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1.
Optom Vis Sci ; 101(4): 195-203, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38684062

ABSTRACT

SIGNIFICANCE: Spatio-Temporal Optical Phase technology utilizes film pairs containing optical elements applied to standard single-vision spectacle lenses. This technology provides a dynamic optical cue that may have efficacy in reducing the rate of myopia progression, but the visual performance of this technology is unknown. PURPOSE: This study aimed to assess the visual performance of film pairs containing optical elements (tests) and a film pair with no optical elements (control). METHODS: In this randomized, single-masked, bilateral wear study, 42 participants aged 18 to 40 years wore four test designs (E, F-1, G, and F-2) and the control. Subjective data (subjective ratings [1 to 10 scale]: clarity of vision [far-away, intermediate, near] and vision [at night, while walking, overall satisfaction], and willingness to purchase [yes/no response]) were collected after 3 days. Visual acuity (VA)-based measures (monocular high/low-contrast VA [6 m], contrast sensitivity [6 m], and binocular high-contrast VA [6 m and 40 cm]) were collected at dispensing. Visual acuity-based measures were also collected while wearing spectacles with no film. Analyses were performed using linear mixed models and the χ2 test. Significance was set at 5%. RESULTS: The control performed better than any test for all subjective ratings (mean differences, 1.6 to 3.1 units: p<0.001), willingness to purchase (p<0.001), and designs F-1 and F-2 for binocular high-contrast VA at 40 cm (p=0.001 and p=0.01, respectively). Clarity of vision was significantly worse with F-2 compared with F-1 and G (p<0.001 and p=0.02, respectively). There were no differences between tests for any other subjective rating (p>0.1), willingness to purchase (p=0.11), or any VA-based measure (p>0.08). There were no differences between control and spectacles with no film for any VA-based measure (p>0.08). CONCLUSIONS: All four test film pairs reduced visual performance compared with control to a degree comparable with other myopia management devices. There was no difference in visual performance between three of the four test film pairs.


Subject(s)
Eyeglasses , Visual Acuity , Humans , Adult , Visual Acuity/physiology , Young Adult , Female , Male , Adolescent , Contrast Sensitivity/physiology , Myopia/physiopathology , Myopia/therapy , Single-Blind Method , Vision, Binocular/physiology , Equipment Design , Refraction, Ocular/physiology
2.
Eye Contact Lens ; 49(2): 63-70, 2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36282205

ABSTRACT

OBJECTIVES: The objective of this study was to compare the visual performance and binocular/accommodative function of two novel S.T.O.P. design (F2 and DT) contact lenses against MiSight when worn by myopic, young adults. METHOD: This was a prospective, randomized, cross-over, single-masked study. Each lens was worn daily wear with overnight peroxide disinfection for approximately 7 days. Visual performance was assessed with subjective ratings (0-100): clarity of vision and lack of ghosting (far away, intermediate, and near), vision when driving, overall vision satisfaction, and with monocular high-contrast and low-contrast visual acuity (HCVA/LCVA) at 6 m, binocular HCVA (6 m, 70 cm, 50 cm, and 40 cm), binocular LCVA (6 m and 70 cm). Binocular function was assessed with heterophorias (3 m and 40 cm). Accommodative function was assessed with monocular accommodative facility (AF: 40 cm) and dynamic monocular accommodative response (AR: 6 m, 70 cm, and 40 cm). RESULTS: F2 was rated higher than MiSight for clarity of vision (near and intermediate) and lack-of-ghosting ( P <0.001), while MiSight was rated higher than DT for clarity of vision (near, P <0.001). MiSight was better than F2 and DT for monocular HCVA (6 m) and binocular HCVA (6 m and 40 cm, P ≤0.02), but the maximum difference was ≤2 letters. There were no differences between designs for heterophoria ( P =0.61) nor were there any differences between DT and MiSight for any accommodative measure ( P >0.1). F2 was higher for monocular-AF ( P =0.007) and lower for AR (70 cm and 40 cm; P ≤0.007) compared with MiSight. CONCLUSIONS: The visual performance and binocular/accommodative function of S.T.O.P. designs F2 and DT were comparable with MiSight. F2 outperformed MiSight in some aspects of subjective visual performance and monocular accommodative function.


Subject(s)
Contact Lenses, Hydrophilic , Presbyopia , Young Adult , Humans , Visual Acuity , Prospective Studies , Accommodation, Ocular , Vision, Binocular/physiology
3.
Clin Exp Optom ; 104(1): 107-114, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32924191

ABSTRACT

CLINICAL RELEVANCE: Diagnosis and monitoring of keratoconus is increasingly being conducted with the aid of imaging equipment such as corneal aberrometry. There is a need to also know the confidence with which ocular aberration measurements can be made. BACKGROUND: To assess the repeatability of lower- and higher-order aberration measurements in patients with keratoconus using the irx3 wavefront aberrometer (Imagine Eyes, Orsay, France) and evaluate correlations with corneal curvature. METHODS: The irx3 wavefront aberrometer was used to measure bilateral lower- and higher-order ocular aberrations on 33 participants with keratoconus. Three measurements were taken from each eye to determine the repeatability of lower-order aberrations (quantified as sphere and cylinder in dioptres) and higher-order aberration co-efficients (up to eighth order in micrometres), coma, trefoil and total higher-order aberration root mean square (in micrometres). Corneal curvature was measured using the Pentacam HR system (OCULUS, Wetzlar, Germany). RESULTS: Repeat measurements for lower-order aberrations resulted in larger co-efficients of repeatability than higher-order aberrations. Similarly, larger co-efficients of repeatability between repeated measures across all Zernike co-efficients were observed in eyes with severe keratoconus (that is, corneal curvature > 52-D) compared to eyes with flatter corneas. The difference between repeated measures tended to be significant for the lower-order aberrations regardless of corneal curvature. The highest correlations with corneal curvature for right and left eyes respectively, were identified for total higher-order aberration root mean square (r = 0.92, p < 0.001 and r = 0.91, p < 0.001), followed closely by coma (r = -0.93, p < 0.001 and r = -0.86, p < 0.001) and the Z (3, -1) co-efficient (r = -0.92, p < 0.001 and r = -0.86, p < 0.001 for right and left eyes, respectively). CONCLUSIONS: Lower-order aberrations tended to be less repeatable, indicating that instrument variability must be considered when monitoring progression. Total higher-order aberration root mean square and third-order aberrations, in particular the vertical coma Z (3, -1) co-efficient, demonstrated a stronger correlation with corneal curvature than the lower-order aberrations.


Subject(s)
Corneal Wavefront Aberration , Keratoconus , Corneal Topography , Corneal Wavefront Aberration/diagnosis , Homeodomain Proteins , Humans , Keratoconus/diagnosis , Prospective Studies , Reproducibility of Results , Transcription Factors
4.
Clin Exp Optom ; 103(6): 756-765, 2020 11.
Article in English | MEDLINE | ID: mdl-32227385

ABSTRACT

Myopia, and especially high myopia, is associated with a number of posterior segment changes that are considered to be mostly a consequence of the increased axial elongation. This can result in mechanical strain, attendant vascular changes, stretching and thinning of tissues, and atrophy/deformation of tissues in later or more advanced stages. Such myopia-related changes are observed as changes and/or abnormalities in the vitreous, choroid, retina and peripheral retina, sclera and/or optic disc. Although many of these changes are benign, at times they may be associated with significant vision impairment that either requires active intervention or may suggest future progression of the disease. This review systematically addresses the posterior segment conditions seen in myopic eyes, describes the features associated with the condition and details management pathways.


Subject(s)
Myopia , Optic Disk , Choroid , Humans , Retina , Sclera
5.
J. optom. (Internet) ; 13(1): 15-28, ene.-mar. 2020. tab, graf
Article in English | IBECS | ID: ibc-195304

ABSTRACT

PURPOSE: To compare the peripheral refraction and spherical aberration profiles along three visual field meridians of 16 commercial single vision (SV), bifocal (BF) and multifocal (MF) test contact lenses with a single vision control. METHOD: Forty-four participants [24.2 ± 2.4 years, SE: -0.50 to -4.50D] were randomly fitted, contra-laterally, with 6 SV's [Air Optix Aqua (control), Acuvue Oasys, Biofinity, Clariti, Night & Day and Proclear], 3 BF's [Acuvue Bifocal low and high add, MiSight] and 8 MF's [Proclear D & N in 1.5 and 2.5D adds; AirOptix, PureVision low & high adds]. Peripheral refraction was performed across horizontal, oblique and vertical meridians, with lenses on eye using the BHVI-EyeMapper. The power vectors M, J0, J45 and the spherical aberration coefficient were analysed. The peripheral refraction and aberration profiles of the test lenses were compared with the profiles of the control lens using curvature and slope coefficients. RESULTS: Compared to the control, a relative peripheral hyperopic shift (M), a less negative J0 curvature coefficient along the horizontal meridian, a less positive J0 curvature coefficient along the vertical meridian, a less negative J45 curvature coefficient along the oblique meridian and a more positive spherical aberration curvature coefficient along most meridians was seen with the Acuvue Bifocal and all center-near multifocal lenses. For the center-distance multifocal lenses the direction of the curvature coefficients of the same refraction and aberration components was opposite to that of the center-near lenses. The greatest differences in the slope coefficients when compared to the control were found for the Acuvue Bifocal lenses and all multifocal contact lenses for the refractive component M and the spherical aberration coefficient along the horizontal visual field meridian, with the Acuvue Bifocal and the center-near multifocal lenses having more positive coefficients and the center-distance lenses having more negative coefficients. CONCLUSION: When worn on eye, different commercially available lens types produce differences in the direction and magnitude of the peripheral refraction and spherical aberration profiles along different visual field meridians. This information may be relevant to refractive development and myopia control


OBJETIVO: Comparar los perfiles de refracción periférica y aberración esférica en tres meridianos del campo visual de 16 lentes de contacto (LC) comerciales de prueba monofocales (VS), bifocales (BF) y multifocales (MF), con control de visión simple. MÉTODO: Colocamos aleatoria y contralateralmente a cuarenta participantes [44,2 ± 2,4 años, SE: -0,5 a -4,5 D]: 6 LC monofocales [Air Optix Aqua (control), Acuvue Oasys, Biofinity, Clariti, Night & Day y Proclear], 3 bifocales [Acuvue Bifocal con adición baja y alta, MiSight] y 8 MF [Proclear D & N con adición de 1,5 y 2,5D; AirOptix, PureVision con adición baja y alta]. Realizamos la refracción periférica en los meridianos horizontal, oblicuo y vertical, con lentillas en un ojo utilizando el BHVI-EyeMapper. Se analizaron los vectores de potencia M, J0, J45 y el coeficiente de aberración esférica. Se compararon los perfiles de refracción periférica y aberración esférica de las LC de prueba con los perfiles de las LC de control utilizando los coeficientes de curvatura y pendiente. RESULTADOS: En comparación con el control, observamos un cambio hiperópico periférico relativo (M), un coeficiente de curvatura J0 menos negativo en el meridiano horizontal, un coeficiente de curvatura J0 menos positivo en el meridiano vertical, un coeficiente de curvatura J45 menos negativo en el meridiano oblicuo, y un coeficiente de curvatura de aberración esférica más positivo en la mayoría de meridianos con las lentillas Acuvue Bifocal y todas las lentillas multifocales de diseño centro-cerca. Para las lentillas multifocales centro-lejos la dirección de los coeficientes de curvatura de los mismos componentes de refracción y aberración fue opuesta a la de las lentillas centro-cerca. Las mayores diferencias en cuanto a coeficientes de pendiente, al compararse con el control, se encontraron en las lentillas Acuvue Bifocal y en todas las lentillas multifocales para el componente refractivo M y el coeficiente de aberración esférica en el meridiano del campo visual horizontal, siendo las lentillas Acuvue Bifocal y las multifocales centro-cerca las que mostraron más coeficientes positivos, y las lentillas centro-lejos las que reflejaron más coeficientes negativos. CONCLUSIÓN: Al colocarse en un solo ojo, las diferentes lentillas comerciales producen diferencias en cuanto a dirección y magnitud de los perfiles de refracción periférica y aberración esférica en los diferentes meridianos del campo visual. Esta información puede ser relevante para el desarrollo refractivo y el control de la miopía


Subject(s)
Humans , Adolescent , Young Adult , Adult , Contact Lenses, Hydrophilic , Corneal Wavefront Aberration/physiopathology , Myopia/therapy , Refraction, Ocular/physiology , Visual Fields/physiology , Prospective Studies , Cross-Over Studies , Double-Blind Method , Equipment Design , Myopia/physiopathology , Visual Acuity/physiology
6.
J Optom ; 13(1): 15-28, 2020.
Article in English | MEDLINE | ID: mdl-30772211

ABSTRACT

PURPOSE: To compare the peripheral refraction and spherical aberration profiles along three visual field meridians of 16 commercial single vision (SV), bifocal (BF) and multifocal (MF) test contact lenses with a single vision control. METHOD: Forty-four participants [24.2±2.4 years, SE: -0.50 to -4.50D] were randomly fitted, contra-laterally, with 6 SV's [Air Optix Aqua (control), Acuvue Oasys, Biofinity, Clariti, Night & Day and Proclear], 3 BF's [Acuvue Bifocal low and high add, MiSight] and 8 MF's [Proclear D & N in 1.5 and 2.5D adds; AirOptix, PureVision low & high adds]. Peripheral refraction was performed across horizontal, oblique and vertical meridians, with lenses on eye using the BHVI-EyeMapper. The power vectors M, J0, J45 and the spherical aberration coefficient were analysed. The peripheral refraction and aberration profiles of the test lenses were compared with the profiles of the control lens using curvature and slope coefficients. RESULTS: Compared to the control, a relative peripheral hyperopic shift (M), a less negative J0 curvature coefficient along the horizontal meridian, a less positive J0 curvature coefficient along the vertical meridian, a less negative J45 curvature coefficient along the oblique meridian and a more positive spherical aberration curvature coefficient along most meridians was seen with the Acuvue Bifocal and all center-near multifocal lenses. For the center-distance multifocal lenses the direction of the curvature coefficients of the same refraction and aberration components was opposite to that of the center-near lenses. The greatest differences in the slope coefficients when compared to the control were found for the Acuvue Bifocal lenses and all multifocal contact lenses for the refractive component M and the spherical aberration coefficient along the horizontal visual field meridian, with the Acuvue Bifocal and the center-near multifocal lenses having more positive coefficients and the center-distance lenses having more negative coefficients. CONCLUSION: When worn on eye, different commercially available lens types produce differences in the direction and magnitude of the peripheral refraction and spherical aberration profiles along different visual field meridians. This information may be relevant to refractive development and myopia control.


Subject(s)
Contact Lenses, Hydrophilic , Corneal Wavefront Aberration/physiopathology , Myopia/therapy , Refraction, Ocular/physiology , Visual Fields/physiology , Adolescent , Adult , Cross-Over Studies , Double-Blind Method , Equipment Design , Humans , Myopia/physiopathology , Prospective Studies , Visual Acuity/physiology , Young Adult
7.
Clin Exp Optom ; 102(4): 378-384, 2019 07.
Article in English | MEDLINE | ID: mdl-30091794

ABSTRACT

The appearance of tessellated fundus in an eye may act as a marker in identifying visual performance, degree of myopia or risk of progression of myopia in a given eye. A systematic literature search using key words was performed using PubMed, Web of Science and Google Scholar and of the 832 studies identified, 10 full-length articles, which met the inclusion criteria, were considered for review. The primary outcome measures were association of tessellated fundus with: (i) visual acuity, (ii) refractive error, (iii) axial length, (iv) choroidal thickness and (v) future progression of myopia when compared to either no myopic maculopathy, or more severe myopic maculopathy. There was no significant difference in the visual acuity noted between eyes with normal fundus and tessellated fundus appearance. Compared to eyes with tessellated fundus, eyes with more severe myopic maculopathy had a four-line decrease in best-corrected visual acuity, more myopia (mean difference 2.75 D, range 0.28-5.78 D) and a longer axial length (mean difference 2 mm, range 2.29 to 1.71 mm). Eyes with tessellated fundus generally exhibited a significant decrease in choroidal thickness compared to eyes with no maculopathy. In mostly older individuals, eyes with tessellated fundus had a better outcome with respect to visual acuity, degree of myopia and axial length compared to other severe myopic maculopathies, but had a worse outcome for choroidal thickness and degree of myopia, compared to eyes with no myopic maculopathy. The features such as reduced choroidal thickness combined with a predilection to infra-temporal and parapapillary regions may indicate regions of stress that are prone to more stretching/atrophic changes. This systematic review demonstrated an association of tessellated fundus with visual acuity, refractive error, axial length and choroidal thickness and hence emphasises the documentation of the presence and location of tessellated fundus appearance that may help in predicting the progression of myopia.


Subject(s)
Axial Length, Eye/pathology , Choroid Diseases/diagnosis , Fundus Oculi , Myopia/diagnosis , Retinal Diseases/diagnosis , Choroid Diseases/physiopathology , Humans , Myopia/physiopathology , Retinal Diseases/physiopathology , Visual Acuity/physiology
8.
Clin Optom (Auckl) ; 10: 75-86, 2018.
Article in English | MEDLINE | ID: mdl-30319298

ABSTRACT

PURPOSE: To compare the visual performance of soft contact lenses reported to reduce myopia progression. METHODS: In a double-blind, randomized, crossover trial, 30 non-presbyopic myopes wore MiSight™, center-distance Proclear® Multifocal (+2.00 D add), and two prototype lenses for 1 week each. High- and low-contrast visual acuities at 6 m, and 70 and 40 cm; stereopsis at 40 cm; accommodative facility at 33 cm; and horizontal phoria at 3 m and 33 cm were measured after 1 week. Subjective performance was assessed on a numeric rating scale for vision clarity, lack of ghosting, vision stability, haloes, overall vision satisfaction, and ocular comfort. Frequency of eye-strain symptoms and willingness to purchase lenses were also reported with categorical responses. Participants reported wearing times (total and visually acceptable). Linear mixed models and chi-square tests were employed in analysis with level of significance set at 5%. Theoretical optical performance of all lenses was assessed with schematic myopic model eyes (-1.00, -3.00, and -6.00 D) by comparing the slope of the edge spread function (ESF), an indicator for optical performance/resolution and the blur patch size of the line spread function, an indicator for contrast, between the lenses. RESULTS: Proclear Multifocal and MiSight provided the best distance acuities. However, the prototype lenses were rated significantly higher for many subjective variables, and there were no subjective variables where commercial lenses were rated significantly higher than the prototypes. Theoretical optical performance showed steeper slopes of the ESF and greater blur patch sizes of the LSP with commercial lenses, supporting the clinical findings of better visual acuities but reduced subjective performance. Participants wore prototypes longer and reported their vision acceptable for longer each day compared to MiSight. Both prototypes had the highest willingness-to-purchase rate. CONCLUSIONS: The prototypes were better tolerated by myopes compared to the commercial soft contact lenses currently used for slowing myopia progression.

9.
Clin Optom (Auckl) ; 10: 9-17, 2018.
Article in English | MEDLINE | ID: mdl-30214337

ABSTRACT

OBJECTIVE: The study aimed to compare the visual performance of contact lenses with and without negative spherical aberration (SA) over 5 days of wear. METHODS: At baseline, 32 myopic participants (aged 18-33 years) were fitted in a randomized order with two lenses (test lens with minimal or no SA and 1-Day Acuvue Moist designed with negative SA) for 5 days (minimum 6 hours wear/day). Participants returned for a follow-up visit. This consisted of on-axis SA measurements; high- and low-contrast visual acuities at 6 m; high-contrast acuities at 70 and 40 cm; low-illumination, low-contrast acuity at 6 m; stereopsis at 40 cm; horizontal phorias at 3 m and 33 cm; and ±2.00 D monocular accommodative facility at 33 cm. Participants also rated (1-10 scale) vision quality (clarity and lack of ghosting for distance, intermediate, near, driving vision and vision stability during day- and night-time), overall vision satisfaction, ocular comfort, and willingness to purchase (yes/no response). RESULTS: 1-Day Acuvue Moist induced significantly (p<0.05) more negative SA at distance (Δ=0.078 µm) and near (Δ=0.064 µm) compared to the test lens, for a 6 mm pupil. There were no significant differences (p>0.05) in acuity, binocular vision, and all subjective metrics except vision stability between lenses where the test lens was rated to provide more stable vision (p<0.05). CONCLUSION: Contrary to expectations, incorporating negative SA in single vision soft contact lenses did not improve visual performance in non-presbyopic adult myopes.

10.
Eye Contact Lens ; 44 Suppl 1: S30-S37, 2018 Sep.
Article in English | MEDLINE | ID: mdl-27341089

ABSTRACT

OBJECTIVES: To investigate whether adaptation of accommodative responses occurred in non-presbyopic myopes fitted with four multifocal contact lens (MFCL) designs. METHODS: Prospective, subject-masked clinical investigation comprising 40 experienced myopic lens wearers (18-25 years) fitted bilaterally with single-vision (SV) control lens (Air Optix Aqua [Alcon, Fort Worth, TX]) and randomized to two of four test MFCL (Proclear MFCL [Distance and Near] [CooperVision, Pleasanton, CA], Air Optix Aqua MFCL, Purevision MFCL [Bausch & Lomb, Rochester, NY]). Lenses were dispensed on a daily wear basis and worn for a minimum of 8 (maximum 14) days over three assessment visits, with a 1-week wash out between stages. Paraxial curvature matched spherical equivalent (M) was measured with lenses on eye using the BHVI-EyeMapper with an internal movable fixation target positioned at target vergences of +1.00 diopter (D) (fogging) and -2.00 to -5.00 in 1.00 D steps (accommodative stimuli). Accommodative facility was assessed by several flips of ±2.00 D/min (cycles/min) at 33 cm and horizontal phoria with a Howell phoria card at distance (3 m) and near (33 cm). RESULTS: For center-distance MFCL (Proclear D), the spherical equivalent (M) at all near vergences became significantly more negative at the follow-up visits compared with the dispensing visit (P<0.029). For all center-near MFCLs and SV lens, M remained invariant during the adaptation period, however (P≥0.267). At distance, M became significantly less minus with Air Optix Aqua MFCL over time (P=0.049). Accommodative facility increased over the three assessment visits for participants wearing Air Optix Aqua SV, Air Optix Aqua MFCL, and PureVision MFCL (P=0.003). Distance and near horizontal phoria remained stable over the three assessment visits for all lens types (P≥0.181). CONCLUSIONS: Adaptation differences were not consistently found for static accommodative measures gauged by M, as measured with lenses on eye, and phoria but were found in dynamic measures (facility), perhaps indicating some learning effects. Accommodative adaptation seems unlikely to occur with long-term MFCL in non-presbyopes.


Subject(s)
Accommodation, Ocular/physiology , Contact Lenses, Hydrophilic , Myopia/rehabilitation , Adult , Cross-Over Studies , Female , Humans , Male , Myopia/physiopathology , Prospective Studies , Visual Acuity/physiology , Young Adult
11.
Optom Vis Sci ; 94(9): 876-885, 2017 09.
Article in English | MEDLINE | ID: mdl-28816867

ABSTRACT

SIGNIFICANCE: The amount of central or peripheral myopic shift, as induced by different multifocal contact lenses when viewing objects at distance or near, may provide insights on the potential efficacy for slowing eye growth. PURPOSE: The present study aims to compare peripheral refraction and higher-order aberration profiles of four multifocal contact lenses with a single vision control lens. METHODS: Thirty-five myopes (age 21.2 ± 2.1 years) completed the trial, of whom 16 wore Air Optix Aqua and Proclear Multifocal Distance and Near (Group 1, spherical equivalent: -2.90 ± 0.95D), whereas 19 wore Air Optix Aqua, Air Optix Multifocal, and PureVision Multifocal (Group 2, spherical equivalent: -2.95 ± 0.78D). Refraction and aberration profiles with lenses were measured using the BHVI-EyeMapper with (-2.00 to -5.00D in 1.00D steps) and without (+1.00D fogging) accommodation. Data were quantified using M2/4 (2nd and 2nd + 4th order), J0, J45, and higher-order aberration coefficients coma C[3, 1] and spherical aberration C[4, 0]. RESULTS: The center-distance lens exhibited a relative peripheral myopic shift in M2/4 and J0, positive on-axis C[4, 0], negative on-axis C[3, 1] and on-axis M4 was less negative for accommodative demands ≤-3.00D (P < .05). Inversely, the center-near lenses showed a relative peripheral hyperopic shift in M2/4 and J0, negative on-axis C[4, 0], positive on-axis C[3, 1] and on-axis M4 was more negative for demands of -2.00 and -3.00D (P < .05). Independent of lens type, relative peripheral M4 significantly decreased during accommodation. Accounting for C[4, 0], a greater change in relative M profiles and accommodative responses was found for multifocal lenses. CONCLUSIONS: Based on the hypothesis that myopic retinal defocus counters eye growth, center-near multifocal lenses exhibited the preferred on-axis features, i.e., producing a central myopic shift at near compared to the control. The center-distance lens exhibited preferred off-axis features, producing relative peripheral myopia, which increased further during accommodation.


Subject(s)
Accommodation, Ocular/physiology , Contact Lenses , Myopia/therapy , Refraction, Ocular/physiology , Aberrometry , Adolescent , Adult , Equipment Design , Female , Humans , Male , Myopia/physiopathology , Prospective Studies , Single-Blind Method , Vision Tests , Visual Acuity , Young Adult
12.
Optom Vis Sci ; 94(2): 197-207, 2017 02.
Article in English | MEDLINE | ID: mdl-27879499

ABSTRACT

PURPOSE: To investigate the impact of the primary (PSA) and secondary (SSA) spherical aberration terms on visual performance (VP) in presbyopes, as measured using multifocal (MFCL) soft contact lenses on eye. METHODS: Seventeen presbyopes (age: 55.1 ± 6.9 years) wore seven commercial lenses (four center-near (MFCL N), one center-distance (MFCL D), one bifocal, and one single vision control). Unaided and with each lens on eye, the PSA and SSA terms were obtained with an aberrometer, the BHVI-EyeMapper (low illumination, natural and 4 mm pupil diameter). High- and low-contrast distance visual acuity, contrast sensitivity, high-contrast visual acuities at near, and range of clear vision were measured. In addition, subjective VP variables included clarity of vision at distance and near, ghosting, and overall vision satisfaction. Pearson's correlation was used to determine the association between the PSA and SSA terms and the VP variables. RESULTS: PSA (natural pupil) was more negative (P < .05) with the MFCL N (mean PSA = -0.053 ± 0.080 µm) and bifocal (PSA = +0.005 ± 0.067 µm) lenses and more positive with the MFCL D lens (PSA = +0.208 ± 0.160 µm) than the control (+0.067 ± 0.072 µm). SSA (natural pupil) was significantly more positive for the MFCL N lenses (mean SSA = +0.025 ± 0.029 µm) compared to the control (SSA = -0.001 ± 0.017 µm). PSA and SSA terms were significantly (P < .05) correlated with 78% and 56% of VP variables, respectively, but the correlation coefficients were weak, ranging between |0.210| and |0.334|. Although distance variables showed improved VP with more positive PSA or negative SSA, most near variables showed improved VP with more negative PSA. Range of clear focus was greater for more negative PSA terms. CONCLUSIONS: The amount and direction of PSA and SSA terms, as measured with different MFCLs on eye, can affect VP at different distances. Results of this study may provide useful information when designing new or optimize existing MFCLs for improved VP at specific distances.


Subject(s)
Contact Lenses, Hydrophilic , Presbyopia/therapy , Visual Acuity/physiology , Aberrometry , Adult , Cross-Over Studies , Female , Humans , Lighting , Male , Middle Aged , Presbyopia/physiopathology , Prospective Studies , Pupil/physiology
13.
J. optom. (Internet) ; 9(1): 5-12, ene.-mar. 2016. ilus, tab, graf
Article in English | IBECS | ID: ibc-146176

ABSTRACT

Purpose: To determine if a fogging lens ameliorates accommodative effects driven by the closed-view design of the BHVI-EyeMapper (EM) instrument. We compared cycloplegic refraction and higher-order aberration measurements of the EM with those obtained with a fogging lens. Methods: Twenty-six, young, participants (15F, 25 ± 5 years, range: 18---35 years, SE: +0.25 D and −3.50 D) with good ocular health were recruited. Five independent measurements of on- and off-axis refraction and higher-order aberrations were recorded across the horizontal visual field, under two conditions: non-cycloplegic measurements with +1.00 D fogging lens and cycloplegia, always in the same sequence. The contralateral eye was occluded during the measurements. Two drops of 1% Tropicamide delivered within 5 min facilitated cycloplegic measurements. All participants were refracted 30 min after installation of the second drop. Results: Mean spherical equivalent measures of the non-cycloplegic condition were significantly more myopic than their cycloplegic counterparts (p < 0.05); approximately by 0.50 D centrally, increasing to 1.00 D towards the periphery. The horizontal astigmatic component, J180, demonstrated small but statistically significant differences between the test conditions. Differences were predominant for eccentricities greater than 30◦, in both nasal and temporal meridians. The oblique astigmatic component, J45, was not significantly different between the test conditions. The primary spherical aberration coefficient C(4, 0) was significantly less positive for the non-cycloplegic state than its cycloplegic counterpart. This result held true across the entire horizontal visual field. The horizontal coma and trefoil coefficients C (3, 1) and C(3, 3) were not significantly different between the two conditions. Conclusions: The use of +1.00 D fogging lens without cycloplegia did not provide complete relaxation of accommodation. The discrepancies between cycloplegic and non-cycloplegic EM measurements were found to be more pronounced for peripheral field angles than central measures, for both M and J180 components (AU)


Objetivo: Determinar si una lente de miopización (fogging) mejora los efectos de acomodación impulsados por el diseño de campo cerrado del dispositivo BHVI-EyeMapper (EM). Comparamos las mediciones de la refracción ciclopéjica y las aberraciones de alto orden realizadas por el EM, con las obtenidas con una lente de miopización. Métodos: Se reunió a veintiséis participantes jóvenes (15M, 25 ± 5 años, rango: 18-35 años, ES: +0,25 D y −3,50 D) con buena salud ocular. Se registraron cinco mediciones independientes de la refracción dentro y fuera de eje y de las aberraciones de alto orden a lo largo del campo visual, bajo dos situaciones diferentes: mediciones no ciclopéjicas con una lente de miopización de +1,00 D, y mediciones ciclopéjicas, siempre en la misma secuencia. El ojo contralateral fue ocluido durante la realización de las mediciones. La administración de dos gotas de Tropicamida 1%, en un plazo de cinco minutos, facilitó las mediciones ciclopéjicas. Todos los participantes fueron sometidos a refracción a los treinta minutos de la instilación de la segunda gota. Resultados: Las mediciones del equivalente esférico de la situación no ciclopéjica reflejaron una miopía más considerable que las ciclopéjicas (p < 0,05); aproximadamente de 0,50 D centrales, incrementándose a 1,00 D hacia la periferia. El componente astigmático horizontal, J180, reflejó unas pequeñas diferencias, aunque estadísticamente significativas, entre las dos situaciones de la prueba. Las diferencias fueron predominantes para excentricidades superiores a 30◦, tanto en los meridianos nasales como en los temporales. El componente astigmático oblicuo, J45, no reflejó una diferencia significativa entre ambas situaciones. El coeficiente de la aberración esférica primaria C (4, 0) fue considerablemente menos positivo en las situaciones no ciclopéjicas que en las ciclopéjicas. Este resultado mantuvo su validez a lo largo de todo el campo visual horizontal. Los coeficientes del coma horizontal y trefoil C(3, 1) y C(3, 3) no reflejaron una diferencia significativa entre ambas situaciones. Conclusiones: El uso de una lente de miopización de +1,00 D, sin ciclopejía, no aporta una relajación completa de la acomodación. Las discrepancias entre las mediciones del dispositivo EM, con y sin ciclopejia, se revelaron más pronunciadas para los ángulos de campo periféricos que para los centrales, para ambos componentes M y J180 (AU)


Subject(s)
Humans , Refraction, Ocular/physiology , Ophthalmoplegia/rehabilitation , Refractive Errors/rehabilitation , Lenses , Optometry/methods , Accommodation, Ocular/physiology , Reference Values
14.
Clin Optom (Auckl) ; 8: 37-46, 2016.
Article in English | MEDLINE | ID: mdl-30214347

ABSTRACT

PURPOSE: Multifocal soft contact lenses (MFCLs) have been proposed and used for controlling the rate of myopia progression; however, little is known on the performance and adaptation with MFCLs in non-presbyopes. This study aims to evaluate the visual performance of four commercially available MFCLs in non-presbyopic myopic eyes during an adaptation period. METHODS: Fifty-two experienced myopic contact lens wearers (67% female; mean age 21.4±2.0 years) were enrolled in this trial and 40 completed the trial. Twenty-six participants (Group 1) wore Lotrafilcon B single vision (SV, control), Omafilcon A MFCL center-distance (D) and center-near (N) and the other 26 participants (Group 2) wore Lotrafilcon B SV, Lotrafilcon B MFCL N, and Balafilcon A MFCL N. Lens order was randomized. Participants wore each allocated lens for a minimum of 8 days over four scheduled visits (dispensing and three follow-up visits) with a 1-week washout period between the lens types. At each visit, high-contrast visual acuity (HCVA) (in logarithm of the minimum angle of resolution [logMAR]) and seven subjective performance variables (via questionnaire) were obtained. Power profiles of each lens type, pupil size, and contact lens centration, with lens placed on the eye, were measured. RESULTS: The SV control outperformed the MFCLs in all variables (P<0.05). There were no significant differences in HCVA over time, with the exception of monocular HCVA with Omafilcon A MFCL N, which at the end of the adaptation period had significantly (P<0.05) improved by 0.10 logMAR. No differences were found between visits for any subjective variables. Subjectively, Lotrafilcon B MFCL N performed best and was the only lens that did not decenter significantly compared to the SV control. Conversely, Omafilcon A MFCL N was the worst performing and most decentered lens (P<0.05, y=-0.39 mm), with the greatest plus area under the power profile. CONCLUSION: MFCLs with greatest power variation across the optic zone, a greater plus area under the distance labeled power profile, and/or lenses that were significantly decentered resulted in the lowest subjective ratings. Over time, quality of vision with MFCLs did not change in non-presbyopic myopic participants, with the exception of Omafilcon A MFCL N, which showed some adaptation effects.

15.
Clin Optom (Auckl) ; 8: 57-69, 2016.
Article in English | MEDLINE | ID: mdl-30214350

ABSTRACT

PURPOSE: The aim of this study was to assess the association between decentration of several commercial multifocal soft contact lenses (MFCLs) and various objective and subjective visual performance variables in presbyopic and non-presbyopic participants. MATERIALS AND METHODS: All presbyopic (age >40 years, near add ≥+1.25 D) and non-presbyopic (age ≥18 years, no near add requirements, spherical equivalent ≤-0.50 D) participants were each fitted bilaterally with six and two MFCLs (test lens), respectively, and with one single vision lens (control lens). Lens decentration, ie, the x- and y-differences between the contact lens and pupil centers, was objectively determined. Third-order aberrations were measured and compared. Visual performance (high- and low-contrast acuities and several subjective variables) was analyzed for any associations (Pearson's correlation, r) with MFCL decentration. RESULTS: A total of 17 presbyopic (55.1±6.9 years) and eight non-presbyopic (31.0±3.3 years) participants completed the study. All lenses displayed a temporal-inferior decentration (x=-0.36±0.29 mm, y=-0.28±0.28 mm, mean ± SD). Compared to the control, a significant inferior decentration was found for the Proclear® MFCL Near lens in both groups (ypresbyopic =-0.26 mm, ynon-presbyopic =-0.70 mm) and for the Proclear® MFCL Distance lens in the non-presbyopic group (ynon-presbyopic =-0.69 mm). In both groups, lens-induced vertical coma (C(3, -1)) was, by at least tenfold, significantly more positive for the Proclear® MFCL Distance lens and significantly more negative for the Proclear® MFCL Near lens. In the presbyopic group, the correlation of total MFCL decentration with vision variables was weak (r<|0.191|). Conversely, a moderate but significant correlation with total MFCL decentration was found in the non-presbyopic group for most of the vision variables, indicating a decrease in vision as decentration increased. CONCLUSION: Certain MFCLs decentered more than others; the same lens designs also induced significant amounts of third-order aberrations. An association between MFCL decentration and seven out of nine vision variables was found in the non-presbyopic group, ie, the group where lenses were most decentered, which had larger pupils and lower levels of inherent third-order aberrations.

16.
Cont Lens Anterior Eye ; 39(1): 38-46, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26228543

ABSTRACT

PURPOSE: To assess visual performance of single vision and multifocal soft contact lenses. METHODS: At baseline, forty-four myopic participants (aged 18-35 years) were fitted bilaterally with a control lens (AirOptix Aqua). At the four follow-up visits, a total of 16 study lenses (5 single vision, 11 multifocal lenses) were fitted contralaterally. After 1h of lens wear, participants rated (scale 1-10) vision clarity (distance, intermediate and near), magnitude of ghosting at distance, comfort during head movement, and overall comfort. Distance high contrast visual acuity (HCVA), central refraction and higher order aberrations, and contact lens centration were measured. RESULTS: For single vision lenses, vision ratings were not significantly different to the control (p>0.005). The control outperformed Acuvue Oasys, Clariti Monthly and Night and Day in HCVA (mean VA: -0.10 ± 0.07 logMAR, p<0.005). Most refraction and higher order aberration measures were not different between lenses. The Night and Day lens showed greatest differences compared to the control, i.e., C[4, 0] was more positive (p<0.005) at distance (Δ=0.019 µm) and near (Δ=0.028 µm). For multifocal lenses, the majority of vision ratings (84%) were better with the control (p<0.005). HCVA was better with the control (p<0.005). Proclear Multifocal lenses showed greatest differences for M, C[3, -1] and C[4, 0] at distance and near, and were inferiorly de-centered (p<0.005). CONCLUSION: Design differences between single vision lenses had a small impact on visual performance. Lenses featuring multifocality decreased visual performance, in particular when power variations across the optic zone were large and/or the lens was significantly de-centered.


Subject(s)
Contact Lenses, Hydrophilic , Contrast Sensitivity/physiology , Myopia/physiopathology , Visual Acuity/physiology , Adolescent , Adult , Equipment Design , Female , Humans , Male , Myopia/therapy , Presbyopia , Prospective Studies , Vision Tests , Young Adult
17.
J Optom ; 9(1): 5-12, 2016.
Article in English | MEDLINE | ID: mdl-26190684

ABSTRACT

PURPOSE: To determine if a fogging lens ameliorates accommodative effects driven by the closed-view design of the BHVI-EyeMapper (EM) instrument. We compared cycloplegic refraction and higher-order aberration measurements of the EM with those obtained with a fogging lens. METHODS: Twenty-six, young, participants (15F, 25±5 years, range: 18-35 years, SE: +0.25 D and -3.50 D) with good ocular health were recruited. Five independent measurements of on- and off-axis refraction and higher-order aberrations were recorded across the horizontal visual field, under two conditions: non-cycloplegic measurements with +1.00 D fogging lens and cycloplegia, always in the same sequence. The contralateral eye was occluded during the measurements. Two drops of 1% Tropicamide delivered within 5 min facilitated cycloplegic measurements. All participants were refracted 30 min after installation of the second drop. RESULTS: Mean spherical equivalent measures of the non-cycloplegic condition were significantly more myopic than their cycloplegic counterparts (p<0.05); approximately by 0.50 D centrally, increasing to 1.00 D towards the periphery. The horizontal astigmatic component, J180, demonstrated small but statistically significant differences between the test conditions. Differences were predominant for eccentricities greater than 30°, in both nasal and temporal meridians. The oblique astigmatic component, J45, was not significantly different between the test conditions. The primary spherical aberration coefficient C(4, 0) was significantly less positive for the non-cycloplegic state than its cycloplegic counterpart. This result held true across the entire horizontal visual field. The horizontal coma and trefoil coefficients C(3, 1) and C(3, 3) were not significantly different between the two conditions. CONCLUSIONS: The use of +1.00 D fogging lens without cycloplegia did not provide complete relaxation of accommodation. The discrepancies between cycloplegic and non-cycloplegic EM measurements were found to be more pronounced for peripheral field angles than central measures, for both M and J180 components.


Subject(s)
Accommodation, Ocular/physiology , Refraction, Ocular/physiology , Sensory Deprivation/physiology , Visual Fields/physiology , Accommodation, Ocular/drug effects , Adult , Eyeglasses , Female , Humans , Male , Mydriatics/pharmacology , Refraction, Ocular/drug effects , Tropicamide/pharmacology , Visual Fields/drug effects , Young Adult
18.
J. optom. (Internet) ; 8(3): 206-218, jul.-sept. 2015. ilus, tab, graf
Article in English | IBECS | ID: ibc-137687

ABSTRACT

Purpose: To compare the contributions of single vision (SVCL) and multifocal contact lenses (MFCL) to the relative peripheral refraction (RPR) profiles obtained via an autorefractor and an aberrometer in a pilot study. Methods: Two instruments, Shin-Nippon NVision K5001 (SN) and COAS-HD, were modified to permit open field PR measurements. Two myopic adults (CF, RB) were refracted (cycloplegia) under eight conditions: baseline (no CL); three SVCLs: Focus Dailies® (Alcon, USA), PureVision® (Bausch & Lomb, USA) and AirOptix® (Alcon, USA); and four MFCLs: AirOptix® (Alcon, USA), Proclear® Distant and Near (Cooper Vision, USA), and PureVision® (Bausch & Lomb, USA). CLs had a distance prescription of −2.00D and for MFCLs, a +2.50D Add was selected. Five independent measurements were performed at field angles from −40◦ to +40◦ in 10◦ increments with both instruments. The COAS-HD measures were analyzed at 3 mm pupil diameter. Results are reported as a change in the relative PR profile, as refractive power vector components: M, J180, and J45. Results: Overall, at baseline, M, J180 and J45 measures obtained with SN and COAS-HD were considerably different only for field angles ≥±30◦, which agreed well with previous studies. With respect to M, this observation held true for most SVCLs with a few exceptions. The J180 measures obtained with COAS-HD were considerably greater in magnitude than those acquired with SN. For SVCLs, the greatest difference was found at −40◦ for AirOptix SV (CF = 3.20D, RB = 1.56D) and for MFCLs it was for Proclear Distance at −40◦ (CF = 2.58D, RB = 1.39D). The J45 measures obtained with SN were noticeably different to the respective measures with COASHD, both in magnitude and sign. The greatest difference was found with AirOptix Multifocal in subject RB at −40◦, where the COAS-HD measurement was 1.50D more positive. In some cases, the difference in the RPR profiles observed between subjects appeared to be associated with CL decentration. Conclusion: For most test conditions, distinct differences were observed between the RPR measures obtained with the two modified instruments. The differences varied with CL design and centration. Although the pilot study supports the interchangeable use of the two instruments for on- and off-axis refraction in unaided eyes or eyes corrected with low/no spherical aberration; we advocate the use of the COAS-HD over the SN for special purposes like refracting through multifocal CLS (AU)


Objetivo: Comparar la contribución de las lentes de contacto monofocales y de las lentes de contacto multifocales (LMF) a los perfiles de la refracción periférica relativa (RPR) obtenidos mediante un autorrefractómetro y un aberrómetro en un estudio piloto. Métodos: Se modificaron dos instrumentos, Shin-Nippon NVision K5001 (SN) y COAS-HD, para permitir las mediciones de la RP de campo abierto. Se refraccionó (bajo cicloplejía) a dos adultos miopes (CF, RB) bajo ocho situaciones: línea basal (sin LC); tres lentes monofocales: Focus Dailies® (Alcon, USA), PureVision® (Bausch & Lomb, USA) y AirOptix® (Alcon, USA); y cuatro LMF: AirOptix® (Alcon, USA), Proclear® dominnate (D) y no dominante (N) (Cooper Vision, USA), y PureVision® (Bausch & Lomb, USA). Las LC tenían una prescripción de distancia de - 2,00D, y para las LMF se seleccionó una adición de +2,50D. Se realizaron cinco mediciones independientes a ángulos de campo comprendidos entre -40◦ y +40◦ en incrementos de 10◦ con ambos instrumentos. Las mediciones de COAS-HD se analizaron con un diámetro de pupila de 3 mm. Los resultados se reportaron como cambios en el perfil de la RPR, como componentes del vector de potencia refractiva: M, J180, y J45. Resultados: En general, en la línea basal, las mediciones M, J180 y J45 obtenidas con SN y COAS-HD fueron considerablemente diferentes sólo para los ángulos de campo ≥ ± 30◦, lo que es plenamente coincidente con los estudios previos. Con respecto a M, esta observación fue cierta para la mayoría de las lentes monofocales con pocas excepciones. Las mediciones de J180 obtenidas con COAS-HD fueron considerablemente superiores en magnitud que aquellas adquiridas con SN. En las lentes monofocales, la mayor diferencia se halló a -40◦ para AirOptix SV (CF = 3,20D, RB = 1,56D), y en las LMF para Proclear D a -40◦ (CF = 2,58D, RB = 1,39D). Las mediciones de J45 obtenidas con SN fueron considerablemente diferentes a las mediciones respectivas con COAS-HD, tanto en magnitud como en signo. La mayor diferencia se halló en AirOptix Multifocal en el sujeto RB a -40◦, donde la medición de COAS-HD reflejó un valor más positivo de 1,50D. En algunos casos, la diferencia en los perfiles de RPR observados entre los sujetos parece estar asociada a la descentralización de la LC. Conclusión: Para la mayoría de las condiciones de la prueba, se observaron distintas diferencias entre las mediciones de la RPR obtenidas con los dos instrumentos modificados. Dichas diferencias variaron según el diseño y el centrado de la LC. Aunque el estudio piloto apoya el uso intercambiable de los dos instrumentos para la refracción dentro y fuera del eje en ojos sin ayuda, u ojos corregidos con aberración esférica baja/nula, abogamos por el uso de COAS-HD en lugar de SN para fines especiales tales como la refracción a través de LC multifocales (AU)


Subject(s)
Humans , Refraction, Ocular/physiology , Myopia/surgery , Refractive Surgical Procedures/methods , Contact Lenses , Contact Lenses, Hydrophilic , Refractive Errors/diagnosis , Refractometry
19.
J Optom ; 8(3): 206-18, 2015.
Article in English | MEDLINE | ID: mdl-25662364

ABSTRACT

PURPOSE: To compare the contributions of single vision (SVCL) and multifocal contact lenses (MFCL) to the relative peripheral refraction (RPR) profiles obtained via an autorefractor and an aberrometer in a pilot study. METHODS: Two instruments, Shin-Nippon NVision K5001 (SN) and COAS-HD, were modified to permit open field PR measurements. Two myopic adults (CF, RB) were refracted (cycloplegia) under eight conditions: baseline (no CL); three SVCLs: Focus Dailies(®) (Alcon, USA), PureVision(®) (Bausch & Lomb, USA) and AirOptix(®) (Alcon, USA); and four MFCLs: AirOptix(®) (Alcon, USA), Proclear(®) Distant and Near (Cooper Vision, USA), and PureVision(®) (Bausch & Lomb, USA). CLs had a distance prescription of -2.00D and for MFCLs, a +2.50D Add was selected. Five independent measurements were performed at field angles from -40° to +40° in 10° increments with both instruments. The COAS-HD measures were analyzed at 3mm pupil diameter. Results are reported as a change in the relative PR profile, as refractive power vector components: M, J180, and J45. RESULTS: Overall, at baseline, M, J180 and J45 measures obtained with SN and COAS-HD were considerably different only for field angles ≥±30°, which agreed well with previous studies. With respect to M, this observation held true for most SVCLs with a few exceptions. The J180 measures obtained with COAS-HD were considerably greater in magnitude than those acquired with SN. For SVCLs, the greatest difference was found at -40° for AirOptix SV (ΔCF=3.20D, ΔRB=1.56D) and for MFCLs it was for Proclear Distance at -40° (ΔCF=2.58D, ΔRB=1.39D). The J45 measures obtained with SN were noticeably different to the respective measures with COAS-HD, both in magnitude and sign. The greatest difference was found with AirOptix Multifocal in subject RB at -40°, where the COAS-HD measurement was 1.50D more positive. In some cases, the difference in the RPR profiles observed between subjects appeared to be associated with CL decentration. CONCLUSION: For most test conditions, distinct differences were observed between the RPR measures obtained with the two modified instruments. The differences varied with CL design and centration. Although the pilot study supports the interchangeable use of the two instruments for on- and off-axis refraction in unaided eyes or eyes corrected with low/no spherical aberration; we advocate the use of the COAS-HD over the SN for special purposes like refracting through multifocal CLs.


Subject(s)
Aberrometry/instrumentation , Contact Lenses, Hydrophilic , Myopia/rehabilitation , Refractometry/instrumentation , Visual Fields/physiology , Adult , Humans , Male , Myopia/physiopathology , Pilot Projects , Refraction, Ocular/physiology , Vision Tests , Young Adult
20.
Cont Lens Anterior Eye ; 38(1): 2-14, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25139719

ABSTRACT

PURPOSE: The purpose of this study was to investigate the optical zone power profile of the most commonly prescribed soft contact lenses to assess their potential impact on peripheral refractive error and hence myopia progression. METHODS: The optical power profiles of six single vision and ten multifocal contact lenses of five manufacturers in the powers -1.00 D, -3.00 D, and -6.00 D were measured using the SHSOphthalmic (Optocraft GmbH, Erlangen, Germany). Instrument repeatability was also investigated. RESULTS: Instrument repeatability was dependent on the distance from the optical centre, manifesting unreliable data for the central 1mm of the optic zone. Single vision contact lens measurements of -6.00 D lenses revealed omafilcon A having the most negative spherical aberration, lotrafilcon A having the least. Somofilcon A had the highest minus power and lotrafilcon A the biggest deviation in positive direction, relative to their respective labelled powers. Negative spherical aberration occurred for almost all of the multifocal contact lenses, including the centre-distance designs etafilcon A bifocal and omafilcon A multifocal. Lotrafilcon B and balafilcon A seem to rely predominantly on the spherical aberration component to provide multifocality. CONCLUSIONS: Power profiles of single vision soft contact lenses varied greatly, many having a negative spherical aberration profile that would exacerbate myopia. Some lens types and powers are affected by large intra-batch variability or power offsets of more than 0.25 dioptres. Evaluation of power profiles of multifocal lenses was derived that provides helpful information for prescribing lenses for presbyopes and progressing myopes.


Subject(s)
Contact Lenses, Hydrophilic , Refraction, Ocular/physiology , Refractive Errors/therapy , Equipment Design , Humans , Refractive Errors/physiopathology , Reproducibility of Results
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