Standard Automated Perimetry Before and After Extended Depth-of-Focus Intraocular Lens Implantation: Longitudinal Changes in Global Indices and Test Reliability

Introduction

Presbyopia-correcting intraocular lenses (IOLs) have evolved substantially, and extended depth-of-focus (EDOF) optics have been introduced to expand the range of functional vision while preserving optical quality. A longitudinal evaluation using standard automated perimetry (SAP) parameters after implantation of trifocal and EDOF lenses has been reported, supporting the relevance of perimetry as a functional outcome in this setting.¹ Other studies have specifically investigated the influence of EDOF IOL implantation on SAP outcomes and visual field sensitivity, providing further evidence of postoperative perimetric behavior in eyes with EDOF optics.^2,3 Earlier work also suggested that multifocal IOLs can influence SAP test results, reinforcing the importance of evaluating perimetry in eyes implanted with presbyopia-correcting lenses.⁴ Because SAP remains central to functional assessment in glaucoma and optic neuropathies, even small systematic shifts in global indices after IOL implantation may affect longitudinal interpretation in patients requiring future visual field monitoring.

Beyond perimetry-focused investigations, evidence syntheses comparing trifocal and EDOF IOLs have summarized postoperative visual performance and optical quality trade-offs across platforms, including systematic reviews and meta-analyses.^5–11 Clinical comparative studies have reported visual acuity, quality of vision, contrast sensitivity, and patient-reported outcomes after bilateral implantation with trifocal or EDOF lenses, providing additional context for functional performance following presbyopia-correcting IOL implantation.^12–18 Reviews of multifocal and EDOF IOL concepts and performance further discuss how design-related light distribution and contrast-related effects may influence threshold-based testing conditions.^19–22

Interpretation of longitudinal SAP findings requires consideration of measurement variability. Test–retest variability is a known feature of automated perimetry, and practical recommendations exist for interpreting change over time in clinical settings.^23,24 In addition, media opacity can affect automated perimetry, and cataract extraction has been associated with changes in visual field measurements, which should be considered when evaluating pre- and postoperative SAP results in cataract populations.^25,26 Therefore, in a before–and–after cataract surgery design, it is important to interpret SAP changes in light of both expected test–retest behavior and the potential influence of cataract removal on perimetric sensitivity. Related work from our group has examined objective and subjective outcomes with contemporary presbyopia-correcting IOL strategies, supporting continued investigation of functional endpoints beyond visual acuity alone.^27,28 Additional clinical reports have examined outcomes of combining EDOF and multifocal approaches, and optical analyses have characterized clinically relevant properties of bifocal, trifocal, and EDOF designs.^29,30

Therefore, the purpose of the present study was to describe SAP parameters before and after EDOF IOL implantation using a longitudinal before–and–after design, focusing on global indices, foveal thresholds, and test-reliability measures.

Methods

Study Design and Ethical Approval

This was a single-center, longitudinal before–and–after observational study. The protocol was reviewed and approved by the Research Ethics Committee of Hospital Oftalmológico de Brasília (HOB), Brasília, DF, Brazil (CAAE: 36566520.3.0000.5667), and all participants provided written informed consent before enrollment. The study adhered to the tenets of the Declaration of Helsinki.

Participants and Eligibility Criteria

Adults aged 50–79 years scheduled for cataract surgery with implantation of an extended depth-of-focus (EDOF) intraocular lens (IOL) were consecutively recruited. Thirteen patients (23 eyes) completed both baseline and follow-up SAP examinations. Eyes were included if no ocular condition was present that could reasonably affect visual field testing. Exclusion criteria comprised known or suspected glaucoma, optic nerve disease, retinal pathology, prior intraocular surgery, uveitis, or neurologic disorders associated with visual field defects. Eyes were also excluded if postoperative complications occurred that could affect visual field testing.

Intraocular Lens and Surgery

All eyes received an EDOF IOL (Symfony) (Tecnis Symfony, Johnson & Johnson Vision, Santa Ana, CA, USA). Phacoemulsification with in-the-bag IOL implantation was performed by the attending surgeon using routine surgical technique. Postoperative topical therapy (antibiotic and anti-inflammatory drops) was administered in accordance with the institutional standard protocol.

Cataract Grading and Visual Acuity

Cataract severity was graded using the Lens Opacities Classification System III (LOCS III), and eyes with nuclear opalescence grades NO2–NO3 were included. Preoperative and postoperative visual acuity of 20/40 or better was required for SAP testing.

Standard Automated Perimetry Protocol

Standard automated perimetry (SAP) was carried out at two time points: preoperatively (baseline) and postoperatively (follow-up), using the same device and test strategy at both visits. SAP was performed using the Humphrey Field Analyzer II (Carl Zeiss Meditec) with the SITA Standard 24–2 strategy (Goldmann size III). Trained technicians performed examinations under standardized instructions. Reliability parameters recorded by the perimeter were used to assess test quality. Tests were considered reliable if fixation losses were <20%, false-positive errors <15%, and false-negative errors <15%. Baseline SAP was obtained within 6 months before surgery, and follow-up SAP was performed 6–12 months after surgery. To minimize potential inter-eye correlation, right and left eyes were analyzed separately. Because SAP measurements show inherent variability across repeated tests and require careful interpretation of longitudinal change, SAP outcomes were considered within the framework of established test–retest behavior and recommendations for monitoring visual field change over time.^23,24 In addition, given that cataract and cataract extraction can influence automated perimetry, baseline-to-follow-up comparisons were interpreted with awareness of cataract-related effects reported in the literature.^25,26 No additional statistical adjustment for cataract-related effects was performed beyond the within-eye before–and–after comparison and the interpretation within published cataract/SAP evidence.

Outcomes

Primary outcomes were changes from baseline to follow-up in global SAP indices and foveal threshold, assessed separately for right and left eyes. Secondary outcomes included SAP reliability indices, specifically false-positive and false-negative rates.

Statistical Analysis

Data are presented as mean ± standard deviation (SD). Baseline and follow-up values were compared using paired statistical tests, with a two-sided significance threshold of p < 0.05. Analyses were performed separately for right and left eyes. Statistical analyses were conducted using standard statistical software. Analyses were performed in R (version 4.2, R Foundation for Statistical Computing, Vienna, Austria). Given the descriptive nature of this longitudinal study, no formal a priori sample size calculation was performed. A post-hoc sensitivity analysis indicated that the current sample size (23 eyes) had limited ability to detect very small changes in mean deviation (eg, approximately 0.3 dB would require n≈97 eyes, assuming SD of paired differences ≈1.3 dB, α = 0.05, two-sided).

Results

Study Population

Thirteen patients (23 eyes) completed both baseline and follow-up SAP examinations. The mean age of the patients was 64.1 years (SD ± 6.2), with 70% male and 30% female.

Standard Automated Perimetry Outcomes

Standard automated perimetry outcomes showed small, non-significant pre-to-postoperative changes in both eyes (Table 1 and Figure 1). Mean deviation (MD) demonstrated mild improvement without statistical significance (right: −1.1 ± 1.2 dB preoperatively vs −0.8 ± 1.2 dB postoperatively, p = 0.32; left: −1.9 ± 0.9 dB vs −1.2 ± 1.1 dB, p = 0.12) (Table 1 and Figure 1). Visual field index (VFI) remained essentially unchanged (right: 99.1% ± 1.1% vs 98.8% ± 1.4%, p = 0.43; left: 98.0% ± 1.1% vs 98.0% ± 2.1%, p = 1.00) (Table 1 and Figure 1).

Table 1 Standard Automated Perimetry Outcomes Before and After EDOF IOL Implantation (Symfony), with Change Scores

Figure 1 Mean change (Post–Pre) in standard automated perimetry (SAP) outcomes before and after extended depth-of-focus intraocular lens (EDOF IOL) implantation (Symfony). The vertical line at 0 indicates no change. The right and left eyes were analyzed separately.

Foveal threshold values were stable over time. Right eyes showed no meaningful change (35.1 ± 1.9 dB vs 35.2 ± 0.9 dB, p = 0.86), while left eyes demonstrated a small, non-significant increase (34.0 ± 1.0 dB vs 34.5 ± 1.3 dB, p = 0.26) (Table 1 and Figure 1). Pattern standard deviation (PSD) also showed no statistically significant change (right: 1.9 ± 0.9 dB vs 1.7 ± 0.4 dB, p = 0.34; left: 1.8 ± 0.3 dB vs 1.9 ± 1.2 dB, p = 0.73) (Table 1 and Figure 1). The change-score visualization shows that outcome deltas were centered near zero for most parameters, with no consistent direction of change across eyes (Figure 1).

Perimetry Reliability Indices

Reliability indices remained stable from baseline to follow-up (Table 2 and Figure 2). False-positive rates were low at both time points and did not change significantly (right: 1.9% ± 2.6% vs 2.1% ± 1.4%, p = 0.75; left: 1.4% ± 2.5% vs 0.5% ± 0.6%, p = 0.21) (Table 2 and Figure 2). False-negative rates were likewise unchanged (right: 1.6% ± 2.1% vs 1.7% ± 3.1%, p = 0.91; left: 2.2% ± 2.9% vs 1.1% ± 1.5%, p = 0.35) (Table 2 and Figure 2). Consistent with these findings, change scores for reliability indices clustered near zero in both eyes, indicating comparable test quality at baseline and follow-up (Figure 2).

Table 2 Standard Automated Perimetry Reliability Indices Before and After EDOF IOL Implantation (Symfony), with Change Scores

Figure 2 Mean change (Post–Pre) in standard automated perimetry (SAP) reliability indices before and after extended depth-of-focus intraocular lens (EDOF IOL) implantation (Symfony). The vertical line at 0 indicates no change. The right and left eyes were analyzed separately.

Discussion

In this longitudinal before–and–after assessment, SAP outcomes following EDOF IOL implantation showed minimal change from baseline to follow-up, with small differences across global indices, foveal thresholds, and reliability measures. The overall pattern was one of stability rather than a directional shift in sensitivity. This result is consistent with the EDOF-focused perimetry literature, in which postoperative SAP indices and visual field sensitivity have generally remained unchanged after implantation, even when specific parameters show small fluctuations.^2,3 Our findings also align with the longitudinal report evaluating SAP parameters after both trifocal and EDOF implantation, which found no clinically meaningful postoperative deterioration overall.¹ The absence of significant changes in reliability indices further supports that the observed outcome differences are unlikely to be driven by systematic changes in test quality.

A useful way to interpret the present results is through the lens of change-score magnitude. The change values for MD, VFI, PSD, and foveal threshold were close to zero. They did not show a consistent pattern across eyes, suggesting that the observed differences are more consistent with expected variability than with a true lens-related effect. Automated perimetry exhibits test–retest variability, and practical guidance emphasizes caution when attributing small pre–post differences to meaningful functional change.^23,24 This is particularly relevant when global indices remain stable, and reliability metrics do not worsen, as in the present dataset.

Unlike diffractive multifocal designs that split light into distinct foci, EDOF optics are intended to extend the range of focus while preserving optical quality. Reviews and meta-analyses have generally reported favorable outcomes with EDOF lenses, including optical quality and patient-reported measures, while acknowledging design- and patient-related trade-offs.^{5–11,19–22} In threshold-based testing, such as SAP, contrast-related effects are expected to manifest as small differences in sensitivity rather than dramatic changes in global indices. The stability observed here supports the clinical impression that routine SAP remains interpretable after EDOF implantation in eyes without ocular comorbidity.

An additional consideration in a before–and–after cataract surgery design is the influence of media opacity and its removal. Cataract can depress perimetric sensitivity, and cataract extraction has been associated with changes in automated perimetry in different settings.^25,26 In principle, improved media clarity after surgery could enhance measured sensitivity, whereas the optical characteristics of presbyopia-correcting lenses could exert opposing effects under certain conditions. The net result observed in this cohort was essentially neutral, with no consistent shift in either direction, suggesting that these factors did not translate into measurable changes in standard SAP indices at the group level. One plausible explanation for the absence of a statistically significant improvement in MD is that baseline SAP indices were already near normal (high VFI and mildly negative MD), limiting the potential for measurable postoperative gains (ceiling effect). In addition, because cataract severity was limited to NO2–NO3, any baseline cataract-related depression in SAP may have been modest, resulting in only small postoperative gains after media clarity improved. Finally, subtle contrast-related effects of EDOF optics in threshold-based testing could offset small improvements from cataract removal, leading to an overall neutral group-level change.

This study has limitations. The analysis is based on summarized group-level results and on separate evaluations of the right and left eyes, which limits patient-level modeling and precludes assessment of the distribution of individual changes. Sample size and follow-up duration may also reduce sensitivity to detect very small effects. Finally, SAP outcomes may be influenced by learning effects, attention, and intrinsic variability despite acceptable reliability indices.^23,24 Sample size and follow-up duration may reduce sensitivity to detect very small effects. However, the observed changes were small, non-directional, and compatible with expected test–retest variability. Future studies, using individual-level data, could quantify inter-eye correlation, explore predictors of change, and incorporate additional measures of optical quality to elucidate mechanisms.

In conclusion, EDOF IOL implantation was associated with stable SAP outcomes in this longitudinal before–and–after evaluation, with small changes in global indices, foveal thresholds, and reliability measures. These findings support the interpretability of SAP following EDOF implantation and are consistent with prior reports on perimetry in eyes with EDOF optics.^1–3