1. Background to Programme Area and Objectives

1.1 Cataract is the most common reason for ophthalmic referral and surgical removal of the lens with implantation of an artificial lens within the eye is the treatment of choice. Posterior capsular opacification is a significant cause for late visual loss. There is no validated medical treatment for cataract. Although prevention or a cure may not be possible in the foreseeable future, an intervention that delayed the onset of cataract would have a major impact. The projects listed below anticipate that an understanding of the basic mechanisms of lens physiology will provide a framework to delay the processes of ageing and subvert the complications of cataract surgery. However, it is recognised that the development of these advances in clinical practice may be delayed. Therefore, for pragmatic reasons, consideration is also given for service provision and new technologies that may provide more immediate relief for affected patients.
1.1.1 Determine how markers of cataractogenesis interact with environmental influences in susceptibility to age-related cataract.
1.1.2 Determine if genetic factors interact with environmental influences to confer a susceptibility to age-related cataract.
1.1.3 Identify environmental risk factors for age related cataract formation and understand their influence on lens opacification.
1.1.4 Evaluation of the safety and efficiacy of changes in the organisation, management and delivery of cataract surgery.
1.1.5 Characterise the mechanism of scarring responses following cataract surgery at a cellular and molecular level.
1.1.6 Evaluate intraocular lens technologies for the prevention of posterior capsular opacification after cataract surgery.
1.1.7 Evaluate strategies to reduce the impact of the major complications of cataract surgery.

  2. Programme plan

Within the structure of the ophthalmic research strategy and where possible, the Trust is undertaking a programme of cataract research activity organised under the following headings:

2.1 Genetics, genotyping and risk factors - studies on the molecular genetics of cataract are ongoing in collaboration with the Institute of Ophthalmology. The identification of a gene associated with congenital cataract was published in Nature Genetics. This work is currently supported by the Wellcome Trust and other research charities and development of this work as outlined in 1,2 and 5 above will increase understanding of the pathogenesis and provide the knowledge needed to plan gene therapy in the future.

2.2 Prevention and surveillance - evaluation of the skills, expertise and training required to facilitate direct referral by optometrists. In collaboration with Bristol Eye Hospital, data on cataract prevalence in the community by deprivation score is being analysed.

2.3 Symptoms, presentation and referral - The Department of Health is currently supporting a project focusing on the development of a computer based model for use in the planning of cataract surgical service and research to strengthen and apply methods of prevalence and incidence estimation. In collaboration with the RCO, a new case control study is about to start on social inequalities and access to cataract surgery. This is a multi-centre study with Leeds, Warrington, Norwich, Moorfields, Bristol, Torbay and Plymouth. Routine data on cataract surgical activity nationally is being analysed by postcode as another part of this project.

2.4 Phenotyping, information and communication - the Trust is taking forward the development of a Phenotyping Unit and is employing a phenotyping technician to work in collaboration with the Image Grading centre. This will facilitate the development of a database to support research into the links between the patient genotype and phenotype.

2.5 Diagnosis, investigations and pathology - investigate the role of
autofluorescence as a measure of cataract progression. Work with manufacturers to assess the visual performance and long term effects of different styles of intra-ocular lenses.

2.6 Clinical Interventions - several proposals have been developed focusing on innovative methods of service delivery that could address the issue of waiting times. This builds on a successful MRC funded RCT of cataract surgical techniques.

2.7 Follow-up - the prevention of visual deterioration after cataract surgery is being addressed by simple organ culture techniques to study the scarring reaction to lens implantation after cataract surgery. Preliminary work has started to develop these organ culture techniques to explore mechanisms for inducing programmed cell death by direct material contact. This work is designed to reduce the incidence of 'after cataract' by inhibiting the proliferation of residual lens cells which cause opacification around the intraocular implant. This opacification is the commonest cause of visual loss following cataract surgery. Research will also be undertaken to investigate the visual outcome following cataract surgery with particular attention to those with poor visual outcome due to complications of surgery.

  3. Future development work in the programme during 2002/3

3.1 In collaboration with a wide network of academic ophthalmologists the Trust will pursue the implementation of the national strategy for ophthalmic research under the following headings and using the concept of the pathway of care as used in section two of this programme.

3.2 Determine how markers of cataractogenesis interact with environmental influences in susceptibility to age-related cataract.

3.3 Determine if genetic factors interact with environmental influences to confer a susceptibility to age-related cataract.

3.4 Identify environmental risk factors for age related cataract formation and understand their influence on lens opacification.

3.5 Evaluate the safety and efficacy of changes in the organisation, management and delivery of cataract surgery.
3.6 Characterise the mechanism of scarring responses following cataract surgery at a cellular and molecular level.

3.7 Evaluate intraocular lens technologies for the prevention of posterior capsular opacification after cataract surgery.

3.8 Evaluate strategies to reduce the impact of the major complications of cataract surgery.