Why is there an epidemic of myopia?

Clinical observation of posterior scleral reinforcement in the treatment of progressive high myopia in Chinese children: a retrospective study

Objective

To observe the efficacy and safety of posterior sclera reinforcement over time.

Methods

This retrospective single-arm cohort study included children with high myopia who underwent the modified Snyder-Thompson type posterior sclera reinforcement surgery from 03/2015 to 08/2018 at Fuzhou Children’s Hospital of Fujian Medical University. Axial length (AL), corneal radius of curvature (CRC), AL/CRC, refractive error, and best-corrected visual acuity (BCVA) were observed from 1 year before the operation to 2 years after.

Results

Nineteen children (33 eyes) with high myopia were included. The patients were 4.9 ± 2.7 (range, 2–10) years of age (three patients were 10 years old, all others were ≤ 7 years old). AL increased from 1 year before surgery to 2 years after surgery (from 25.31 ± 1.59 to 26.76 ± 1.52, P < 0.001). The refractive error was smaller 1 year before surgery than at the other timepoints (all P < 0.05). BCVA improved over time (P < 0.001). Changes over time were also observed in horizontal CRC (hCRC), AL/hCRC, AL/vertical CRC (vCRC), and AL/CRC (all P < 0.001), but not in vCRC (P = 0.304). The increase of AL at 2 years after surgery was smaller than at 1 year before surgery and 1 year after surgery (both P < 0.001). The increase of AL/CRC at 2 years after surgery was smaller than at 1 year before surgery (0.04 ± 0.04 vs. 0.07 ± 0.04; P = 0.008).

Conclusion

In the short term, posterior scleral reinforcement surgery can delay the increase of AL of progressive high myopia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02375-1.

Long-term progression of myopic maculopathy in degenerative myopia as imaged by SD-OCT and IR imaging

CLINICAL RELEVANCE

Clinicians can benefit from developing an understanding of the natural disease progression of myopic maculopathy in degenerative myopia using optical coherence tomography (OCT).

BACKGROUND

The prevalence of high myopia is constantly increasing. In this work, infrared imaging and OCT is used to study the natural course of the disease.

METHODS

This is a retrospective longitudinal study. Medical records of 72 patients with high myopia (< 6.00 D) and a minimum five-year follow-up period were analysed. Collected data on all enrolled patients included demographic characteristics and medical history, as well as recordings on best-corrected visual acuity, slitlamp examination, OCT, and fluorescein angiography in cases of suspected myopic choroidal neovascularisation. Images were independently marked by two graders.

RESULTS

The mean age of patients was 54.6 ± 14.4 years (59.72% female) with baseline logMAR best-corrected visual acuity of 0.22 ± 0.28. At baseline examination, 70.83% of the study group showed signs of maculopathy and 62.5% diffuse or patchy atrophy. During follow-up, 22.2% of patients with any type of atrophy showed enlarged affected areas. Two patients with baseline lacquer cracks developed new lesions. There was a weak correlation between patient age and maculopathy progression (r = 0.233; p = 0.03). While central retinal thickness was not associated with maculopathy progression (p = 0.203), a moderate correlation was found between choroidal thickness and maculopathy progression (r = -0.516; p < 0.001).

CONCLUSION

Lesion characteristics in myopic degeneration have been elucidated, taking advantage of the ongoing technological advances in retinal imaging. The understanding of disease patterns and progression is essential for appropriate management of patients, while discovering biomarkers which lead to choroidal neovascularisation development is of urgent importance to establish international diagnostic criteria and treatment protocols.

Proteomic analysis of aqueous humor in patients with pathologic myopia

Complications from pathologic myopia (PM) are a major cause of visual impairment and blindness. However, an efficient clinical therapeutic strategy for PM is still lacking. The aim of this study was to quantitatively compare the proteomic profiles of aqueous humor between PM and non-PM cataract patients. Twenty aqueous humor samples from each group were analyzed with label-free quantitative proteomic analysis to identify the differentially expressed proteins for function enrichment analyses and protein-protein interaction network construction. Hub protein was validated with ELISA using an independent cohort consisting of 20 samples from each group and its receiver operating characteristic (ROC) curve analysis was conducted. A total of 583 proteins were identified and 101 proteins were found to be differentially expressed, including 63 up-regulated proteins and 38 down-regulated proteins. The bioinformatics analysis suggested that PM is closely associated with immunity and inflammation interactions, and remodeling of extracellular matrix. Apolipoprotein A-I (ApoA1) was enriched as the hub protein of the network with the highest score, degree and centrality. ROC analysis showed that ApoA1 could distinguish PM from controls with an area under the curve of 0.963 (p < 0.001). The findings could provide potential clues for further study on the molecular mechanisms and developing new treatments for PM, especially related to immunity and inflammation interactions. ApoA1 may be a potential key protein and therapeutic target in human PM. SIGNIFICANCE: It is important and urgent to discover the mechanisms of pathologic myopia (PM) to inhibit its progression. This study applied the quantitative proteomic analysis to study aqueous humor from patients with or without PM, aiming to discover dysregulated proteins related to PM. Our results suggested that those dysregulated proteins are closely associated with immunity and inflammation interactions, and remodeling of extracellular matrix. The findings from this study could provide potential clues for further research on the molecular mechanisms and developing new treatments for PM, especially related to immunity and inflammation. ApoA1 may be a potential key protein and therapeutic target in human PM.

Three-year outcomes of macular buckling for macular holes and foveoschisis in highly myopic eyes

BACKGROUND

To assess the functional and structural outcomes of macular buckling using a silicone sponge-titanium exoplant for the treatment of foveoschisis (FS) and full-thickness macular holes (FTMHs) in highly myopic eyes.

METHODS

Forty-nine consecutive patients with high myopia who underwent macular buckling for the treatment of FS and FTMHs were included. The outcomes measured included the anatomical success rate with FS resolution, retinal reattachment, MH closure, best corrected visual acuity (BCVA), axial length (AL) and complications of surgery. Moreover, the correlations between the BCVA at year three and series of factors, including age, duration of symptoms, baseline BCVA, AL, surgical type, preoperative macular status and severity of myopic maculopathy, were analysed.

RESULTS

This study involved 28 patients (28 eyes) with FS and 21 patients (21 eyes) with FTMHs with macular detachment. Retinal reattachment was achieved in 100% of cases, while MH closure was achieved in 76.19% of cases. The BCVA significantly improved one year after macular buckling in the FS cases and two years after macular buckling in the FTMH cases, and it remained stable throughout the rest of the follow-up period. The mean AL decreased by 2.09 mm postoperatively. No major perioperative complications were observed, although one patient needed to explant the buckling device due to intolerable diplopia.

CONCLUSION

Macular buckling with a silicone sponge-titanium exoplant may represent a safe and effective surgical option for the treatment of FS and FTMH in highly myopic eyes. Macular buckling showed a high closure rate and virtually no tendency to recur.

Long-Term Natural Course of Pathologic Myopia in Chinese Patients

PURPOSE

To investigate the natural progression in Chinese patients with pathological myopia (PM) and its associated factors.

METHODS

The medical records of 28 patients with PM (worse than -6 diopter), including 31 eyes of 21 children and 12 eyes of 7 adults, were studied. All of the patients underwent a complete ophthalmologic examination at least twice over 3-year period, including the measurement of refractive error (shown as spherical equivalent, SE), axial length (AL), intraocular pressure, visual acuity (uncorrected visual acuity, UCVA, and best-corrected visual acuity, BCVA), and dilated fundus examination.

RESULTS

The median AL of adults increased significantly from 29.8 mm to 31.43 mm over 5.4 years follow-up (P=0.0037), accompanied with the median SE progressing significantly from -16.4 D to -18.94 D (P=0.0005). Similarly, the median AL of children increased significantly from 26.13 mm to 27.81 mm over 3.9 years (P=0.0001). However, the improvements of UCVA and BCVA in children were significant (P=0.0304, 0.0001), and they had a negative correlation with age (P=0.0010, 0.0005). Also, UCVA and BCVA in children with bilateral PM were significantly better than those with unilateral PM (P=0.0385, 0.0210).

CONCLUSIONS

Fundus degenerations in children with pathological myopia may lead its way since the age of 10 years. Besides, children with bilateral pathological myopia can have parallel development in visual acuity.

A Bioengineering Approach to Myopia Control Tested in a Guinea Pig Model

Purpose

To investigate the biocompatibility of an injectable hydrogel and its ability to control myopia progression in guinea pigs.

Methods

The study used a hydrogel synthesized from acrylated hyaluronic acid with a conjugated cell-binding peptide and enzymatically degradable crosslinker. Seven-day-old guinea pigs were first form deprived (FD) with diffusers for 1 week. One group was kept as an FD-only control; two groups received a sub-Tenon's capsule injection of either hydrogel or buffer (sham surgery) at the posterior pole of the eye. Form deprivation treatments were then continued for 3 additional weeks. Treatment effects were evaluated in terms of ocular axial length and refractive error. Safety was evaluated via intraocular pressure (IOP), visual acuity, flash electroretinograms (ERG), and histology.

Results

Both hydrogel and sham surgery groups showed significantly reduced axial elongation and myopia progression compared to the FD-only group. For axial lengths, net changes in interocular difference (treated minus control) were 0.04 ± 0.06, 0.02 ± 0.09, and 0.24 ± 0.08 mm for hydrogel, sham, and FD-only groups, respectively (P = 0.0006). Intraocular pressures, visual acuities, and ERGs of treated eyes were not significantly different from contralateral controls. Extensive cell migration into the implants was evident. Both surgery groups showed noticeable Tenon's capsule thickening.

Conclusions

Sub-Tenon's capsule injections of both hydrogel and buffer inhibited myopia progression, with no adverse effects on ocular health. The latter unexpected effect warrants further investigation as a potential novel myopia control therapy. That the hydrogel implant supported significant cell infiltration offers further proof of its biocompatibility, with potential application as a tool for drug and cell delivery.

Effect of pregnancy in myopia progression: the SUN cohort

PurposePrevious studies have suggested that pregnancy may induce myopia progression. However, no longitudinal study with a large sample size and long-term follow-up has assessed this association. Our objective was to investigate whether pregnancy was related to mid- or long-term myopic refraction changes.Patients and methodsA prospective study was conducted in a Mediterranean cohort. The study included 10 401 women (20-50 years old) from the SUN Project. SUN project is a multipurpose, prospective, and dynamic cohort of university graduates conducted in Spain. The recruitment of participants started in 1999 and it is permanently open. All participants in this cohort had university studies. Participants were followed up for a period of up to 14 years, and pregnancy and refractive changes were assessed through baseline and biennial questionnaires. Pregnancies and myopia were repeatedly assessed in each biennial follow-up questionnaire during a total of 14 years of follow-up.ResultsPregnancy was inversely associated with the risk of myopia development or progression during each of the 2 years periods, with fully adjusted hazard ratio=0.61; (95% confidence interval=0.49-0.75) after adjusting for known potential confounders.ConclusionTo our knowledge this is the first large-longitudinal assessment in young adult women, showing that pregnancy is inversely associated with myopia development or progression. Further studies are needed to confirm these epidemiological findings.

Prevalence and Risk Factors for Refractive Error in Adult Chinese Americans: The Chinese American Eye Study

PURPOSE

To estimate the prevalence of refractive errors in adult Chinese Americans, and to evaluate factors associated with myopia and high myopia.

DESIGN

A population-based, cross-sectional study.

METHODS

Chinese Americans 50 years and older residing in Monterey Park, California, were recruited. Noncycloplegic automated refraction with supplemental subjective refraction was performed. Myopia, high myopia, hyperopia, and high hyperopia were defined as a spherical equivalent of <-0.5 diopter (D), <-5.0 D, >+0.5 D, and ≥+3.0 D, respectively. Astigmatism and high astigmatism were defined as a cylinder of >0.5 D and >2.25 D, respectively. Risk factor assessment was guided by a conceptual model.

RESULTS

Data from 4144 participants were analyzed. The overall prevalence of myopia, high myopia, hyperopia, high hyperopia, astigmatism, and high astigmatism in the right eye was 35.1% (95% confidence interval, 33.6%-36.6%), 7.4% (6.6%-8.3%), 40.2% (38.7%-41.8%), 2.7% (2.2%-3.3%), 45.6% (44.1%-47.2%), and 3.7% (3.1%-4.3%), respectively. The prevalence of myopia and high myopia was lower among older individuals (P < .05). Reversed age trends were observed for the other refractive errors (P < .05). There was no sex difference in the prevalence of refractive errors, except for a higher prevalence of hyperopia among female subjects (P = .010). Age, acculturation, education, income, marital status, birth country, history of ocular disease, nonocular comorbidities, and recent eye examination were associated with prevalence of myopia. All of these factors, except for acculturation, were also associated with high myopia.

CONCLUSIONS

Our data present the first population-based estimates of the prevalence of refractive errors among adult Chinese Americans. Compared with whites, Hispanics, and blacks, Chinese Americans have a higher burden of myopia, high myopia, and astigmatism.

Imposed Optical Defocus Induces Isoform-Specific Up-Regulation of TGFβ Gene Expression in Chick Retinal Pigment Epithelium and Choroid but Not Neural Retina

PURPOSE

This study investigated the gene expression of TGFβ isoforms and their receptors in chick retina, retinal pigment epithelium (RPE), and choroid and the effects of short-term imposed optical defocus.

METHODS

The expression of TGFβ isoforms (TGF-β1, 2, 3) and TGFβ receptors (TGFBR1, 2, 3) was examined in the retina, RPE, and choroid of young White-Leghorn untreated chicks (19 days-old). The effects on the expression of the same genes of monocular +10 and -10 D defocusing lenses, worn for either 2 or 48 h by age-matched chicks, were also examined by comparing expression in treated and untreated fellow eyes. RNA was purified, characterized and then reverse transcribed to cDNA. Differential gene expression was quantified using real-time PCR.

RESULTS

All 3 isoforms of TGFβ and all 3 receptor subtypes were found to be expressed in all 3 ocular tissues, with apparent tissue-dependent differences in expression profiles. Data are reported as mean normalized expression relative to GAPDH. Sign-dependent optical defocus effects were also observed. Optical defocus did not affect retinal gene expression but in the RPE, TGF-β2 expression was significantly up-regulated with +10 D lenses, worn for either 2 h (349% increase ± 88%, p < 0.01) or 48 h (752% increase ± 166%, p < 0.001), and in the choroid, the expression of TGF-β3 was up-regulated with -10 D lenses, worn for 48 h (147% increase ± 9%, p < 0.01).

CONCLUSIONS

The effects of short term exposure to optical defocus on TGFβ gene expression in the RPE and choroid, which were sign-dependent and isoform specific, provide further supporting evidence for important roles of members of the TGFβ family and these two tissues in local signal cascades regulating ocular growth.

Human electroretinal responses to grating patterns and defocus changes by global flash multifocal electroretinogram

The electrical response of the retina was examined as a function of retinal region, using stimuli of various spatial frequencies in the first experiment. In the second experiment, the regional response of the retina to defocus at high and low spatial frequencies was investigated. Twenty three subjects were recruited for global flash multifocal electroretinogram (mfERG) in experiment 1. Black and white gratings (printed on plastic transparent sheets) of four spatial frequencies (SF), 0.24, 1.2, 2.4 and 4.8 cycle per degree were presented in front of the mfERG stimulation. The amplitudes and implicit times of the direct (DC) and induced (IC) components of mfERG responses were pooled into six concentric rings for analysis. There was low amplitude DC at low SF, which increased with increasing SF, and which decreased with increasing eccentricity. The IC was high in amplitude at all SF and reduced in amplitude with increasing eccentricity. Our findings suggested that outer and inner retina had different characteristics in processing spatial details. In experiment 2, Twenty-three young adults were recruited for mfERG measurement. The retinal electrical responses for low (0.24cpd) and high (4.8cpd) SF under fully corrected conditions of short-term negative defocus (-2D) and short term positive defocus (+2D) conditions were measured. There was a sign-dependent response to defocus in the DC response, mainly in peripheral regions. The sign dependent response at low SF was more obvious than that at high SF, and was located more peripherally. The IC response showed no clear trends for either defocus condition. The human retina seems to have a decoding system for optical defocus, which was tuned for low spatial frequency, and was located in the retinal near periphery.

Ocular higher-order aberrations in a school children population

PURPOSE

The primary objective of the study was to explore the statistics of ocular higher-order aberrations in a population of primary and secondary school children.

METHODS

A sample of 557 children aged 10-15 years were selected from two primary and two secondary schools in Heraklion, Greece. Children were classified by age in three subgroups: group I (10.7±0.5 years), group II (12.4±0.5 years) and group III (14.5±0.5 years). Ocular aberrations were measured using a wavefront aberrometer (COAS, AMO Wavefront Sciences, USA) at mesopic light levels (illuminance at cornea was 4lux). Wavefront analysis was achieved for a 5mm pupil. Statistical analysis was carried out for the right eye only.

RESULTS

The average coefficient of most high-order aberrations did not differ from zero with the exception of vertical (0.076μm) and horizontal (0.018μm) coma, oblique trefoil (-0.055μm) and spherical aberration (0.018μm). The most prominent change between the three groups was observed for the spherical aberration, which increased from 0.007μm (SE 0.005) in group I to 0.011μm (SE 0.004) in group II and 0.030μm (SE 0.004) in group III. Significant differences were also found for the oblique astigmatism and the third-order coma aberrations.

CONCLUSIONS

Differences in the low levels of ocular spherical aberration in young children possibly reflect differences in lenticular spherical aberration and relate to the gradient refractive index of the lens. The evaluation of spherical aberration at certain stages of eye growth may help to better understand the underlying mechanisms of myopia development.

Spectral- and time-domain optical coherence tomography measurements of macular thickness in young myopic eyes

PURPOSE

To evaluate the variation in macular retinal thickness and volume in young Chinese myopic patients using time-domain optical coherence tomography (Stratus TD-OCT) and spectral-domain optical coherence tomography (Cirrus HD-OCT).

METHODS

Ninety-two eyes of 92 myopic subjects were recruited in this study. Based upon spherical equivalence (SE), subjects were divided into two groups: the low to moderate myopia group (-0.5 D ≤ SE < -6.0 D), and the high myopia group (SE ≥ -6.0 D). Stratus TD-OCT and Cirrus HD-OCT were used to compare macular retinal thickness and volume between the two groups. Bland-Altman analysis and Pearson correlation were used to measure agreement between the two OCT systems.

RESULTS

Average macular retinal thickness and total macular volume measured by Cirrus HD-OCT and Stratus TD-OCT of the low to moderate myopia group were 283.52 ± 12.14 μm and 245.38 ± 8.55 μm, respectively, and 10.08 ± 0.37 mm3 and 6.85 ± 0.26 mm3, respectively, and the high myopia groups were 269.58 ± 10.72 μm and 235.65 ± 7.54 μm, respectively, and 9.71 ± 0.36 mm3 and 6.52 ± 0.25 mm3, respectively. The measurements of the two OCTs showed that macular retinal thickness of the parafovea was significantly lower in the high myopia group compared with the low to moderate myopia group, except at the fovea (all P-values less than 0.001, except at the fovea). Using the Bland-Altman method and Pearson correlation, measurements of macular thickness in nine macular retinal subfields and total macular volumes showed good agreement between the two OCTs in myopic eyes (all P-values less than 0.001), with better agreement in the low to moderate myopia group than in the high myopia group.

CONCLUSIONS

The average macular retinal thickness of the fovea did not vary with myopia, while the total volume and retinal thickness of the parafovea were thinner with increasing myopia. There was good agreement between the two OCTs in myopic eyes in all macular subfields, and the Cirrus HD-OCT system provided thicker macular retinal thickness measurements than the Stratus TD-OCT system.

VIRTUAL SLIDES

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1683223414107652.

The efficacy and safety of modified Snyder-Thompson posterior scleral reinforcement in extensive high myopia of Chinese children

BACKGROUND

To observe the efficacy and safety of modified Snyder-Thompson posterior scleral reinforcement in extensive high myopia of Chinese children. We had a retrospective design, and included a control group of children with natural progression of high myopia.

METHODS

This study included 64 eyes in 41 Chinese children with extensive high myopia who underwent modified Snyder-Thompson posterior scleral reinforcement surgery (PSR group), and 17 eyes in 11 age- and myopia-matched children who wore spectacles (control group). The mean follow-up was 4.99 ± 1.3 years in the PSR group and 4.48 ± 1.3 years in the control group. Axial length, spherical equivalent (SE), uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA) and fundus examinations were recorded before and after treatment, and complications were noted.

RESULTS

The mean change in SE at the end of the follow-up period was 1.5 ± 1.44 diopters (D) and 3.02 ± 1.57D in the PSR and control groups respectively. These changes were equivalent to an increase in axial length of 1.27 ± 0.54 mm and 2.05 ± 0.91 mm respectively. The PSR group showed less myopic progression and less eye elongation (p < 0.001). A notable increase in UCVA was only found in the PSR group (p = 0.0001). The improvement in BCVA was significantly greater in the PSR group (p = 0.0354). There were no serious complications of PSR surgery.

CONCLUSION

The modified Snyder-Thompson PSR surgery was effective and safe in controlling extensive high myopia of Chinese children.

Peripapillary scleral deformation and retinal nerve fiber damage in high myopia assessed with swept-source optical coherence tomography

PURPOSE

To study peripapillary morphologic changes in highly myopic eyes using swept-source optical coherence tomography at a longer wavelength.

DESIGN

Prospective cross-sectional study.

METHODS

Peripapillary regions of 196 eyes of 107 patients with high myopia (refractive error, <-8.0 diopters or axial length, >26.0 mm) were analyzed quantitatively and qualitatively with an swept-source optical coherence tomography prototype system that uses a tunable laser light source operated at a 100,000-Hz A-scan repetition rate in the 1-μm wavelength region. The visual field was evaluated by standard automated perimetry. Area of peripapillary atrophy β and presence of scleral protrusion temporal to the optic disc were assessed.

RESULTS

Peripapillary atrophy β area, but not disc area, was significantly larger in eyes with visual field defect (3.16 ± 2.70 mm(2); range, 0.00 to 12.85 mm(2)) than those without visual field defect (2.31 ± 2.83 mm(2); range, 0.00 to 17.70 mm(2)). Temporal scleral protrusion was detected by color stereo disc photography in 22 (19.5%) of 113 eyes with visual field defect and in 4 (4.8%) of 83 eyes without visual field defect. Scleral bending demonstrated a wide range of angles (mean, 31.0 ± 21.1 degrees; range, 2 to 80 degrees). The angle of scleral bending, but not the distances from scleral bend to disc margin or foveal center, correlated significantly with retinal nerve fiber layer thickness above the bend (r = -0.557, P = .007) and visual field defect severity (r = -0.445, P = .038).

CONCLUSIONS

Swept-source optical coherence tomography visualizes peripapillary deep structures in high myopia. Some cases of high myopia may be affected by direct scleral compression or stretching at the peripapillary region.

Myopia-related optic disc and retinal changes in adolescent children from singapore

PURPOSE

To examine early myopia-related optic disc and retinal changes in a Singapore Chinese adolescent sample without confounding ocular or systemic disease.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

Children aged 12 to 16 years at a follow-up visit for Singapore Cohort Study of Risk Factors for Myopia.

METHODS

Detailed eye examinations, including cycloplegic autorefraction and contact biometry, were performed. Retinal photographs were acquired using nonmydriatic retinal photography among children who attended follow-up examinations in 2006, and were graded for myopia-related optic disc signs and macular changes by a single experienced grader. Optic nerve head parameters were measured adjusting for camera and ocular magnification with appropriate formulae.

MAIN OUTCOME MEASURES

Optic disc changes (tilt, beta peripapillary atrophy [β-PPA], and optic nerve parameters) and macular changes (staphyloma, lacquer cracks, Fuchs' spot, and chorioretinal atrophy).

RESULTS

Retinal photography data were available for 1227 children (median age, 14 years; range 12-16). Tilted optic discs were found in 454 subjects (37%), and were associated with myopic spherical equivalent refractions (-3.6 diopters [D] vs -1.3 D; P<0.0001), higher cylindrical error (0.9 vs 0.7 D; P = 0.0001) and longer axial length (24.93 vs 23.96 mm; P<0.0001). The pattern of distribution of the axes of the tilted discs and corneal curvature were similar (P = 0.4). All linear optic nerve parameters, except vertical disc diameter (P = 0.15), were significantly smaller in eyes with than without tilted discs (P <0.001) after adjusting for confounders. Apart from 20 cases, all eyes with tilted optic discs had associated β-PPA. We identified only 1 case each (0.1% prevalence) of staphyloma and lacquer cracks in this sample.

CONCLUSIONS

In this Asian adolescent population, tilted optic discs were highly prevalent, in contrast with the lower prevalence reported in Caucasian populations. Eyes with tilted discs tended to have smaller optic cups with smaller cup-to-disc ratios, and were associated with myopic refraction, higher astigmatism, and longer axial length. There were similar patterns of distribution between the axis of disc tilt and the axis of corneal curvature, which could have embryologic origins. In contrast with optic disc changes, myopic macular changes were rare in this age group, suggesting that these changes may develop later in life.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Association between high myopia and progression of visual field loss in primary open-angle glaucoma

BACKGROUND/PURPOSE

Taiwan has a very high prevalence rate of myopia. We retrospectively studied the influence of myopia on the progression of visual field (VF) loss in primary open-angle glaucoma (POAG) patients.

METHODS

We studied 515 POAG patients for a minimum follow-up period of 5 years. VF examination was performed with Humphrey perimeter, 30-2 SITA standard program, every 6 months. A point-wise numerical comparison was applied to judge the VF changes. Test points showing more than 1.0 dB of sensitivity loss in mean defect were identified. A location was considered to have progression if it was detected on two consecutive visits. Progression of VF loss was confirmed if three or more test points deteriorated. Multivariate logistic regression was used to evaluate the association between progression of VF loss and various risk factors.

RESULTS

There were 262 cases. Progression of VF loss occurred in 57 eyes (21.8%) during the 5-year follow-up period. Logistic regression revealed that the deterioration was associated with older age, higher mean intraocular pressure, larger vertical cup-to-disc ratio, and greater myopic refraction status. The incidence of VF loss progression was 15.1% in the group of eyes with myopia less than -3 D, 10.5% in the group with -3 D to -6 D, 34.4% in the group with -6 D to -9 D, and 38.9% in the group with myopia greater than -9 D.

CONCLUSION

POAG patients with myopia greater than -6 D had a greater progression of VF loss.

Long-term remission of myopic choroidal neovascular membrane after treatment with ranibizumab: a case report

Introduction

Myopia has become a big public health problem in certain parts of the world. Sight-threatening complications like choroidal neovascularisation membranes occur in up to 10% of pathological myopia, and natural history studies show a trend towards progressive visual loss. There are long-term financial and quality-of-life implications in this group of patients, and treatment strategies should aim for long-term preservation of vision.

Case presentation

A 56-year-old Caucasian woman presented with a best-corrected visual acuity of 6/6-1 in her right eye and 6/24 in her left. Fundal examination revealed pathological myopia in both eyes and an elevated lesion associated with pre-retinal haemorrhage in the left macula. Ocular coherence tomography and fundus fluorescein angiogram confirmed a subfoveal classic choroidal neovascularisation membrane. The patient decided to proceed with intravitreal ranibizumab (0.5 mg) therapy. One month after treatment, best-corrected visual acuity improved to 6/12 in her left eye, with complete resolution subretinal fluid on ocular coherence tomography. After three months, best-corrected visual acuity further improved to 6/9, which was maintained up to 16 months post-treatment.

Conclusion

We suggest intravitreal ranibizumab as an alternative treatment for long-term remission of myopic choroidal neovascular membrane. It also suggests that myopic choroidal neovascularisation membranes may require fewer treatments to achieve sustained remission. Furthermore, this could serve as a feasible long-term management option if used in conjunction with ocular coherence tomography.

Prevalence of habitual refractive errors and anisometropia among Dutch schoolchildren and hospital employees

PURPOSE

Refractive error (RE) is suggested to cause not only visual impairment, but also functional problems such as aspecific health complaints and lower levels of school achievement. During the last few decades the prevalence of myopia has increased worldwide, especially in Asia. We investigated the prevalence of habitual RE and anisometropia in a Dutch population of children and employees.

METHODS

In a cross-sectional study, RE in both eyes of 520 children (aged 11-13 years) and 444 hospital employees (aged 17-60 years) were measured using an autorefractometer. The measurements were performed without using a cycloplegium. Pearson's correlation coefficient (r) was used to analyse correlations between the right and left eyes. Chi-square tests were used to test the differences between subgroups according to gender and age.

RESULTS

In schoolchildren 28% of right eyes were myopic (> 0.50 D) and 8% hyperopic (> 0.50 D). Pearson's r between right and left eyes for spherical equivalent power (SEP) was 0.93. The mean cylinder deviation in right eyes was 0.26 D (range 0.00-4.50 D). Anisometropia > 1.00 D was present in 4.6% of children; 22% of children were not optimally (> 0.50 D) corrected. In hospital employees, 30% of right eyes were myopic (> 0.50 D) and 10% hyperopic (> 0.50 D). Pearson's r between right and left eyes for SEP was 0.53. The mean cylinder deviation in right eyes was 0.35 D (range 0.00-5.75 D). Anisometropia > 1.00 D was present in 25% of employees. Anisometropia was more frequently present in employees aged 40-60 years, than in those aged 17-39 years (30% versus 18%; p = 0.02, Cramer's V = 0.15).

CONCLUSIONS

Refractive errors are common in children aged 11-13 years and in working adults aged 17-60 years. Distributions of sphere and cylinder deviations are similar for Dutch schoolchildren and hospital employees. Surprisingly, anisometropia proved to be more prevalent with age. In children many eyes are not optimally corrected. Increased attention should be paid to uncorrected and miscorrected REs.

Myopia and associated pathological complications

Besides the direct economic and social burden of myopia, associated ocular complications may lead to substantial visual loss. In several population and clinic-based cohorts, case-control and cross-sectional studies, higher risks of posterior subcapsular cataract, cortical and nuclear cataract in myopic patients were reported. Patients with high myopia (spherical equivalent at least -6.0 D) are more susceptible to ocular abnormalities. The prevalent risks of glaucoma were higher in myopic adults, and risks of chorioretinal abnormalities such as retinal detachment, chorioretinal atrophy and lacquer cracks increased with severity of myopia and greater axial length. Myopic adults were more likely to have tilted, rotated, and larger discs as well as other optic disc abnormalities. Often, these studies support possible associations between myopia and specific ocular complications, but we cannot infer causality because of limitations in study methodology. The detection and treatment of possible pathological ocular complications is essential in the management of high myopia. The ocular risks associated with myopia should not be underestimated and there is a public health need to prevent the onset or progression of myopia.

Orthokeratology for myopic children: wolf in sheep's clothing?

Orthokeratology attempts to reduce myopia by remoulding the corneal shape with contact lenses. A recent resurgence is predicated on new contact lens designs with a prefigured back contact surface and higher oxygen transmissibility. This Clinical Controversy presents an analysis of the risk factors associated with orthokeratology and its suitability for children, followed by commentaries from specialists who have an interest in the method. Some state that there is a lack of data on relative risks of corneal infection and that there is a need for large-scale randomized controlled studies; however, opinion is expressed by others that orthokeratology is a clinically safe procedure using modern lenses. It is noted that the physiological and biophysical bases of orthokeratology are virtually unknown, and further research on the human cornea is indicated to scientifically establish the safety of orthokeratology. Prospective patients, and their parents in the case of children, should be fully informed of the risks.