Repeatability of the amplitude of accommodation measured by a new generation autorefractor

Subjective and objective measurements of the amplitude of accommodation: Revisiting the existing methods and clinical evaluation of newer techniques

PURPOSE

To evaluate the repeatability and agreement of established and newer methods for measuring the amplitude of accommodation in non-presbyopic and early presbyopic individuals.

METHODS

The amplitude of accommodation of 81 participants was measured using five different methods (two push-up techniques, two minus lens techniques and one objective technique) with different measurement principles. Among these, two new techniques were introduced: an electronic push-up and a minus lens technique with a tunable lens. Three repeated measurements were performed with each method. The repeatability limit and non-parametric Bland-Altman analysis were used to describe the repeatability and agreement of each method.

RESULTS

The repeatability limit was between ±0.7 D and ±1.4 D for the minus lens techniques, around ±1.8 D for the push-up methods and ±1.4 D for the objective procedure. The largest differences in median values were found between the push-up and objective methods.

CONCLUSIONS

Push-up methods are most likely to overestimate accommodation, while the objective method gives the lowest results. New techniques show good repeatability for measuring the amplitude of accommodation. Among the subjective methods, the minus lens technique with the tunable lens gives the best repeatability, is one of the fastest and gives results most similar to the objective method.

Comparison of pupil size measurement: Repeatability and agreement across four devices with different measurement principles under varied lighting conditions

AIM

To evaluate the repeatability of pupil size measurements obtained with four different devices under varying lighting conditions and to assess the agreement between them.

METHODS

This prospective study included 80 healthy participants with a mean age of 27.5 ± 8.8 years (range 19-58). Pupil size was measured under mesopic (4 lux) and low photopic (50 lux) conditions using two open-field devices (tabletop and handheld PowerRefractors) and two closed-field devices (MS-39 and NIDEK Tonoref III). Three consecutive measurements were taken per eye for each device. Repeatability was analysed using the repeatability limit (R Limit), while the agreement was assessed with Bland-Altman analysis.

RESULTS

All devices demonstrated R Limits lower than 1 mm under both low photopic and mesopic conditions. The NIDEK Tonoref III had the best repeatability under low photopic conditions (R Limit = 0.52 mm), while the tabletop PowerRefractor had the best R Limit under mesopic conditions (0.68 mm). The agreement analysis under mesopic conditions revealed smaller mean differences and narrower limits of agreement (LoA) (approximately 2 mm) among devices with similar designs (tabletop with handheld PowerRefractor and MS-39 with NIDEK Tonoref III), while combinations of designs exhibited wider variability. Mesopic conditions yielded more consistent LoA across all device pairs.

CONCLUSIONS

All devices showed excellent repeatability. Instruments with similar measurement designs demonstrated better agreement, particularly under low photopic conditions. Significant variability existed when comparing open- and closed-field devices. These findings underscore the importance of selecting appropriate instruments for clinical and research applications, and highlight the need for further validation of pupillometry devices.

Establishing the cutoff value of near visual acuity for assessment of early presbyopia

PURPOSE

There is limited evidence to evaluate the numerical cutoff point for detecting early presbyopia. Thus, we aimed to establish a clinically relevant optimal cutoff value of near visual acuity for detecting early presbyopia.

STUDY DESIGN

Prospective diagnostic accuracy study.

METHODS

We included consecutive individuals aged ≥ 20 years with a binocular-corrected distance visual acuity of ≥ 20/25 who did not undergo ophthalmic surgery between December 17, 2020 and December 19, 2021, at two healthcare facilities in Japan. Binocular distance-corrected near visual acuity at 40 cm, accommodative amplitude, awareness of presbyopia, and Near Activity Visual Questionnaire scores were examined. The optimal cutoff values of distance-corrected near visual acuity for diagnosing early presbyopia were evaluated using receiver operating characteristic plots.

RESULTS

Among 115 participants, 74 (64.3%) had presbyopia. The proportion of participants with no difficulty performing near-vision tasks decreased markedly when near visual acuity decreased to 20/20 (> 0.00 logMAR). A cutoff value of 0.00 logMAR for distance-corrected near visual acuity was optimal, showing high sensitivity of 56.76% and specificity of 92.68%, as opposed to the commonly used cutoff value of 0.40 logMAR (20/50; sensitivity, 9.46% and specificity, 100%) for diagnosing early presbyopia.

CONCLUSION

Near visual acuity of 0.00 logMAR (20/20) could be the optimal cutoff value for diagnosing early presbyopia.

Impact of Refractive Status on Presbyopia Progression among Patients with Presbyopia

PURPOSE

To explore the impact of refractive status on presbyopia progression among patients with presbyopia.

METHODS

This retrospective observational study included patients with presbyopia who visited the Seventh Affiliated Hospital of Sun Yat-sen University and Shenzhen Polytechnic Medical College between May 2018 and August 2022. The amplitude of accommodation (AMP) and near addition power (ADD) at 6 months and 1 year were collected.

RESULTS

A total of 103 patients with presbyopia were included in this study: 42 patients with myopia, 23 patients with emmetropia, and 38 patients with hyperopia. There were significant differences in ΔAMP(6-month) and ΔADD(6-month) among patients with different refractive statuses, and the values of emmetropic patients and hyperopic patients were higher than in myopic patients (all P < 0.001). The ΔAMP(1-year) and ΔADD(1-year) of hyperopic patients were significantly higher than in emmetropic patients and myopic patients (all P < 0.001). The ΔADD(1-year) of emmetropic patients was greater than in myopic patients (P = 0.045), but there were no significant differences in ΔAMP(1-year) between patients with emmetropia and myopia (P = 0.090).

CONCLUSIONS

The progression of presbyopia in hyperopic patients was relatively more significant than for emmetropia, followed by myopia. The prescription of presbyopia glasses might need to be replaced more frequently in patients with hyperopia.

Repeatability of the Accommodative Response Measured by the Grand Seiko Autorefractor in Children With and Without Amblyopia and Adults

PURPOSE

To assess test-retest repeatability of the accommodative response (AR) in children with and without amblyopia and adults using the Grand Seiko autorefractor.

DESIGN

Prospective reliability assessment.

METHODS

Test-retest of accommodation was obtained while participants viewed 20/150 sized letters at 33 cm using the Grand Seiko autorefractor in children 5 to <11 years with amblyopia (n=24) and without amblyopia (n=36), and adults 18 to <35 years (n=34). Bland-Altman 95% limits of agreement (LOA) and intraclass correlation coefficients (ICCs) were used to assess repeatability and reliability. The AR between the fellow and amblyopic eyes of children with amblyopia and eye 1 and eye 2 of the visually normal participants was assessed using group comparisons.

RESULTS

The 95% LOA of the AR was greatest in the amblyopic eyes (-1.25 diopters [D], 1.62 D) of children with amblyopia. The 95% LOA were similar between the fellow eyes (-0.88 D, 0.74 D) of children with amblyopia and both eyes of the children without amblyopia (eye 1: -0.68 D, 0.71 D; eye 2: -0.59 D, 0.70 D) and the adults (eye 1: 95% LOA = -0.49 D, 0.45 D; eye 2: LOA = -0.66 D, 0.67 D). ICCs revealed the Grand Seiko autorefractor as a reliable instrument for measuring AR.

CONCLUSIONS

The Grand Seiko autorefractor was more repeatable and reliable when measuring the AR in children and adults without amblyopia than in the amblyopic eye in children with amblyopia. It is recommended that multiple measures of the AR be obtained in amblyopic eyes to improve the precision of measures.

Comparison of the Amplitude of Accommodation Measured Using a New-Generation Closed-Field Autorefractor with Conventional Subjective Methods

Purpose: This study aims to compare and assess the agreement of the objective amplitude of accommodation (AA) measured using a new-generation closed-field autorefractor with conventional subjective methods. Methods: In total, 84 healthy individuals with an age range of 19 to 50 years participated in this cross-sectional study. AA was measured objectively with a Nidek autorefractor (AR-1a; Nidek Co., Ltd., Tokyo, Japan) and subjectively using push-up (PU) and minus-lens (ML) methods in a random order. Comparison between different methods was performed using repeated-measures analysis of variance and the Bonferroni test for pairwise comparisons. In addition to the Pearson correlation, the Bland and Altman method and the intraclass correlation coefficient were used to determine the agreement between the three techniques. Only the right-eye results were used for analysis. Results: AA measured using the Nidek autorefractor (3.43 ± 1.94 D) was significantly lower than that measured with PU (7.67 ± 2.38 D; p < 0.001) and ML (7.60 ± 2.81 D; p < 0.001) methods. The difference between the subjective methods was not significant statistically (p = 1.0). The correlation for Nidek measurements and PU and ML methods was moderate (r = 0.5502 and r = 0.6832, respectively), while it was strong when comparing subjective methods (r = 0.7821). The limits of agreement for Nidek vs. PU, Nidek vs. ML, and PU vs. ML methods were −8.28 to −0.23 D, −8.19 to −0.15 D, and −3.38 to 3.51 D, respectively. Conclusions: There was a moderate agreement between AA obtained with subjective methods and objective Nidek measurements. The objective AA measurements obtained with a new Nidek autorefractor were significantly lower than subjective measurements.

Comparison of the results of four different refraction measurement devices in children with retinoscopy

Purpose: The purpose of this study was to compare the results of 4 different autorefractometer devices with the results of retinoscopy in children. Methods: A total of 120 eyes of 60 patients aged between 6 and 18, who applied to Afyonkarahisar Health Sciences University unit of Pediatric Ophthalmology, were included in the study. Refraction with Plusoptix A09 (photoscreener) without cycloplegia was the first to be measured. Spherical and cylindrical values were recorded. Then, half an hour after the patients were instilled 2 drops of cyclopentolate with an interval of 5 minutes, dilated retinoscopy was performed, and spherical and cylindrical values were recorded. Autorefractometer measurements with cycloplegia were performed with Canon RK-F1 autorefractometer, Nidek Tonoref III and Retinomax K-Plus 3, and spherical and cylindrical values were recorded. Results: The mean age of the patients was 11.02 ± 2.1. The mean spherical equivalents were Canon RKF1 autorefractometer +0.045 ± 2.49, Nidek TonoRef III +0.023 ± 2.48, Retinomax K-Plus 3 +0.078 ± 1.42, Plusoptix A09 -0.119 ± 2.20, retinoscopy +0.124 ± 2.65. Moreover, the mean cylindrical values were Canon RK-F1 autorefractometer -0.893 ± 0.69, Nidek TonoRef III -0.927 ± 0.72, Retinomax K-Plus 3 -0.888 ± 0.73, Plusoptix A09 -0.883 ± 0.719, retinoscopy -0.923 ± 0.71. The statistical values compared with retinoscopy; Canon RKF1 spherical equivalent (p=0.376), cylindrical (p=0.515), Nidek TonoRef III spherical equivalent (p=0.485), cylindrical (p=0.198), Retinomax K-Plus 3 spherical equivalent (p=0.141), cylindrical (p=0.058), Plusoptix A09 spherical equivalent (p=0.085) and cylindrical (p=0.086) values were not different. Conclusions: In spherical and cylindrical refractive error detection, all 4 devices showed reasonable and consistent results compared to retinoscopy.

Dynamics of the accommodative response after smoking cannabis

PURPOSE

Cannabis is the most widely consumed illicit drug worldwide. It has been suggested that cannabis could generate blurred vision during reading tasks. The goal of this study was to objectively assess the acute effects of smoking cannabis on the dynamics of ocular accommodation. The influence of other factors, including target distance and the direction of accommodation, as well as personal characteristics, were also analysed.

METHODS

Nineteen young people who were occasional cannabis users participated in the study (mean age 22.53 [3.12] years). Their usage profiles were evaluated by means of the Cannabis Use Disorders Identification Test-revised (CUDIT-r). The dynamics of the accommodative response were evaluated using an open-field auto refractor (Grand Seiko WAM-5500). The participants completed two different experimental sessions, one week apart, and in random order (baseline session and after smoking cannabis). During these sessions, the amplitude of the response (D), mean velocity (D/s), peak velocity (D/s), response time (s), accommodative lag (D) and accommodation variability (D) were measured.

RESULTS

The results indicated that cannabis use had a significant main effect on the mean accommodation/disaccommodation velocity (F_1,13  = 7.21; p = 0.02; η p 2  = 0.396). Cannabis consumption also interacted significantly with other factors. Response time showed a significant two-way interaction between condition × target distance (F_1,13  = 11.71; p = 0.005; η p 2  = 0.474) and condition × accommodation direction (F_1,13  = 8.71; p = 0.01; η p 2  = 0.401). For mean velocity, two-way interactions were found between condition × age (F_1,13  = 6.03; p = 0.03; η p 2  = 0.354), condition × CUDIT-r score (F_1,13  = 6.03; p = 0.03; η p 2  = 0.356) and condition × target distance (F_1,13  = 7.20; p = 0.02; η p 2  = 0.396).

CONCLUSIONS

These findings suggest that cannabis use can alter the accommodation process, although further studies should be carried out to explore the role of attention deficits. According to these results, certain daily activities that depend on an accurate accommodative function may be affected by cannabis use.

Difference in Pupillary Diameter as an Important Factor for Evaluating Amplitude of Accommodation: A Prospective Observational Study

Presbyopia is increasing globally due to aging and the widespread use of visual display terminals. Presbyopia is a decrease in the eye's amplitude of accommodation (AA) due to loss of crystalline lens elasticity. AA differs widely among individuals. We aimed to determine the factors that cause presbyopia, other than advanced age, for early medical intervention. We examined 95 eyes of 95 healthy volunteers (33 men, 62 women) aged 22-62 years (mean: 37.22 ± 9.77 years) with a corrected visual acuity of ≥1.0 and without other eye afflictions except ametropia. Subjective refraction, AA, maximum and minimum pupillary diameters during accommodation, axial length of the eye, and crystalline lens thickness were measured. AA was measured using an auto refractometer/keratometer/tonometer/pachymeter. The difference between maximum and minimum pupillary diameters was calculated. On multiple regression analysis, age and difference in pupillary diameter were both significantly and independently associated with AA in participants aged <44 years, but not in those aged ≥45 years. Our results suggest that the difference in pupillary diameter could be an important age-independent factor for evaluating AA in healthy individuals without cataract. Thus, improving the difference in pupillary diameter values could be an early treatment target for presbyopia.