Phakic IOL for ectatic corneas
Phakic IOLs effective for fine-tuning refraction in keratoconus patients
Phakic IOLs can provide a safe and effective means of treating residual refractive errors in patients with stable keratoconus and other ectatic dystrophies and corneal pathologies where laser refractive surgery is not a viable option, according to Tamer O. Gamaly FRCS.
“Phakic IOLs can provide fast rehabilitation and a wide range of correction of stable refractive error, including myopia and compound myopic astigmatism for these more complicated cases where LASIK is not possible,” Dr Gamaly told delegates attending the World Ophthalmology Congress in Barcelona.
The problem of refractive errors in keratoconic patients is familiar to any surgeon who deals with such patients on a regular basis, said Dr Gamaly.
“These patients often come to us not because they have a weak cornea but rather because of a refractive problem that is bothering them. Phakic IOLs enable us to treat these patients with abnormal corneas since they not suitable for laser refractive surgery, which would weaken the structural stability of the cornea further,” he said.
Phakic lenses may be used in combination with standard keratoconus treatment modalities such as collagen cross-linking (CXL), intracorneal ring implants or after deep anterior lamellar keratoplasty, said Dr Gamaly.
“This is a big advantage as we can treat their cone while also taking care of their refractive errors and giving them better quantity and quality of vision,” he said.
The ideal patient for phakic IOL correction is one with an abnormal or topographically suspect cornea with a residual refractive error whose refraction has been stable for at least two years, said Dr Gamaly.
“Patients should also have stable topography for at least one year, with a clear central cornea, and realistic expectations. This is important so the patient understands that you will try to give them the best corrected vision possible but that 20/20 might not be attainable,” he said.
Dr Gamaly said he usually considers implanting phakic lenses to correct residual refractive errors for cases of confirmed or suspect keratoconus (forme fruste) or ectatic corneal dystrophies or post-LASIK ectasia.
The contraindications for phakic IOL implantation include unstable refraction, progressive cone, scarred central cornea or unrealistic expectations, added Dr Gamaly.
“The take-home message is that phakic IOLs can be used when no other laser refractive surgery procedure can be performed. In keratoconus cases, we need to be sure of stability both in terms of refraction and topography, to use all available options to get the best visual outcomes, and continue to follow up the patient every three to six months,” he said.
Tamer O. Gamaly: tamergamaly2010 @gmail.com