This prospective, non-randomized case-series study was performed at the San Marino State Hospital (Republic of San Marino). The study was conducted in accordance with the tenets of the Declaration of Helsinki, and the Institutional review board approval was obtained from the Hospital medico-legal committee prior to study commencement. All patients were fully informed on the surgical procedure and any vision concerns after IOL implantation were addressed, they were required to provide written consent for their surgical procedure and for allowing use of anonymized medical records for investigation purposes.

Patients presenting with bilateral cataract were scheduled for routine phacoemulsification cataract surgery, receiving one of the following IOLs: RayOne T, PanOptix, or the AcrySof monofocal. Patients were included into the study if they were aged 18 years or older, if they had bilateral cataract limiting visual acuity, corneal astigmatism of 0.75 D or less, and regular corneal tomography.

Exclusion criteria included previous ocular surgery (including refractive surgery), regular corneal astigmatism greater than 0.75 D, irregular astigmatism, large angle kappa and other optical or systemic conditions affecting visual acuity (such as macular disease, amblyopia, infection, ocular trauma, etc.), or anomalies of the lens capsule or zonules which could affect postoperative centration or tilt of the IOL (such as pseudoexfoliation syndrome).

The RayOne Trifocal (Rayner, Worthing, UK) is a one-piece hydrophilic aspheric lens that has an overall diameter of 12.5 mm. The optic has a diameter of 6.0 mm. The diffractive region covers the central 4.5 mm of the optic and thereafter the zone provides monocular distance vision. RayOne Trifocal (model RA0603F) has a patented diffractive profile with 16 rings on the optic surface for reduced potential visual disturbances and improved night vision. The haptic, which has an angulation of 0 degrees, consists of a closed loop with anti-vaulting haptic (AVH) technology that ensures rotational and centrational stability. The powers are available from 0.00 to +30.00 D, in 0.50 D increments. The addition powers are +3.5 D for near and +1.75 D for intermediate vision [10]. The IOL is preloaded in the RayOne injector system (Rayner, UK) across the entire power range and allows implantation through a 2.2 mm incision. This injector has a syringe-style design to aid a single-handed IOL delivery technique.

The AcrySof IQ PanOptix (Alcon Laboratories Inc., Fort Wort, TX, USA) is a panfocal IOL with quadrifocal technology. The IOL is a single piece made from hydrophobic acrylic with a 6.0 mm optic, 2 open-loop haptics, and an overall diameter of 13.0 mm. The IOL incorporates an ultraviolet and blue light–filter. The optic diffractive structure is in the central 4.5 mm of the anterior surface with power additions of +2.17 D for intermediate and +3.25 D for near [9, 11].

The AcrySof IQ monofocal IOL (Alcon Laboratories Inc) model SN60WF is a single-piece IOL with proprietary blue light filtering chromophores that filter light in a manner that approximates the crystalline lens in the 400–475 nm blue light wavelength range. The lens is made from a high refractive index soft acrylate/methacrylate copolymer and its configuration is anterior asymmetric biconvex. The posterior aspheric surface is designed with negative spherical aberration to compensate for the positive spherical aberration of an average cornea [18].

More technical specifications of the three IOLs are summarized in Table 1.

All surgeries were performed by the same experienced surgeon (AM) using topical anaesthesia. A standard technique of sutureless microincision phacoemulsification was performed for the implantation of the RayOne T, PanOptix, and Acrysof monofocal IOLs; 2.4 mm corneal incision was placed in temporal side, the capsulorhexis diameter was 5.2 mm and the IOL was implanted in the capsular bag. The IOL centering and capsulorhexis size were performed with the assistance of an intraoperative digital system (Verion Image Guided System, Alcon Laboratories, Inc., Fort Worth, TX). No intraoperative complications occurred at any level during all surgeries.

Preoperative assessments consisted of a full ophthalmologic examination for ocular morbidities, visual acuity, manifest refraction, and slit-lamp examination.

After surgery and at all follow-up visits, any visible decentration and tilt were assessed and documented. Postoperative complications were also assessed and documented. In addition to routine checks immediately after surgery, postoperative examinations were performed 1 month, 3 months, and 12 months after surgery. Postoperative follow-ups included assessments of the monocular and binocular uncorrected and corrected visual acuity at far (4 m), intermediate (70 cm), and near vision (30 cm). Distance visual acuity was assessed using the MOS 22 optotype (Dueffe Tecnovision, Pergine Valsugana, Italy) and was measured in LogMAR. Near and intermediate visual acuities were assessed using the MNREAD Acuity Chart (Precision Vision, LaSelle, IL). Subjective refraction was assessed only at the final follow-up visit and was performed using sphere, cylinder, and manifest residual spherical equivalent (MRSE) notations. The binocular defocus curves were evaluated under photopic conditions (85 candelas/m${}^2$) using defocusing lenses from –4.00 to +2.00 D, in 0.50 D steps of blur. Contrast sensitivity was assessed using the MOS 22 optotype at photopic (85 cd/m${}^2$) and mesopic conditions (6 cd/m${}^2$). Aberrometric examination was performed with Osiris aberrometer (Costruzione Strumenti Oftalmici, Florence, Italy) to evaluate low order (LOA) and high order (HOA) aberrations at full pupil diameter. Patient satisfaction and spectacle independence were determined using the self-administered NEI-RQL-42 (National Eye Institute Refractive Error Quality of Life Instrument-42) questionnaire [19]. All examinations were performed by the same experienced examiner (AI) using the same investigative protocol.

The calculation of the required sample size was based on the monocular uncorrected distance visual acuity (UDVA). Based on previous data analyses for a similar study [20], a difference of 0.1 logMAR units was assumed to be clinically significant and considered a standard deviation of 0.05 logMAR. Based on this assumption, it was calculated that for an alpha value of 0.05 and power of 0.80, 30 eyes were required in each group.

Statistical analysis was carried out with Excel Version 14.0.0 for Mac (Microsoft Corporation, Redmond, WA). Data from the three study groups were first compared together using a repeated-measures ANOVA. If significant differences were found, the groups were compared two at a time using the Student t test for independent samples for parametric data and the Mann-Whitney test for non-parametric data. A Welch test was used to compare two groups at a time in some items in the patient questionnaire. Categorical data was evaluated using the Fisher’s Exact test for small samples. Differences were considered to be statistically significant if p 0.05.

Compared to the preoperative values, significant improvements in the residual manifest sphere values over time were observed for each of the three IOLs (Time effect F(1,47) = 15.21, p 0.001), with a mean manifest sphere value at the 12-month follow-up visit of –0.03 $\pm$ 0.13 D, –0.08 $\pm$ 0.18 D, and –0.09 $\pm$ 0.20 D, for the RayOne T, PanOptix, and the AcrySof monofocal IOLs, respectively. These values did not significantly vary among the three groups (Interaction effect, F(2.45) = 0.35, p = 0.705), nor did they significantly vary at each follow-up visit (Group effect, F(2,47) = 1.08, p = 0.595).

The cylinder did not statistically differ among the three IOL groups over time (Interaction effect, F(2,45) = 0.07, p = 0.9358), nor at each time visit (Group effect, F(2,47) = 0.37, p = 0.6919). Overall, the cylinder values remained stable over time for each group (Time effect F(1,47) = 1.73, p = 0.1949), with a mean cylinder value at 12-month follow-up of –0.11 $\pm$ 0.13 D, –0.17 $\pm$ 0.22 D, and –0.05 $\pm$ 0.41 D, for the RayOne T, PanOptix, and the AcrySof monofocal IOLs, respectively. Fig. 1A, shows the distribution of refractive cylinder; all eyes in the RayOne T and PanOptix IOL groups were within $\pm$ 0.50 D of the attempted correction. Of the AcrySof monofocal group, 75% of eyes were within $\pm$ 0.50 D and 100% of eyes were within $\pm$ 1.00 D of attempted correction.

Fig. 1.

Postoperative refractive accuracy as measured at the 12-month follow-up visit. (A) Postoperative refractive cylinder; (B) Manifest spherical equivalent refraction (MRSE) accuracy. There were no significant differences among the three groups during the follow-up.

Compared to the preoperative values, a significant improvement in the postoperative residual manifest spherical equivalent over time was observed for each of the three IOLs (Time effect F (1,47) = 13.6, p 0.001), with a MRSE measured at the final follow-up of –0.08 $\pm$ 0.15 D, –0.14 $\pm$ 0.18 D, and –0.11 $\pm$ 0.24 D, for the RayOne T, PanOptix, and the AcrySof monofocal IOL, respectively. These values did not significantly vary among the three groups (Interaction effect, F (2,45) = 0.27, p = 0.7668), nor did they significantly vary at each time visit (Group effect, F (2,47) = 0.33, p = 0.7197). Fig. 1B, shows the distribution of the MRSE in the three IOL groups. With all tested IOLs, all eyes were within $\pm$0.50 D of the attempted correction and, therefore, also within $\pm$1 D of intended correction.

All postoperative monocular uncorrected and corrected visual outcomes calculated at 1, 3, and 12 months after surgery are shown in Table 2, and all postoperative binocular uncorrected and corrected visual outcomes are shown in Table 3. A statistically significant difference was found in monocular and binocular uncorrected distance visual acuity (UDVA) among the three IOL groups at each follow-up visit (Group effect, F (2,141) = 4.05, p = 0.024; Group effect, F (2,69) = 7.58, p = 0.003 for monocular and binocular UDVA, respectively), with the RayOne T IOL leading to better improvement in distance visual acuity compared to the other two IOLs (p 0.01, Tables 2 and 3). Monocular and binocular distance-corrected visual acuity (DCVA) did not significantly differ between any of the postoperative measurements within each IOL group, nor was the degree of improvement significantly different between the treatment groups.

Fig. 2A, shows the cumulative distribution of monocular UDVA and DCVA for the three IOLs. The UDVA was 20/20 or better (logMAR equivalent 0.0 or better) in 63% of eyes in the AcrySof monofocal group, in 75% of eyes in the PanOptix group, and in 100% of eyes in the RayOne T group. All eyes treated with each of the tested IOLs achieved a DCVA of 20/25 or better (logMAR equivalent 0.1 or better).

Fig. 2.

Cumulative distribution of post-operative monocular visual acuity for distance, intermediate and near as measured at the 12-month follow-up visit. RayOne T and PanOptix performed better in uncorrected intermediate and near visual acuity compared to AcrySof monofocal. (A) UDVA and DCVA. (B) UIVA and DCIVA. (C) UNVA and DCNVA.

Improvements in monocular and binocular uncorrected intermediate visual acuity (UIVA) significantly varied among the three IOL groups at each follow-up visit (Interaction effect, F (6,135) = 105.51, p 0.001); interaction effect, F (6,63) = 72.15, p 0.001 for monocular and binocular values, respectively), with the AcrySof monofocal group leading to worse UIVA compared to the other two IOL groups (p 0.001, Tables 2 and 3). Monocular and binocular distance-corrected intermediate visual acuity (DCIVA) did not significantly change between any of the postoperative measurements within each group of IOLs, and the degree of improvement remained comparable between the treatment groups. The cumulative distribution of post-operative monocular UIVA and DCIVA is shown in Fig. 2B. The UIVA was 20/25 or better (logMAR equivalent 0.1 or better) in 100% of eyes in the RayOne T group, in 94% of eyes in the PanOptix group; none of eyes in the AcrySof monofocal group achieved this acuity target. 100% of eyes in the RayOne T and AcrySof monofocal groups and 94% of eyes in the PanOptix group achieved a DCIVA of 20/25 or better.

A statistically significant difference was found in monocular and binocular uncorrected near visual acuity (UNVA) among the three IOL groups at each follow-up visit (Interaction effect, F (6,135) = 81.42, p 0.001), with the AcrySof monofocal group leading to worse UNVA compared to the other two IOL groups (p 0.001, Tables 2 and 3). Monocular and binocular distance-corrected near visual acuity (DCNVA) did not significantly differ between any of the postoperative measurements within each group of IOLs, nor was the degree of improvement significantly different between the treatment groups. Fig. 2C shows the cumulative distribution of monocular UNVA and DCNVA for the three IOL groups. The UNVA was 20/25 or better (logMAR equivalent 0.1 or better) in 75% of eyes in the RayOne T group, in 56% of eyes in the PanOptix group; none of eyes in the AcrySof monofocal group achieved this acuity target. All eyes in the RayOne T and PanOptix groups achieved a DCNVA of 20/20 or better (logMAR equivalent 0.0 or better).

Defocus curves for the three treatment groups at 1 month, 3 months, and 12 months postoperative are depicted in Fig. 3. At each evaluation, peak visual acuity occurred in all three groups at 0.0 D, at which point there were no differences in visual acuity among the three treatment groups. With a couple of exceptions, both the RayOne T and the PanOptix groups had significantly better visual acuity than the AcrySof monofocal group at every other defocus interval at every postoperative examination. The exceptions were: at 1 month postoperative, the RayOne T and AcrySof monofocal groups were not significantly different at –0.5 D (p = 0.097); and at 12 months postoperative, the RayOne T and AcrySof monofocal groups were not significantly different at –0.5 D (p = 0.089) and the PanOptix and AcrySof monofocal groups were not significantly different at +1.0 D (p = 0.061). There were no significant differences between the RayOne T and the PanOptix groups at any defocus interval.

Fig. 3.

Binocular defocus curves under photopic conditions after cataract surgery. The defocus curves did not significantly change at (A) 1 month, (B) 3 months, (C) 12 months of follow-up.

Photopic and mesopic contrast sensitivity graphs (measured in log contrast threshold) for the three treatment groups at 1 month, 3 months, and 12 months after surgery are depicted in Fig. 4. Under both photopic and mesopic conditions, all three treatment groups peaked in contrast sensitivity at 3 cycles per degree of visual angle at all three postoperative timepoints. Likewise, under both photopic and mesopic condition and in all three postoperative evaluations, contrast sensitivity was significantly higher for the AcrySof monofocal group than either the RayOne T or the PanOptix groups at every level in the range tested (p 0.05 for the 3-month evaluation under photopic conditions, and p 0.001 for all the other tests). There were no significant differences between the RayOne T and the PanOptix groups at any spatial frequencies.

Fig. 4.

Results of contrast sensitivity under photopic and mesopic conditions during the follow-up after cataract surgery. Contrast sensitivity under photopic conditions did not significantly change at (A) 1 month, (B) 3 months, (C) 12 months as well as under mesopic conditions at (D) 1 month, (E) 3 months, and (F) 12 months.

Aberrometric examination was performed after surgery with the CSO aberrometer (OSIRIS) to evaluate Low order (LOA) and High Order (HOA) aberrations. Ocular, corneal and internal aberrations were assessed at 12 months after surgery in the three groups at full pupillary diameter. Full results are described in Table 4. Aberrometric data points were quantified in root mean square (RMS) values in micrometers ($\mu$m), and mean values for both LOA and HOA aberrations compared between the RayOne T and PanOptix groups, with the monofocal group used as a control group (Fig. 5). The mean pupillary diameter was not significantly different between all three groups (p = 0.374).

Fig. 5.

Ocular, corneal and internal aberrations at the 12-month follow-up visit. Low order (LOA) and High Order (HOA) aberrations are reported for each IOL.

In the RayOne T group, mean full pupillary diameter was 3.486 $\pm$ 0.499 millimeters. Overall total ocular aberrometry was 0.538 $\pm$ 0.254 $\mu$m with LOA 0.462 $\pm$ 0.239 $\mu$m and HOA 0.141 $\pm$ 0.043 $\mu$m. The total corneal aberrometry was 0.226 $\pm$ 0.111 with LOA 0.162 $\pm$ 0.112 $\mu$m and HOA 0.145 $\pm$ 0.057 $\mu$m. The total internal aberrometry was 0.490 $\pm$ 0.270 with LOA 0.438 $\pm$ 0.272 $\mu$m and HOA 0.145 $\pm$ 0.049 $\mu$m. Internal primary coma, primary trefoil and spherical aberration were 0.058 $\pm$ 0.033 $\mu$m, 0.071 $\pm$ 0.038 $\mu$m and –0.004 $\pm$ 0.049 $\mu$m respectively.

In the PanOptix group, mean full pupillary diameter was 3.739 $\pm$ 0.598 millimeters. Overall total ocular aberrometry was 0.543 $\pm$ 0.184 $\mu$m with LOA 0.491 $\pm$ 0.175 $\mu$m and HOA 0.187 $\pm$ 0.103 $\mu$m. The total corneal aberrometry was 0.246 $\pm$ 0.061 with LOA 0.188 $\pm$ 0.059 $\mu$m and HOA 0.146 $\pm$ 0.058 $\mu$m. The total internal aberrometry was 0.539 $\pm$ 0.242 with LOA 0.471 $\pm$ 0.183 $\mu$m and HOA 0.176 $\pm$ 0.076 $\mu$m. Internal primary coma, primary trefoil and spherical aberration were 0.071 $\pm$ 0.059 $\mu$m, 0.094 $\pm$ 0.061 $\mu$m and 0.013 $\pm$ 0.032 $\mu$m respectively.

In the AcrySof monofocal group, mean full pupillary diameter was 3.808 $\pm$ 0.878 millimeters. Overall total ocular aberrometry was 0.453 $\pm$ 0.198 $\mu$m with LOA 0.408 $\pm$ 0.181 $\mu$m and HOA 0.157 $\pm$ 0.068 $\mu$m. The total corneal aberrometry was 0.243 $\pm$ 0.066 with LOA 0.181 $\pm$ 0.098 $\mu$m and HOA 0.154 $\pm$ 0.062 $\mu$m. The total internal aberrometry was 0.426 $\pm$ 0.205 with LOA 0.348 $\pm$ 0.170 $\mu$m and HOA 0.147 $\pm$ 0.060 $\mu$m. Internal primary coma, primary trefoil and spherical aberration were 0.085 $\pm$ 0.049 $\mu$m, 0.128 $\pm$ 0.107 $\mu$m and 0.014 $\pm$ 0.036 $\mu$m respectively.

The aberrometric values were similar in the three groups. The total ocular and internal aberrations showed lower values in the Acrysof Monofocal group compared to the PanOptix and RayOne T groups, as well as the total ocular and internal LOA values. No statistically significant differences were identified between the three groups regarding total ocular and internal HOA values (p $>$ 0.05). The total corneal aberrometry values were found to be lower in RayOne T group (RayOne T 0.226 $\pm$ 0.111 $\mu$m, PanOptix 0.246 $\pm$ 0.061 $\mu$m, Acrysof Monofocal 0.243 $\pm$ 0.066 $\mu$m), but no statistically significant differences were found between the three groups.

At the 12-month follow up, all patients implanted with either the RayOne T or the PanOptix IOLs rated all items on the NEI RQL-42 Questionnaire highly (Fig. 6). All of these patients gave a score of 100 (corresponding to complete satisfaction) in the following categories: clarity of vision; diurnal fluctuations; activity limitations; worry about eyesight; appearance of their eyes; dependence on corrective lenses; problems with suboptimal correction; how well their expectations were met; and overall satisfaction with their correction. Patients in the RayOne T group gave a mean score of 100 for near vision satisfaction, and those in the PanOptix group gave a mean score of 96.88 (range: 93.75–100); the mean score given for distance vision satisfaction in the RayOne T group was 95.62 (range: 88.33–100), and was 92.08 (range: 78.33–100) in the PanOptix group. When scoring on dysphotopic phenomena, patients in the RayOne T and PanOptix groups scored 92.23 (range: 70.83–100) and 84.38 (range: 37.5–100) for glare respectively. Additionally they gave a score of 100 and 91.52 (range: 71.42–100) for other optical symptoms, respectively. There were no significant differences in the responses to any of the questions between the RayOne T and PanOptix groups.

Fig. 6.

Results of the NEI RQL — 42 questionnaire on the visual QoL outcomes obtained at 12 months after cataract surgery.