Astigmatism Bilateral, Cataract Bilateral
Conditions
Keywords
toric intraocular lens, dynamic stability, balance, post-cataract surgery, fear of falling, visual function, quality of life
Brief summary
Cataracts are the major cause of blindness in the world. Cataract surgery, being the most performed surgery in the world today, provide correction by extracting the natural lens from its capsular bag and replaced by an artificial intraocular lens (IOL) implantation. In the UK, almost all patients undergoing cataract surgery by the NHS are given monofocal intraocular lenses (IOLs) which do not correct corneal astigmatic error. It is estimated that around 20% of the population has over 1.50DC of corneal astigmatism. Uncorrected astigmatism not only increase spectacle dependency and reduce quality of life post surgically, but it also adversely affects the overall economic costs. Specialised toric IOLs offer the opportunity to correct pre-existing corneal astigmatism. Previous work has shown a link between reduced vision and balance or mobility. Full correction of refractive error may have greater impact on lifestyle than previously thought.
Detailed description
This is a single centre, parallel randomized controlled trial study comparing the dynamic stability and visual outcomes of cataract patient with astigmatism implanted with mono-focal Toric versus non-Toric IOLs. 140 cataracts patients with astigmatism awaiting cataract correction surgery at the Royal Eye infirmary of the University Hospitals of Plymouth NHS Trust will be recruited in this study over a two year period. The participants will be randomly assigned to be implanted with either Toric IOLs or standard non-Toric IOLs. Three additional study visits will be arranged for them. One visit before the cataract surgery, second visit at three to six months after the first eye cataract surgery and third visit at three to six months after the second eye cataract surgery. The primary assessment outcome is dynamic balance measured by movement sensors (accelerometer) during walk and turn, crossing over obstacle and stair walking. The secondary outcomes include eye tracking during movement activities, visual functions, risk of fall questionnaires and vision-specific quality of life questionnaire. This project is funded by Carl Zeiss Meditec AG, led by the University of Plymouth and sponsored by University Hospitals Plymouth NHS Trust . The project also involves collaboration with the University of Glasgow and the Plymouth Marjon University.
Interventions
DEVICEToric intraocular lens Zeiss AT TORBI
Intraocular lenses are medical devices that are implanted in patients during cataract surgery. At Plymouth University NHS trust the standard lens is a monofocal non-Toric lens unless the patient has astigmatism greater than 4.00D. This study involves implantation of a toric lens in the intervention group where astigmatism is greater than 1.00D. The lens is called the toric IOLS- Zeiss AT TORBI, will be implanted bilaterally instead of standard monofocal IOLs- Zeiss CT ASPHINA, used in routine cataract surgery within NHS.
Sponsors
Carl Zeiss Meditec AG
Glasgow Caledonian University
University of St Mark and St John Plymouth
University Hospital Plymouth NHS Trust
University of Plymouth
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Investigator)
Masking description
investigators will be blinded to which types of IOLs implanted to the cataract patients
Intervention model description
randomised control trial
Eligibility
Sex/Gender
ALL
Age
50 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* bilateral significant corneal astigmatism \>1.0D * on waiting list for bilateral cataract surgery in NHS
Exclusion criteria
* pre-existing eye pathology which may be aggravated by intraocular implant * previous intraocular/ corneal surgery * History of uveitis, glaucoma, proliferative diabetic retinopathy or IDDM, pseudoexfoliation, macular degeneration that may affect potential best corrected visual acuity of 20/40 or better * Micropthalmia * corneal decompensation or endothelial insufficiency * pars planitis * high myopia * participants using a systematic medication that is known to cause ocular side effects * participated in a concurrent clinical trial or have participated in an opthalmology clinical trial within the last 30 days * unable or not willing to cooperate for the follow up period * pregnant women * unable to give informed consent * unable to walk with or without walking aids independently for at least 20m * unable to walk up/down stairs independently using aids or handrail
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Jerk from the centre of mass Visit 1 | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Assessed during functional activities using accelerometers |
| Jerk from the centre of mass Visit 2 | First reassessment will be carried out at study visit 2 around 3-6 months after the first cataract IOL replacement surgery | Assessed during functional activities using accelerometers |
| Jerk from the centre of mass Visit 3 | Final reassessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | Assessed during functional activities using accelerometers |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Visual acuity Visit 1 | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Aided vision measured on a LogMAR acuity chart |
| Visual acuity Visit 2 | First reassessment will be carried out at study visit 2 around 3-6 months after the first cataract IOL replacement surgery | Aided vision measured on a LogMAR acuity chart |
| Visual acuity Visit 3 | Final reassessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | Aided vision measured on a LogMAR acuity chart |
| Mean spherical refraction Visit 1 | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Mean spherical refraction assessed through subjective refraction |
| Mean spherical refraction Visit 2 | First reassessment will be carried out at study visit 2 around 3-6 months after the first cataract IOL replacement surgery | Mean spherical refraction assessed through subjective refraction |
| Mean spherical refraction Visit 3 | Final reassessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | Mean spherical refraction assessed through subjective refraction |
| Astigmatic power J0 Visit 1 | Baseline assessment will be carried out at study visit 1 before the cataract surgery | J0 assessed through subjective refraction and expressed in vector form |
| Astigmatic power J0 Visit 2 | First reassessment will be carried out at study visit 2 around 3-6 months after the first cataract IOL replacement surgery | J0 assessed through subjective refraction and expressed in vector form |
| Astigmatic power J0 Visit 3 | Final reassessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | J0 assessed through subjective refraction and expressed in vector form |
| Astigmatic power J45 Visit 1 | Baseline assessment will be carried out at study visit 1 before the cataract surgery | J45 assessed through subjective refraction and expressed in vector form |
| Astigmatic power J45 Visit 2 | First reassessment will be carried out at study visit 2 around 3-6 months after the first cataract IOL replacement surgery | J45 assessed through subjective refraction and expressed in vector form |
| Astigmatic power J45 Visit 3 | Final reassessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | J45 assessed through subjective refraction and expressed in vector form |
| Contrast sensitivity Visit 1 | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Contrast sensitivity measured in log units |
| Unaided vision Visit 1 | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Unaided vision measured on a LogMAR acuity chart |
| Contrast sensitivity Visit 3 | Final reassessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | Contrast sensitivity measured in log units |
| Rotation of IOL at visit 1 | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Rotation of IOL relative to operation |
| Rotation of IOL at visit 2 | First assessment will be carried out at study visit 2 around 3-6 months after the first cataract IOL replacement surgery | Rotation of IOL relative to operation |
| Rotation of IOL at visit 3 | Final reassessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | Rotation of IOL relative to Operation |
| Tilt of IOL at Visit 1 | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Tilt of IOL assessed using image analysis |
| Tilt of IOL at Visit 2 | assessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | Tilt of IOL assessed using image analysis |
| Tilt of IOL at Visit 3 | assessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | Tilt of IOL assessed using image analysis |
| Centration of IOL at Visit 1 | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Centration of IOL assessed using image analysis |
| Centration of IOL at Visit 2 | assessment at study visit 2 around 3-6 months after the first eye cataract IOL replacement surgery | Centration of IOL assessed using image analysis |
| Centration of IOL at Visit 3 | assessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | Centration of IOL assessed using image analysis |
| Fear of falling | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Fear of falling measured using revised fear of falling questionnaire (FFR) |
| Risk of fall | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Risk of fall in daily activities measured by Short Fall Efficacy Scale Questionnaire (Short FFS-I) |
| Cataract related quality of life | Baseline assessment will be carried out at study visit 1 before the cataract surgery | Using Catract patient reported outcome measure CAT-PROM5 questionnaire |
| Contrast sensitivity Visit 2 | First reassessment will be carried out at study visit 2 around 3-6 months after the first cataract IOL replacement surgery | Contrast sensitivity measured in log units |
| Unaided visionVisit 2 | First reassessment will be carried out at study visit 2 around 3-6 months after the first cataract IOL replacement surgery | Unaided vision measured on a LogMAR acuity chart |
| Unaided vision Visit 3 | Final reassessment at study visit 3 around 3-6 months after the second eye cataract IOL replacement surgery | Unaided vision measured on a LogMAR acuity chart |
Countries
United Kingdom
Contacts
Primary ContactSherrie T Choy, MSc
Outcome results
None listed