Abstract: Complications of myopia have become an important public health issue with serious socio-economic burdens. Prevention and treatment are both important. The Taiwan Student Vision Care Program (TSVCP) promoted by Ministry of Education (MOE) has been carried out for 3 decades in Taiwan. The myopia prevalence has increased rapidly to a high level and therefore myopia prevention has continued to be the most important item in the program. Therefore, TSVCP aims to decrease the prevalence of myopia, in order to decrease the high myopia related blindness in the future. Recently, outdoor activity has been found to be an important protective factor for myopia and was implemented in TSVCP since 2010. Afterwards, the nationwide vision impairment rate (uncorrected vision 20/25 or less) of elementary school students declined unprecedentedly and continuously in recent years. Evidence-based protective and risk factors for myopia are now clearer. Widespread acknowledgement of myopic disease, preventing the onset of myopia, prompt diagnosis, and early treatment to control progression are all important.
Abstract: Pathologic myopia is the major cause of the loss of the best-corrected visual acuity (BCVA) worldwide, especially in East Asian countries. The loss of BCVA is caused by the development of myopic macula patchy, myopic traction macula patchy, and myopic optic neuropathy (or glaucoma). The development of such vision-threatening complications is caused by eye deformity, characterized by a formation of posterior staphyloma. The recent advance in ocular imaging has greatly facilitated the clarification of pathologies and pathogenesis of pathological myopia and myopia-related complications. These technologies include ultra-wide field fundus imaging, swept-source optical coherence tomography, and 3D MRI. In addition, the new treatments such as anti-VEGF therapies for myopic choroid all neovascularization have improved the outcome of the patients. Swept-source OCT showed that some of the lesions of myopic maculopathy were not simply chorioretinal atrophy but were Bruch’s membrane holes. Features of myopic traction maculopathy have been analyzed extensively by using OCT. The understanding the pathophysiology of complications of pathologic myopia is considered useful for better management of this blinding eye disease.
Abstract: The biological mechanisms of eye growth and refractive development are increasingly well characterised, a result of many careful studies that have been carried out over many years. As the outer coat of the eye, the sclera has the ultimate impact on the restraint or facilitation of eye growth, thus any changes in its biochemistry, ultrastructure, gross morphology and/or biomechanical properties are critical in refractive error development and, in particular, the development of myopia. The current review briefly revisits our basic understanding of the structure and biomechanics of the sclera and how these are regulated and modified during eye growth and myopia development. The review then applies this knowledge in considering recent advances in our understanding of how the mechanisms of scleral remodelling may be manipulated or controlled, in order to constrain eye growth and limit the development of myopia, in particular the higher degrees of myopia that lead to vision loss and blindness. In doing so, the review specifically considers recent approaches to the strengthening of the sclera, through collagen cross-linking, scleral transplantation, implantation or injection of biomaterials, or the direct therapeutic targeting and manipulation of the biochemical mechanisms known to be involved in myopia development. These latest approaches to the control of scleral changes in myopia are, where possible, placed in the context of our understanding of scleral biology, in order to bring a more complete understanding of current and future therapeutic interventions in myopia, and their consequences.
Abstract: Cataract surgery is one of the most commonly performed surgeries among the elderly today. The volume of cataract surgeries has dramatically increased in the past few decades due to technological advancements leading to decreased morbidity, better overall outcomes, and increased expectation for correction of refractive error and spectacle independence after cataract surgery. The number of cataract surgeries is expected to continue to rise with the increase of the elderly population. Thus, accurate predictions of intraocular lens (IOL) power and the ability to correct for any postoperative refractive errors are critical. Despite the improved ability of cataract surgeons to accurately calculate IOL power, postoperative refractive errors still do occur due to various reasons such as imperfect preoperative measurements, toric-lens misalignment, and existing or surgically-induced astigmatism. The aim of this article is to review the various surgical options, including intraocular and corneal refractive surgical approaches, to correct post-operative refractive errors after cataract surgery.
Background: To measure the anterior and posterior segment structural features of acute primary angle-closure (APAC) eyes.
Methods: A total of 36 subjects with unilateral APAC were recruited in this study. The ocular biometric characteristics were measured by anterior segment optical coherence tomography (AS-OCT) and swept source optical coherence tomography (SS-OCT), respectively at baseline, 2 weeks, and 1 month after surgical intervention.
Results: At baseline, when compared with the fellow eyes, APAC-affected eyes showed significantly greater corneal thickness (P=0.004), shallower anterior chamber depth (ACD) (P<0.001), smaller anterior chamber area (ACA) (P=0.013), angle opening distance at 750 μm from the scleral spur (AOD750) (P=0.002), trabecular–iris space area at 750 μm from the scleral spur (TISA750) (P=0.033), angle recess area (ARA) (P=0.014), and iris area (IARE) (P=0.003), less iris curvature (ICURVE) (P=0.003), and larger lens vault (LV) (P=0.030). After intervention, the corneal thickness was significantly decreased at 1 month (P<0.001), while ACD, ACA, and AOD750 were significantly increased at 2 weeks and 1 month (all P<0.017). Changes in ACD were correlated with decreasing LV (P<0.05). The posterior segment parameters did not change over the 4-week period.
Conclusions: When compared with the fellow eyes, APAC-affected eyes had greater corneal thickness, shallower anterior chamber, narrower angle, less ICURVE, and larger LV. After intervention, the corneal thickness was decreased, while the shallower anterior chamber was relieved to some extent.
Background: To investigate the microstructural features of parapapillary gamma zone and beta zone and their relationship with three-dimensional optic disc shape in non-myopic eyes.
Methods: This cross-sectional study included 62 non-myopic eyes with parapapillary gamma or beta zone and 70 control eyes. On the spectral domain optical coherent tomography (SD-OCT) images, we measured the area of gamma zone and beta zone, the length of border tissue, and related disc parameters. The disc ovality index, disc rotation degrees around three axes, Bruch’s membrane opening (BMO) ovality ratio were calculated based on the SD-OCT images.
Results: The parapapillary gamma zone composed by externally oblique border tissue was found in inferior, nasal and temporal quadrants of the non-myopic eyes. The presence of gamma zone in non-myopic eyes was correlated with smaller disc ovality index, larger rotation degree around vertical and horizontal axes, and larger BMO ovality ratio (P<0.001). Compared with the non-temporal gamma zone group, eyes with temporal gamma zone had a longer axial length and rotated more around vertical axes (P<0.001). Multivariate analysis showed that the area of gamma zone was correlated with the disc ovality index (P<0.001). The presence and area of beta zone was correlated with age (P<0.01).
Conclusions: In non-myopic eyes, the parapapillary gamma zone composed by external oblique border tissue was significantly associated with the disc ovality and disc rotations around vertical and horizontal axes. From a biomechanical perspective, parapapillary gamma zone may contribute to the optic disc stability in association with the structure of BMO.
Abstract: Artificial intelligence (AI) methods have become a focus of intense interest within the eye care community. This parallels a wider interest in AI, which has started impacting many facets of society. However, understanding across the community has not kept pace with technical developments. What is AI, and how does it relate to other terms like machine learning or deep learning? How is AI currently used within eye care, and how might it be used in the future? This review paper provides an overview of these concepts for eye care specialists. We explain core concepts in AI, describe how these methods have been applied in ophthalmology, and consider future directions and challenges. We walk through the steps needed to develop an AI system for eye disease, and discuss the challenges in validating and deploying such technology. We argue that among medical fields, ophthalmology may be uniquely positioned to benefit from the thoughtful deployment of AI to improve patient care.
Background: To record the corneal, and anterior chamber depth changes after performing recession versus resection of horizontal recti muscles.
Methods: Consecutive patients who underwent isolated lateral rectus muscle recession or resection February 2014 to January 2015 were prospectively studied. Refractive error (spherical equivalent); K1, K2, and mean k reading, anterior and posterior corneal elevation; and anterior chamber depth were measured (Pentacam) before, 1 month, and 3 months after surgery. Patients who could not maintain reliable fixation and those with a history of eye surgery were excluded. Pre- and postoperative measurements were compared by analysis of variance.
Results: A total of 36 eyes of 23 patients (average age, 16 years) were included. Rectus muscle recession was performed in 24 eyes; and resection was performed in 12 eyes. Statistically significant changes in mean keratometry of recession group only. Central anterior elevation, and central anterior chamber depth were significant when both groups are compared at first month after surgery. Changes became regressive at the end of the third month. Although a significant change of central anterior elevation persisted.
Conclusions: In recession group, the mean K was the only statistically significant variable by the first postoperative month. Comparing the both groups, the anterior corneal elevation, and central anterior chamber depth revealed a significant difference by the end of the first postoperative month. After 3 months, all parameters showed a statistical insignificant difference between the recession and resection groups except the anterior corneal elevation.
