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Concept: Refractive surgery

27

PURPOSE. TO INVESTIGATE THE SHORT-TERM EFFECT OF ORTHOKERATOLOGY (ORTHO-K) LENS WEAR ON THE ANTERIOR SEGMENT LENGTH FOR VALIDATING THE USE OF AXIAL LENGTH FOR MONITORING MYOPIC PROGRESSION AFTER ORTHO-K TREATMENT. METHODS. THIRTY-SEVEN AND 39 SUBJECTS (AGED 7-10) WERE RANDOMLY ASSIGNED TO WEAR ORTHO-K AND SINGLE-VISION SPECTACLES, RESPECTIVELY. CENTRAL CORNEAL THICKNESS (CCT), ANTERIOR CHAMBER DEPTH (ACD), CRYSTALLINE LENS THICKNESS (LT), AND ANTERIOR SEGMENT LENGTH (ASL: summation of CCT, ACD and LT) were measured before and 6-month after the treatment under cycloplegia. Changes in these parameters were evaluated and compared between the two groups of subjects. Results. There were no significant between-group differences in the baseline data (p>0.37). After 6 months of lens wear, in the ortho-k group, CCT was significantly reduced by 0.009±0.009 mm (p<0.001) while ACD and LT remained unchanged (p>0.15). In the spectacle group, ACD was significantly increased by 0.01±0.03 mm (p=0.008) while CCT and LT remained unchanged (p>0.06). In both groups of subjects, ASL did not changed significantly but axial length was significantly increased by 0.10±0.10 mm and 0.20±0.11 mm in the ortho-k and the spectacle groups, respectively (p<0.001). Conclusions. Eyeball elongation occurred in children wearing both ortho-k and single-vision spectacles. Since, ASL was not affected by ortho-k treatment, axial length measured reflects the true growth of the eyeball and is a valid parameter for monitoring myopic progression in ortho-k treated eyes.

Concepts: Eye, Cornea, Myopia, Refractive surgery, Lens, Orthokeratology, Contact lens, Accommodation

25

To estimate the prevalence of refractive error in adults across Europe. Refractive data (mean spherical equivalent) collected between 1990 and 2013 from fifteen population-based cohort and cross-sectional studies of the European Eye Epidemiology (E(3)) Consortium were combined in a random effects meta-analysis stratified by 5-year age intervals and gender. Participants were excluded if they were identified as having had cataract surgery, retinal detachment, refractive surgery or other factors that might influence refraction. Estimates of refractive error prevalence were obtained including the following classifications: myopia ≤-0.75 diopters (D), high myopia ≤-6D, hyperopia ≥1D and astigmatism ≥1D. Meta-analysis of refractive error was performed for 61,946 individuals from fifteen studies with median age ranging from 44 to 81 and minimal ethnic variation (98 % European ancestry). The age-standardised prevalences (using the 2010 European Standard Population, limited to those ≥25 and <90 years old) were: myopia 30.6 % [95 % confidence interval (CI) 30.4-30.9], high myopia 2.7 % (95 % CI 2.69-2.73), hyperopia 25.2 % (95 % CI 25.0-25.4) and astigmatism 23.9 % (95 % CI 23.7-24.1). Age-specific estimates revealed a high prevalence of myopia in younger participants [47.2 % (CI 41.8-52.5) in 25-29 years-olds]. Refractive error affects just over a half of European adults. The greatest burden of refractive error is due to myopia, with high prevalence rates in young adults. Using the 2010 European population estimates, we estimate there are 227.2 million people with myopia across Europe.

Concepts: Epidemiology, Statistics, Ophthalmology, Myopia, Refractive surgery, Presbyopia, Eyeglass prescription, Refractive error

24

Myopia is an important public health issue, and high myopia may lead to severe complications if left untreated. Orthokeratology lenses, worn overnight to reshape the cornea, are one of many recent modalities used to slow down the progression of myopia in children. This treatment has been proven successful, as evidenced by decreased spherical refractive error and axial length relative to the control at interval follow-up ranging from 6 months to 5 years. In this systematic review, the authors collected published controlled studies that analyzed the efficacy of orthokeratology lens wear and calculated longitudinal relative changes in axial length, revealing a weighted average of -45.1% change in axial length at the 2-year follow-up. The exact mechanism by which orthokeratology lenses reduce myopia progression is unknown, but research shows that the corneal reshaping decreases peripheral hyperopic defocus and therefore increases peripheral myopic defocus to likely reduce stimuli for axial elongation and subsequent development of myopia. Use of orthokeratology lenses is generally safe, but cases of associated infectious keratitis may have a higher incidence of virulent organisms such as Pseudomonas, Acanthamoeba, and antibacterial-resistant strains of Staphylococcus, partially due to the required overnight use of these lenses. Orthokeratology is regarded as one of the most effective non-pharmacologic measures to slow progression of myopia in children and, with regular follow-up to ensure safety, continues to be one of the most effective treatments for myopia management around the world. [J Pediatr Ophthalmol Strabismus. 201X;XX(X):XX-XX.].

Concepts: Cornea, Myopia, Refractive surgery, Lens, Astigmatism, Orthokeratology, Contact lens, Glasses

17

To evaluate the safety and efficacy of corneal collagen crosslinking (CXL) for the treatment of corneal ectasia after laser refractive surgery.

Concepts: Surgery, Laser, Cornea, Refractive surgery, Astigmatism, LASIK, Keratoconus, Multicenter trial

7

Laser in-situ keratomileusis (LASIK) is a commonly performed surgical procedure used to correct refractive error. LASIK surgery involves cutting a corneal flap and ablating the stroma underneath, with known damage to corneal nerves. Despite this, the epidemiology of persistent pain and other long-term outcomes after LASIK surgery are not well understood. Available data suggest that approximately 20-55% of patients report persistent eye symptoms (generally regarded as at least 6 months post-operation) after LASIK surgery. While it was initially believed that these symptoms were caused by ocular surface dryness, and referred to as “dry eye,” it is now increasingly understood that corneal nerve damage produced by LASIK surgery resembles the pathologic neuroplasticity associated with other forms of persistent post-operative pain. In susceptible patients, these neuropathological changes, including peripheral sensitization, central sensitization, and altered descending modulation, may underlie certain persistent dry eye symptoms after LASIK surgery. This review will focus on the known epidemiology of symptoms after LASIK and discuss mechanisms of persistent post-op pain due to nerve injury that may be relevant to these patients. Potential preventative and treatment options based on approaches used for other forms of persistent post-op pain and their application to LASIK patients are also discussed. Finally, the concept of genetic susceptibility to post-LASIK ocular surface pain is presented.

Concepts: Surgery, Laser, Cornea, Ophthalmology, Refractive surgery, LASIK, Keratoconus, Keratomileusis

3

To review the published literature on the efficacy of topical atropine for the prevention of myopic progression in children.

Concepts: Glaucoma, Myopia, Refractive surgery, Eye examination, Optometry

3

To examine internal astigmatism (IA) in myopes and non-myopes using a new method to assess compensation of corneal astigmatism (CA) by IA, to look for predictors of high IA in young adult myopes, and to determine if as CA changes IA changes to reduce refractive astigmatism (RA) in an active compensatory process in myopes.

Concepts: Myopia, Refractive surgery, Lens, Astigmatism, Refractive error

3

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.

Concepts: Medicine, Visual acuity, Myopia, Refractive surgery, Eyeglass prescription, Contact lens, Eye examination, Refractive error

3

A 29-year-old man presented with blurred vision, photophobia, and pain after trauma to his left eye caused by a screwdriver. He had a history of moderate myopia (visual acuity, 20/25) and had undergone uneventful bilateral laser-assisted in situ keratomileusis (LASIK) 10 years previously. On examination, he had a 180-degree traumatic corneal flap dislocation with an inverted tear in the temporal cornea (Panel A, fluorescein dye). After repositioning of the flap, a disposable contact lens, used as a therapeutic bandage, was placed on the cornea. Topical antibiotics and glucocorticoids were administered. One month postoperatively, his previous visual acuity had recovered and . . .

Concepts: Eye, Visual acuity, Cornea, Ophthalmology, Refractive surgery, Lens, Orthokeratology, Contact lens

2

High myopia is known to be a risk factor for long-term regression after laser refractive surgery. There have been few studies about the correction of moderate myopias that did not need retreatment after long-term follow-up. We evaluated 10 years of change in visual acuity and refractive power in eyes with moderate myopia after laser refractive surgery.

Concepts: Ophthalmology, Myopia, Refractive surgery, Lens, LASIK, Refractive error