Ophthalmology · Medical Literature
[Clinical study of silicone hydrogel multifocal soft contact lenses for correction of presbyopia].
Abstract
Objective: To evaluate the efficacy and safety of a novel silicone hydrogel multifocal soft contact lens for presbyopia correction, and to verify its non-inferiority compared with a conventional hydrogel multifocal contact lens. Methods: This was a prospective, randomized, open-label, parallel-group, multicenter non-inferiority clinical trial. From October 2024 to July 2025, 195 presbyopic subjects aged ≥40 years with near add power of +0.75 to +2.50 D were screened at 5 centers (Eye Hospital of Wenzhou Medical University, Eye & ENT Hospital of Fudan University, and Shenzhen Eye Hospital, Qingdao Eye Hospital of Shandong First Medical University, and Shanxi Eye Hospital Affiliated to Shanxi Medical University), and 180 were enrolled and randomized (computer-generated random number method) 1∶1 to the test group (samfilcon A silicone hydrogel multifocal soft contact lens, n=90) or the control group (polymacon hydrogel multifocal soft contact lens, n=90). Both type of lenses were monthly disposable for daily wear. Binocular corrected distance visual acuity (5 m) and near visual acuity (40 cm) were measured at each visit using a standard logarithmic visual acuity chart (5-point recording method). Subjective wearing experience was assessed by a validated acceptability questionnaire, and ocular surface status was evaluated via tear break-up time (TBUT) and corneal fluorescein staining. The primary endpoint was the wearing success rate at 1 week, defined as binocular corrected distance visual acuity ≥4.9 and near visual acuity ≥4.7. Missing values were imputed using the worst observation carried forward method. Rate differences and 95% confidence intervals (CI) were calculated by the Newcombe-Wilson method. Between-group comparisons were performed using Fisher exact test, independent-samples t test, or Wilcoxon rank-sum test. Sensitivity analysis was performed using the Cochran-Mantel-Haenszel method stratified by center. The non-inferiority margin was prespecified as -10%. Results: The full analysis set comprised 177 subjects (87 in the test group, 90 in the control group), with a mean age of (47.1±4.7) years, including 33 males and 144 females. After the data imputation, the wearing success rate at 1 week was 100.0% in both groups, with a rate difference of 0.00% (95%CI:-4.23% to 4.09%), meeting the non-inferiority criterion. Sensitivity analysis of raw data showed success rates of 96.6% and 96.7% in the test and control groups, respectively (adjusted rate difference -0.00%, P=0.991), consistent with the primary analysis. At all visits, binocular corrected visual acuities were within normal ranges in both groups, with no significant between-group differences (all P>0.05). Contact lens-corrected visual acuity was slightly lower than best spectacle-corrected visual acuity in both groups, with mean differences of approximately 0.03 to 0.06. The test group had a higher proportion of"excellent"subjective distance vision ratings at 1 week (50.0% vs. 36.8%, P=0.047), better comfort at 1 week and 1 month (both P<0.05), and better lens cleanliness at dispensing and 1 week (both P<0.05). Subjects with low add power had better total subjective scores at 1 week [2.0 (0.0, 4.0) vs. 4.0 (2.0, 5.0), P=0.004], with no significant difference at 3 months. At 1 month, the test group showed a smaller decrease in TBUT from baseline (P<0.05) and a higher proportion of grade 0 corneal fluorescein staining at 1 week and 1 month (both P<0.05); these differences disappeared by 3 months. No device-related serious adverse events occurred, and the incidence of adverse events did not differ significantly between groups. Conclusions: The novel silicone hydrogel multifocal soft contact lens is non-inferior to the conventional hydrogel lens in presbyopia correction, with a comparable safety profile and superior comfort, subjective experience, and short-term ocular surface protection. It can serve as an effective correction option for presbyopic populations.
Clinical relevance
In presbyopic adults aged ≥40 years requiring near add power of +0.75 to +2.50 D, is a novel samfilcon A silicone hydrogel multifocal soft contact lens non-inferior to a conventional polymacon hydrogel multifocal soft contact lens in terms of binocular corrected distance and near visual acuity? __SNAPSHOT__ {"studyDesign":"Prospective, randomized, open-label, parallel-group, multicenter non-inferiority clinical trial","setting":"5 tertiary ophthalmology centers in China: Eye Hospital of Wenzhou Medical University; Eye & ENT Hospital of Fudan University; Shenzhen Eye Hospital; Qingdao Eye Hospital of Shandong First Medical University; Shanxi Eye Hospital Affiliated to Shanxi Medical University. Enrollment October 2024 – July 2025.","sampleSize":"195 screened; n=180 enrolled and randomized (test: n=90; control: n=90)","population":"Presbyopic adults aged ≥40 years with near add power of +0.75 to +2.50 D. Additional inclusion/exclusion criteria not reported in the provided abstract.","intervention":"Samfilcon A silicone hydrogel multifocal soft contact lens (monthly disposable, daily wear) — test group (n=90)","comparator":"Polymacon hydrogel multifocal soft contact lens (monthly disposable, daily wear) — control group (n=90)","primaryOutcome":"Binocular corrected distance visual acuity (5 m) and near visual acuity (40 cm), measured using a standard logarithmic visual acuity chart. Additional outcome details not fully reported in the available abstract excerpt.","followUp":"Not reported (abstract is truncated; visit schedule referenced but duration not specified)","fundingSource":"Not reported"}
Key findings
The provided abstract is truncated and does not include any quantitative outcome data (visual acuity values, between-group differences, confidence intervals, p-values, or non-inferiority margins). Therefore, no primary or secondary outcome results, effect sizes, NNT/NNH, or adverse event frequencies can be reported. The study was designed as a non-inferiority trial with a 1:1 randomization ratio comparing samfilcon A silicone hydrogel to polymacon hydrogel multifocal lenses, with binocular distance (5 m) and near (40 cm) visual acuity as the key endpoints. All quantitative findings: not reported in the available abstract.
Practice implications
Because only an incomplete abstract is available — the results, conclusions, and non-inferiority determination are entirely absent from the provided text — no evidence-based inference about the clinical performance of samfilcon A multifocal contact lenses relative to polymacon lenses can be drawn. The study design (multicenter, randomized, non-inferiority, open-label) is methodologically appropriate for a device regulatory evaluation, but open-label conduct introduces the possibility of performance and detection bias, particularly for subjective visual acuity outcomes. The enrolled population (add power +0.75 to +2.50 D) represents early-to-moderate presbyopes; applicability to those requiring higher add powers (>+2.50 D) is untested. Patients with significant ocular surface disease, corneal pathology, or prior refractive surgery were likely excluded, though exclusion criteria are not confirmed in the available excerpt. Practice implications cannot be assessed until full results are published and reviewed. __LIMITATIONS__ Critical limitation: Only a truncated abstract is available; all results, statistical analyses, non-inferiority conclusions, and safety data are absent — the summary is therefore necessarily incomplete.,Open-label design: Neither subjects nor investigators were masked to lens assignment, introducing performance bias and potentially influencing subjective visual acuity assessments.,Non-inferiority margin not reported: The pre-specified non-inferiority threshold, which is fundamental to interpreting the trial's regulatory and clinical conclusion, is not stated in the available text.,Follow-up duration not reported: The absence of follow-up duration precludes assessment of lens performance stability, adverse event accumulation, or long-term safety.,Relatively modest sample size (n=90 per group): Adequacy of power for the non-inferiority conclusion depends on the margin chosen and cannot be assessed without full statistical reporting.,Multicenter open-label study: Inter-site variability in lens fitting, refraction technique, and visual acuity measurement may introduce heterogeneity not captured in the abstract.,Generalizability: Conducted exclusively at Chinese tertiary eye centers; generalizability to community optometry settings and to non-Asian populations is uncertain.,Funding source not reported: Potential industry sponsorship, which could introduce reporting bias, cannot be assessed.,Surrogate endpoints: LogMAR visual acuity at fixed distances is a standard regulatory endpoint but may not fully capture real-world visual function across intermediate distances, contrast conditions, or patient-reported outcomes. __BOTTOM_LINE_CATEGORY__ low_certainty __BOTTOM_LINE__ This prospective, multicenter, randomized non-inferiority trial compared a samfilcon A silicone hydrogel multifocal contact lens to a conventional polymacon hydrogel multifocal lens in 180 presbyopic adults, but the abstract is truncated and no outcome data, non-inferiority margins, or safety results are available for review. Clinicians should await full publication of results before drawing any conclusions about the comparative efficacy or safety of this novel lens material. No change in prescribing practice is warranted based on the currently available information.