Search

The progression of myopia in young adults due to inadequate accommodation is currently one of the global research challenges. Studies have demonstrated that multifocal contact lenses have a different effect on accommodative response. The aim of this study was to assess the accommodative lag using various design multifocal contact lenses at different working distances. The study was conducted on 10 emmetropic subjects aged 22â28 years. An open-field autorefractor PowerRef 3 was used to assess the response of eye accommodation to stimuli placed at a distance of 25 cm and 40 cm for subjects wearing monofocal and multifocal contact lenses. To determine the effectiveness of contact lens design for accommodative lag compensation, the results of the accommodative lag with and without contact lenses were compared. The measured accommodative lag for stimuli at 40 cm was 1.05 ± 0.11 D and for stimuli at 25 cm 1.53 ± 0.11 D. Regarding the effect of multifocal contact lenses, it was determined that the near vision power zone in the centre of the lens reduces the accommodative lag, while the respective distance vision power zone does not produce a statistically significant change. The near power zone in the centre of the multifocal contact lens effectively affects the accommodative lag by reducing accommodation inaccuracy as effectively as spherical contact lenses with positive power. The addition design for multifocal lenses (Med or Hi) does not significantly affect the accommodative lag. The results of centre-distance multifocal contact lenses depend on the strength of the addition used.

Purpose: To study the relationship between the amplitude of accommodation (AA) measured by the Royal Air Force (RAF) rule and near addition (NA) prescribed in presbyopic patients to assess how far practice is different from theoretical recommendations. Methods: Patients, aged 40 to 60 years with best corrected vision of 6/6 N5 were included in this cross sectional observational study. AA was measured using the RAF rule. Refined with near Duochrome chart, the NA was given with the chart at 40 cm. Accommodative reserve was calculated from the measured AA, NA required and the calculated additional accommodation expended by the patient for reading. The percentage of reserve was calculated with and without the correction for depth-of-field. Results: A total of 130 patients were studied. In the patients above 50 years of age, the negative correlation of AA with age was -0.298 (P = 0.065) and AA and NA was -0.365 (P = 0.002) was weak. Among the patients aged between 40 and 50 years, the negative correlation of AA with Age and NA were strong; -0.853 (P < 0.0001) and -0.823 (P < 0.0001) respectively. When prescribing glasses, 62.01% (CI 58.78 to 65.23) and 90.93% (CI 62.50 to 119.37) of the AA was found to be kept in reserve for patients below and above 50 years of age respectively. Conclusion: Accommodative reserve kept in our study patients when prescribing NA was two to three times the theoretical recommendation. High percentage of accommodation kept in reserve suggest that the measured AA is not activated normally and require higher NA and one should not rely on patient's ability to generate accommodative power especially in patients over 50 years.

The progression of myopia in young adults due to inadequate accommodation is currently one of the global research challenges. Studies have demonstrated that multifocal contact lenses have a different effect on accommodative response. The aim of this study was to assess the accommodative lag using various design multifocal contact lenses at different working distances. The study was conducted on 10 emmetropic subjects aged 22-28 years. An openfield autorefractor PowerRef 3 was used to assess the response of eye accommodation to stimuli placed at a distance of 25 cm and 40 cm for subjects wearing monofocal and multifocal contact lenses. To determine the effectiveness of contact lens design for accommodative lag compensation, the results of the accommodative lag with and without contact lenses were compared. The measured accommodative lag for stimuli at 40 cm was 1.05 ± 0.11 D and for stimuli at 25 cm 1.53 ± 0.11 D. Regarding the effect of multifocal contact lenses, it was determined that the near vision power zone in the centre of the lens reduces the accommodative lag, while the respective distance vision power zone does not produce a statistically significant change. The near power zone in the centre of the multifocal contact lens effectively affects the accommodative lag by reducing accommodation inaccuracy as effectively as spherical contact lenses with positive power. The addition design for multifocal lenses (Med or Hi) does not significantly affect the accommodative lag. The results of centredistance multifocal contact lenses depend on the strength of the addition used. [ABSTRACT FROM AUTHOR]

Purpose: To study the relationship between the amplitude of accommodation (AA) measured by the Royal Air Force (RAF) rule and near addition (NA) prescribed in presbyopic patients to assess how far practice is different from theoretical recommendations.Methods: Patients, aged 40 to 60 years with best corrected vision of 6/6 N5 were included in this cross sectional observational study. AA was measured using the RAF rule. Refined with near Duochrome chart, the NA was given with the chart at 40 cm. Accommodative reserve was calculated from the measured AA, NA required and the calculated additional accommodation expended by the patient for reading. The percentage of reserve was calculated with and without the correction for depth-of-field.Results: A total of 130 patients were studied. In the patients above 50 years of age, the negative correlation of AA with age was -0.298 (P = 0.065) and AA and NA was -0.365 (P = 0.002) was weak. Among the patients aged between 40 and 50 years, the negative correlation of AA with Age and NA were strong; -0.853 (P < 0.0001) and -0.823 (P < 0.0001) respectively. When prescribing glasses, 62.01% (CI 58.78 to 65.23) and 90.93% (CI 62.50 to 119.37) of the AA was found to be kept in reserve for patients below and above 50 years of age respectively.Conclusion: Accommodative reserve kept in our study patients when prescribing NA was two to three times the theoretical recommendation. High percentage of accommodation kept in reserve suggest that the measured AA is not activated normally and require higher NA and one should not rely on patient's ability to generate accommodative power especially in patients over 50 years. [ABSTRACT FROM AUTHOR]

AIM:To investigate the influence of monovision design of cataract surgery on the prognosis visual quality in cataract patients. METHODS: Totally 84 cases cataract patients(168 eyes)who receiving cataract surgery were enrolled from February 2016 to February 2017 in our hospital to conduct a prospective study. According to the different near addition in the monovision design, patients were divided into low near addition group(1.25D-1.75D)and high near addition group(2.25D-2.75D), each group was 42 cases. At postoperative 6mo, the binocular uncorrected near visual acuity, uncorrected intermediate visual acuity, uncorrected distance visual acuity and stereoscopic vision were compared between two groups. The visual function survival quality score before and after treatment were compared. RESULTS: The binocular uncorrected intermediate and distance visual acuity in the low near addition group respectively was 0.27±0.20, 0.09±0.08, and that in the high near addition group respectively was 0.29±0.25, 0.10±0.07, which had no statistically significant difference between two groups(P>0.05). The binocular uncorrected near visual acuity in the high near addition group was 0.03±0.06, which was significantly better than the low near addition group 0.07±0.04, the difference was statistically significant(PP>0.05). After treatment, the VF-14 score both significantly increased in the two groups(PP>0.05). CONCLUSION: Two kinds of near addition have similar advantages to cataract patients after cataract surgery on uncorrected visual acuity, the quality of visual function and stereopsis.

Copyright of Journal of Optometry is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To compare and contrast standard and alternative versions of refractor head (phoropter)-based charts used to determine reading addition. Methods: Forty one presbyopic subjects aged between 42 and 60 years were tested. Tentative additions were determined using a red-green background letter chart, and 4 cross-grid charts (with white, red, green, or red-green backgrounds) which were used with the fused cross cylinder (FCC) method. The final addition for a 40 cm working distance was determined for each subject by subjectively adjusting the tentative additions. Results: There were significant differences in the tentative additions obtained using the 5 methods (repeated measuresanova, p < 0.001). The mean differences between the tentative and final additions were <0.10 D and were not clinically meaningful, with the exception of the red-green letter test, and the red background in the FCC method. There were no significant differences between the tentative and final additions for the green background in the FCC method ( p > 0.05). The intervals of the 95% limits of agreement were under ±0.50 D, and the narrowest interval (±0.26 D) was for the red-green background. Conclusions: The 3 FCC methods with a white, green, or red-green background provided a tentative addition close to the final addition. Compared with the other methods, the FCC method with the red-green background had a narrow range of error. Further, since this method combines the functions of both the fused cross-cylinder test and the duochrome test, it can be a useful technique for determining presbyopic additions. [ABSTRACT FROM AUTHOR]

Background: The use of plus lenses to compensate for the reduction in the range of accommodation associated with presbyopia, brings the near point of accommodation to a comfortable distance for near visual tasks. Our aim was to compare the tentative near addition determined using the most common procedures with the final addition prescribed in presbyopic patients. Methods: Sixty-nine healthy subjects with a mean age of 51.0 years (range 40 to 60 years) were studied. Tentative near additions were determined using seven different techniques: dynamic retinoscopy, amplitude of accommodation (AA), age-expected addition, binocular fused cross-cylinder with and without myopisation, near duochrome, and balance of negative and positive relative accommodation. The power of the addition was then refined to arrive at the final addition. Results: The mean tentative near additions were higher than the final addition for every procedure except for the fused cross-cylinder without initial myopisation and age-expected addition methods. These biases were small in clinical terms (less than 0.25 D) with the exception of the AA procedure (0.34 D). The intervals between the 95% limits of agreement differed substantially and were always higher than ±0.50 D. Conclusions: All the techniques used displayed similar behaviour and provided a tentative addition close to the final addition. Due to the wide agreement intervals observed, the likelihood of error is high and supports the idea that any tentative addition has to be adjusted according to the particular needs of each patient. Among the methods examined here, we would recommend the age-expected procedure, as this technique produced results that correlated best with the final addition. [ABSTRACT FROM AUTHOR]