Accuracy and stability of accommodation and vergence responses during sustained near tasks in uncorrected hyperopes

A survey of prescribing philosophy in childhood hyperopia among optometrists in Ghana

CLINICAL RELEVANCE

Hyperopia is a common refractive error in young children and has the potential to affect their visual, educational and general development. Management of childhood hyperopia presents significant intra-and inter-professional differences partly because evidence-based guidelines to inform when and how to prescribe for hyperopia are insufficient.

PURPOSE

This study investigated the prescribing philosophy in childhood hyperopia among optometrists in Ghana and the challenges faced in managing childhood hyperopia.

METHODS

An online questionnaire was distributed to optometrists in Ghana to evaluate the prescribing philosophy in childhood hyperopia. The questionnaire assessed factors, which could influence prescribing patterns in participants including age, symptoms, emmetropisation, and magnitude of hyperopia in patients. Challenges encountered in the management of childhood hyperopia in children were also investigated.

RESULTS

Ninety-one optometrists responded to the questionnaire with the mean age of participants being 32.3 ± 5.6 years. Most participants (67,(74%)) surveyed reported using some clinical guidelines in the management of childhood hyperopic refractive errors. The magnitude of bilateral hyperopia that practitioners were willing to prescribe decreased with increasing age of the patient (p < 0.0001). Most participants preferred modification of the amount of bilateral hyperopia found during cycloplegic refraction and also indicated a preference for prescribing a lesser amount of astigmatism. Lack of instrumentation for paediatric assessment was the main challenge reported in the management of hyperopic refractive errors.

CONCLUSION

The spectacle prescribing philosophies in childhood hyperopia amongst optometrists in Ghana largely follow existing clinical guidelines, although, in some instances, there were mismatches between the existing guidelines and their preferred pattern. Regular continuing professional development, which highlights emerging evidence on prescribing in childhood hyperopia, would be desirable.

Comparative Analysis of Physiological Vergence Angle Calculations from Objective Measurements of Gaze Position

Eccentric photorefractometry is widely used to measure eye refraction, accommodation, gaze position, and pupil size. While the individual calibration of refraction and accommodation data has been extensively studied, gaze measurements have received less attention. PowerRef 3 does not incorporate individual calibration for gaze measurements, resulting in a divergent offset between the measured and expected gaze positions. To address this, we proposed two methods to calculate the physiological vergence angle based on the visual vergence data obtained from PowerRef 3. Twenty-three participants aged 25 ± 4 years viewed Maltese cross stimuli at distances of 25, 30, 50, 70, and 600 cm. The expected vergence angles were calculated considering the individual interpupillary distance at far. Our results demonstrate that the PowerRef 3 gaze data deviated from the expected vergence angles by 9.64 ± 2.73° at 25 cm and 9.25 ± 3.52° at 6 m. The kappa angle calibration method reduced the discrepancy to 3.93 ± 1.19° at 25 cm and 3.70 ± 0.36° at 600 cm, whereas the linear regression method further improved the accuracy to 3.30 ± 0.86° at 25 cm and 0.26 ± 0.01° at 600 cm. Both methods improved the gaze results, with the linear regression calibration method showing greater overall accuracy.

The concept of cone opponency may extend beyond accommodation, to myopiagenesis and emmetropization, for a better peripheral defocus lens

Myopia has ever-rising prevalence in the past few decades globally. Its pathogenesis is still not adequately elucidated especially at the signal transduction level. For the environmental risk factors, there is a large body of fragmented knowledge about the visual inputs for accommodation, myopiagenesis and emmetropization, with the latter two being essentially local processes. The red-green and yellow-blue chromatic pathways, together with the underlying L-M and S-(L+M) cone opponency, seem to be the common denominator amongst them. In this review, experimental and observational evidence are summarized to delineate the interplay of them. This review may establish the pivotal role of longitudinal chromatic aberration (LCA) for a mechanistic approach to future research in myopia control. This review looks into the mechanistic processes underlying myopiagenesis and emmetropization, specifically focusing on chromatic aberration and cone opponency in vision as pivotal components. The roles of longitudinal chromatic aberration (LCA) and cone contrast in myopia onset and development are intriguing. How visual input and chromatic pathways (specifically, red-green and blue-yellow cone opponency) contribute to accommodation that may trigger emmetropization mechanisms, thereby influencing eye growth patterns are explored and discussed. In brief, this manuscript delves into the physiology of visual processing and highlights a foundational aspect of visual science that may account for a "Go" or "Stop" signaling in axial eye growth. It further proposes a metric to gauge myopia-inhibiting optical devices such as the peripheral defocus lenses, for its best iteration. Future research in the above-mentioned areas is warranted.

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.

Academic performance and musculoskeletal pain in adolescents with uncorrected vision problems

BACKGROUND

Undetected vision problems are common in school children, and a prevalence of up to 40% has previously been reported. Uncorrected vision and lack of optimal eye wear can have a significant impact on almost all aspects of everyday life, such as development and learning, academic performance, pain and discomfort, and quality of life. This study aimed to analyze the relationship between uncorrected vision problems, educational outcomes, and musculoskeletal pain symptoms.

METHODS

A total of 152 school children (15.1 ± 0.8 years, mean ± SD; 40% males) were included in the study. All participants were recruited from a free-of-charge school vision testing program in Kathmandu, Nepal. Academic grades were collected from the school records of the participants' nationwide final grade examinations. A questionnaire was used to record the use of digital devices, screen time, and associated symptoms, including musculoskeletal pain (Wong-Baker FACES Pain Rating Scales).

RESULTS

A total of 61 children (40%) had uncorrected vision, with a cycloplegic refraction of SER - 0.53 ± 0.52 (mean ± SD). Children with uncorrected vision had significantly more third division grades (26 vs. 9%, p = 0.004) and shoulder pain in general/during screen use (66 vs. 43/40%, p = 0.008/0.003; 2.1/1.9 vs. 1.1/1.0 mean pain score, p = 0.002/0.001) compared with children with normal vision. Sex based subanalyses showed that only girls with uncorrected vision had more third division grades (25 vs. 4%, p = 0.006), and only boys with uncorrected vision had more shoulder pain in general/during screen use (76 vs. 28/31%, p < 0.001; 2.2/2.4 vs. 0.7 mean pain score, p < 0.001), compared with children with normal vision.

CONCLUSIONS

The results of this study showed that even small refractive errors may impact educational outcomes and musculoskeletal pain in adolescents. Most of the participating children had low myopia, easily corrected with glasses. This suggests that regular eye examinations are important in school children, and there is a need for raised awareness among parents, and school- and healthcare personnel.