that lenses in highly myopic eyes are exposed to higher levels of oxygen than normal eyes owing to earlier vitreous liquefaction and, hence, are subjected to oxidative insults. Here, we first compared the methylation levels of six essential antioxidant genes (GSTP1, NRF2, OGG1, TXN, TXNRD1 and TXNRD2) between highly myopic cataract (HMC) and age-related cataract (ARC) lens epithelial samples via Sequenom MassARRAY. We found that specific CpG units in the promoters of GSTP1 and TXNRD2 were hypermethylated and that the expression levels of these two genes were lower in the HMC group than in the ARC group. A luciferase reporter assay confirmed the significance of differentially methylated fragments in the activation of transcription. The importance of GSTP1 and TXNRD2 in antioxidant capacity was confirmed by overexpression or knockdown experiments on cultured lens epithelial cells (LECs). In addition, the expression of DNA methyl transferase 1 (DNMT1) was higher in the lens epithelium of HMC patients than that of ARC patients, and the expression of GSTP1 and TXNRD2 was upregulated by use of a DNMT inhibitor in cultured LECs. Finally, we mimicked the intraocular environment of highly myopic eyes by treating LECs with hydrogen peroxide (H₂O₂) and observed both alterations in the methylation status of the GSTP1 and TXNRD2 promoters and time-dependent altered expression levels. Therefore, we propose that in an environment with high oxygen, in which lenses in highly myopic eyes are immersed, there exists a vicious cycle composed of increased oxidative stress and decreased enzymatic antioxidants via the hypermethylation of antioxidant genes.

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Vitreous liquefaction generates a high-O2 environment surrounding the lens.

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In highly myopic eyes, vitreous liquefaction occurs earlier and results in severer nuclear cataract.

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Methylation levels of GSTP1 and TXNRD2 were elevated in lens epithelium of highly myopic eyes.

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Increased oxidation and decreased enzymatic antioxidant via hypermethylation form a vicious circle in highly myopic eyes.

Influence of Overnight Orthokeratology on Corneal Surface Shape and Optical Quality

Purpose

To investigate the changes of corneal surface shape and optical quality during orthokeratology.

Methods

49 eyes of 26 patients (10.63 ± 2.02 years old) who underwent overnight orthokeratology for myopia were prospectively examined. The corneal surface shape parameters, including surface regularity index (SRI) and surface asymmetry index (SAI), were attained with an OPD-III SCAN. The higher-order aberrations and higher-order Strehl ratios were calculated under a 3 mm pupil diameter before orthokeratology, 1 month, 3 months, and 6 months after orthokeratology. A P value of less than 0.05 was statistically significant.

Results

Months after orthokeratology, SRI and SAI were both showing a significant increase in comparison with those before orthokeratology (P < 0.001). After orthokeratology, for a 3 mm pupil, the higher-order Strehl ratio presented a reduction of 0.217 μm (P < 0.001), and the higher-order aberration root mean square (HOA RMS) showed a mean increase of 0.100 μm (P < 0.001). There were significant increases in spherical aberration (P < 0.001) and coma (P = 0.044) after orthokeratology. Trefoil showed a slight reduction at month 6 after orthokeratology, but there was no statistical significance (P = 0.722).

Conclusion

Overnight orthokeratology for a correction of myopia resulted in a significant improvement in refractive error but increased corneal irregularity and ocular higher-order aberrations, especially in spherical aberration.

Risk factors of age-related cataract in a Chinese adult population: the Taizhou Eye Study

IMPORTANCE

Cataract risk factors data will provide epidemic evidence for cataract prevention.

BACKGROUND

This study aimed to study the risk factors for age-related cataract in a Chinese adult population.

DESIGN

This is a population-based, cross-sectional study.

PARTICIPANTS

A total of 10 234 eligible subjects ≥45 years old (response rate: 78.1%) were included in the study.

METHODS

We conducted detailed eye examinations including presenting visual acuity, best-corrected visual acuity, slit lamp examination of lens opacities and fundus examination. Questionnaires about lifestyle were administered. Measurements of blood pressure, heart rate and body mass index were collected. Serological metabolic indicators, including fasting blood glucose, triglycerides, cholesterol, lipoprotein, were also evaluated. We used stepwise multivariate logistic regression model to evaluate the association of these risk factors with any cataract and subtypes of cataract.

MAIN OUTCOME MEASURES

Odds ratios of risk factors for cataract were calculated.

RESULTS

For any cataract, we found age, gender (female), increased outdoor activity, no outdoor eye protection, high myopia, high low-density lipoprotein, low high-density lipoprotein, lower education level and increased pickled food intake were independent risk factors. When further examined the risk factors of different subtypes of cataract, we found that these risk factors also existed, but there were slight differences among different subtypes. In addition, for cortical cataract, lower annual family income and high diastolic pressure were additional independent risk factors.

CONCLUSIONS AND RELEVANCE

Reduced outdoor activity, outdoor eye protection, prevention of high myopia, higher education level, controlled blood pressure, improved high-density lipoprotein and low-density lipoprotein levels and reduced pickled food intake may help to reduce the risk of age-related cataract development.

[Secondary diseases in high myopia]

BACKGROUND

Eyes with high myopia (axial length ≥ 26.5 mm) do not just have a different size. Due to morphological and structural changes there is a considerably increased risk for many different secondary diseases.

OBJECTIVE

Determination of the incidence and mortality in high myopia, discussion of effects and clinical signs, presentation of treatment recommendations and counselling.

MATERIAL AND METHODS

A systematic search of the literature was carried out and a discussion on basic principles and epidemiological investigations is presented.

RESULTS

Findings due to high myopia are not in a closed state but undergo continuous changes. Choroidal neovascularization (adjusted prevalence 2.5-5%), staphyloma, foveoschisis and peripheral retinal degeneration are examples of problems contributing to the increased rate of visual impairment and blindness related to myopia. High myopia is associated with a clearly increased risk of retinal detachment after lens surgery (hazard ratio 6.1) and particularly more frequently in younger people. The associated primary open-angle glaucoma (odds ratio 2.46) is often recognized too late due to relatively low values of intraocular pressure.

CONCLUSION

Understanding of atrophic areas and staphyloma has benefited from recent advances in imaging (e.g. magnetic resonance imaging, optical coherence tomography and wide-field imaging) that complement and explain histological findings. Knowledge of the associated risk profile is of major clinical relevance.

[Epidemiology of refractive errors]

Refractive errors are very common and can lead to severe pathological changes in the eye. This article analyzes the epidemiology of refractive errors in the general population in Germany and worldwide and describes common definitions for refractive errors and clinical characteristics for pathologicaal changes. Refractive errors differ between age groups due to refractive changes during the life time and also due to generation-specific factors. Current research about the etiology of refractive errors has strengthened the influence of environmental factors, which led to new strategies for the prevention of refractive pathologies.

The investigation on the role of mitochondrial fusion protein 1 in the development of myopia

Purpose:

The aim of this study is to preliminarily investigate the expression of mitochondrial fusion protein 1 (MFN1) in a lens-induced animal myopia (LIM) model and to explore the relationship between MFN1 and the visual development.

Materials and Methods:

MFN1 gene expression in guinea pigs was examined during the development of minus LIM, 15 tri-colored guinea pigs were obtained, and one eye of each pig was randomly selected and treated with −7.00D lenses. Ocular refraction and axial length were collected before intervention and 1, 2, and 3 weeks after intervention. After the refraction and axial length measurements at 1, 2, and 3 weeks of lens intervention, five guinea pigs were randomly selected. MFN1 expression in the retina of both eyes was tested by immunohistochemistry technique.

Results:

MFN1-positive cells could be observed in the retina of both eyes. The positive cells in the LIM eyes were staining deeper, and much more positive cells could be observed. Furthermore, MFN1-positive expression could be seen mainly in ganglion cells after 1 week of minus lens intervention, and with time extension, more and more positive cells appeared in the rod-cone cell and bipolar cell layer, and this phenomenon could not be found in the normal control eyes.

Conclusion:

This study suggested that MFN1 might be correlated to the development of myopia.

Meta-analysis and review: effectiveness, safety, and central port design of the intraocular collamer lens

The purpose of this review is to summarize relevant data from publications appearing in the peer-reviewed scientific literature over the past decade since US Food and Drug Administration approval of the implantable collamer lens (ICL), and, in particular, to review studies relating to sizing methodology, safety, and effectiveness, as well as more recent studies reporting clinical outcomes of the V4c Visian ICL with KS Aquaport, VICMO. A literature search was conducted using two databases, PubMed.gov and Science.gov, to identify all articles published after 2005 related to the Visian ICL (STAAR Surgical, Inc.). Articles were examined for their relevance to sizing methodology, clinical safety, and effectiveness, and the references cited in each article were also searched for additional relevant publications. The literature review revealed that all currently reported methods of determining the best-fit size of the ICL achieve similarly satisfactory results in terms of vault, the safe distance between the crystalline lens and the ICL. Specifically, meta-analysis demonstrated that sulcus-to-sulcus and white-to-white measurement-based sizing methods do not result in clinically meaningful nor statistically significant differences in vault (two-sample two-sided t-test using pooled mean and standard deviations; t (2,594)=1.33; P=0.18). The reported rates of complications related to vault are very low, except in two case series where additional risk factors such as higher levels of myopia and older age impacted the incidence of cataract. On the basis of preclinical studies and initial clinical reports, with up to 5 years of follow-up, the new VICMO central port design holds promise for further reduction of complications. Given its safety record and the significant improvement in vision and quality of life that the ICL makes possible, the benefits of ICL implantation outweigh the risks.

The Prevalence of Open-Angle Glaucoma by Age in Myopia: The Korea National Health and Nutrition Examination Survey

PURPOSE

To investigate the prevalence of open-angle glaucoma (OAG) in myopia by age.

MATERIALS AND METHODS

A cross-sectional study using a stratified, multistage, probability cluster survey. Participants in the Korean National Health and Nutrition Examination Survey between 2010 and 2011 were included. A standardized protocol was used to interview every participant and perform comprehensive ophthalmic examinations. Glaucoma was diagnosed according to the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) criteria.

RESULTS

After adjusting for age and sex, there was a positive correlation between OAG prevalence and increasing myopic refractive error except in participants with hyperopia. Younger participants with higher myopic refractive error had higher OAG prevalence than older participants with lower myopic refractive error. Participants with high myopia (OR 3.90, 95% confidence interval (CI) 2.30-6.59) had significantly greater age- and sex-adjusted odd ratios (ORs) than did those with emmetropia who were younger than 60 years.

CONCLUSIONS

These data suggest that OAG develops earlier in participants with high myopia than in others. There was a high prevalence of OAG in participants with high myopia, even in those 19-29 years of age. Therefore, OAG screening should be performed earlier in participants with high myopia than is suggested by traditional guidelines.