- Email: [email protected]
Keynote Address: The patient; the weakest link?
Abstracts of the 2011 BCLA Annual Clinical Conference / Contact Lens & Anterior Eye 34, Supplement 1 (2011) S1–S43
Towards a functional accommodating IOL: bulk properties of the crystalline lens and synthetic analogues Jane H Bramhill*, Brian J Tighe Biomaterials Research Unit CEAC Aston University, Birmingham, UK *E-mail address: [email protected] Purpose: The mechanical properties of current intraocular lenses (IOL) bear little resemblance to those of the functioning crystalline lens, largely because their properties are dictated by constraints of manufacture and surgical insertion. A review of the age-related bulk properties of the natural lens and characterisation of current materials provides an essential basis for the design of novel accommodating injectable IOLs. Method: A review of the current literature relating to stiffness and refractive index of both the juvenile and ageing crystalline lens has been carried out. Characterisation of current IOL materials under tension, compression and shear has been carried out and compared with results for a range of nontoxic injectable gels based on biomimetic sulphonated monomers containing interpenetrants such as hyaluronic acid (a conventional viscoelastic). Results: Various reports confirm that the stiffness (modulus) of the natural crystalline lens typically increases by a factor of 100 during the lifetime of an individual from its birth value of ca 100Pa to a value of around 10,000Pa. There is concurrent loss of accommodation due to this increasing stiffness. Current IOL materials are well above the top end of this modulus range (ca 100,000Pa), whereas injectable gels based on lightly crosslinked sulphonate copolymers with water contents around 60% result in materials having moduli of 1500 – 3000Pa even when interpenetrated with hyaluronic acid. Conclusions: Current IOL materials have too great a stiffness to allow for accommodation. Design criteria for a biomimetic injectable accommodating IOL have been obtained from studies of stiffness increase and accommodation loss of the natural lens.
S5
Compliance: just how bad is it? Lyndon Jones E-mail address: [email protected] Despite all of the advances in the contact lens field over the years, noncompliance remains a major concern. This course will review various aspects of non-compliance with contact lens wear and care and provide delegates with the latest information regarding the complexity and magnitude of this problem. It will also provide some practical advice for practitioners on how to enhance compliance.
Compliance: new strategies Charles McMonnies E-mail address: [email protected] This lecture will demonstrate new strategies for increasing compliance in contact lens patients and describe the use of behaviour modification and the principles of social influence to improve compliance. Lessons have been taken from methods used to improve compliance in areas such as the treatment of glaucoma and amblyopia. Having non-compliant patients understand why each step in contact lens care and maintenance is important can be the basis for modifying their behaviour. In addition, an appreciation of the potential consequences of non-compliance, which range from symptoms of dryness and other forms of discomfort, chronic red eyes, inferior vision, having to return to spectacles, to infection and permanent loss of vision, may also contribute significantly to improved compliance.
CONFERENCE SESSION 6 – Corneal Dystrophy Keynote Address: A simple guide to corneal dystrophy
CONFERENCE SESSION 5 – The Alliance of Compliance
William Ayliffe
Keynote Address: The patient; the weakest link?
E-mail address: [email protected]
Kathy Dumbleton
Corneal dystrophies are inherited abnormalities of the cornea. Most are rare but their striking clinical appearance has fascinated observers for over a century. Wilelm Erb in 1884 introduced the term dystophe (dys = wrong, trophe = nourishment) concerning wasting disease of muscles, In 1890 Arthur Groenow published two cases of noduli corneae (a case of Macular and a case of Granular corneal dystrophy) and Biber published a case of lattice dystrophy. In 1919 Fuchs applied the word dystrophy to the cornea proposing that these conditions were caused by lack of nourishment. Subtle variants in appearance led to byzantine classifications. Fortunately with the advent of genetic mapping a simpler more accurate system has been possible. This lecture is intended to guide the practitioner through the different types of corneal dystrophy and to give an update on the new classification system. Examples of the conditions will be illustrated to help with diagnosis. The role of optometrists in managing these conditions will be highlighted and guidelines for referral will be proposed. Following the presentation attendees will have a thoroughly up to date overview of this complex subject and will be able to diagnose and treat cases with confidence.
E-mail address: [email protected] Despite all of the advances in the contact lens field over the years, noncompliance remains a major concern and the “weakest link” continues to be the patient. This lecture will review the patient’s role in non-compliance with contact lens wear and care. Results from several studies evaluating patient compliance, which have recently been conducted at the Centre for Contact Lens Research, will be presented. The possible consequences associated with wearing lenses for longer than recommended will be considered and a number of strategies to educate and improve patient compliance will be discussed.
The practitioner; the weakest link? Fiona Stapleton 1,2, *, Yvonne Wu 1,2 , Jaya Dantam 1,2 , Mark Willcox 1,2 , Hua Zhu 1,2 Brien Holden Vision Institute, Sydney, Australia; 2 School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
Contact lens management of corneal Dystrophies
*E-mail address: [email protected]
Jonathan Jackson
Despite improvements in solution technology, contact lens storage cases are frequently contaminated with microorganisms, with contemporary studies estimating 50-70% of cases showing contamination. Since case contamination is associated with both corneal infection and corneal infiltrates, limiting case contamination remains an important goal for the industry, regulatory agencies and for practitioners. This presentation will review the information we give our patients on cleaning/replacement of storage cases and how effective these steps are both in the laboratory and in clinical studies. Recently silver impregnated contact lens storage cases have been introduced in an attempt to reduce the frequency and level of microbial contamination of cases. We will discuss how effective these new technologies are against microbial biofilms formed in contact lens cases and how we might recommend their use for our contact lens wearing patients.
E-mail address: [email protected]
1
In this presentation, I will endeavour to demonstrate how contact lens practitioners can use a wide range of contact lenses (soft/rigid gas permeables/hybrids and sclerals) to improve visual and life quality in adults diagnosed with a corneal dystrophy. In some cases, lenses will be used to improve visual acuity and to correct regular or irregular refractive errors, whereas in others, lenses will be used to relieve symptoms of pain, glare or irritation. In others, examples of how contact lenses can be used following surgical intervention, to ensure that the optimal refractive correction is provided thus enhancing binocularity. Individual case reports will be used to illustrate the improvements lenses can render in life quality.
Towards a functional accommodating IOL: bulk properties of the crystalline lens and synthetic analogues Jane H Bramhill*, Brian J Tighe Biomaterials Research Unit CEAC Aston University, Birmingham, UK *E-mail address: [email protected] Purpose: The mechanical properties of current intraocular lenses (IOL) bear little resemblance to those of the functioning crystalline lens, largely because their properties are dictated by constraints of manufacture and surgical insertion. A review of the age-related bulk properties of the natural lens and characterisation of current materials provides an essential basis for the design of novel accommodating injectable IOLs. Method: A review of the current literature relating to stiffness and refractive index of both the juvenile and ageing crystalline lens has been carried out. Characterisation of current IOL materials under tension, compression and shear has been carried out and compared with results for a range of nontoxic injectable gels based on biomimetic sulphonated monomers containing interpenetrants such as hyaluronic acid (a conventional viscoelastic). Results: Various reports confirm that the stiffness (modulus) of the natural crystalline lens typically increases by a factor of 100 during the lifetime of an individual from its birth value of ca 100Pa to a value of around 10,000Pa. There is concurrent loss of accommodation due to this increasing stiffness. Current IOL materials are well above the top end of this modulus range (ca 100,000Pa), whereas injectable gels based on lightly crosslinked sulphonate copolymers with water contents around 60% result in materials having moduli of 1500 – 3000Pa even when interpenetrated with hyaluronic acid. Conclusions: Current IOL materials have too great a stiffness to allow for accommodation. Design criteria for a biomimetic injectable accommodating IOL have been obtained from studies of stiffness increase and accommodation loss of the natural lens.
S5
Compliance: just how bad is it? Lyndon Jones E-mail address: [email protected] Despite all of the advances in the contact lens field over the years, noncompliance remains a major concern. This course will review various aspects of non-compliance with contact lens wear and care and provide delegates with the latest information regarding the complexity and magnitude of this problem. It will also provide some practical advice for practitioners on how to enhance compliance.
Compliance: new strategies Charles McMonnies E-mail address: [email protected] This lecture will demonstrate new strategies for increasing compliance in contact lens patients and describe the use of behaviour modification and the principles of social influence to improve compliance. Lessons have been taken from methods used to improve compliance in areas such as the treatment of glaucoma and amblyopia. Having non-compliant patients understand why each step in contact lens care and maintenance is important can be the basis for modifying their behaviour. In addition, an appreciation of the potential consequences of non-compliance, which range from symptoms of dryness and other forms of discomfort, chronic red eyes, inferior vision, having to return to spectacles, to infection and permanent loss of vision, may also contribute significantly to improved compliance.
CONFERENCE SESSION 6 – Corneal Dystrophy Keynote Address: A simple guide to corneal dystrophy
CONFERENCE SESSION 5 – The Alliance of Compliance
William Ayliffe
Keynote Address: The patient; the weakest link?
E-mail address: [email protected]
Kathy Dumbleton
Corneal dystrophies are inherited abnormalities of the cornea. Most are rare but their striking clinical appearance has fascinated observers for over a century. Wilelm Erb in 1884 introduced the term dystophe (dys = wrong, trophe = nourishment) concerning wasting disease of muscles, In 1890 Arthur Groenow published two cases of noduli corneae (a case of Macular and a case of Granular corneal dystrophy) and Biber published a case of lattice dystrophy. In 1919 Fuchs applied the word dystrophy to the cornea proposing that these conditions were caused by lack of nourishment. Subtle variants in appearance led to byzantine classifications. Fortunately with the advent of genetic mapping a simpler more accurate system has been possible. This lecture is intended to guide the practitioner through the different types of corneal dystrophy and to give an update on the new classification system. Examples of the conditions will be illustrated to help with diagnosis. The role of optometrists in managing these conditions will be highlighted and guidelines for referral will be proposed. Following the presentation attendees will have a thoroughly up to date overview of this complex subject and will be able to diagnose and treat cases with confidence.
E-mail address: [email protected] Despite all of the advances in the contact lens field over the years, noncompliance remains a major concern and the “weakest link” continues to be the patient. This lecture will review the patient’s role in non-compliance with contact lens wear and care. Results from several studies evaluating patient compliance, which have recently been conducted at the Centre for Contact Lens Research, will be presented. The possible consequences associated with wearing lenses for longer than recommended will be considered and a number of strategies to educate and improve patient compliance will be discussed.
The practitioner; the weakest link? Fiona Stapleton 1,2, *, Yvonne Wu 1,2 , Jaya Dantam 1,2 , Mark Willcox 1,2 , Hua Zhu 1,2 Brien Holden Vision Institute, Sydney, Australia; 2 School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
Contact lens management of corneal Dystrophies
*E-mail address: [email protected]
Jonathan Jackson
Despite improvements in solution technology, contact lens storage cases are frequently contaminated with microorganisms, with contemporary studies estimating 50-70% of cases showing contamination. Since case contamination is associated with both corneal infection and corneal infiltrates, limiting case contamination remains an important goal for the industry, regulatory agencies and for practitioners. This presentation will review the information we give our patients on cleaning/replacement of storage cases and how effective these steps are both in the laboratory and in clinical studies. Recently silver impregnated contact lens storage cases have been introduced in an attempt to reduce the frequency and level of microbial contamination of cases. We will discuss how effective these new technologies are against microbial biofilms formed in contact lens cases and how we might recommend their use for our contact lens wearing patients.
E-mail address: [email protected]
1
In this presentation, I will endeavour to demonstrate how contact lens practitioners can use a wide range of contact lenses (soft/rigid gas permeables/hybrids and sclerals) to improve visual and life quality in adults diagnosed with a corneal dystrophy. In some cases, lenses will be used to improve visual acuity and to correct regular or irregular refractive errors, whereas in others, lenses will be used to relieve symptoms of pain, glare or irritation. In others, examples of how contact lenses can be used following surgical intervention, to ensure that the optimal refractive correction is provided thus enhancing binocularity. Individual case reports will be used to illustrate the improvements lenses can render in life quality.