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Journal: Clinical & experimental optometry : journal of the Australian Optometrical Association

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PURPOSE: The aim was to determine the extent of daily disposable contact lens prescribing worldwide and to characterise the associated demographics and fitting patterns. METHODS: Up to 1,000 survey forms were sent to contact lens fitters in up to 40 countries between January and March every year for five consecutive years (2007 to 2011). Practitioners were asked to record data relating to the first 10 contact lens fits or refits performed after receiving the survey form. Survey data collected since 1996 were also analysed for seven nations to assess daily disposable lens fitting trends since that time. RESULTS: Data were collected in relation to 97,289 soft lens fits, of which 23,445 (24.1 per cent) were with daily disposable lenses and 73,170 (75.9 per cent) were with reusable lenses. Daily disposable lens prescribing ranged from 0.6 per cent of all soft lenses in Nepal to 66.2 per cent in Qatar. Compared with reusable lens fittings, daily disposable lens fittings can be characterised as follows: older age (30.0 ± 12.5 versus 29.3 ± 12.3 years for reusable lenses); males are over-represented; a greater proportion of new fits versus refits; 85.9 per cent hydrogel; lower proportion of toric and presbyopia designs and a higher proportion of part-time wear. There has been a continuous increase in daily disposable lens prescribing between 1996 and 2011. The proportion of daily disposable lens fits (as a function of all soft lens fits) is positively related to the gross domestic product at purchasing power parity per capita (r(2) = 0.55, F = 46.8, p < 0.0001). CONCLUSIONS: The greater convenience and other benefits of daily disposable lenses have resulted in this modality capturing significant market share. The contact lens field appears to be heading toward a true single-use-only, disposable lens market.

Concepts: Cornea, Myopia, Lens, Contact lens, Corrective lens, Intraocular lens, Purchasing power parity, National accounts

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The aim was to evaluate the visual performance provided with a contact lens-based pinhole design against a simultaneous vision multifocal contact lens.

Concepts: Cornea, Myopia, Lens, Contact lens, Corrective lens, Book of Optics, Intraocular lens, Glasses

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Mini-scleral lenses are an increasingly popular contact lens modality; however, there are relatively few reports regarding the unique aspects of their fitting and potential complications. We report a complication of mini-scleral lens wear in a 44-year-old female patient using the lenses for keratoconus. Her mini-scleral contact lenses were non-fenestrated and fitted to vault over the cornea and seal at the periphery. The patient presented with an acute red eye (non-ulcerative keratitis), characterised by unilateral severe conjunctival and limbal hyperaemia, corneal infiltration and pain. Refitting the lens to increase the corneal vault clearance did not prevent recurrence of the keratitis, some five months later. Successful prevention of further episodes of the acute red eye was achieved through improved patient compliance with lens cleaning, disinfection and lens case procedures. Lens hygiene may be particularly important for mini-scleral lenses with a sealed fitting.

Concepts: Eye, Cornea, Lens, Orthokeratology, Contact lens, Contact lenses, Keratitis, Keratoconus

27

Three patients had unilateral vitreomacular traction (VMT) syndrome and the diagnosis was confirmed by spectral domain-type optical coherence tomography (OCT). All patients were female aged 51, 55 and 62 years. All denied surgical intervention. In one patient, rapid spontaneous resolution of the vitreomacular traction with a complete posterior vitreous detachment (PVD) and a normal foveal contour was achieved within 15 days. In the remaining two cases a complete PVD could be detected as late as seven months after the initial presentation. In one, though the vitreomacular adhesion released spontaneously, there was a minimal residual epiretinal membrane. In all three eyes, visual acuity was considerably improved. Spontaneous, uneventful resolution has been rarely reported in the natural course of VMT but several recent studies with the aid of OCT have shown that spontaneous resolution might be more common than previously known. In light of our cases, we believe that there is still room to search for OCT clues in eyes with VMT to predict eyes with higher likelihood of spontaneous resolution, thereby avoiding unnecessary pharmacologic and/or surgical intervention.

Concepts: Optics, Retina, Eye, Visual acuity, Ophthalmology, Vitreous humour, Epiretinal membrane, Posterior vitreous detachment

27

We describe an unusual case of unilateral optic nerve hypoplasia (ONH) in a patient with contralateral anisometropic/strabismic amblyopia. A seven-year-old boy presented with visual acuities of 6/12 R and 6/18 L and eccentric fixation in the left eye. Cycloplegic retinoscopy was R +1.50/-0.50 × 180 and L +5.25 DS. Funduscopy revealed optic nerve hypoplasia of the right eye. The patient fixated with his better-seeing right eye, despite the optic nerve hypoplasia. His reduced vision may be attributed to optic nerve hypoplasia in the right eye and amblyopia in the left. Although optic nerve hypoplasia can occur with ipsilateral amblyopia, we believe this is the first reported case of unilateral optic nerve hypoplasia in the fellow eye of an amblyopic patient.

Concepts: Left-wing politics, Visual perception, Visual system, Right-wing politics, Optic nerve, Optic nerve hypoplasia

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BACKGROUND: The aim of this study was to analyse the visual quality of the AcrySof IQ SN60WF(®) intraocular lens (IOL) when combined with different corneal profiles. METHODS: Ten eyes of 10 participants with no prior history of refractive or cataract surgery were evaluated. An adaptive optics visual simulator was used to simulate the wavefront aberration pattern of an aspheric aberration-correcting IOL (AcrySof IQ SN60WF(®) ). Normal corneas (group A), low and high myopic corneal ablations (groups B and C, respectively) and low and high hyperopic corneal ablations (groups D and E, respectively) were also simulated. Monocular distance visual acuities at 100, 50 and 10 per cent of contrast were measured. RESULTS: At 100, 50 and 10 per cent contrast, no differences were found between groups A and B (p > 0.06 for all contrasts). Group A obtained better values than groups C, D and E for all contrasts (p = 0.031, p = 0.038, p = 0.032 at 100, 50 and 10 per cent of contrast, respectively). At the same time, group B obtained better values than groups C, D and E (p = 0.041, p = 0.042, p = 0.036 at 100, 50 and 10 per cent of contrast, respectively). Within the five groups, the worst results were always obtained for group E (p = 0.017, p = 0.021 and p = 0.025 at 100, 50 and 10 per cent of contrast, respectively). CONCLUSIONS: The results suggest that the aspheric aberration-correcting IOL studied provides comparable results, when it is combined with normal corneas and with corneas with simulated low myopic ablations. When negative amounts of residual spherical aberration after cataract surgery are expected to be achieved, IOLs with more positive spherical aberration should be considered.

Concepts: Optics, Simulation, Lens, Presbyopia, Contact lens, Intraocular lens, Spherical aberration

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A non-linear isotropic finite element (FE) model of a 29-year-old human crystalline lens was constructed to study the effects of various geometrical parameters on lens accommodation.

Concepts: Mathematics, Fundamental physics concepts, Carbon, Eye, Lens, Cardinality, Accommodation

1

Supernumerary punctum is an under-reported congenital anomaly, in which there is more than one lacrimal punctum. Although usually asymptomatic, supernumerary puncta have been reported to cause dry eye or epiphora (excessive tearing) and should be included in their differential diagnosis. Tearing is often associated with dry eyes and can lead to discontinuation of contact lens wear. A comprehensive evaluation of the causes of tearing may uncover other contributory factors of epiphora. This case report highlights unilateral inferior double puncta in an otherwise asymptomatic patient. Due to increased evacuation of tears in the affected eye, manual occlusion of the puncta was advocated to allow topical medication to be more efficacious.

Concepts: Medical terms, Eye, Cornea, Topical, Tears, Corneal ulcer, Lacrimal gland, Lacrimal punctum

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Necrotising retinopathies can be visually devastating. Most often associated with the viral family Herpesviridae and seen in both immune-competent and immunocompromised hosts, possible complications of necrotising retinopathies include progressive retinal necrosis with or without macular involvement, optic neuropathy and ultimately, secondary retinal detachment. Examples include progressive outer retinal necrosis, acute retinal necrosis and cytomegaloviral retinitis. If diagnosed early and treated aggressively, visual complications can be prevented; however, there is no current consensus on the most appropriate antiviral regimen for each of the different varieties of necrotising herpetic retinopathy. This paper reviews aspects of varieties of necrotising herpetic retinopathy, including pathophysiology, treatment and diagnostic testing.

Concepts: Medical terms, Diagnosis, Retina, Ophthalmology