Natural history of choroidal neovascularization in high myopia

Genetic Polymorphisms in VEGFR Coding Genes (FLT1/KDR) on Ranibizumab Response in High Myopia and Choroidal Neovascularization Patients

A severe form of myopia defined as pathologic/high myopia is the main cause of visual impairment and one of the most frequent causes of blindness worldwide. It is characterized by at least 6 diopters or axial length (AL) of eyeball > 26 mm and choroidal neovascularization (CNV) in 5 to 10% of cases. Ranibizumab is a humanized recombinant monoclonal antibody fragment targeted against human vascular endothelial growth factor A (VEGF-A) used in the treatment of CNV. It acts by preventing VEGF-A from interacting with its receptors (VEGFR-1 and -2) encoded by the FLT1 and KDR genes. Several studies found that the KDR and FLT1 genotypes may represent predictive determinants of efficacy in ranibizumab-treated neovascular age-related macular degeneration (nAMD) patients. We performed a retrospective study to evaluate the association of single nucleotide polymorphisms (SNPs) in VEGFR coding genes with the response rate to ranibizumab in patients with high myopia and CNV. In the association study of genotypes in FLT1 with the response to ranibizumab, we found a significant association between two FLT1 variants (rs9582036, rs7993418) with ranibizumab efficacy at the 12-month follow-up. About the KDR gene, we found that two KDR variants (rs2305948, rs2071559) are associated with best-corrected visual acuity (BCVA) improvement and KDR (rs2239702) is associated with lower rates of BCVA worsening considering a 12-month follow-up period.

Pathologic myopia: advances in imaging and the potential role of artificial intelligence

Pathologic myopia is a severe form of myopia that can lead to permanent visual impairment. The recent global increase in the prevalence of myopia has been projected to lead to a higher incidence of pathologic myopia in the future. Thus, imaging myopic eyes to detect early pathological changes, or predict myopia progression to allow for early intervention, has become a key priority. Recent advances in optical coherence tomography (OCT) have contributed to the new grading system for myopic maculopathy and myopic traction maculopathy, which may improve phenotyping and thus, clinical management. Widefield fundus and OCT imaging has improved the detection of posterior staphyloma. Non-invasive OCT angiography has enabled depth-resolved imaging for myopic choroidal neovascularisation. Artificial intelligence (AI) has shown great performance in detecting pathologic myopia and the identification of myopia-associated complications. These advances in imaging with adjunctive AI analysis may lead to improvements in monitoring disease progression or guiding treatments. In this review, we provide an update on the classification of pathologic myopia, how imaging has improved clinical evaluation and management of myopia-associated complications, and the recent development of AI algorithms to aid the detection and classification of pathologic myopia.

Genetic Polymorphisms Affecting Ranibizumab Response in High Myopia Patients

High myopia is an ophthalmic pathology that affects half of the young adults in the United States and Europe and it is predicted that a third of the world’s population could be nearsighted at the end of this decade. It is characterized by at least 6 diopters or axial length > 26 mm and, choroidal neovascularization (CNV) in 5 to 11% of cases. Ranibizumab is a recombinant humanized monoclonal antibody fragment. It is an anti-vascular endothelial growth factor (anti-VEGF) drug used in the treatment of CNV. Many genetic polymorphisms have been associated with interindividual differences in the response to ranibizumab, but these associations were not yet assessed among patients with high myopia and CNV. We performed a retrospective study assessing the association of genetic polymorphisms with response to ranibizumab in patients with CNV secondary to high myopia (mCNV). We included genetic polymorphisms previously associated with the response to drugs used in CNV patients (bevacizumab, ranibizumab, aflibercept, and photodynamic therapy (PDT)). We also included genetic variants in the VEGFA gene. Based on our results, ARMS2 (rs10490924) and CFH (rs1061170) are associated with response to ranibizumab in high myopia patients; and, included VEGFA genetic polymorphisms are not associated with ranibizumab response in our population but might be related to a higher risk of CNV.

Efficacy of Conbercept in the Treatment of Choroidal Neovascularization Secondary to Pathologic Myopia

Purpose: To observe the clinical efficacy of conbercept in the treatment of choroidal neovascularization (CNV) secondary to pathologic myopia. Methods: We used retrospective analysis of the clinical data of 20 patients (24 eyes) with pathologic myopia choroidal neovascularization (PM-CNV). All patients were treated with intravitreal injection of conbercept 0.5 mg (0.05 ml), a vascular endothelial growth factor (VEGF) receptor fusion protein, and all patients completed at least 6 months of follow-up. Fundus, best corrected visual acuity (BCVA), fundus fluorescein angiography (FFA), optical coherence tomography (OCT), multifocal electroretinogram (mfERG) were assessed before and after treatment. Primary outcome was the functional change in amplitude by mfERG and secondary outcome was the structural change in central macular thickness (CRT) by OCT. The CNV area, leakage of CNV lesions, ocular and systemic adverse events were observed before and after treatment. Results: The BCVA were 64.33 ± 10.83 letters, 65.42 ± 11.24 letters, 67.67 ± 7.07 letters after treatment 1, 3, 6 month, respectively, which showed improvement compared with the baseline (P < 0.05). The CRT decreased significantly from 308.50 ± 45.48 μm to 219.63 ± 30.27 μm, 221.33 ± 40.65 μm, 220.96 ± 33.09 μm after treatment 1, 3, 6 month, respectively (P < 0.05). The P1 response of mfERG amplitude improved from 40.71 ± 9.69 nv/deg2 to 50.67 ± 9.48 nv/deg2, 54.92 ± 8.45 nv/deg2, 55.67 ± 6.74 nv/deg2 after treatment 1, 3, 6 month, respectively (P < 0.05). After 6 months of treatment, the leakage of CNV lesions disappeared in 20 (83.3%) eyes, and the leakage area of CNV lesions was significantly reduced in 4 (16.7%) eyes. Conclusion: The intravitreal injection of conbercept significantly reduced CRT and the CNV area, inhibited the leakage of CNV, improved the BCVA, increased the response of mfERG amplitude, and restored the retinal function. The intravitreal injection of conbercept can change the morphology and function of the macular in PM-CNV, which is safe and effective for the treatment of PM-CNV.

IMI Pathologic Myopia

Pathologic myopia is a major cause of visual impairment worldwide. Pathologic myopia is distinctly different from high myopia. High myopia is a high degree of myopic refractive error, whereas pathologic myopia is defined by a presence of typical complications in the fundus (posterior staphyloma or myopic maculopathy equal to or more serious than diffuse choroidal atrophy). Pathologic myopia often occurs in eyes with high myopia, however its complications especially posterior staphyloma can also occur in eyes without high myopia.

Owing to a recent advance in ocular imaging, an objective and accurate diagnosis of pathologic myopia has become possible. Especially, optical coherence tomography has revealed novel lesions like dome-shaped macula and myopic traction maculopathy. Wide-field optical coherence tomography has succeeded in visualizing the entire extent of large staphylomas. The effectiveness of new therapies for complications have been shown, such as anti-VEGF therapies for myopic macular neovascularization and vitreoretinal surgery for myopic traction maculopathy.

Myopia, especially childhood myopia, has been increasing rapidly in the world. In parallel with an increase in myopia, the prevalence of high myopia has also been increasing. However, it remains unclear whether or not pathologic myopia will increase in parallel with an increase of myopia itself. In addition, it has remained unclear whether genes responsible for pathologic myopia are the same as those for myopia in general, or whether pathologic myopia is genetically different from other myopia.

Longitudinal Evaluation of the Structural and Functional Changes Associated with Glaucoma in Myopia

SIGNIFICANCE

This study ascertains that myopia is a risk factor for glaucoma progression among eyes with primary open angle glaucoma. Myopic eyes with primary open angle glaucoma may benefit from measurement and incorporation of axial length information into clinical decision making.

PURPOSE

The purpose of this study was to estimate the rate of change in retinal nerve fiber layer (RNFL) thickness and the rate of change in visual field of glaucoma patients with and without myopia.

METHODS

We conducted a prospective, observational cohort study where we analyzed 245 eyes of 135 glaucoma patients followed for a mean period of 6.08 years. All the subjects had RNFL imaging and standard automated perimetry performed for both eyes in the same visit every 4 months for at least 60 months.

RESULTS

The rate of change of average RNFL thickness and visual field index (VFI) was -0.29 μm/y (95% confidence interval, -1.80 to +1.23 μm/y) and -0.30%/y (95% confidence interval, -2.24 to +1.64%/y), respectively, after adjusting for age, axial length, IOP, baseline RNFL thickness, signal strength, and correlation between fellow eyes. Axial length, as a continuous variable, was not associated with the rates of change of average RNFL thickness and VFI. However, high myopic eyes with axial lengths of ≥26.0 and ≥26.5 mm had an average rate of change of RNFL thickness of 0.15 and 0.16 μm/y faster than eyes with axial lengths of less than 26 and 26.5 mm, respectively. Similarly, myopic eyes with an axial length of ≥26.5 mm were associated with a 0.21%/y faster rate of VFI reduction.

CONCLUSIONS

Both RNFL and visual field progression rates are faster in myopic glaucomatous eyes with an axial length of ≥26.5 mm than in eyes <26.5 mm. However, the small difference that supports high myopia as a risk factor for progression does not indicate the clinical importance or significance of axial length.

Clinical observations of acute onset of myopic optic neuropathy in a real-world setting

AIM

To describe the clinical features of acute myopic onset of optic neuropathy and observe the effects of retrobulbar and systemic glucocorticoid therapy in a real-world setting.

METHODS

A retrospective observational case series included 18 patients with a clinical diagnosis of acute onset of myopic optic neuropathy in a real-world setting. While the patients were using retrobulbar and systemic glucocorticoid therapy, various imaging examination data were analysed, and the clinical features of myopic optic neuropathy were summarized for 6mo to 2y.

RESULTS

The included group of patients with acute onset of myopic optic neuropathy consisted mostly of females (n=11). The visual field (VF) showed abnormalities in bilateral eyes, including the spread of physiological blind spots, central and paracentral dark spots, and centripetal peripheral VF reduction; but central vision with no subjective changes. The visual evoked potential (VEP) was abnormal in all eyes with vision loss. The best corrected visual acuity (BCVA) was improved from 1.04±0.63 to 0.47±0.57 (logMAR) after glucocorticoid treatment (P<0.05). In patients with a short course (within 1wk), recovery was fast and achieved the same BCVA as recorded before the onset within 6d. However, in patients with the long course (1 to 2wk), recovery was slow and did not achieve the BCVA recorded before the onset within 10d. The changes of intraocular pressure (IOP) were not obvious before and after treatment (18.68±5.30 vs 19.55±5.34 mm Hg, P>0.05). There was no recurrence during long-term follow-up observation.

CONCLUSION

The acute onset of myopic optic neuropathy is characterized by BCVA and VF abnormalities in bilateral eyes. Retrobulbar and systemic glucocorticoid therapy is effective.

Myopia

Myopia, also known as short-sightedness or near-sightedness, is a very common condition that typically starts in childhood. Severe forms of myopia (pathologic myopia) are associated with a risk of other associated ophthalmic problems. This disorder affects all populations and is reaching epidemic proportions in East Asia, although there are differences in prevalence between countries. Myopia is caused by both environmental and genetic risk factors. A range of myopia management and control strategies are available that can treat this condition, but it is clear that understanding the factors involved in delaying myopia onset and slowing its progression will be key to reducing the rapid rise in its global prevalence. To achieve this goal, improved data collection using wearable technology, in combination with collection and assessment of data on demographic, genetic and environmental risk factors and with artificial intelligence are needed. Improved public health strategies focusing on early detection or prevention combined with additional effective therapeutic interventions to limit myopia progression are also needed.

Results of Ranibizumab Treatment of the Myopic Choroidal Neovascular Membrane according to the Axial Length of the Eye

Aim

A retrospective evaluation of the results of treatment of myopic choroidal neovascularization (mCNV) with intravitreal injections of ranibizumab in a pro re nata (PRN) regimen in three groups of patients distributed according to axial length.

Methods

The paper presents a retrospective multicenter study carried out with the cooperation of several Departments of Ophthalmology in the Czech Republic. The study included 60 eyes of 60 patients suffering from mCNV, divided according to axial length into three groups. The first group consisted of 20 patients with an axial length of the eyes shorter than 28 mm (Group 1), the second group included 27 patients with axial lengths ranging from 28 mm to 29.81 mm (Group 2), and 13 patients had axial lengths longer than 30 mm (Group 3). All patients were first administered 3 initial intravitreal ranibizumab injections at monthly intervals (loading phase), and other injections were administered according to a PRN treatment regimen. Patients were evaluated before treatment and then at intervals of 3, 6, 9, and 12 months. The effect of ranibizumab treatment on the functional and morphological parameters of the affected eye was evaluated.

Results

The average baseline BCVA ± SD in Group 1 was 52.6 ± 12.5 letters of ETDRS optotypes, and at the end of the one-year follow-up, it was 63.3 ± 11.8 letters. The average baseline of CRT ± SD in this group was 377.4 ± 80.0 μm, and in the 12th month, it was 311.1 ± 63.7 μm. The average baseline BCVA ± SD in Group 2 was 50.2 ± 9.0 ETDRS letters, and at the end of the follow-up, it was 60 ± 12.4 letters. The average baseline of CRT ± SD in Group 2 was 391.2 ± 85.2 μm, and in the 12th month, it was 323.9 ± 91.2 μm. In Group 3, the average baseline of BCVA was 48.5 ± 14.5 ETDRS letters, and at the end of the one-year follow-up, it was 55.7 ± 16.1 letters. The average baseline CRT ± SD for Group 3 was 342.1 ± 94.9 μm, and after 12 months, it was 287.8 ± 88.4 μm. An improvement of BCVA by ≥15 letters of ETDRS optotypes was achieved by 3 patients of 20 (15%) in Group 1, by 5 patients of 27 (18.5%) in Group 2, and by 3 patients of 13 (23.1%) in Group 3. All these changes were statistically significant in comparison with the input values (p < 0.05).

Conclusion

Ranibizumab treatment in patients with mCNV in our study resulted in statistically significant improvement in BCVA and a decrease in CRT in all groups of patients. Our results from a routine clinical practice correspond with the results of large clinical studies; we confirm a particularly good effect of treatment in patients with axial lengths of the eye smaller than 28 mm.

Outcome Predictors of SD-OCT-Driven Intravitreal Ranibizumab in Choroidal Neovascularization due to Myopia

PURPOSE

To analyze the efficacy and outcome predictors of SD-OCT (spectral-domain optical coherence tomography)-driven ranibizumab treatment in patients with choroidal neovascularization due to myopia (mCNV).

METHODS

This prospective investigator-initiated study includes 20 patients with treatment-naïve mCNV. Evaluation included best-corrected visual acuity (BCVA), morphological SD-OCT parameters, and treatment frequency.

RESULTS

From baseline to month 12, BCVA improved from 58.5 ± 16.9 to 66.1 ± 14.9 letters. Central retinal thickness (CRT) significantly decreased, and qualitative SD-OCT parameters improved. Better baseline visual acuity (VA), lower spherical equivalent, better inner/outer segment line and external limiting membrane integrity showed a significant positive effect on BCVA outcome. Less fluctuation in CRT (worst minus best CRT) indicated better BCVA at 12 months. No serious adverse events occurred.

CONCLUSIONS

SD-OCT-guided intravitreal ranibizumab treatment in mCNV was efficient and safe. We determined useful predictive factors in regard to VA outcome after 12 months.

Design and Baseline Characteristics of the HELP Study: An Extended and Long-Term Observation of Pathological Myopia in Caucasians

PURPOSE

To assess the natural disease progression of high myopia in Caucasians considered at risk for the development of myopic choroidal neovascularization (mCNV).

METHODS

Subjects were recruited in 25 clinical sites between June 2014 and June 2016. Main inclusion criteria included axial length of ≥26 mm, best-corrected visual acuity ≥0.05 decimal equivalent and presence of at least one out of five predefined morphological disease risk criteria. These were (1) subfoveal choroidal thinning < 50 µm, (2) enhanced choroidal curvature length > 6,300 µm, (3) lacquer cracks, (4) patchy atrophy > 5 mm2 and (5) preexisting mCNV in the fellow eye (German Clinical Trial Register DRKS00007761).

RESULTS

A total of 150 participants (66% females) with a mean age of 57.2 (±12.7) years (range 21.9-86.2 years) were included. The disease criteria most frequently encountered were choroidal thinning (33.3%) and lacquer cracks (32.7%). Enhanced choroidal curvature length was detected in only 8 subjects and always occurred in combination with other disease criteria. Presence of patchy atrophy was found to be more common in older subjects (p = 0.0012) and also associated with a more severe disease manifestation.

CONCLUSION

The baseline data of this study indicate that enhanced choroidal curvature might be less common in Caucasians than in Asian populations. Further, disease severity in patients with high myopia is relatively high in the presence of patchy atrophy.

MiSight Assessment Study Spain (MASS). A 2-year randomized clinical trial

PURPOSE

To compare myopia progression in children randomized to MiSight contact lenses (CLs) versus children corrected with single-vision spectacles (SV) over a 2-year period.

METHODS

Subjects aged 8 to 12 with myopia (-0.75 to -4.00 D sphere) and astigmatism (< -1.00 D cylinder) were assigned to the lens study group (MiSight) or the control group (single vision). Measurements of visual acuity and subjective refraction were taken at 6-month intervals, and axial length, anterior chamber, corneal power, and cycloplegic autorefraction were measured at the baseline, 12-month, and 24-month visits.

RESULTS

Eighty-nine subjects were recruited. Forty-fix children were assigned to the MiSight group, and 33 to the single-vision spectacle group. In total, 74 children completed the clinical trial, with the following parameters at the beginning of the study: n =  41 in the MiSight group (age: 11.01 ± 1.23 years, spherical equivalent: -2.16 ± 0.94 D, gender: male: 21, female: 20) and n = 33 in the single-vision group (age: 10.12 ± 1.38 years, spherical equivalent: -1.75 ± 0.94 D, gender: male: 12, female: 21). After 2 years of follow-up, myopia progressed slowly in the MiSight group compared to the control group (0.45 D vs 0.74 D, p < 0.001) and there was less axial elongation in the MiSight group compared to the single-vision group (0.28 mm vs 0.44 mm, p < 0.001). Therefore, use of MiSight CLs produced lower myopia progression (39.32%) and lower axial growth of the eye (36.04%) at 2 years compared to spectacle use.

CONCLUSIONS

MiSight contact lens wear reduces axial elongation and myopia progression in comparison to distance single-vision spectacles in children. ClinicalTrials.gov Identifier: NCT01917110.

Insight into high myopia and the macula

The incidence of myopia is constantly on the rise. Patients of high myopia and pathological myopia are young and can lose vision due to a number of degenerative changes occurring at the macula. With the emergence of new technologies such as swept-source optical coherence tomography (OCT) and OCT angiography, our understanding of macular pathology in myopia has improved significantly. New conditions such as myopic traction maculopathy have been defined. Early, noninvasive detection of myopic choroidal neovascularization and its differentiation from lacquer cracks is possible with a greater degree of certainty. We discuss the impact of these new exciting and promising technologies and management of macular pathology in myopia. Incorporation of OCT in the microscope has also improved macular surgery. New concepts such as fovea-sparing internal limiting membrane peeling have emerged. A review of literature and our experience in managing all these conditions are discussed.

Complications of Pathologic Myopia

Pathologic myopia (PM) is one of the leading causes of visual impairment worldwide. The pathophysiology of PM is not fully understood, but the axial elongation of the eye followed by chorioretinal thinning is suggested as a key mechanism. Pathologic myopia may lead to many complications such as chorioretinal atrophy, foveoschisis, choroidal neovascularization, rhegmatogenous retinal detachment, cataract, and glaucoma. Some complications affect visual acuity significantly, showing poor visual prognosis. This article aims to review the types, pathophysiology, treatment, and visual outcome of the complications of PM.

Aqueous Levels of Pigment Epithelium-Derived Factor and Macular Choroidal Thickness in High Myopia

Purpose. To investigate the correlation between aqueous and serum levels of pigment epithelium-derived factor (PEDF) and macular choroidal thickness in high myopia patients, both with and without choroidal neovascularization (CNV). Methods. Serum and aqueous levels of PEDF were measured by enzyme-linked immunosorbent assay in 36 high myopia patients (36 eyes) with no CNV (non-CNV group), 14 high myopia patients (14 eyes) with CNV (CNV group), and 42 nonmyopia patients (42 eyes) (control group). Macular choroidal thickness was measured by enhanced-depth imaging optical coherence tomography. Results. Aqueous levels of PEDF were significantly higher in CNV group compared with non-CNV (P < 0.001) and control (P < 0.001) groups. Macular choroidal thicknesses were significantly decreased in the non-CNV and CNV groups compared with the control (P < 0.001) group. A statistically significant difference (P = 0.012) was found between the CNV and non-CNV groups. There was a positive correlation between aqueous PEDF and macular choroidal thickness in the non-CNV group (P = 0.005), but no correlation with the CNV group. No correlation between serum PEDF and macular choroidal thickness was detected in the three groups. Conclusion. Variations in aqueous PEDF levels coincide with changes in macular choroidal thickness in high myopia patients with no CNV, while no such relationship exists in high myopia patients with CNV.

BMP-2 Is Involved in Scleral Remodeling in Myopia Development

The development of myopia is associated with scleral remodeling, but it is unclear which factors regulate this process. This study investigated bone morphogenetic protein-2 (BMP-2) expression in the sclera of guinea pigs with lens-induced myopia (LIM) and after recovery from myopia and evaluated the effect of BMP-2 on extracellular matrix (ECM) synthesis in human scleral fibroblasts (HSFs) cultured in vitro. Lens-induced myopia was brought about in two groups of guinea pigs (the lens-induced myopia and myopia recovery groups) by placing -4.00 D lenses on the right eye for three weeks. The left eye served as a contralateral control. In the recovery group, the lenses were removed after one week. The refractive power and axial length of the eyes were measured, and the BMP-2 expression levels in the sclera were measured. After three weeks, the lens-induced eyes acquired relative myopia in both groups of guinea pigs. Immunostaining of the eyeballs revealed significantly decreased BMP-2 expression in the posterior sclera of the myopic eyes compared to the contralateral eyes. One week after lens removal, BMP-2 expression recovered, and no differences were observed between the experimental and contralateral eyes in the recovery group. HSFs were cultured with BMP-2 or transforming growth factor-β1 (TGF-β1). Type I and type III collagen synthesis was significantly up-regulated following BMP-2 treatment in culture after one and two weeks, but the ratio of type III to type I collagen mRNA was not increased. Biosynthesis of glycosaminoglycan (GAG) and aggrecan was increased in HSFs treated with BMP-2. Some chondrogenesis-associated genes expression increased in HSFs treated with BMP-2. From this study, we concluded that BMP-2 is involved in scleral remodeling in the development and recovery of lens-induced myopia.

Correlation of macular choroidal thickness with concentrations of aqueous vascular endothelial growth factor in high myopia

PURPOSE

To investigate the association of both aqueous and serum vascular endothelial growth factor (VEGF) levels and macular choroidal thickness in high myopia.

MATERIALS AND METHODS

VEGF concentrations were measured in aqueous and serum samples via enzyme-linked immunosorbent assay (ELISA) and compared between high myopia (n = 36 eyes, 36 patients) and normal control (n = 42 eyes, 42 patients) eyes. Macular choroidal thickness, the distance from the retinal pigment epithelium (RPE) to the scleral interface, was determined via enhanced depth-imaging optical coherence tomography (EDI-OCT). Axial length was measured using the intraocular (IOL) lens Master.

RESULTS

Aqueous levels of VEGF from high myopia patients were significantly lower compared with those from control persons (61.4 ± 27.6 versus 122.6 ± 52.4 pg/ml; p < 0.001), respectively. Macular choroidal thickness of high myopia patients was significantly lower compared with that of control persons (111.1 ± 45.0 versus 230.6 ± 81.8 μm; p < 0.001), respectively. Aqueous levels of VEGF were significantly associated with both macular choroidal thickness (R(2)= 0.641; p < 0.001) and axial length (R(2)= 0.679; p < 0.001) in high myopia patients. In addition, there was a significantly negative correlation between macular choroidal thickness and axial length (R(2)= 0.69; p < 0.001). However, no correlation between serum VEGF and either macular choroidal thickness or axial length was detected in high myopia patients (R(2)= 0.009; p = 0.59; R(2)= 0.00002; p = 0.981).

CONCLUSIONS

Macular choroidal thickness was significantly correlated with aqueous, but not serum, levels of VEGF in highly myopic eyes. Macular choroidal thickness may be of predictive value for identifying aqueous VEGF levels in high myopia patients and may, thus, be a useful prognostic modality.

Myopic choroidal neovascularisation: current concepts and update on clinical management

Choroidal neovascularisation (CNV) is a common vision-threatening complication of myopia and pathological myopia. Despite significant advances in understanding the epidemiology, pathogenesis and natural history of myopic CNV, there is no standard definition of myopic CNV and its relationship to axial length and other myopic degenerative changes. Several treatments are available to ophthalmologists, but with the advent of new therapies there is a need for further consensus and clinical management recommendations. Verteporfin photodynamic therapy has been an established treatment for subfoveal myopic CNV for many years, but this treatment does not restore visual acuity and is associated with long-term chorioretinal atrophy. More recently, clinical trials investigating the efficacy and safety of anti-vascular endothelial growth factor agents in patients with myopic CNV have demonstrated substantial visual acuity gains and quality of life increases compared with photodynamic therapy. These enhanced outcomes provide updated evidence-based clinical management guidelines of myopic CNV, and increase the need for a generally accepted definition for myopic CNV. This review critically summarises the latest myopic CNV literature in the context of clinical experience and recommends a myopic CNV treatment algorithm.

RADIANCE: a randomized controlled study of ranibizumab in patients with choroidal neovascularization secondary to pathologic myopia

OBJECTIVE

To compare the efficacy and safety of ranibizumab 0.5 mg, guided by visual acuity (VA) stabilization or disease activity criteria, versus verteporfin photodynamic therapy (vPDT) in patients with visual impairment due to myopic choroidal neovascularization (CNV).

DESIGN

Phase III, 12-month, randomized, double-masked, multicenter, active-controlled study.

PARTICIPANTS

Patients (N = 277) with visual impairment due to myopic CNV.

METHODS

Patients were randomized to receive ranibizumab on day 1, month 1, and thereafter as needed guided by VA stabilization criteria (group I, n = 106); ranibizumab on day 1 and thereafter as needed guided by disease activity criteria (group II, n=116); or vPDT on day 1 and disease activity treated with ranibizumab or vPDT at investigators' discretion from month 3 (group III, n = 55).

MAIN OUTCOME MEASURES

Mean average best-corrected visual acuity (BCVA) change from baseline to month 1 through months 3 (primary) and 6, mean BCVA change and safety over 12 months.

RESULTS

Ranibizumab treatment in groups I and II was superior to vPDT based on mean average BCVA change from baseline to month 1 through month 3 (group I: +10.5, group II: +10.6 vs. group III: +2.2 Early Treatment Diabetic Retinopathy Study [ETDRS] letters; both P<0.0001). Ranibizumab treatment guided by disease activity was noninferior to VA stabilization-guided retreatment based on mean average BCVA change from baseline to month 1 through month 6 (group II: +11.7 vs. group I: +11.9 ETDRS letters; P<0.00001). Mean BCVA change from baseline to month 12 was +13.8 (group I), +14.4 (group II), and +9.3 ETDRS letters (group III). At month 12, 63.8% to 65.7% of patients showed resolution of myopic CNV leakage. Patients received a median of 4.0 (group I) and 2.0 (groups II and III) ranibizumab injections over 12 months. No deaths or cases of endophthalmitis and myocardial infarction occurred.

CONCLUSIONS

Ranibizumab treatment, irrespective of retreatment criteria, provided superior BCVA gains versus vPDT up to month 3. Ranibizumab treatment guided by disease activity criteria was noninferior to VA stabilization criteria up to month 6. Over 12 months, individualized ranibizumab treatment was effective in improving and sustaining BCVA and was generally well tolerated in patients with myopic CNV.

Choroidal neovascularization in pathological myopia

Myopic choroidal neovascularization (CNV) is one of the leading causes of visual impairment worldwide. The clinical and socioeconomic impact of myopic CNV in Asian countries is particularly significant due to rising trend in the prevalence and severity of pathological myopia. The exact pathogenesis of myopic CNV remains unclear and there is paucity of information with respect to incidence and risk factors for myopic CNV from prospective studies. Furthermore, there are no recognized measures that may prevent or delay the development of CNV in eyes with pathological myopia. Advances have been made in the diagnosis and characterization of myopic CNV over the years. Until recently, treatment modalities for myopic CNV were limited to thermal laser photocoagulation and photodynamic therapy with verteporfin, both these modalities primarily aim at prevention of further visual loss. In the last 5 years, inhibitors of vascular endothelial growth factor (VEGF) have been used successfully and may improve vision to some extent. Nevertheless, the long-term safety and efficacy of anti-VEGF agents remains unknown. Furthermore, the risk of developing chorioretinal atrophy remains the key factor in determining the final visual outcome. This review article summarizes the current literature on myopic CNV, highlighting new evolving diagnostic and treatment modalities, prognostic factors influencing visual outcome, and areas of future research.

Mimickers of age-related macular degeneration

In the Western World, the leading cause of irreversible blindness is Age- Related Macular Degeneration (ARMD). It can have significant visual impairment, and it is important that the practicing ophthalmologist is knowledgeable in the diagnosis and treatment of ARMD. Equally important is knowledge in the diagnosis of other disease entities that may mimic ARMD, as this may change the prognosis, treatment and visual outcome of patients. This article discusses those diseases that mimic ARMD and their distinguishing features.

Intravitreal ranibizumab (Lucentis) for the treatment of myopic choroidal neovascularization

BACKGROUND

Macular choroidal neovascularization (CNV) is one of the most vision-threatening complications of myopia, which can lead to severe vision loss. The purpose of this study was to evaluate the safety and efficacy of intravitreal ranibizumab in the treatment of myopic CNV.

METHODS

We conducted a prospective, consecutive, interventional study of patients with subfoveal or juxtafoveal CNV secondary to pathologic myopia (PM) treated with intravitreal injection of ranibizumab in the Jules Gonin University Eye Hospital from June 2006 to February 2008. Best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and fluorescein angiography (FA) were performed at baseline and monthly for all patients. Indications for retreatment were loss in BCVA associated either with persistent leakage from CNV shown on FA, and/or evidence of CNV activity on OCT.

RESULTS

The study included 14 eyes of 14 patients. The mean spherical equivalent refractive error was -12.5 (range, -8.0 D to -16.0 D). Mean time of follow-up was 8.4 months (range from 3 to 16 months, SD: 3). The mean number of intravitreal injections administered for each patient was 2.36 (SD 1.5). The mean initial visual acuity (VA) was 0.19 decimal equivalent (log-MAR: 0.71, SD: 0.3). A statistically significant improvement to a mean VA of 0.48 decimal equivalent (log-MAR:0.32, SD: 0.25) was demonstrated at the final follow-up. VA improved by a mean of 3.86 (SD 2.74) lines. Nine patients (64%) demonstrated a gain of 3 or more lines. Mean central macular thickness (CMT) measured with OCT was 304 microm (SD: 39) at the baseline, and was reduced significantly at the final follow-up to 153 microm (SD: 23). Average CMT reduction was 170 microm (SD: 57). No injection complications or drug-related side effects were noted during the follow-up period.

CONCLUSIONS

In this small series of eyes with limited follow-up, intravitreal ranibizumab was a safe and effective treatment for CNV secondary to PM, resulting in functional and anatomic improvements.

The role of heredity in determining central retinal thickness

AIMS

To examine the relative roles of genetic and environmental factors in central retinal thickness, by performing a classical twin study.

METHODS

310 subjects were recruited from the TwinsUK adult registry at St Thomas' Hospital. Optical coherence tomography (Zeiss, stratus OCT3) was used to measure the average retinal thickness in the central 1 mm diameter area. The covariance of central retinal thickness (CRT), within MZ and DZ twin pairs, was compared and genetic modelling techniques were used to determine the relative contributions of genes and environment to the variation in CRT observed in this population.

MAIN OUTCOME MEASURE

CRT (average retinal thickness in the central 1 mm diameter area, centred on the fovea).

RESULTS

The mean CRT of all subjects was 212.1 microm (range 165-277). CRT was statistically related to refractive error, with increasing myopia associated with a thinner CRT. CRT was more highly correlated within MZ twin pairs (r = 0.88) than with DZ twin pairs (r = 0.58), suggesting a genetic role. A model combining additive genetic and unique environmental factors provided the best fitting model and gave a heritability estimate of 0.90.

CONCLUSION

Genetic factors appear to play an important role in CRT, with a heritability estimate of 0.90.

Vision Loss in Younger Patients: A Review of Choroidal Neovascularization

Choroidal neovascularization (CNV) is a common cause of vision loss in patients <50 years of age. In these patients, CNV is often the result of pathologic myopia, ocular histoplasmosis syndrome, angioid streaks, or idiopathic causes. Rarely, CNV is seen in children, usually in association with inherited macular dystrophies such as Best's disease (vitelliform macular dystrophy) or drusen of the optic nerve. This article discusses the role of optometrists in the detection and management of CNV. Untreated CNV can cause rapid deterioration of central vision and is associated with a poor prognosis. Optometrists may be able to improve the prognosis of younger patients with CNV by recognizing the signs, symptoms, and risk factors for CNV and promptly referring patients with suspected CNV to a retina specialist. They can also help patients by providing long-term support and rehabilitation. Recent treatment advances, such as the availability of verteporfin (Visudyne; Novartis Pharma AG, Basel, Switzerland) therapy, that are applicable to younger patients with CNV have increased the importance of early detection of CNV and prompt referral of patients to a specialist who can treat CNV.

Laser photocoagulation for choroidal neovascularisation in pathologic myopia

BACKGROUND

Pathologic myopia is usually defined as the need for a spectacle correction of -6 diopters or higher. Choroidal neovascularisation (CNV) is the most commonly occurring cause of visual loss in people with pathologic myopia. In myopic macular degeneration the occurrence of newly formed vessels in the macula often leads to a fibrotic pigmented scar causing a blind spot in the centre of the visual field.

OBJECTIVES

The primary objective of this review was to examine the effects of laser photocoagulation for CNV associated with pathologic myopia. A secondary objective was to compare the effects of different photocoagulation techniques.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) on The Cochrane Library (Issue 2, 2005), MEDLINE (1966 to July 2005), EMBASE (1980 to July 2005, week 28), LILACS (July 2005) and the reference lists of included studies.

SELECTION CRITERIA

We included randomised controlled trials comparing photocoagulation with observation or comparing different photocoagulation techniques in people with CNV associated with myopia of -6 diopters or higher.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results for eligibility.

MAIN RESULTS

Two studies were included that enrolled people with CNV located at 100 microns or more from the foveal centre. One study compared photocoagulation with observation. At the final examination, 16/35 participants randomised to photocoagulation versus 31/35 randomised to observation had visual acuity of 20/100 or worse after 6 to 48 months. The second study randomised 27 eyes (26 patients) to photocoagulation with three laser wavelengths (9 eyes per group). The number of eyes losing two or more lines was 2 (577 nm), 3 (590 nm) and 3 (620 nm) after 3 to 17 months. In both studies comparisons were made using outcomes assessed at the final examination. As the final examination took place at different follow-up times it was difficult to interpret the findings and it was impossible to extract data for further analyses.

AUTHORS' CONCLUSIONS

Despite its use over several years the effectiveness of laser photocoagulation for myopic CNV has not been established. Although there was a suggestion of short-term effectiveness in one small study on non-subfoveal CNV the results were potentially biased. Observational studies suggest that the enlargement of the atrophic laser scar after laser treatment of non-subfoveal CNV could be a potentially vision-threatening long-term complication, even in eyes free of CNV recurrence.

Verteporfin : a review of its use in the management of subfoveal choroidal neovascularisation

Verteporfin (Visudyne) therapy (photodynamic therapy with intravenous liposomal verteporfin) is the first treatment to effectively prevent the loss of visual acuity in patients with subfoveal choroidal neovascularisation (CNV) secondary to age-related macular degeneration (AMD), pathological myopia or presumed ocular histoplasmosis syndrome (POHS). In adult patients with classic subfoveal CNV or occult with no classic subfoveal CNV secondary to AMD, or subfoveal CNV secondary to pathological myopia or POHS, verteporfin therapy slows or prevents loss of visual acuity. In well designed clinical trials, verteporfin therapy was superior to placebo in patients with subfoveal classic-containing CNV and occult with no classic CNV secondary to AMD at 12 and/or 24 months (Treatment of Age-related macular degeneration with Photodynamic therapy [TAP] Investigation and Verteporfin In Photodynamic therapy [VIP-AMD] trial) and in patients with pathological myopia at 12 months (Verteporfin In Photodynamic therapy [VIP-PM] trial). Limited data suggest that verteporfin therapy also prevents loss of visual acuity in patients with subfoveal CNV secondary to POHS. Verteporfin therapy was generally well tolerated in clinical trials; most adverse events were mild to moderate in intensity and transient. The most frequently reported verteporfin therapy-related adverse events (incidence >2%) were visual disturbance, injection-site reactions, photosensitivity reactions and infusion-related back pain. Approximately 5% of patients with occult with no classic subfoveal CNV secondary to AMD reported severe vision decrease within 7 days of treatment in clinical trials; 3 months later, several patients had recovered some of this loss.

CONCLUSION

Photodynamic therapy with verteporfin, the first photosensitiser approved for the treatment of subfoveal CNV, is a well tolerated treatment that stabilises or slows visual acuity loss in adult patients with predominantly classic or occult with no classic subfoveal CNV secondary to AMD, and subfoveal CNV secondary to pathological myopia or POHS. Thus, verteporfin therapy provides a valuable option for the management of these patients for whom treatment options are few, and should be considered as a first-line therapy in these difficult-to-manage conditions.