The development of presbyopia in hyperopic people aged between 45 and 65 is a serious refractive problem that, until recently, has had no practical solution. Individuals in this category are not usually considered to be "patients" but, nevertheless, face real problems with their everyday near and distance sight. We call this problem "hyperopic presbyopia".
The use of bifocal or multifocal glasses and contact lenses are not always a practical treatment solution and methods such as modified monovision through the implantation of monofocal intraocular lenses (IOLs), laser treatment and accommodative IOLs each come with their own difficulties. However, the new pseudo-accommodative AcrySof ReSTOR IOL from Alcon does seem to offer a viable alternative.
The AcrySof ReSTOR lens uses a combination of three technologies: apodization, diffraction and refraction, providing the recipient with more than one point of focus. Trials of the lens demonstrated that it could significantly improve visual acuity (VA) whilst also diminishing glare and halos. The ability of this lens to deliver a full range of vision makes it ideal for those patients who lost accommodation after cataract surgery, as well as for hyperopic presbyopes.
When patients over 45, particularly hyperopes, develop presbyopia, they become candidates for lens exchange using this new IOL and last year we had the opportunity to work with the AcrySof ReSTOR and we saw some excellent results.
Our study included 65 patients with a refraction range of between +1D and +6D, although the majority of the patients were low degree hyperopes (+1.5D to +2.5D). All patients underwent clear lens exchange with implantation of the ReSTOR lens in both eyes. The mean patient age was 53.5 years (range 35-65 years). No one had manifest cataract formation.
Refractive lens exchange was performed on all patients by the same surgeon with a standard clear corneal approach using topical anaesthesia. The preoperative preparation of the hyperopic eyes included the use of osmotic agents such as carbonic anhydrase inhibitors and/or mannitol, in order to increase the depth of the anterior chamber. In two patients implantation of the lens was performed simultaneously in both eyes.
There were no intraoperative complications and 45 eyes gained one or more lines of VA. A particularly noteworthy improvement in postoperative VA was observed in the amblyopic right eye of one patient who was significantly hyperopic in both eyes (OD = +6.75 sph, OG = +6.00 sph). This patient was the youngest of the group at just 35 years, and he gained three lines of VA in his right eye one month after baseline. The near vision restoration of this eye was also considerable. The loss of accommodation after clear lens exchange in this young patient was substituted by the multifocality of the ReSTOR lens, which I believe is a most important observation of our study.
Cataract & refractive surgery: two disciplines become one
Modern cataract surgery has become refractive surgery with the optimisation of vision quality after lens removal. We are able today to replace the crystal lens with the new technology multifocal IOL, AcrySof ReSTOR, treating hyperopia and presbyopia simultaneously. Our study showed that the lens delivers the full range of vision to refractive hyperopes, leaving them free from spectacles and unwanted symptoms.
There are, of course, a number of crucial criteria for ensuring such successful outcomes: good patient selection, good biometry and a good surgical technique (the AcrySof lens can be injected through an incision of between just 3 and 3.2 mm). As the pseudo-accommodative IOLs come into their own, and news of their success spreads, we are likely to see more and more hyperopic people in their fifties and sixties opting for lens exchange, perhaps before they have even developed the first signs of cataract.
Zissis Bisogiannis, MD, FEBO is Director of the Department of Ophthalmology at Mitera Hospital, Athens, Greece. He states that he holds no financial interest in the products, technologies or companies mentioned herein. Dr Bisogiannis may be reached by Tel: +30 210 723 5217 or E-mail: firstname.lastname@example.org