Intraocular Straylight and Multifocal Soft Contact Lens Fit With a Myopia Control Approach

OBJECTIVES

Center-distance multifocal contact lenses (MFCLs) are used to slow myopia progression. We examined the effect of two MFCLs on intraocular straylight values in myopic individuals.

METHODS

Twenty-five young myopic adults were enrolled and were fit with three contact lenses (Biofinity sphere, Biofinity Multifocal, and NaturalVue Multifocal) in a random order over two study visits. Pupil size (NeurOptics VIP-300, Laguna Hills, CA) and contact lens centration were measured. Right eye intraocular straylight measurements were collected (OCULUS C-Quant; Wetzlar, Germany) and compared with a spectacle trial lens. Log straylight (LogSL) values and straylight residuals were analyzed using repeated-measures analyses of variance with Tukey-corrected post hoc t -tests.

RESULTS

The mean participant age (±SD) was 24.1±1.5 years, and right eye spherical equivalent refractive error was -3.38±1.53 DS. There was no difference in mesopic pupil size between visits ( P =0.68) and no difference in contact lens centration between lenses ( P =0.99). LogSL values differed by lens type ( P =0.004). LogSL with the spectacle trial lens was significantly greater than with each contact lens type (all P <0.05), but there were no significant differences in LogSL between the three contact lenses (all P >0.05). There was no difference between the three contact lens designs for straylight residuals ( P =0.33).

CONCLUSIONS

Measured intraocular straylight for both MFCLs was not different than with a spherical soft contact lens. A significant increase in intraocular straylight with spectacle trial lens correction was observed compared with all contact lenses.

Contrast Sensitivity with Center-distance Multifocal Soft Contact Lenses

SIGNIFICANCE

The contrast sensitivity (CS) function provides a more detailed assessment of vision than visual acuity. It was found that center-distance multifocal contact lens designs that are increasingly being prescribed for myopia control reduce distance photopic and mesopic CS in nonpresbyopic patients across a range of spatial frequencies.

PURPOSE

This study aimed to determine the effect of center-distance multifocal soft contact lenses (MFCLs) on CS under photopic and mesopic conditions in nonpresbyopic patients.

METHODS

Twenty-five myopic, nonpresbyopic adults were fitted binocularly with three lenses: Biofinity single vision contact lens (SVCL), Biofinity Multifocal D +2.50 add, and NaturalVue Multifocal in random order. Contrast sensitivity was measured at distance (4 m) under photopic and mesopic conditions and at near under photopic conditions. Log CS by spatial frequency and area under the log contrast sensitivity function (AULCSF) were analyzed between lenses.

RESULTS

Distance photopic CS at each spatial frequency was higher with the SVCL than the MFCLs (P < .001), but there was no difference between the MFCLs (P = .71). Distance mesopic CS from 1.5 to 12 cycles per degree (cpd) was higher with the SVCL than the MFCLs (all P < .02); however, at 18 cpd, there was no difference in CS between NaturalVue and the SVCL (P = .76), possibly because of spurious resolution. Photopic AULCSF for the SVCL was roughly 10% greater than both MFCLs. Contrast sensitivity at near was generally similar between lenses, only slightly lower with the NaturalVue at 11 and 15.5 cpd, but AULCSF at near was not different between lenses (P > .05).

CONCLUSIONS

Multifocal contact lenses reduce distance contrast sensitivity under both photopic and mesopic conditions. There is no clinically significant difference in near CS among all three lenses. These data show that MFCLs have effects on vision that are not captured by standard high-contrast visual acuity testing.

Visual Performance of Center-distance Multifocal Contact Lenses Fit Using a Myopia Control Paradigm

PURPOSE

The purpose of this study was to examine the visual performance of center-distance MFCLs in nonpresbyopic adults under different illumination and contrast conditions compared with a single-vision contact lens (SVCL).

METHODS

Twenty-five adult subjects were fit with three different lenses (CooperVision Biofinity D MFCL +2.50 add, Visioneering Technologies NaturalVue MFCL, CooperVision Biofinity sphere). Acuity and reading performance were evaluated.

RESULTS

A statistically significant difference in high-contrast distance acuity was observed (Biofinity, -0.18 ± 0.06; Biofinity MFCL, -0.14 ± 0.08; NaturalVue MFCL, -0.15 ± 0.03; repeated-measures [RM] ANOVA, P = .02). Under mesopic, high-contrast conditions, MFCLs performed worse than SVCLs (Biofinity, -0.05 ± 0.091; Biofinity MFCL, +0.03 ± 0.09; NaturalVue MFCL, +0.05 ± 0.091; RM-ANOVA, P < .0001). Under low-contrast conditions, MFCLs performed one line worse in photopic lighting and two lines worse under mesopic conditions (RM-ANOVA, P < .0001). Glare reduced acuity by 0.5 logMAR for all lenses (RM-ANOVA, P < .001). A statistically significant difference in near acuity was observed (RM-ANOVA, P = .02), but all lenses achieved acuity better than -0.1 logMAR (Biofinity, -0.16 ± 0.06; Biofinity MFCL, -0.17 ± 0.04; NaturalVue MFCL, -0.13 ± 0.08). Reading performance in words per minute (wpm) was worse with MFCLs (Biofinity MFCL, 144 ± 22 wpm; NaturalVue MFCL, 150 ± 28 wpm) than with SVCLs (156 ± 23 wpm; RM-ANOVA, P = .02) regardless of letter size (RM-ANOVA, P = .13). No difference in acuity between the MFCLs was detected (RM-ANOVA: all, P > .05).

CONCLUSIONS

Multifocal contact lenses perform similarly to SVCLs for high-contrast targets and display reduced low-contrast acuity and reading speed. Practitioners should recognize that high-contrast acuity alone does not describe MFCL visual performance.

The use of interviews with surrogate respondents in a case-control study of oral cancer

The purpose of this study was to assess the possible bias that may occur in case-control studies when exposure information is not collected from all potentially eligible cases. The data used in this study were collected in the metropolitan area of Atlanta as part of a multicenter, population-based, case-control study of oropharyngeal cancer. In-person interviews were conducted with 112 cases (67.9 percent) and information on an additional 23 ill or deceased cases (13.9 percent) was collected through surrogate respondents. The cases about whom information was collected from surrogate respondents had more advanced disease at the time of diagnosis and were more likely to be black and less educated than cases who were interviewed in person. Cigarette smoking and consumption of hard liquor were more common among the cases about whom information was collected through surrogates. Therefore, failure to include such information would have resulted in underestimates of the strength of association between these exposures and the risk of oropharyngeal cancer.

Increase in high-grade lymphomas in young men

The relative frequencies of non-Hodgkin's lymphoma (NHL) subtypes and primary sites of presentation in young men before and during the acquired immunodeficiency syndrome epidemic were studied. Diagnostic pathological specimens were reviewed and classified according to the Working Formulation grades for cases of NHL in men aged 20-49 years identified through a population-based cancer registry. 76% of the lymphomas diagnosed in 1981-82 were intermediate or high grade, compared with 29% of those diagnosed in 1976-77. This increase was still significant when men aged 20-39 years and 40-49 years were grouped separately, and for married men. The proportion of extranodal lymphomas diagnosed in men aged 20-39 years also rose significantly from the early to the later period.

Patient attitudes toward physician consent in epidemiologic research

Attitudes of patients toward the necessity of physician consent in epidemiologic studies were assessed. Questionnaires were mailed to women with breast, endometrial and ovarian cancers who had previously participated in a personal interview study (N = 692). Of respondents (N = 514), only 2 per cent would have preferred their physician to have withheld approval, and half considered physician permission necessary. Thirty-five per cent reported that their doctor talked to them about the study prior to the interview. Implications of including physician consent in study protocols are discussed.