A Intra-patient Comparison of Closed Loop and Plate Haptic Toric Intraocular Lenses

A Randomised Intra-patient Comparison of Closed Loop and Plate Haptic Toric, Aspheric, Aberration Neutral, Hydrophilic Acrylic Intraocular Lenses in Patients With Bilateral Astigmatism

During cataract surgery an artificial lens is implanted in the eye. These artificial lenses are called intraocular lenses (IOLs) and there are many different types of IOL designs. Your eyes have astigmatism, which is a normal and common characteristic of the eye. If left uncorrected the astigmatism would mean that you would need to wear spectacles for viewing distance objects. New IOL designs called toric IOLs help to correct the astigmatism to improve your vision after cataract surgery. This study has been designed to look at how well a toric IOL corrects this astigmatism so that you do not need to wear spectacles for viewing distance objects. There are many designs of these toric IOLs and for this study we are looking to compare two different designs of toric IOLs by putting one lens in your right eye and a different type of lens in your left eye. Both lenses are commercially available and are commonly implanted IOLs. Using new non-invasive methods we hope to be able to better judge the visual performance of these lenses and the ability of these lenses to correct astigmatism. In addition the study will involve imaging and examining the IOLs to determine the prevalence of any post-operative complications.

Inclusion Criteria:

• Age 50-75 years, bilateral significant corneal astigmatism >1.50D.
• Requiring a Toric IOL within the following power range:
• Sphere +6.00D to +30.00D
• Cylinder +1.00D to +6.00D

Exclusion Criteria:

• Amblyopia,
• predicted bilateral post-op corneal astigmatism of <1.50D,
• irregular astigmatism,
• dilated pupil size smaller than 5mm,
• macular pathology,
• glaucoma,
• retinal disease,
• corneal disease,
• abnormal iris,
• pupil deformation and
• any previous corneal or intraocular surgery.