Optometric Technology Group

Thursday 19 April 2012

Long term effects of the daily wear of senofilcon silicone hydrogel contact lenses on eyelid tissues.

Cont Lens Anterior Eye. 2012 Mar 7. [Epub ahead of print]

Long term effects of the daily wear of senofilcon A silicone hydrogel contact lenses on eyelid tissues.

Guillon M, Maïssa C.

Source

OTG Research & Consultancy, London, UK.

Abstract

PURPOSE:

Eyelid changes have been reported with silicone hydrogel contact lenses. It is hypothesized that those changes are associated with the mechanical interaction between the contact lens front surface and eyelid tissues and, are specific to contact lens type rather than a general effect of the lens category. The purpose of this study was to assess the effect of refitting into a silicone hydrogel on a daily wear basis to current contact lens wearers, lapsed wearers and neophytes on eyelid physiology.

METHODS:

The investigation was a 2-year prospective investigation of ACUVUE(®) OASYS((R))with HYDRACLEAR(®)Plus (senofilcon A) used with care systems, representative of current practice.

RESULTS:

90 subjects were enrolled of whom 64 subjects completed the investigation. The results obtained were as follows:

CONCLUSIONS:

The results of the study demonstrated that senofilcon A, worn on a daily wear basis and replaced every 2 weeks, did not produce any eyelid tissue changes in previous non-contact lens wearers at baseline and revealed no change or a slight improvement of the eyelid tissues of established contact lens wearers.

Monday 16 April 2012

Contact lens-induced circumlimbal staining in silicone hydrogel contact lenses worn on a daily wear basis.

Eye Contact Lens. 2012 Jan;38(1):16-26.

Contact lens-induced circumlimbal staining in silicone hydrogel contact lenses worn on a daily wear basis.

Maïssa C, Guillon M, Garofalo RJ.

Source

Department of Optometric Technology Group Research & Consultancy, London, United Kingdom. cmaissa@otg.co.uk

Abstract

OBJECTIVES:

The principal objective of the study was to measure the conjunctival staining produced in the circumlimbal region by silicone hydrogel contact lenses with different edge designs. The secondary objective was to investigate the association between circumlimbal staining and comfort.

METHODS:

Four silicone hydrogel contact lenses: ACUVUE OASYS (knife edge design), AIR OPTIX, Biofinity (chisel edge rounded edge combination), and PureVision (rounded edge design), and 1 hydrogel contact lens, ACUVUE 2 (knife edge design), were tested. The study was conducted on a cohort population of 27 established soft contact lens wearers, who wore each contact lens type, in a random order, for a period of 10 (±2) days. Circumlimbal staining was measured in a double-masked fashion through image analysis of digital photographs of lissamine green taken under controlled experimental conditions.

RESULTS:

The results obtained showed that contact lens edge design was the primary factor controlling circumlimbal staining for silicone hydrogel lenses: a rounded edge away from the ocular surface produced the lowest staining (average, 0.19%) and a knife edge in close apposition to the ocular surface produced the highest staining (average, 1.34%). Contact lens material rigidity was also identified to affect circumlimbal staining and an inverse association between circumlimbal staining and contact lens comfort was demonstrated: the rounded edge design produced the lowest comfort (72 of 100) and the knife edge design produced the highest (87 out of 100).

CONCLUSION:

Soft contact lens wear induces circumlimbal staining, the level of staining being influenced by the contact lens edge design. However, high level of circumlimbal staining is not associated with decreased comfort.

Thursday 12 April 2012

Long-term effects of the daily wear of senofilcon A silicone hydrogel contact lenses on corneal and conjunctival tissues.

Optometry. 2010 Dec;81(12):680-7.

Long-term effects of the daily wear of senofilcon A silicone hydrogel contact lenses on corneal and conjunctival tissues.

Guillon M, Maïssa C.

Source

OTG Research & Consultancy, 66 Buckingham Gate, London, England. mguillon@otg.co.uk

Abstract

PURPOSE:

The objective of the investigation was to show that, because of their overall properties, Acuvue® Oasys™ with Hydraclear® Plus brand (senofilcon A) silicone hydrogel contact lenses achieve excellent ocular tissue tolerance during long-term daily wear.

METHODS:

The 2-year investigation was a prospective daily wear analysis of Acuvue® Oasys™ with Hydraclear® Plus (senofilcon A) silicone hydrogel contact lenses replaced every 2 weeks and used in conjunction with a representative range of care systems.

RESULTS:

The 2-year results compared with the subjects' baseline ocular status on entering the study revealed:

CONCLUSIONS:

The quantification of the effects on the ocular tissues of 2 years of daily wear of senofilcon A, by mainly previously successful daily soft contact lens wearers, showed an excellent biocompatibility. The results support the hypothesis that senofilcon A contact lenses, when worn on a 2-week daily wear regimen, maintain excellent long-term ocular tissue tolerance.

Monday 9 April 2012

Long-term effects of the extended wear of senofilcon A silicone hydrogel contact lenses on ocular tissues.

Optometry. 2010 Dec;81(12):671-9.

Long-term effects of the extended wear of senofilcon A silicone hydrogel contact lenses on ocular tissues.

Guillon M, Maïssa C.

Source

OTG Research & Consultancy, 66 Buckingham Gate, London, England. mguillon@otg.co.uk

Abstract

PURPOSE:

The objective of the investigation was to show that, because of their overall properties, Acuvue® Oasys™ with Hydraclear™ Plus brand (senofilcon A) silicone hydrogel contact lenses achieve excellent ocular tissue tolerance during long-term extended wear.

METHODS:

The investigation was a 2-year, prospective, extended wear investigation of senofilcon A silicone hydrogel contact lenses worn for up to 6 nights without removal.

RESULTS:

The 2-year results compared with the subjects' baseline ocular statuses on entering the study revealed:

CONCLUSIONS:

The quantification of the effects on the ocular tissues of 2 years of extended wear of senofilcon A, by mainly previously successful daily soft contact lens wearers, found an excellent biocompatibility. The results support the hypothesis that senofilcon A contact lenses, when worn on a 6-night/7-day extended wear regimen, maintain excellent long-term ocular tissue tolerance.

Thursday 5 April 2012

Tear film evaporation - effect of age and gender.

Cont Lens Anterior Eye. 2010 Aug;33(4):171-5. Epub 2010 Apr 9.

Tear film evaporation--effect of age and gender.

Guillon M, Maïssa C.

Source

OTG Research & Consultancy, London, UK.

Abstract

PURPOSE:

Dry eye is more prevalent in older patients and among them more marked in women than men. The increase in dry eye with aging is traditionally thought to be associated with a decrease in tear production enhanced by hormonal changes. Clinical evidence of an abnormal lipid production system in older patients, in particular women is established. It is therefore postulated that the greater prevalence of dry eye problems in an older population has an evaporative component.

METHODS:

Tear film evaporation was measured with the Oregon Health Sciences University Evaporimeter at 30% and 40% humidity.

RESULTS:

160 subjects less than 45 years old and 57 subjects aged 45 years or more formed the study population. The results revealed a significant effect of age (p < 0.001), gender (p < 0.001) and their interaction (p < 0.001): (i) the rate of evaporation was higher in the older age group at both humidities; (ii) the rate of evaporation was overall higher for women; and (iii) the synergic effect of age and gender was very marked: the rate of evaporation of older women was 34-80% higher than that of older men and 36-69% than younger women.

CONCLUSIONS:

Aging of the tear film includes a significant evaporative component characterised by higher tear film evaporation for the over 45 compared to younger people. Further, in the over 45 years of age, a significantly greater tear film evaporation was recorded in women than men. The findings have significant implications for the management of presbyopic dry eye sufferers.

Monday 2 April 2012

Evaluation of the effects on conjunctival tissues of eyedrops

Cont Lens Anterior Eye. 2010 Apr;33(2):93-9.

Evaluation of the effects on conjunctival tissues of Optive eyedrops over one month usage.

Guillon M, Maissa C, Ho S.

Source

OTG Research & Consultancy, London, UK. mguillon@otg.co.uk

Abstract

The objective was to compare the effect on conjunctival tissues of the repeated use, over a one-month period, of Optive compared to Hylocomod eyedrops by a population of dry eye sufferers. The rationale for the study was that among dry eye sufferers who attend eye care practices for symptomatic relief, a large number present with conjunctival anomalies evidenced by tissue staining and that conjunctival recovery is essential to their successful long term management. The hypothesis tested was that the decrease in conjunctival staining with Optive is at least as good, and possibly greater, than that with Hylocomod. The cohort population was made up of 47 subjects (11 male and 26 female) aged 42+/-16 years with at least mild dry eye symptoms and conjunctival and/or corneal staining. The population included contact lens wearers (n=26) and non-wearers (n=21). The subjects were randomly allocated to use one of the two study products; they were instructed to use the products as often as needed but at least three times a day. Conjunctival staining was rated on forced choice scales and measured objectively using digital photographs and image analysis. The findings showed that, whereas the staining at the start of the investigation was similar (p=0.318-0.664), staining after one month of use was significantly less with Optive than Hylocomod (p=0.028-0.002). The results demonstrated that the regular use of Optive over one month was significantly superior to Hylocomod in improving conjunctival status by producing a greater reduction in the staining of dry eye sufferers.

Thursday 29 March 2012

Tear film dynamics and lipid layer characteristics--effect of age and gender

Cont Lens Anterior Eye. 2010 Aug;33(4):176-82. Epub 2010 Mar 3.

Tear film dynamics and lipid layer characteristics--effect of age and gender.

Maïssa C, Guillon M.

Source

OTG Research & Consultancy, London, UK. cmaissa@otg.co.uk

Abstract

PURPOSE:

Dry eye disease is significantly more prevalent in older subjects and among them more marked in women than men. Further, it is established that the tear film dynamics of dry eye sufferers is different to that of normal. It is therefore postulated that the greater prevalence of dry eye problems with advancing age is at least in part related to poorer tear film dynamics.

METHODS:

Tear film dynamics (non-invasive break up time) and lipid characteristics (lipid layer thickness and contamination) were assessed using the Tearscope lighting system.

RESULTS:

160 Subjects less than 45 years old and 58 subjects aged 45 years or more formed the study populations. The tear film stability was mostly influenced by age; the break up time was statistically significantly shorter for the older age group (p < 0.001). The lipid layer was also significantly thinner (p = 0.013) for the subjects aged 45 years or older with a very marked synergic effect of age and gender. The lipid layer of older women was significantly thinner and more contaminated than that of younger women (p = 0.002 and < 0.001) and of older men (p = 0.034 and 0.004).

CONCLUSIONS:

Aging of the tear film is characterised by its destabilisation associated with significant changes in the tear lipid layer producing less protection from evaporation in the older population; the observed changes are more marked in women than in men. The findings have significant implications for the management of presbyopic dry eye sufferers, for whom decreasing evaporative problems is essential.