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Study into the efficacy of a refractive multifocal intraocular lens implant
Author(s) -
Kotecha A.
Publication year - 1996
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1046/j.1475-1313.1996.96849945.x
Subject(s) - multifocal intraocular lens , intraocular lens , medicine , phacoemulsification , implant , astigmatism , ophthalmology , refractive error , cornea , lens (geology) , surgery , optometry , eye disease , visual acuity , optics , physics
In the last decade there has been a significant advance in the types and materials of intraocular lens implants available. Recently, there has been a trend towards developing a multifocal intraocular lens (IOL) implant and, with advances in surgical techniques, there is the possibility of abolishing the need for postoperative spectacle correction completely. For the last seven years at the Croydon Eye Unit we have been involved in four multicentre clinical trials into the efficacy of the bizonal refractive form of multifocal IOL design. The results presented focus on the IOLAB 8191M multifocal implant, with a near central zone of 1.5 mm diameter, and a +4.00 D addition. When implanted, this is equivalent to a spectacle addition of +2.80 D. The surgical technique used was phacoemulsification with capsularrhexis, but incision size had to be increased to 6.0 mm in order to insert the IOL. However, postoperative corneal astigmatism was still well controlled, and this returned to preoperative values in 82% patients within 5 weeks. From previous studies we found that patients with a preoperative corneal astigmatism of <1.00 D performed significantly better postoperatively (study inclusion criteria specific <2.00 D of corneal astigmatism for patient qualification). To data, 245 8191M multifocals have been implanted in Europe, 228 of which have had a minimum of 3 months follow‐up. At our centre, 47 eyes have been implanted with the 8191M, 85% of whom have had at least a 12 month postoperative follow‐up. Our results have shown 64% patients achieving unaided visions of 6/12 or better for distance, and 84% J3 or better for near. In 45 eyes, acuity measurements with the distance correction in place indicates that 100% of eyes achieved 6/12 or better for distance, and 96% J3 or better for near. The effects of glare, tested with the Brightness Acuity Tester (BAT), showed no significant detrimental effect on visual acuity, and this was also shown to be independent of pupil size. In summary, the refractive design of multifocal IOL has been shown to give successful visual results. However, in order to achieve excellent results from multifocal designs of IOL, it is essential to have an astigmatically neutral form of surgery and accurate biometry.