PresbyLASIK versus multifocal refractive IOLs

PresbyLASIK treatment uses the principles of LASIK surgery to create a multifocal corneal surface aimed at reducing near vision spectacle dependence in presbyopic patients. This treatment constitutes the next step in the correction of presbyopia after monovision LASIK.^1-3 Among the presbyLASIK techniques, central presbyLASIK⁴ creates a central area, which is hyperpositive for near vision leaving the midperipheral cornea for far vision.⁵ Positive clinical results of this surgical technique have been recently reported⁴ and also tested objectively with a light propagation algorithm.⁶

We recently performed a study comparing the visual outcomes achieved by patients who underwent presbyLASIK with the simulated results that they would have obtained from a multifocal IOL implant, such the Array multifocal IOL.¹¹

A total of 10 hyperopic eyes that underwent central presbyLASIK surgery with Presby-One software (Technovision) using a H. Eye Tech. Technovision excimer laser (Technovision and Bausch & Lomb) platform were included in this study. The mean age was 57 (ranging from 52 to 68) and mean preoperative spherical equivalent was 1.28±0.87 D. The mean value and standard deviation of the distance visual acuity with and without correction were 1.02±0.13 and 0.37±0.15, respectively. All patients had a corneal curvature (SimK) between 40 D and 48 D, a horizontal iris diameter (white-to-white) between 11.5 mm and 12.0 mm, central corneal thickness of no less than 500 μm and no signs of cataract observed using a slit lamp. Pupil diameter ranged from 2.5 mm (photopic conditions) to 6.0 mm (mesopic conditions).

Assessment before presbyLASIK surgery consisted of a complete ophthalmologic examination including topography (CSO topographer; CSO), biometry (IOL master; Carl Zeiss Meditec), pachymetry (Ophthasonic; Technar), and manifest refraction. Distance visual acuity was tested using the decimal scale visual charts at 4 m; uncorrected distance visual acuity and best corrected distance visual acuity were tested under normal light conditions (approximately 90 cd/m² ) using 100% contrast optotypes. Postoperative follow-up exams took place at one day, one week and one, three and six months after surgery. For the purpose of this study only the six months data was used.

A 1.5 mm circumferential transition zone of gradually changing power connects the portion of the cornea corrected for distance with the region corrected for near. The ablation pattern was performed with proprietary Presby-One software using the H. Eye Tech. Technovision excimer laser platform. This excimer laser uses a flying spot of 0.8 mm with a repetition rate of 50 Hz and an eye tracker system with a mean response time of 10 ms.