Recent developments in eye surgery

In the last two decades, eye surgery has become a micro-surgical speciality. Cataract surgery has been transformed by changes in local anaesthesia, implants, phakoemulsification and small incision surgery which allows compressible silicone or acrylic implants to be inserted through a 3-mm incision. The implant power can be more accurately measured by new formulae and the use of A-Scan ultrasonography.

The developments in vitreous surgery have enabled membranes to be peeled off the retina and macular holes to be repaired and have also increased the success rate in retinal detachment surgery with the additional use of gases and silicone oil inserted into the vitreous cavity.

Some paralytic squints can be helped by the use of adjustable sutures or injections of botulinum toxin into the overacting muscles. Refractive error can be treated either by surgery (radial keratometry) or by the excimer laser. This can be combined with LASIK surgery (laser in situ keratomeilusis) which involves removing a cornea) flap and doing the laser surgery at a deeper level. There have been some concerns about defective contrast sensitivity and problems with night vision after laser correction of myopia. Phakic implants have also been used to correct high refractive errors.

Corneal topography can help in making corneal and refractive surgery more accurate, and the increased use of CT and MRI scans helps to diagnose orbital and intracranial lesions involving the optic pathways (Fig 36.35Fig 36.37). Fluorescein angiography and indocyanine green angiography help in the diagnosis and occasional treatment of macular lesions. The only advantage of indocyanine green is that the vascularisation of the choroid is much easier to see.