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 Ϯ 12.5 versus 29.3 Ϯ 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.

Soft contact lens wear can induce corneal warpage mimicking keratoconus. Had the standard treatment for keratoconus been implemented before resolution of the warpage, it could have proven injurious to the patient, because the treatment itself could have provided an impetus for the protrusion to remain or perhaps even progress. Our case gives clinicians reason to pause when dealing with contact lens wearers presenting with corneal curvature irregularities such as keratoconus or ectasia, because of the possibility of lens-induced warpage.

The dispensing and wear of prescription contact lenses without a proper selection and fit led to bilateral corneal erosions in this patient. Though our case occurred in Taiwan, a jurisdiction where prescription contact lens sale is not regulated, the authors note that such a scenario could occur in jurisdictions where contact lens sale is regulated if, after confirmation of back vertex power, no effort is made to ensure that a purchased lens is safe or appropriate for a patient, such as when lenses are purchased through internet suppliers or in certain commercial retail settings.

A flap loss is rare and serious among various flap-related complications of LASIK. It can occur intra-operatively, early post-operatively or late post-operatively and can be classified aetiologically as iatrogenic or traumatic. Here, we report a case of late traumatic flap loss caused by a scratch from a cat's paw and successfully treated by PRK. A review of the literature indicates that this is the first case of late traumatic flap loss, for which the patient received a PRK re-treatment. With the increasing popularity of LASIK, the incidence of either iatrogenic or traumatic flap loss may increase and the awareness of this complication and the importance of its management should not be overlooked. CASE REPORTA 28-year-old woman underwent bilateral wavefront LASIK on 17 February 2007. The preoperative refractions were -6.00/ -2.25 ¥ 170 in the right eye and -8.00/ -2.50 ¥ 165 in the left eye for a visual acuity of 6/6 in both eyes. The keratometric values were 43.25@165/45.5@75 and 43.25@165/45.25@75 in the right and left eyes, respectively. The preoperative pachymetric readings were 562 mm for the right eye and 559 mm for the left eye. An automated microkeratome (Moria M2, Moria, Anthony, France) was used to create the flap with a superior hinge, followed by ablation with an excimer laser (VISX STAR S4 Inc, Santa Clara, CA) with the CustomVue software (VISX Inc, Santa Clara, CA). The attempted correction was -6.11/-1.94 ¥ 169 in the right eye and -8.15/-1.98 ¥ 165 in the left eye. The diameters of ablation zone were 8.0 mm in both eyes and the calculated ablation depth was 119 mm in the right eye and 151 mm in the left eye. The surgical course was uneventful. Six months after LASIK, her unaided vision was 6/6 in both eyes.On 20 January 2008, 11 months after LASIK, the left eye of this patient was scratched by a cat's paw, while she was playing with the cat in a pet store. The patient suffered from severe ocular pain and she noted a sudden decrease in visual acuity. She was sent to an emergency service, where a LASIK flap loss was diagnosed. A bandage contact lens was inserted with topical medications.Two days later, she came to our clinic. On examination, the unaided vision of the left eye was 6/150 and the VA was 6/15 with a manifest refraction of -4.50/-1.25 ¥ 75. A central corneal epithelial defect was found; it was 8 ¥ 8 mm in size and corresponded to the area of the previous LASIK flap (Figure 1). Topical 0.3% ciprofloxacin hydrochloride (Alcon Laboratories Inc, Fort Worth, TX), 0.1% fluorometholone (Alcon Laboratories Inc, Fort Worth, TX) and artificial tears were prescribed with a bandage contact lens for the affected eye. Four days after the flap loss, the epithelial defect healed and a moderate corneal haze presenting at the nasal and temporal sides remained, however, it spared the central visual axis (Figure 2). Three months after the flap loss, the unaided vision of the left eye was 6/18 and the VA was 6/9 with a refraction of -1.50/-0.75 ¥ 68. The topography showed an irregular astigmatism at that t...

The aim of this study was to determine the relationship between relative peripheral refraction and retinal shape by 2-D magnetic resonance imaging in high myopes. Thirty-five young adults aged 20 to 30 years participated in this study with 16 high myopes (spherical equivalent < −6.00 D) and 19 emmetropes (+0.50 to −0.50 D). An open field autorefractor was used to measure refractions from the center out to 60° in the horizontal meridian and out to around 20° in the vertical meridian, with a step of 3 degrees. Axial length was measured by using A-scan ultrasonography. In addition, images of axial, sagittal, and tangential sections were obtained using 2-D magnetic resonance imaging. The highly myopic group had a significantly relative peripheral hyperopic refraction and showed a prolate ocular shape compared to the emmetropic group. The highly myopic group had relative peripheral hyperopic refraction and showed a prolate ocular form. Significant differences in the ratios of height/axial (1.01 ± 0.02 vs. 0.94 ± 0.03) and width/axial (0.99 ± 0.17 vs. 0.93 ± 0.04) were found from the MRI images between the emmetropic and the highly myopic eyes (p < 0.001). There was a negative correlation between the retina’s curvature and relative peripheral refraction for both temporal (Pearson r = −0.459; p < 0.01) and nasal (Pearson r = −0.277; p = 0.011) retina. For the highly myopic eyes, the amount of peripheral hyperopic defocus is correlated to its ocular shape deformation. This could be the first study investigating the relationship between peripheral refraction and ocular dimension in high myopes, and it is hoped to provide useful knowledge of how the development of myopia changes human eye shape.

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