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At least 19 recordsLinked to original sources
PubMed2026

Repeated low-level red-light therapy for improving asthenopic symptoms and accommodation in presbyopia.

BACKGROUND: To assess the short-term effectiveness of repeated low-level red light (RLRL) therapy in relieving asthenopia and enhancing accommodation in presbyopia. METHODS: This randomized, parallel-group, double-masked clinical trial enrolled adults with presbyopia and self-reported asthenopia. Participants were allocated using computer-generated randomization and randomly assigned at a 1:1 ratio to RLRL or sham groups. Blinding included participants, examiners, assessors, and statisticians. The primary outcome was the change from baseline in the Computer Vision Syndrome Questionnaire (CVS-Q) score at day 31. Secondary outcomes were the change in accommodative amplitude (AA), Near Activity Visual Questionnaire (NAVQ) score, habitual near visual acuity, near-addition power, accommodative facility, positive and negative relative accommodation, binocular cross-cylinder response, and accommodative convergence-to-accommodation ratio. Continuous outcomes were analyzed using linear mixed-effects models. RESULTS: Sixty-four of 66 randomized participants (aged 41-62 years) completed the 1-month trial. At day 31, RLRL showed greater improvement than sham in CVS-Q score (adjusted mean difference, -1.75 points; 95% CI, -3.10 to -0.39), binocular AA (1.09 D; 95% CI, 0.37 to 1.82), and NAVQ score (-8.07 points; 95% CI, -14.17 to -1.97). The effect on AA was most pronounced in a subgroup of eyes with baseline amplitude >2.0 D (adjusted mean difference 1.33 D; 95% CI 0.32-2.34). Other measures did not differ between groups at each visit. No treatment-related adverse events were reported. Adherence was similar between groups (mean compliance: 98.2% vs 97.5%). CONCLUSIONS: Short-term treatment with RLRL significantly reduced asthenopic symptoms and improved accommodative amplitude in individuals with presbyopia.Trial registration: NCT06745661 (registered December 8, 2024).

Humans↗
PubMed1992

Cause and treatment of presbyopia with a method for increasing the amplitude of accommodation.

To understand the mechanism and cause of accommodation and presbyopia, the sclera in the region of the ciliary body of presbyopic patients was expanded. The amplitude of accommodation was increased in all presbyopic patients. A unique hypothesis of accommodation based on increased zonular tension is presented, which when applied clinically, results in a treatment for presbyopia.

Accommodation, Ocular↗
PubMed1991

The increasing sclerosis of the human lens with age and its relevance to accommodation and presbyopia.

By means of a fine conical probe and a miniature dynamometer, the resistance to penetration of different lens layers was measured. In clear human lenses the power of resistance of the lens nucleus increases with age, mostly due to the "hardening" of the nucleus. A distinct hardening of the nucleus as opposed to the cortex has been found to occur in lenses as young as 20 years of age. This "firmness" of the lens nucleus, occurring between the ages of 20 and 60 years, coincides with the decrease in accommodation range and the onset of presbyopia.

Accommodation, Ocular↗
PubMed1975

Exophoria at near in presbyopia.

The exophoria at near working distances through a plus lens addition which exists in presbyopia was investigated in order to explain the paradoxical lack of asthenopic symptoms associated with this condition. Fixation disparity measurements indicate that the exophoria which is measured by the von Graefe technique does not exist under binocular conditions. Further analysis indicates that presbyopes may have unrestrained use of accommodative convergence.

Accommodation, Ocular↗
PubMed1989

Presbyopia correction and the accommodation in reserve.

One method of determining the additional correction for presbyopia suggests leaving a percentage of the amplitude of accommodation in reserve. The rationale for this assumption seems logical because using all of the available accommodation is not sustainable without discomfort. However there is no empirical evidence indicating what percentage of the amplitude of accommodation should actually be left in reserve. Common figures adopted have been one-half and one-third. In this investigation the percentage of accommodation used is deduced mathematically after having determined the following: 1. The 'add' by the direct subjective clinical method. 2. Measured the amplitude of accommodation. 3. Measured the reading distance in 305 presbyopes ranging from 40 to 83 years of age. The results showed a small decline in the amplitude of accommodation up to the age of 52, after which age the measurements were scattered about a steady level. This finding suggests that after the age of 52 the results are based on the depth-of-focus of the eye. Females had slightly greater accommodation than males of the same age. The power of the add was significantly correlated to the age of the subject. The mean percentage of accommodation used for the 305 subjects was found to be 50.7%, thus confirming the rule of leaving half of the accommodation in reserve, although there were large variations: there were differences between males and females and with age the percentage of measured accommodation used, after having determined the correct add, diminished. Similarly the percentage of accommodation also decreased for shorter reading distances.

Accommodation, Ocular↗
PubMed1989

Contrast sensitivity with contact lens corrections for presbyopia.

We measured contrast sensitivity at three distances (330 mm, 660 mm and 4 m) with six contact lens and two multifocal spectacle corrections for presbyopia. The two spectacle corrections were D-segment bifocals and trifocals and the contact lens corrections were distance contact lens with lookover spectacles, soft progressive bifocals, soft concentric bifocals, monovision, modified monovision, and hard crescent segment bifocals. The spectacle corrections in general gave better results for the contrast sensitivity function (CSF), than did the contact lens corrections. Distance contact lenses with lookover spectacles performed best of the contact lens corrections used. However, the differences in CSF between the various contact lens corrections were small and not statistically significant.

Adolescent↗
PubMed1991

Induced hyperphoria in anisometropic presbyopia.

Anisometropia occurring either as a result of physiological or acquired etiologies may present a challenge to the optometrist if the patient is presbyopic. Fortunately, many patients with anisometropic presbyopia are able to adapt to near induced hyperphoria. There are, however, several options available for the optical management of symptomatic patients with near induced hyperphoria. These include: displacement of the distance optical centers, setting the bifocal segment higher than usual, using a combination of these two, dissimilar bifocal segments, slab-off prism and contact lenses. This paper reviews clinical considerations as well as the available spectacle management options.

Adaptation, Ocular↗
PubMed1990

Presbyopia and the dentist: the effect of age on clinical vision.

Vision is extremely important in dentistry where many clinical tasks requiring fine discrimination are performed. Presbyopia, an inability to focus sharply on near objects, affects all dentists in the later years of their practising lives and may have adverse effects on the practice of dentistry. This study examined the visual acuity of 172 practising dentists using a reduced Snellen chart imaged at 25 cm and 33 cm. Twenty-seven per cent failed the near vision test, having acuity of less than 6/9 at 25 cm, while 18 per cent had acuity of less than 6/7.5 at 33 cm; 96 per cent of those who failed at 25 cm and 93.5 per cent of those who failed at 35 cm were 45 years of age or more. Working distance (operating distance) was found to be significantly greater in dentists over the age of 45 than in a group of undergraduate dental students. No statistically significant relationship between visual acuity and working distance could be demonstrated. Regular examinations by qualified personnel are essential for dentists who should have their eyes checked every 2 years after the age of 40. Dentists should discuss their specific requirements for the practice of dentistry with their eye-care specialist. A suggested minimum standard of visual acuity for practising dentists is 6/7.5 at 33 cm.

Adult↗
PubMed1989

The path to presbyopia: straight or crooked?

The non-linear trends in the mean amplitude of accommodation with age that are observed in transverse studies as presbyopia is approached can be explained in terms of the summated effect of many individual linear trends. Increases in the near addition that may be required by patients after their early fifties are probably associated with an age-dependent decrease in acuity, which necessitates a closer working distance to increase angular subtense, rather than with any continuing decline in accommodation.

Accommodation, Ocular↗
PubMed1976

[Convergent strabismus in the age of presbyopia (author's transl)].

Based on 15 case reports it can be shown, that the onset of a convergent squint is even possible in the age of presbyopia, independent of the patient's refraction. The clinical picture resembles that of a divergence paralysis or the convergent strabismus of the Bielschowsky type. In 13 cases the decompensation of a previous esophoria may have caused this distance-esodeviation; a divergence paralysis is not probable. In two cases change of orthophoria to esotropia could be observed. Therefore we share the opinion of v. Graefe, that an increased tonicity of the internal recti induced for compensation of weak convergence in aged individuals may cause esotropia. Treatment with prisms for distant vision is easy and effective. No case required surgery.

Aged↗
PubMed1989

Accommodation and presbyopia in the human eye--aging of the anterior segment.

Ocular biometric parameters and accommodative amplitude were measured by various techniques in 100 normal emmetropic human subjects age 18-70 yr. Anterior chamber depth decreased and lens thickness increased linearly over the entire age group. Accommodative amplitude declined linearly until a stable nadir was reached at about age 50 yr. The respective slopes and intercepts of the age-dependent decline in anterior chamber depth were essentially the same for measurements made independently by optical pachmetry, A-scan ultrasonography, and slit-lamp Scheimpflug photography. The age-dependent increase in lens thickness differed in slope and intercept for measurements made by photography and ultrasonography if the generally accepted lenticular sound velocity was assumed for all subjects. However, if putative lenticular sound velocity was adjusted for age, the relationships given by the two techniques were essentially identical. Total anterior segment length (defined as the distance between the anterior corneal and posterior lens surfaces), vitreous cavity length (distance between the posterior lens and anterior retinal surfaces), and total globe length were all independent of age. This constellation of findings indicates that the human lens grows throughout adult life while the globe does not, that thickening of the lens completely accounts for shallowing of the anterior chamber with age, but that the posterior surface of the lens remains fixed in position relative to the cornea and retina.

Accommodation, Ocular↗
PubMed1991

Prandial presbyopia: the muffin man.

Transient blurring of near vision can be due to a variety of causes. We report the case of a 35-year-old man with a 10-year history of blurring of near vision that begins 30 to 45 seconds after he starts to eat and that lasts until 10 to 15 minutes after he stops eating. Magnetic resonance imaging and computed tomography of the brain and orbits did not reveal any abnormality, and stimulation of individual cranial nerves did not result in a loss of near vision. Retinoscopic refraction revealed the loss of 1.5 dioptres of accommodative power in each eye one minute after he began to eat. To the best of our knowledge such blurring of vision at near, immediately after initiating a meal, has not been previously reported. The neuroanatomy of the accommodation and of the gustatory pathways are discussed, as they may relate to this patient's visual complaint.

Accommodation, Ocular↗