The effect of lens design on dysphotopsia in different acrylic IOLs

Abstract

Purpose To compare the incidence and severity of all grades of dysphotopsia in three types of acrylic intraocular lenses: the Acrysof MA30 BA and MA60 BM IOLs (Alcon) and the Akreos Fit one-piece IOL (Bausch and Lomb). Methods In all 111 patients were prospectively recruited who had undergone uncomplicated cataract surgery in the previous 12 months. Patients were assessed using a combination of a questionnaire and standardised provocation test, and were scored on a grading scale of 0-6 (0 indicating no glare and 6 indicating the most severe symptoms). Results The overall incidence of dysphotopsia was 77.7%. Patients with absent or mild symptoms (scoring 2 or less on the grading scale) were greater in the group implanted with the Akreos IOLs (49/65 eyes, 75%) as opposed to (44/92 eyes, 48%) of the eyes implanted with Acrysof lenses. Patients with more marked symptoms of glare as judged by scores of 5-6 were uncommon, but more prevalent in the Acrysof lenses (12/92 eyes, 13%) compared to the Akreos lenses (3/65 eyes, 4.6%) respectively. Statistically the Mann-Whitney test showed that there was significantly less dysphotopsia with the Akreos lens when compared to the Acrysof MA30 (P ¼ 0.005) and MA60 lenses (P ¼ 0.002). Conclusion This study demonstrates that dysphotopsia symptoms are commonly seen in certain brands of Acrylic IOLs. However, differences in design (not only related to the edge) significantly reduce the incidence of moderate and severe grades of dysphotopic symptoms.

Comparison of pseudophakic dysphotopsia with Akreos Adapt and SN60-AT intraocular lenses

“…Moreover, 20.7% of patients with the Akreos IOL reported persistent dysphotopsia at 8 weeks. This is similar to the figure recently reported by Shambhu et al, 14 who found a 75% incidence of mild or no symptoms. Because their data used combined questionnaire and provocation light test criteria, it is difficult to directly correlate this with clinically relevant symptoms.…”

“…8 Both IOLs are square edged, although the Akreos IOL has a 50% greater edge thickness, which one would expect to be a significant factor in a positive dysphotopsia edge effect. 6,7 A previous study 14 showed the incidence of dysphotopsia to be lower with the SN60-AT IOL (68.7% asymptomatic at 8 weeks) than with MA30BA and MA60BM IOLs (48% had mild or no symptoms). As Shambhu et al 14 state, the SN60-AT is a yellow-tinted acrylic IOL with a frosted edge design, which could explain the lower incidence of dysphotopsia with this lens.…”

“…6,7 A previous study 14 showed the incidence of dysphotopsia to be lower with the SN60-AT IOL (68.7% asymptomatic at 8 weeks) than with MA30BA and MA60BM IOLs (48% had mild or no symptoms). As Shambhu et al 14 state, the SN60-AT is a yellow-tinted acrylic IOL with a frosted edge design, which could explain the lower incidence of dysphotopsia with this lens. 18 The reasons for the differences in the incidences of negative dysphotopsia are not clear, and the cause of such light phenomenon has remained elusive.…”

“…Shambhu et al 14 recently compared 3 truncated-edged IOLs: the AcrySof MA30BA and MA60BM (Alcon) and…”

Negative dysphotopsia: The enigmatic penumbra

“…A few years later, Erie et al 16,17 found that reflections from the front and back surfaces of equiconvex unequal biconvex designs and a higher index of refraction optic materials were also factors that increased the relative intensity of the reflected light from 300-to 3500-fold above that of the crystalline lens. Several subsequent studies [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] confirmed these factors to be important in producing positive dysphotopsia.…”