Akkommodation und Presbyopie

The Effect of Age on Binocular Vision Normative Values

PURPOSE

To establish a relationship between age and horizontal heterophoria, horizontal fusional vergence amplitudes, and vergence facility testing.

METHODS

The sample consisted of 112 patients with a mean age of 39.8 ± 14.97 years (range: 18 to 65 years) and was composed of 61 women (54.5%) and 51 men (45.5%). The non-presbyopic group included patients 18 to 39 years old (n = 49) and the presbyopic group included patients 41 to 65 years old (n = 63). Binocular vision was studied by heterophoria horizontal magnitude (prism diopters [PD]), horizontal fusional vergences amplitudes (PD), and vergence facility testing (cycles per minute [cpm]) and quantified with a combination of 3 PD base-in and 12 PD base-out prisms.

RESULTS

Significant differences were obtained in near heterophoria with compensation (exophoria increased by 3.74 PD, t = 2.12, P < .05), distance positive fusional vergence (PFV) recovery (decreased by 2.86 PD, t = 3.03, P < .01), near PFV blur (decreased by 3.13 PD, t = 1.98, P = .05), near PFV break (decreased by 4.45 PD, t = 2.75, P < .01), near PFV recovery (decreased by 4.69 PD, t = 3.30, P < .01), and vergence facility testing (decreased by 2.63 PD, t = 2.77, P < .01).

CONCLUSIONS

The results indicated an increase of exophoria, a decrease in near positive horizontal fusional vergences, and vergence facility was dependent on age; thus, the authors suggest that changes in the normal values should be considered for each age range. [J Pediatr Ophthalmol Strabismus. 2020;57(6):363-371.].

Is it possible to relate accommodative visual dysfunctions to neck pain?

The aim of this study was to establish whether there is a relationship between conditions of accommodative visual dysfunctions and cervical complaints. Fifty-two participants were included. Variables were accommodative amplitude, positive and negative relative accommodation (NRA), accommodative response, and accommodative facility. Subjects were classified as accommodative insufficiency, accommodative excess, or normal. Neck complaints were measured with the Neck Disability Index, the Visual Analogue Scale, and by cervical range of motion, deep flexor muscle activation score, and performance index. We found the following significant relationships: between NRA and both performance index and left-side bending; accommodative amplitude right-eye with right-side bending and with left-side bending; accommodative amplitude left-eye with right-side bending; and accommodative facility left-eye with both performance index and left-side bending. In accommodative amplitude right-eye, aIl participants showed significant values and greater than those with accommodative excess. In both groups, performance index values were decreased. Greater pain and lower right-rotation were found in participants with accommodative excess than in those with accommodative insufficiency. We conclude that accommodative dysfunctions are related to low performance index, decreased range of motion, as well as greater neck pain.

Anterior Segment Changes during Accommodation in Accommodative Esotropia

Purpose

To evaluate the anterior segment biometric parameters of non-accommodative and accommodative refractive accommodative esotropia (RAE).

Methods

Eighty-one eyes of 81 patients were included in this prospective, case-control study. The patients were divided into three groups as follows: the RAE group (n = 31), the hypermetropia group (n = 25), and the emmetropia group (n = 25). Measurements were obtained in the non-accommodative (0.0 diopters) and accommodative status (-5.0 diopters) using a Pentacam HR. The anterior chamber depth (ACD), anterior chamber volume (ACV), pupil diameter (PD), and anterior chamber angle (ACA) were evaluated at all four quadrants.

Results

The ACD, ACV and PD values in the RAE group were lower than those of the other groups in both states (p < 0.05). The ACD values were lower in the hypermetropia group than in the emmetropia group for the non-accommodative status (p = 0.024) but were similar for the accommodative status (p = 0.225). PD and ACV values were lower in the hypermetropia group than in the emmetropia group in both states (non-accommodative status, p = 0.011 and p = 0.022; accommodative status, p = 0.026 and p = 0.034, respectively). Changes in ACD, ACV and PD during accommodation (Δ) were not significant in the RAE group but were significant for the other groups (hypermetropia: ΔACD, p = 0.001; ΔACV, p = 0.001; ΔPD, p = 0.002; emmetropia: ΔACD, p < 0.001; ΔACV, p = 0.001; ΔPD, p < 0.001). These changes were significantly lower in the hypermetropia group than in the emmetropia group (ΔACD, p = 0.012; ΔACV, p = 0.031; ΔPD, p = 0.034).

Conclusions

The anterior chamber in RAE patients was shallower and the increase in convexity of the anterior surface or forward movement of the crystalline lens was more limited during accommodation in RAE.

Repeatability of topographic and aberrometric measurements at different accommodative states using a combined topographer and open-view aberrometer

PURPOSE

To evaluate the repeatability of corneal first-surface aberrations and aberrometric measurements of a combined aberrometer-topographer (iTrace Visual Function Analyzer) for 5 accommodative stimuli.

SETTING

Department of Ophthalmology, Goethe-University, Frankfurt, Germany.

DESIGN

Prospective case series.

METHODS

Eyes of young adults with low to moderate myopia or hyperopia were examined in 2 measurement series comprising 3 corneal topography measurements and wavefront measurements focusing on targets at 5 distances (0.4, 0.5, 0.6, 1.0, and 4.0 m). Repeatability was analyzed using the standard deviation (SD) within 6 measurements and the coefficient of repeatability (CoR) by Bland-Altman analysis of the means of the 2 measurement series.

RESULTS

Fifty eyes (50 subjects) were evaluated. The lowest calculated mean SD/CoR measurements using the aberrometer function at 5 target distances were 0.07 μm/0.14 μm for total ocular aberrations root mean square (RMS), 0.07 μm/0.16 μm for lower-order aberrations (LOAs) RMS, 0.03 μm/0.66 μm for higher-order aberrations (HOAs) RMS, 0.10 diopter (D)/0.22 D for sphere, 0.08 D/0.13 D for cylinder, and 0.09 D/0.21 D for the spherical equivalent (SE). Repeatability of the total RMS, LOAs RMS, sphere, and SE measurements improved with increasing target distance (P < .01 for aberrometric values; P < .03 for refractive values). Measurement reproducibility using the corneal topographer showed mean SDs/CoRs of 0.19 μm/0.41 μm for total RMS, 0.19 μm/0.39 μm for LOAs RMS, and 0.08 μm/0.23 μm for HOAs RMS.

CONCLUSION

The aberrometer showed satisfactory results for measurement repeatability at all target distances and declining repeatability with increasing accommodation effort.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

[Comparison of two different surgical treatments of presbyopia for hyperopic patients over 55 years old: Presbylasik (Supracor) and Prelex (presbyopic lens exchange)]

INTRODUCTION

The management of presbyopic patients is a medical, surgical and economic issue. We wondered which procedure, whether a Presbylasik technique called Regular Supracor or the intraocular surgery of clear lens replacement by a trifocal diffractive lens (presbyopic lens exchange [Prelex]), provided the best results (in visual acuity and satisfaction) for our hyperopic and presbyopic patients between 55 and 70. The aim of this study was to compare the safety and efficacy of the two techniques (at one week and three months) and to assess patients' quality of life.

METHODS

This study is a retrospective monocentric clinical trial conducted between June 2011 and March 2014, on 21 hyperopic presbyopic patients (mean age 60.9 years), in the "hôpital d'instruction des armées-Percy" (Clamart); 13 patients underwent the corneal treatment of Presbylasik (with the Intralase FS60 femtosecond laser [AMO, USA] and the Technolas 217P excimer laser [Technolas Perfect Vision, GmbH] following the Zyoptix Tissue-Saving algorithm adjusted with a nomogram and the Regular Supracor mode), and 8 patients underwent clear lens extraction (Prelex), through bimanual phacoemulsification and implantation of diffractive trifocal intraocular lenses (Finevision Micro F, PhysIOL(*)).

RESULTS

Mean uncorrected binocular distance and near vision visual acuity in the Supracor group were respectively 0.03 (-0.2-0.1) LogMar and 0.23 (0.06-0.36) one week postoperatively and 0.031 (-0.2-0.1) and 0,166 (0.06-0.36) three months postoperatively. In the Prelex group, the mean uncorrected one week binocular VA was 0.025 (0-0.1) for distance vision and 0.165 (0.06-0.18) for near distance and the three months visual acuity was 0 (-0.1-0.1) and 0.105 (0.06-0.18) for distance and near vision. All Prelex patients were spectacle-free at all distances, whereas 4 Supracor patients required spectacles for near vision postoperatively. Seven of 11 patients in the Supracor group and 100% of the Prelex patients were completely satisfied. Both groups experienced halos, but patients reported more halos in the Prelex group (75%). One eye required intraocular lens exchange and four eyes (16.7%) required a new corneal procedure in the Supracor group.

CONCLUSION

Both surgeries are safe and effective modalities in the management of hyperopic and presbyopic patients. However, the Prelex procedure seems to be more appropriate for patients over 55 years of age.

Introduction of lens-angle reconstruction surgery in rabbit eyes

Purpose

In this study, we examined the stability of the lens-angle supporter (LAS) for accommodation restoration by comparing intraocular lens (IOL) location, after-cataract and ciliary body damage after cataract surgery in rabbits.

Methods

Eight rabbits were divided into experimental and control groups of four rabbits each. Phacoemulsification and irrigation and aspiration were performed in all rabbits. This was followed by an LAS and IOL insertion in the four experimental rabbits. In the four control rabbits, only an IOL insertion was performed. Six months after the surgery, the location of the IOL, the conditions of the lens capsule and ciliary body were evaluated using a slitl-amp examination and Miyake-Apple view.

Results

For the experimental group, the ultrasound biomicroscope results showed normal LAS and IOL positioning in all four cases. According to the slitlamp examination and Miyake-Apple view, the IOL was positioned at the center, with less after-cataract and damage to the ciliary body. For the control group, ultrasound biomicroscope results indicated a higher IOL position than normal, as well as a single case of IOL decentering. According to the slit-lamp examination and Miyake-Apple view, the IOL was decentered with more severe after-cataract and ciliary body damage.

Conclusions

The LAS has the potential to maintain a stable IOL position while producing less after-cataract when used in lens-angle reconstruction for correction of presbyopia. Moreover, LAS implantation incurs less damage to the ciliary body.

Automatic intraocular lens segmentation and detection in optical coherence tomography images

We present a new algorithm for automatic segmentation and detection of an accommodative intraocular lens implanted in a biomechanical eye model. We extracted lens curvature and position. The algorithm contains denoising and fan correction by a multi-level calibration routine. The segmentation is realized by an adapted canny edge detection algorithm followed by a detection of lens surface with an automatic region of interest search to suppress non-optical surfaces like the lens haptic. The optical distortion of lens back surface is corrected by inverse raytracing. Lens geometry was extracted by a spherical fit. We implemented and demonstrated a powerful algorithm for automatic segmentation, detection and surface analysis of intraocular lenses in vitro. The achieved accuracy is within the expected range determined by previous studies. Future improvements will include the transfer to clinical anterior segment OCT devices.

Biomechanical eye model and measurement setup for investigating accommodating intraocular lenses

We present a biomechanical eye model to induce pseudophakic accommodative movement for evaluation of the focal shift of accommodative intraocular lenses. Therefore, an accommodative intraocular lens (IOL) was implanted into freshly enucleated porcine eyes. The eyes were glued into a mechanical apparatus to expand the ciliar body effectuating mechanical accommodation. An optical coherence tomographer was used to measure positional and geometrical changes of the IOL for different levels of expansion. The expansion unit allowed stretching of the globe of several millimeters. With the biomechanical eye model we were able to simulate the mechanical functionality of accommodation as well as to measure the lens vault and change in geometry. Accommodative vault could only be measured with an intact vitreous, indicating that the vitreous plays an important role for the functionality of accommodative IOLs.