Comparison of Dynamic Retinoscopy and Autorefraction for Measurement of Accommodative Amplitude

The etiology, diagnostics, and treatment of the spasm of the near reflex - a narrative review

Physiological adaptation of the eye to the visual perception of near objects consists of the "near triad": convergence, accommodation, and pupil miosis. Normally, these tend to revert when one stops fixating on a near object. Spasm of the near reflex (SNR) is a pathological phenomenon, which manifests itself by the persistence of the above-mentioned adjustments, which prevents the eye from returning to its relaxed state. In this narrative review, we aim to summarize the etiology, diagnostics, treatment, and prevention of SNR. The literature review was performed by searching online databases. The clinical presentation of SNR is diverse; it presents as isolated accommodative spasm more frequently than impairment of all three components of the near triad. Patients usually present with fluctuations in visual acuity, blurred vision, diplopia, and asthenopia. The etiology is not fully understood. Potential causes include neuroanatomic, organic, and psychogenic disorders. The diagnosis is clinical, based on the constellation of symptoms and assessment of the near triad. The diagnostic golden standard is a cycloplegic examination of refraction, preferably using cyclopentolate hydrochloride (1%, 0.5%, or 0.1% solution). The first-line treatment requires the administration of a cycloplegic drug in combination with plus lenses, flipper lenses, optical fogging, or miotics. For secondary cases, causal treatment should be implemented. Prevention of SNR should be based on eliminating modifiable risk factors. We propose including screening for SNR symptoms in every ophthalmic examination, especially among patients with psychogenic or neural disorders, after brain trauma, or young adults spending much time in front of computer screens.

Retinoscopes: Past and present

BACKGROUND

Retinoscopy is arguably the most important method in the eye clinic for diagnosing and managing refractive errors. Advantages of retinoscopy include its non-invasive nature, ability to assess patients of all ages, and usefulness in patients with limited cooperation or communication skills.

AIM

To discuss the history of retinoscopes and examine current literature on the subject.

METHODS

A search was conducted on the PubMed and with the reference citation analysis (https://www.referencecitationanalysis.com) database using the term "Retinoscopy," with a range restricted to the last 10 years (2013-2023). The search string algorithm was: "Retinoscopy" (MeSH Terms) OR "Retinoscopy" (All Fields) OR "Retinoscopes" (All Fields) AND [(All Fields) AND 2013: 2023 (pdat)].

RESULTS

This systematic review included a total of 286 records. Publications reviewed iterations of the retinoscope into autorefractors, infrared photo retinoscope, television retinoscopy, and the Wifi enabled digital retinoscope.

CONCLUSION

The retinoscope has evolved significantly since its discovery, with a significant improvement in its diagnostic capabilities. While it has advantages such as non-invasiveness and broad applicability, limitations exist, and the need for skilled interpretation remains. With ongoing research, including the integration of artificial intelligence, retinoscopy is expected to continue advancing and playing a vital role in eye care.

BCLA CLEAR Presbyopia: Evaluation and diagnosis

It is important to be able to measure the range of clear focus in clinical practice to advise on presbyopia correction techniques and to optimise the correction power. Both subjective and objective techniques are necessary: subjective techniques (such as patient reported outcome questionnaires and defocus curves) assess the impact of presbyopia on a patient and how the combination of residual objective accommodation and their natural DoF work for them; objective techniques (such as autorefraction, corneal topography and lens imaging) allow the clinician to understand how well a technique is working optically and whether it is the right choice or how adjustments can be made to optimise performance. Techniques to assess visual performance and adverse effects must be carefully conducted to gain a reliable end-point, considering the target size, contrast and illumination. Objective techniques are generally more reliable, can help to explain unexpected subjective results and imaging can be a powerful communication tool with patients. A clear diagnosis, excluding factors such as binocular vision issues or digital eye strain that can also cause similar symptoms, is critical for the patient to understand and adapt to presbyopia. Some corrective options are more permanent, such as implanted inlays / intraocular lenses or laser refractive surgery, so the optics can be trialled with contact lenses in advance (including differences between the eyes) to better communicate with the patient how the optics will work for them so they can make an informed choice.

Utility of retinoscopy to examine peripheral refraction

PURPOSE

This study explored whether retinoscopy (RET) provides comparable results of relative peripheral refraction (RPR) to open-field autorefractometry (AR) in myopic subjects.

METHODS

Peripheral refraction was measured in 20 myopic and 20 control adult subjects. Both central and peripheral refraction (20° nasal and temporal eccentricity) were measured using RET and open-field AR. Differences in the median central spherical equivalent (SE), median RPR, and median J45/J180 power vectors between the RET and AR techniques were analyzed. Moreover, Bland - Altman plots were used to assess the agreement between RET and AR methods for RPR measurements in MG.

RESULTS

For MG, the median RPR values were positive (hyperopic shift), and no significant differences were observed between the RET and AR techniques with respect to RPR measurement. In addition, we did not observe any significant differences in the RPR values between the nasal and temporal eccentricities for either the RET or AR technique for myopic subjects. There was also a significant correlation and agreement between the RET and AR technique for RPR measurements. With respect to central refraction, the median SE was slightly more positive for the RET than for the AR technique. Inside the CG, we also found significant correlation between the RET and AR technique for RPR measurements, and we observed a myopic shift in peripheral eccentricities.

CONCLUSION

Our results show that retinoscopy may be a useful tool for objective measurements of RPR in myopic subjects and may be used interchangeably with the open-field AR method in everyday clinical practice.

Comparison of proximal and minus lens autorefraction techniques to measure monocular accommodative amplitude

SIGNIFICANCE

This study provides a faster method for objectively measuring accommodative amplitude with an open-field autorefractor in a research setting.

PURPOSE

Objective measures of accommodative amplitude with an autorefractor take time because of the numerous stimulus demands tested. This study compares protocols using different amounts and types of demands to shorten the process.

METHODS

One hundred participants were recruited for four age bins (5 to 9, 10 to 14, 15 to 19, and 20 to 24 years) and monocular amplitude measured with an autorefractor using three protocols: proximal, proximal-lens (letter), and proximal-lens (picture). For proximal, measurements were taken as participants viewed a 0.9 mm "E" placed at 13 demands (40 to 3.3 cm = 2.5 to 30 D). The other protocols used a target (either the "E" or a detailed picture) placed at 33 and 12.5 cm followed by 12.5 cm with a series of lenses (-2, -4, and -5.5 D). Adjustments were made for lens effectivity for the three lens conditions, which were thus 9.6, 11.1, and 12.0 D for individuals without additional spectacle lenses. Accommodative amplitude was defined as the greatest response measured with each technique. One-way analysis of variance was used to compare group mean amplitudes across protocols and differences between letter protocols by age bin.

RESULTS

Amplitudes were significantly different between protocols (p < 0.001), with proximal having higher amplitudes (mean ± standard deviation, 8.04 ± 1.70 D) compared with both proximal-lens protocols (letter, 7.48 ± 1.42 D; picture, 7.43 ± 1.42 D) by post hoc Tukey analysis. Differences in amplitude between the proximal and proximal-lens (letter) protocol were different by age group (p = 0 .003), with the youngest group having larger differences (1.14 ± 1.58 D) than the oldest groups (0.17 ± 0.58 and 0.29 ± 0.48 D, respectively) by post hoc Tukey analysis.

CONCLUSIONS

The proximal-lens protocols took less time and identified the maximum accommodative amplitude in participants aged 15 to 24 years; however, they may underestimate true amplitude in younger children.

Objective and subjective assessment of accommodative insufficiency

SIGNIFICANCE

A variety of subjective and objective procedures are available to measure the amplitude of accommodation. However, it is unclear whether the standard criterion of Hofstetter's minimum minus 2 D can be used to diagnose accommodative insufficiency with each of these techniques.

PURPOSE

The use of objective dynamic retinoscopy and three subjective techniques to diagnosis accommodative insufficiency was examined.

METHODS

A total of 632 subjects between 8 and 19 years of age were enrolled. Accommodative lag, monocular accommodative facility, and subjective (push-up, modified push-down, and minus lens) and objective (dynamic retinoscopy) amplitude of accommodation were quantified. Accommodative insufficiency was diagnosed based on Hofstetter's minimum minus 2 D for each subjective method, as well as adding an additional subjective criterion (either accommodative lag exceeding 0.75 D or monocular accommodative facility falling below the age-expected norms).

RESULTS

The prevalence of accommodative insufficiency was lowest and highest with the push-up (7.9 and 1%) and dynamic retinoscopy (94 and 12%) procedures when measured without and with the additional subjective criteria, respectively. Comparing the validity of dynamic retinoscopy against the traditional criterion, moderate to low sensitivity and high specificity were found. However, adding the additional subjective criteria improved the findings with moderate to high sensitivity and high specificity. Using a cutoff for dynamic retinoscopy of 7.50 D showed moderate diagnostic accuracy based on likelihood ratios.

CONCLUSIONS

It is clear that a revised definition of accommodative insufficiency is required, which must include the method of assessing accommodation. The various objective and subjective methods for quantifying the amplitude of accommodation are not interchangeable, and subjective assessment does not provide a valid measure of the accommodative response.

Reliability and Agreement of an Integrated Platform for Intelligent Visual Function Measurement

INTRODUCTION

Phoropters are widely accepted for clinical use in refraction examination and visual function assessment. This study assessed the reliability of the new Inspection Platform of Visual Function (IPVF) in comparison with the conventional equipment phoropter (TOPCON VT-10) in visual function assessment.

METHODS

This prospective study enrolled 80 eyes of 80 healthy subjects. The horizontal phoria at distance and near (Phoria_D and Phoria_N, respectively) was measured with the von Graefe method, negative/positive relative accommodation (NRA/PRA) was measured with the positive/negative lens method, and accommodative amplitude (AMP) was measured with the minus lens method. Data of three consecutive measurements with each instrument were evaluated using the intraclass correlation coefficient (ICC) for repeatability, and the agreement of the two instruments was evaluated using a Bland-Altman plot.

RESULTS

The ICCs of the three consecutive measurements for phoria, NRA/PRA, and AMP using the IPVF instrument were high (0.87-0.96), indicating high repeatability. The ICCs of the three consecutive measurements using the phoropter were high (0.914-0.983) for phoria, NRA, and AMP, indicating high repeatability, while that of PRA was 0.732 (between 0.4 and 0.75), indicating acceptable repeatability. The 95% limits of agreement of phoria, NRA/PRA, and AMP were narrow, indicating good agreement between the two instruments.

CONCLUSION

The repeatability of both instruments was high, and the IPVF instrument was slightly better in terms of PRA repeatability than the phoropter. The agreement of phoria, NRA/PRA, and AMP measured by the new IPVF instrument and phoropter was also satisfactory.

Effect of illuminance and colour temperature of LED lighting on asthenopia during reading

PURPOSE

A self-controlled study to determine the influence of illuminance and correlated colour temperature (CCT) of light-emitting diode (LED) lighting on asthenopia.

METHODS

Twenty-two healthy postgraduates (nine women) were recruited to read under eight LED lighting conditions with four illuminances (300 lx, 500 lx, 750 lx and 1000 lx) and four CCTs (2700, 4000, 5000 and 6500 K) for 2 h. A subjective asthenopia questionnaire, the optical quality analysis system (OQAS) and an inflammatory cytokine assay were used to assess the levels of asthenopia.

RESULTS

Increased asthenopia was observed after reading, but the degree varied with lighting conditions. There were significant differences among the groups in terms of subjective symptoms (inattention, eye pain, dry eye and total score), optical performance parameters (modulation transfer function [MTF] cut-off frequency, Strehl ratio [SR], objective scattering index [OSI], mean OSI and accommodative amplitude [AA]) as well as inflammatory cytokines in the tears (epidermal growth factor [EGF], transforming growth factor [TGF]-α, interleukin [IL]-6, IL-8, macrophage inflammatory protein [MIP]-1β, tumour necrosis factor [TNF]-α, TNF-β and vascular endothelial growth factor [VEGF]-A). All of the subjective and objective measurements collectively suggested that asthenopia was lessened for the 500 lx-4000 K condition. However, asthenopia was significantly worse for 300 lx-2700 K and 1000 lx-6500 K in terms of subjective symptoms and objective optical performance, respectively.

CONCLUSIONS

LED illuminance and CCT do have a significant effect on asthenopia during reading. 500 lx-4000 K lighting resulted in the lowest level of asthenopia. Conversely, low illuminance at low CCT (300 lx-2700 K) and high illuminance at high CCT (1000 lx-6500 K) promoted more severe asthenopia.

Validation of the PowerRef 3 for Measuring Accommodation: Comparison With the Grand Seiko WAM-5500A Autorefractor

Purpose

This validation study examines the PowerRef 3 as a method for measuring accommodation objectively. We assess agreement with refractive measurements obtained simultaneously by the Grand Seiko WAM-5500A autorefractor.

Methods

Refractive measurements were recorded simultaneously using the PowerRef 3 and WAM-5500A in 32 noncyclopleged participants aged 15 to 46 years. Accommodative states were recorded for 10 seconds at six accommodative demands (5 diopters [D], 4 D, 3 D, 2.5 D, 2 D, and 0 D) while participants fixated a high-contrast Maltese cross. WAM-5500A measurements were converted to power in the vertical meridian for comparison with PowerRef 3 data. Dioptric difference values were computed, and agreement was assessed using Bland-Altman plots with 95% limits of agreement (LOA) and intraclass correlation coefficient analyses.

Results

The mean absolute dioptric differences measured 0.14 D or less across accommodative demands. Analyses showed an excellent intraclass correlation coefficient across the tested demands (0.93). Bland-Altman plots indicated a bias of -0.02 D with 95% LOA of -1.03 D to 0.99 D. The 95% LOA was smallest for the 3 D demand (-0.71 D to 0.64 D), and largest at 5 D demand (-1.51 D to 1.30 D).

Conclusions

The mean dioptric differences between the PowerRef 3 and WAM-5500A autorefractor were small and not clinically significant. While some variability in agreement was observed depending on the tested demand, the PowerRef 3 demonstrated good agreement with the WAM-5500A.

Translational Relevance

The PowerRef 3 may be used to obtain objective measures of accommodation both monocularly and binocularly and provides a more flexible method, especially in pediatric populations.

Developing dynamic defocus curve for evaluating dynamic vision accommodative function

Background

To assess dynamic visual acuity (DVA) under different defocus statuses and explore the assessment of dynamic vision accommodation.

Methods

Twenty subjects (6 males and 14 females) aged 18 to 35 were recruited. Nonmydriatic subjective refraction (sphere and cylinder) and accommodative tests including negative relative accommodation (NRA), positive relative accommodation (PRA), binocular cross cylinder (BCC) and accommodative facility using a flipper were performed. Binocular static visual acuity (SVA) and DVA at 40 degrees per second (dps) were measured under different defocus statuses (+1.5D to -4D in -0.5D steps) based on the refractive error fully corrected. Static and dynamic defocus curves were plotted. The area under the curve (AUC) and corrected dynamic vision accommodation (CDVAc) were calculated.

Results

The study showed that the dynamic defocus curve fitted the cubic curve properly (p<0.001). DVA was significantly worse than SVA at all defocused statuses (p<0.001), and the difference was more significant at greater defocus diopters. Single factor analysis indicated that CDVAc was significantly correlated with NRA-PRA (p=0.012) and AUC_dynamic (p<0.001). Significant associations were observed between AUC_dynamic and PRA (p=0.013) as well as NRA-PRA (p=0.021). Meanwhile, DVA was positively correlated with PRA at 0D, -1.0D, -1.5D, -2.5D and -3.0D (p<0.05) and with NRA-PRA at 0D, -1.0D, -1.5D, -2.0D and -2.5D (p<0.05). Multiple factor regression analysis indicated that CDVAc (0D ~ -3.5D) and SVA (+1.5D ~ +1.0D & -2.5D ~ -4.0D) were significant influential factors for defocused DVA (p<0.05).

Conclusions

Our study demonstrated that DVA had a defocus curve similar to that of SVA. CDVAc was feasible for the assessment of dynamic vision accommodative function. The dynamic defocus curve test could efficiently be applied in the evaluation of dynamic visual performance under different defocus statuses.