Effect of decentration and tilt on the in vitro optical quality of monofocal and trifocal intraocular lenses.

PURPOSE: To evaluate and compare the effect of decentration and tilt on the optical quality of monofocal and trifocal intraocular lenses (IOL). METHODS: Optical quality of a monofocal IOL (AcrySof IQ SN60WF; Alcon Laboratories, Inc., USA) and a trifocal IOL (AcrySof IQ PanOptix; Alcon Laboratories, Inc., USA) was assessed using an in vitro optical bench (OptiSpheric IOL R&D; Trioptics GmbH, Germany). At apertures of 3.0 mm and 4.5 mm, modulation transfer function (MTF) at spatial frequency of 50 lp/mm, MTF curve and the United States Air Force (USAF) resolution test chart of the two IOLs were measured and compared at their focus with different degrees of decentration and tilt. Optical quality at infinity, 60 cm and 40 cm and the through-focus MTF curves were compared when the two IOLs were centered at apertures of 3.0 mm and 4.5 mm. Spectral transmittance of the two IOLs was measured by the UV-visible spectrophotometer (UV 3300 PC; MAPADA, China). RESULTS: The SN60WF and the PanOptix filtered blue light from 400 to 500 nm. Both IOLs at the far focus and the PanOptix at the intermediate focus showed a decrease in optical quality with increasing decentration and tilt. The PanOptix demonstrated enhanced optical quality compared to the previous gradient at the near focus at a decentration range of 0.3-0.7 mm with a 3.0 mm aperture, and 0.5 mm with a 4.5 mm aperture, whereas other conditions exhibited diminished optical quality with increasing decentration and tilt at the focus of both IOLs. When the two IOLs were centered, the SN60WF had better optical quality at infinity, while the PanOptix had better optical quality at 60 cm and 40 cm defocus. The optical quality of the SN60WF exceeded that of the PanOptix at far focus, with a 3 mm aperture decentration up to 0.7 mm and a 4.5 mm aperture decentration up to 0.3 mm; this observation held true for all tilts, irrespective of aperture size. As both decentration and tilt increased, the optical quality of the SN60WF deteriorated more rapidly than that of the PanOptix at the far focal point. CONCLUSIONS: The SN60WF showed a decrease in optical quality with increasing decentration and tilt. Optical quality of the PanOptix at the near focus increased in some decentration conditions and decreased in some conditions, while it showed a decrease at the other focuses with increasing decentration. While tilt only had a negative effect on optical quality. When both IOLs were centered, the PanOptix provided a wider range of vision, while the SN60WF provided better far distance vision. At the far focus, the SN60WF has better resistance to tilt than the PanOptix, but the optical quality degrades more quickly when decentered and tilted.

Algorithm of automatic identification of diabetic retinopathy foci based on ultra-widefield scanning laser ophthalmoscopy.

AIM: To propose an algorithm for automatic detection of diabetic retinopathy (DR) lesions based on ultra-widefield scanning laser ophthalmoscopy (SLO). METHODS: The algorithm utilized the FasterRCNN (Faster Regions with CNN features)+ResNet50 (Residua Network 50)+FPN (Feature Pyramid Networks) method for detecting hemorrhagic spots, cotton wool spots, exudates, and microaneurysms in DR ultra-widefield SLO. Subimage segmentation combined with a deeper residual network FasterRCNN+ResNet50 was employed for feature extraction to enhance intelligent learning rate. Feature fusion was carried out by the feature pyramid network FPN, which significantly improved lesion detection rates in SLO fundus images. RESULTS: By analyzing 1076 ultra-widefield SLO images provided by our hospital, with a resolution of 2600×2048 dpi, the accuracy rates for hemorrhagic spots, cotton wool spots, exudates, and microaneurysms were found to be 87.23%, 83.57%, 86.75%, and 54.94%, respectively. CONCLUSION: The proposed algorithm demonstrates intelligent detection of DR lesions in ultra-widefield SLO, providing significant advantages over traditional fundus color imaging intelligent diagnosis algorithms.

Visual impairment and blindness caused by retinal diseases: A nationwide register-based study.

Background: Retinal disorders cause substantial visual burden globally. Accurate estimates of the vision loss due to retinal diseases are pivotal to inform optimal eye health care planning and allocation of medical resources. The purpose of this study is to describe the proportion of visual impairment and blindness caused by major retinal diseases in China. Methods: A nationwide register-based study of vitreoretinal disease covering all 31 provinces (51 treating centres) of mainland China. A total of 28 320 adults diagnosed with retinal diseases were included. Participants underwent standardised ocular examinations, which included best-corrected visual acuity (BCVA), dilated-fundus assessments, and optical coherence tomography. Visual impairment and blindness are defined using BCVA according to the World Health Organization (WHO) (visual impairment: <20/63-≥20/400; blindness: <20/400) and the United States (visual impairment: <20/40-≥20/200; blindness: <20/200) definitions. The risk factors of vision loss were explored by logistic regression analyses. Results: Based on the WHO definitions, the proportions for unilateral visual impairment and blindness were 46% and 18%, respectively, whereas those for bilateral visual impairment and blindness were 31% and 3.3%, respectively. Diabetic retinopathy (DR) accounts for the largest proportion of patients with visual impairment (unilateral visual impairment: 32%, bilateral visual impairment: 60%) and blindness (unilateral blindness: 35%; bilateral blindness: 64%). Other retinal diseases that contributed significantly to vision loss included age-related macular degeneration, myopic maculopathy, retinal vein occlusion, and rhegmatogenous retinal detachment and other macular diseases. Women (bilateral vision loss: P = 0.011), aged patients (unilateral vision loss: 45-64 years: P < 0.001, ≥65 years: P < 0.001; bilateral vision loss: 45-64 years: P = 0.003, ≥65 years: P < 0.001 (reference: 18-44 years)) and those from Midwest China (unilateral and bilateral vision loss: both P < 0.001) were more likely to suffer from vision loss. Conclusions: Retinal disorders cause substantial visual burden among patients with retinal diseases in China. DR, the predominant retinal disease, is accountable for the most prevalent visual disabilities. Better control of diabetes and scaled-up screenings are warranted to prevent DR. Specific attention should be paid to women, aged patients, and less developed regions.

Effect of optional biometric parameters in the Kane formula on intraocular lens power calculation.

PURPOSE: To investigate the effect of the optional biometric parameters lens thickness (LT) and center corneal thickness (CCT) in the Kane formula on intraocular lens (IOL) power calculation. METHODS: A cross-sectional study included consecutive cataract patients who received uncomplicated cataract surgery with IOL implantation from May to September 2022 were enrolled. The ocular biometric parameters were obtained using IOLMaster 700 and then inputted into online Kane formula calculator. The IOL power was calculated for targeting emmetropia and compared between groups: not omitting (NO) group, omitting LT and CCT (OLC) group, omitting LT (OL) group and omitting CCT (OC) group. Further, according to the axial length (AL), anterior chamber depth (ACD), and mean keratometry (Km), the eyes were divided into three subgroups, respectively. RESULTS: 1005 eyes of 1005 consecutive patients were included. There was no significant difference in IOL power between NO group and OC group (P = 0.064), and the median absolute difference (MedAD) was 0.05D. The IOL power in NO group showed significant differences from OLC group and OL group respectively (P < 0.001), and both MedAD values were 0.18D. Among AL subgroups, MedAD ranged from 0.06D to 0.35D in short eyes. Among ACD subgroups, the above values ranged from 0.06D to 0.23D in shallow ACD subgroup. Among Km subgroups, these values ranged from 0.05D to 0.31D in steep Km subgroup. CONCLUSION: The optional biometric parameter CCT has no effect on the calculation results of the Kane formula, whereas the parameter LT has a great influence on the Kane formula results for the IOL power calculation in cataract patients with short AL, shallow ACD and steep Km.

The Mechanosensitive Piezo1 Channel Mediates Mechanochemical Transmission in Myopic Eyes.

Purpose: To identify the expression of the mechanosensitive ion channel Piezo1 in the retina of guinea pigs with form deprivation myopia (FDM) and to investigate mechanisms by which Piezo1 channels might regulate myopia. Method: Sixty 3-week-old guinea pigs were divided into four groups randomly: normal control, FDM, FDM + vehicle control (DMSO), and FDM + Piezo1 inhibitor (GsMTx4). Measurements of spherical equivalent (SE) and axial length (AL) of the guinea pig were taken using retinoscopy and A-scan ultrasound examination, respectively. Location of Piezo1 protein was determined using immunohistochemistry. The histological structure and thickness changes of the guinea pig retina were observed by hematoxylin and eosin. Expression of Piezo1 in the retina was detected using quantitative RT-PCR and Western blot. Reactive oxygen species (ROS) levels in the retina were measured using flow cytometry. Result: After 4 weeks of form deprivation, the FDM group exhibited a significantly increased myopic degree and axial length compared with the normal control group (all P < 0.001), and had higher expression levels of Piezo1 and ROS than the normal control group (P < 0.001 and P = 0.002, respectively). Piezo1 protein expression was down-regulated in guinea pigs given GsMTx4 compared with the DMSO group (P = 0.037). Additionally, the GsMTx4 group showed lower myopic degree (P < 0.001) and lower ROS levels (P = 0.019) compared with the DMSO group. Conclusions: The Piezo1 channel may be activated in the retinas of FDM guinea pigs and be involved in the development of myopia by regulating intraocular ROS levels.

All-trans retinoic acid regulates the expression of MMP-2 and TGF-ß2 via RDH5 in retinal pigment epithelium cells.

AIM: To investigate the effect of all-trans retinoic acid (ATRA) on retinol dehydrogenase 5 (RDH5), matrix metalloproteinase-2 (MMP-2) and transforming growth factor-ß2 (TGF-ß2) transcription levels, and the effect of RDH5 on MMP-2 and TGF-ß2 in retinal pigment epithelium (RPE) cells. METHODS: After adult RPE cell line-19 (ARPE-19 cells) intervened with gradient concentrations of ATRA (0-20 µmol/L) for 24h, flow cytometry was used to detect the proliferation and apoptosis of cells in each group, and quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect RDH5, MMP-2 and TGF-ß2 mRNA expression. Then, after ARPE-19 cells transfected with three different siRNA targets for 48h, the RDH5 knockdown efficiency of each group and expression of MMP-2 and TGF-ß2 mRNA within them was detected by qRT-PCR. RESULTS: Flow cytometry results showed that ATRA could inhibit the proliferation of RPE cells and promote the apoptosis of RPE cells, and the difference of apoptosis was statistically significant when the ATRA concentration exceeded 5 µmol/L and compared with the normal control group (P=0.027 and P=0.031, respectively). qRT-PCR results showed that ATRA could significantly inhibit the expression level of RDH5 mRNA (P<0.001) and promote the expression of MMP-2 and TGF-ß2 mRNA (P=0.03 and P<0.001, respectively) in a dose-dependent manner, especially when treated with 5 µmol/L ATRA. The knockdown efficiency of RDH5 siRNA varies with different targets, among which RDH5 siRNA-435 had the highest knockdown efficiency, i.e., more than 50% lower than that of the negative control group (P=0.02). When RDH5 was knocked down for 48h, the results of qRT-PCR showed that the expressions of MMP-2 and TGF-ß2 mRNA were significantly up-regulated (P<0.001). CONCLUSION: ATRA inhibits the expression of RDH5 and promotes MMP-2 and TGF-ß2, and further RDH5 knockdown significantly upregulates MMP-2 and TGF-ß2. These findings suggest that RDH5 may be involved in an epithelial-mesenchymal transition of RPE cells mediated by ATRA.

Cataract surgery is not associated with post-operative binocular vision anomalies in age-related cataract patients.

PURPOSE: To compare the binocular vision status of patients pre- and post-cataract surgery, and to investigate the risk factors for patients who develop binocular vision anomalies post-surgery. METHODS: A prospective study of patients (≥50 years) who elected to undergo bilateral cataract surgery was implemented. A comprehensive binocular vision test battery including stereopsis, ocular alignment, fusional vergence, vergence facility, near point of convergence and the Convergence Insufficiency Symptom Survey (CISS) was administered before the first surgery and at the third visit after surgery on the second eye. A detailed diagnostic classification protocol was applied to identify the presence of binocular vision anomalies pre- and post-surgery. RESULTS: Seventy-three participants were included at baseline, 24 (33%) of whom were diagnosed with non-strabismic binocular vision anomalies (NSBVA), mainly convergence insufficiency (18/73, 25%). Fifty-one participants completed the post-operative evaluation, 17 (33%) of whom had NSBVA pre-surgery and 13 (26%) post-surgery (p = 0.48). There were a number of conversions from NSBVA to normal binocular vision and vice versa. Logistic regression showed that the adjusted odds ratio of pre-existing NSBVA diagnosis for predicting the risk of post-operative NSBVA was 6.37 (p < 0.01). There were no significant changes in most binocular vision measures post-surgery, except for a significant improvement in the CISS score (p < 0.01, Cohen's d = 0.83). CONCLUSIONS: Binocular vision anomalies, especially convergence insufficiency, are prevalent in the age-related cataract population. Cataract surgery does not appear to be a significant risk factor for the development of new binocular vision anomalies. A pre-existing binocular vision anomaly is the main risk factor for predicting a post-operative binocular vision anomaly in this population.

Repeatability of i.Profiler for measuring wavefront aberrations in healthy eyes.

PURPOSE: To evaluate the repeatability of wavefront aberration measurements and the correlation between corneal aberration and pupil size in normal eyes using a wavefront-based autorefractor (i.ProfilerPlus; Carl Zeiss Vision, Germany). METHODS: A prospective cross-sectional study. Wavefront aberrations, including spherical aberration (SA) (Z40), coma (Z3-1, Z31), trefoil (Z3-3, Z33) and total higher-order aberrations (tHOA), were measured at different pupil diameters. The repeatability was evaluated using one-way ANOVA method, and statistical indicators including within-subject standard deviation (Sw), test-retest repeatability (TRT), and intra-class correlation coefficient (ICC). The correlations between corneal aberrations and pupil sizes were evaluated by Pearson correlation analysis. RESULTS: A total of 96 healthy young volunteers were enrolled. Corneal and ocular higher-order aberrations (HOA) measured by i.Profiler showed Sw < 0.01 µm, TRT < 0.10 µm, ICC > 0.90. There was a linear positive correlation between the corneal HOA and pupil size. The correlation coefficient between SA and tHOA was the largest (r = 0.996, P < 0.001). CONCLUSIONS: The measurements of wavefront aberrations by i.Profiler are highly repeatable. Corneal HOA was significantly dependent on pupil size. SA was the most influential aberration for visual quality in this study.

Preoperative binocular vision characteristics in the age-related cataract population.

BACKGROUND: This study is the first part of the "Binocular Vision Anomalies after Cataract Surgery" study that aimed to investigate the impact of cataract surgery on binocular vision status in adults with age-related cataract. This study aimed to investigate the preoperative binocular vision status of participants with age-related cataract. METHODS: Patients who elected to undergo bilateral cataract surgery (≥50 years of age) were recruited. Clinical measures of binocular vision including stereopsis, ocular alignment, fusional vergence, vergence facility, convergence amplitude and a symptom survey related to binocular vision anomalies were administered. A detailed classification protocol was established to identify the presence of binocular vision anomalies. The frequency of specific binocular vision anomalies and normative data of binocular vision measures were reported. RESULTS: A total of 73 subjects were evaluated. No strabismus was detected in the cohort. Non-strabismic binocular vision anomalies were detected in 24 subjects (32.9%), of whom 18 (24.7%) had convergence insufficiency, 3 (4.1%) had basic exophoria, 2 (2.7%) had convergence excess, and 1 (1.4%) had fusional vergence dysfunction. Decreased vergence facility and convergence amplitude were more common compared to the pre-presbyopes (P < 0.01). CONCLUSION: Binocular vision problems, especially convergence insufficiency, are common in the adults with age-related cataract. The study results demonstrate that the lack of normative binocular vision data for the presbyopic population is a significant gap in the literature and suggest the need for a study of normative data for this population. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (NCT03592615, USA).

Expression of SCO1 and SCO2 after form-deprivation myopia in Guinea pigs.

PURPOSE: The retina is a highly energy-consuming tissue associated with visual development, and the reduced quality of retinal imaging can be related to myopia. Synthesis of cytochrome c oxidase 1 (SCO1) and synthesis of cytochrome c oxidase 2 (SCO2) are involved in ATP (adenosine triphosphate) synthesis and energy metabolism. This study aimed to observe the morphologic changes and investigate the expression of SCO1 and SCO2 induced by form-deprivation myopia (FDM) in the retina and sclera of guinea pigs. METHODS: Thirty-six 3-week-old male guinea pigs were randomly assigned to one of two groups: (1) the model group (n = 18), in which the right eyes were covered by a thin opaque balloon as FDM group, and the left eyes were uncovered and served as the contralateral control group; (2) the blank control group (n = 18), in which bilateral eye received no manipulation. Eyeballs were enucleated for histological analysis. The retina and sclera of the guinea pigs were separated to determine the protein and mRNA expression levels of SCO1 and SCO2, respectively. RESULTS: After four weeks of form deprivation (FD), the refractive degree and axial length increased significantly (P < 0.001). The retinal and scleral tissues were moderately thinner, and the ganglion cells and the cells of inner and outer nuclear layers in the retina became fewer. Compared with the contralateral control group (P < 0.001) and the blank control group (P < 0.001), the collagen content of the sclera became less in the FDM group. The protein and mRNA expression levels of SCO1 and SCO2 in the FDM group were significantly lower than those in the contralateral control group and the blank control group (P < 0.05). CONCLUSIONS: The morphologies of the retina and sclera were changed, and the expression of SCO1 and SCO2 at the protein and transcription levels was significantly reduced in the FDM group. Given these changes, SCO1 and SCO2 genes may be involved in myopic progression.

Impact of different clear corneal incision sizes on anterior corneal aberration for cataract surgery / Impacto de diferentes tamanhos de incisões em córnea clara nas aberrações da córnea anterior em cirurgia de catarata

ABSTRACT Purpose: To investigate the impact of different sizes of steep meridian clear corneal incisions for phacoemul sification on anterior corneal higher-order aberrations. Methods: Medical records of patients who underwent 2.2-mm coaxial micro-incision cataract surgery or 2.75-mm coaxial small-incision cataract surgery were retrospectively reviewed. Only patients with preexisting anterior corneal astigmatism <2.00 diopters (D) and ≥0.50 D who underwent a steep meridian clear corneal incision were included. Primary outcomes were 3rd- to 6th-order anterior corneal higher-order aberrations with an 8-mm pupil. Anterior corneal astigmatism and effective phaco time were evaluated as secondary outcomes. Preoperative and 3-month postoperative outcomes were evaluated. Results: Anterior corneal astigmatism significantly decreased after both procedures; however, there was no significant difference found in surgically induced anterior corneal astigmatism between the two procedures (p=0.146). Although the total higher-order aberrations did not significantly change after both procedures, the group comparison showed a significant difference in surgically induced total higher-order aberrations (a decrease of 0.337 ± 1.156 mm in 2.2-mm coaxial micro-incision cataract surgery and an increase of 0.106 ± 0.521 mm in 2.75-mm coaxial small-incision cataract surgery, p=0.046). Spherical aberrations significantly decreased after 2.2-mm coaxial micro-incision cataract surgery (p=0.001), whereas they did not change significantly after 2.75-mm coaxial small-incision cataract surgery (p=0.564). Coma did not significantly change after either of the procedures. Trefoil did not significantly change after 2.2-mm coaxial micro-incision cataract surgery (p=0.361), whereas it significantly increased after 2.75-mm coaxial small-incision cataract surgery (p<0.001). There was no significant difference shown in effective phaco time between the procedures. A significantly positive correlation was shown between surgically induced anterior corneal astigmatism and coma in 2.75-mm coaxial small-incision cataract surgery (r=0.387, p=0.006). There was no significant correlation found between any surgically induced higher-order aberration changes and effective phaco time. Conclusions: The results showed that 2.2-mm coaxial micro-incision cataract surgery and 2.75-mm coaxial small-incision cataract surgery did not significantly degrade the total higher-order aberrations of the anterior cornea. However, the surgically induced changes in total higher-order aberration showed a significant difference between the two procedures, with a slight reduction after 2.2-mm coaxial micro-incision cataract surgery and a slight increase after 2.75-mm coaxial small-incision cataract surgery. Phaco time and power used during surgery had no impact on corneal aberrations.

RESUMO Objetivo: Investigar o impacto de diferentes ta manhos de incisões em córnea clara com meridiano íngreme para facoemulsificação com aberrações de mais alta ordem da córnea anterior. Métodos: Foram retrospectivamente revisados os prontuários médicos de pacientes que se submeteram a cirurgias de catarata com microincisões coaxiais de 2,2 mm ou com incisões coaxiais pequenas de 2,75 mm. Foram apenas incluídos pacientes com astigmatismo preexistente da córnea anterior <2,00 dioptrias (D) e ³0,50 D, e submetidos a incisões em córnea clara com meridiano íngreme. Os desfechos primários foram aberrações da córnea anterior da 3ª à 6ª ordem com uma pupila de 8 mm. O astigmatismo da córnea anterior e o tempo efetivo de facoemulsificação foram avaliados como desfechos secundários. Os desfechos pré-operatório e pós-operatório aos 3 meses também foram avaliados. Resultados: O astigmatismo da córnea anterior diminuiu significativamente após ambos os procedimentos, mas não se encontrou nenhuma diferença significativa entre os dois procedimentos quanto ao astigmatismo da córnea anterior, induzido pela cirurgia (p=0,146). Embora as aberrações totais de mais alta ordem não se tenham alterado significativamente após ambos procedimentos, a comparação entre os grupos revelou uma diferença significativa nas aberrações totais de mais alta ordem, induzidas pela cirurgia (uma diminuição de 0,337 ± 1,156 mm na cirurgia de catarata por microincisão coaxial de 2,2 mm e um aumento de 0,106 ± 0,521 mm na cirurgia de catarata por incisão coaxial pequena de 2,75 mm; p=0,046). A aberração esférica diminuiu significativamente após cirurgia de catarata por microincisão coaxial de 2,2 mm (p=0,001), mas não se alterou significativamente após cirurgia de catarata por incisão coaxial pequena de 2,75 mm (p=0,564). A aberração de coma não mudou significativamente após qualquer dos procedimentos. O trifólio não se alterou significativamente após cirurgia de catarata por microincisão coaxial de 2,2 mm (p=0,361), mas aumentou significativamente após cirurgia de catarata por incisão coaxial pequena de 2,75 mm (p<0,001). Nenhuma diferença significativa se evidenciou quanto ao tempo efetivo de faco-emulsificação entre os dois procedimentos. Houve uma correlação positiva significativa entre o astigmatismo da córnea anterior, induzido pela cirurgia e a aberração de coma na cirurgia de catarata por incisão coaxial pequena de 2,75 mm (r=0,387, p=0,006). Não foi encontrada correlação significativa entre as alterações nas aberrações totais de mais alta ordem, induzidas pela cirurgia e o tempo efetivo de faco-emulsificação. Conclusões: Nem a cirurgia de catarata por microincisão coaxial de 2,2 mm, nem aquela por incisão coaxial pequena de 2,75 mm degradaram significativamente as aberrações totais de mais alta ordem da córnea anterior. Porém, as alterações nas aberrações totais de mais alta ordem, induzidas pela cirurgia mostraram uma diferença significativa entre os dois procedimentos, com uma ligeira redução na cirurgia de catarata por microincisão coaxial de 2,2 mm e um pequeno aumento na cirurgia de catarata por incisão coaxial pequena de 2,75 mm. O tempo de facoemulsificação e a potência utilizada durante a cirurgia não tiveram impacto nas aberrações corneanas.

Comparison of visual quality after implantation of A1-UV and SN60WF aspheric intraocular lens.

AIM: To compare the visual performance of pseudophakic eyes implanted with A1-UV and SN60WF aspheric intraocular lens (IOL), and to investigate the correlations between visual quality parameters and pupil size. METHODS: This prospective comparative study included 105 eyes of 90 patients with age-related cataract who underwent uneventful phacoemulsification. The subjects were divided into two groups according to the implanted IOL type. Three months postoperatively, visual acuity and contrast sensitivity were measured, wave-front aberrations were assessed using a KR-1W aberrometer (Topcon), and objective optical quality parameters were performed using an optical quality analysis system-OQAS II (Visiometrics). Independent sample t-test and Spearman correlation analysis were used for data analysis. RESULTS: There were no significant differences found in visual acuity, contrast sensitivity and visual quality parameters between the two groups (P>0.05). The measured intraocular spherical aberration (SA) in A1-UV IOL eyes of -0.19±0.05 µm was close to the designed SA value of -0.20 µm. The modulation transfer function cutoff, Strehl ratio and OQAS values were negatively correlated with pupil size in both groups (P<0.01). CONCLUSION: The subjective and objective visual quality in pseudophakic eyes with A1-UV and SN60WF IOLs are comparable. For aspheric IOL eyes, visual quality decreases with increasing pupil size.

Agreement of ocular biometric measurements in young healthy eyes between IOLMaster 700 and OA-2000.

This prospective cross-sectional study aimed to evaluate the agreement of two new biometers for measuring ocular biometric parameters in young healthy eyes. Ocular biometric parameters were measured using IOLMaster 700 and OA-2000. Power vector analyses of Cartesian (J0) and oblique (J45) components of corneal astigmatism were performed. The right eyes of 103 healthy volunteers were analyzed. The 95% limits of agreement ranged from -0.03 to 0.03 mm, -0.08 to 0.07 mm, -0.18 to 0.18 diopters (D), -1.09 to 1.16 D, -1.18 to 1.15 D for axial length (AL), anterior chamber depth (ACD), mean keratometry, J0 and J45 respectively, which were all comparable between the two biometers, while significant differences were detected in lens thickness (LT), central corneal thickness (CCT), white-to-white (WTW) and pupil diameter (PD). Predicted intraocular lens (IOL) powers were comparable between the two biometers by Haigis and Barrett Universal II formulas, while not by SRK/T, Hoffer Q and Holladay 2. Excepting CCT, WTW and PD meaurements, IOLMaster 700 and OA-2000 have excellent agreement on ocular biometric measurements and astigmatism power vectors, which provides more options for ocular biometric measurements and enables constant optimization for IOL power calculation.

Impact of different clear corneal incision sizes on anterior corneal aberration for cataract surgery.

PURPOSE: To investigate the impact of different sizes of steep meridian clear corneal incisions for phacoemul sification on anterior corneal higher-order aberrations. METHODS: Medical records of patients who underwent 2.2-mm coaxial micro-incision cataract surgery or 2.75-mm coaxial small-incision cataract surgery were retrospectively reviewed. Only patients with preexisting anterior corneal astigmatism <2.00 diopters (D) and ≥0.50 D who underwent a steep meridian clear corneal incision were included. Primary outcomes were 3rd- to 6th-order anterior corneal higher-order aberrations with an 8-mm pupil. Anterior corneal astigmatism and effective phaco time were evaluated as secondary outcomes. Preoperative and 3-month postoperative outcomes were evaluated. RESULTS: Anterior corneal astigmatism significantly decreased after both procedures; however, there was no significant difference found in surgically induced anterior corneal astigmatism between the two procedures (p=0.146). Although the total higher-order aberrations did not significantly change after both procedures, the group comparison showed a significant difference in surgically induced total higher-order aberrations (a decrease of 0.337 ± 1.156 mm in 2.2-mm coaxial micro-incision cataract surgery and an increase of 0.106 ± 0.521 mm in 2.75-mm coaxial small-incision cataract surgery, p=0.046). Spherical aberrations significantly decreased after 2.2-mm coaxial micro-incision cataract surgery (p=0.001), whereas they did not change significantly after 2.75-mm coaxial small-incision cataract surgery (p=0.564). Coma did not significantly change after either of the procedures. Trefoil did not significantly change after 2.2-mm coaxial micro-incision cataract surgery (p=0.361), whereas it significantly increased after 2.75-mm coaxial small-incision cataract surgery (p<0.001). There was no significant difference shown in effective phaco time between the procedures. A significantly positive correlation was shown between surgically induced anterior corneal astigmatism and coma in 2.75-mm coaxial small-incision cataract surgery (r=0.387, p=0.006). There was no significant correlation found between any surgically induced higher-order aberration changes and effective phaco time. CONCLUSIONS: The results showed that 2.2-mm coaxial micro-incision cataract surgery and 2.75-mm coaxial small-incision cataract surgery did not significantly degrade the total higher-order aberrations of the anterior cornea. However, the surgically induced changes in total higher-order aberration showed a significant difference between the two procedures, with a slight reduction after 2.2-mm coaxial micro-incision cataract surgery and a slight increase after 2.75-mm coaxial small-incision cataract surgery. Phaco time and power used during surgery had no impact on corneal aberrations.

Optical quality in low astigmatic eyes with or without cylindrical correction.

PURPOSE: To investigate whether optical quality could be improved by cylindrical correction for low astigmatic eyes with different amounts and axis orientations in patients with myopia up to - 3.00 diopters (D). METHODS: A cross-sectional study enrolling healthy young eyes with 0 to - 3.00 D myopia and - 0.50 to - 0.75 D myopic astigmatism was implemented. With a repeated-measures design, outcome measures were sequentially obtained for each subject under two correction modalities: spherocylindrical correction and spherical correction. Subjective refraction was used to determine the refractive prescriptions accordingly in the two correction modalities to obtain optimal subject-reported visual acuity. Primary outcomes were optical quality parameters including objective scatter index (OSI), modulation transfer function (MTF) cut-off, Strehl ratio (SR), and a simulated contrast visual acuity-optical quality analysis system (OQAS) values (OV) obtained by a double-pass system. Corrected distance visual acuity (CDVA) was measured as a secondary outcome. Outcome comparisons between the two correction modalities were performed by grouping in different amounts (- 0.50 D, - 0.75 D) and axes (with the rule, WTR; against the rule, ATR; oblique, OBL) of astigmatism. RESULTS: A total of 194 eyes of 194 subjects were evaluated. Significantly better CDVA were shown by spherocylindrical correction for all types of astigmatism except for - 0.50 D WTR astigmatism (P = 0.831). For eyes with - 0.50 D WTR astigmatism, better outcome was only shown in OSI with spherocylindrical correction (P = 0.019). For eyes with - 0.50 D ATR and OBL astigmatism, spherocylindrical correction demonstrated better outcomes in all parameters except for SR (P > 0.05). For eyes with - 0.75 D astigmatism, significantly better outcomes in all optical quality parameters were shown with spherocylindrical correction regardless of the axis (P < 0.05). CONCLUSIONS: Eyes with ATR or OBL myopic astigmatism may benefit in optical quality and visual acuity by combining a cylindrical correction even with a low amount down to - 0.50 D. However, optical quality and visual acuity improvement are limited for WTR astigmatic eyes when the amount of astigmatism is less than - 0.75 D.

Myopia genetics in genome-wide association and post-genome-wide association study era.

Genome-wide association studies (GWAS) of myopia and refractive error have generated exciting results and identified novel risk-associated loci. However, the interpretation of the findings of GWAS of complex diseases is not straightforward and has remained challenging. This review provides a brief summary of the main focus on the advantages and limitations of GWAS of myopia, with potential strategies that may contribute to further insight into the genetics of myopia in the post-GWAS or omics era.

Objective optical quality in eyes with customized selection of aspheric intraocular lens implantation.

BACKGROUND: To compare the postoperative optical quality in eyes with customized selection and random selection of aspheric intraocular lens (IOL) implantation. METHODS: A prospective, nonrandomized study was implemented in adult cataract patients who underwent unilateral phacoemulsification with aspheric IOL implantation. Patients were allocated into two treatment groups: a customized group and a control group. In the customized group, the aspheric IOL selection was based on the corneal spherical aberration to enable the postoperative target ocular spherical aberration closest to zero; in the control group, the aspheric IOLs were chosen using a random strategy. Primary outcome measurements included the following objective optical quality assessments: higher-order aberrations obtained by a Hartmann-shack aberrometer at 4 mm and 6 mm pupil diameters; objective scatter index (OSI), modulation transfer function (MTF) cut-off, Strehl ratio (SR) and a simulated contrast visual acuity-optical quality analysis system value (OV) obtained by a double-pass system with a 4-mm aperture. Subjective visual acuity was measured as secondary outcome. All the patients were followed up for 3 months. RESULTS: Eighty-four patients in the customized group and 78 patients in the control group were evaluated. There was no significant difference in postoperative visual acuity between the two groups (P > 0.05). Significantly less ocular higher-order aberrations were shown in the customized group (P < 0.05). No significant difference was shown in OSI, MTF cut-off, SR and OV between the two groups (P > 0.05). CONCLUSIONS: Although customized selection of aspheric IOL implantation showed less postoperative ocular aberrations, it performed similarly to random selection of aspheric IOL implantation in terms of postoperative visual acuity, simulated contrast visual acuity, intraocular scatter, modulation transfer function and Strehl ratio. TRIAL REGISTRATION: Retrospectively registered on 07/06/2019. Registration number: ChiCTR1900024356 .

Evaluation of Visual Quality in Pseudophakic Eyes with Different Ocular Spherical Aberrations.

Purpose: To evaluate the effects of different residual total ocular spherical aberration (SA) on objective and subjective visual quality in pseudophakic eyes. Methods: This prospective consecutive study comprised 171 patients with age-related cataract and undergone unilateral uneventful phacoemulsification. All participants were divided into four groups based on residual ocular SA at 6 mm pupil: negative SA (≤-0.10 µm, group A), neutral SA (0.00 ± 0.05 µm, group B), slightly positive SA (0.10 ± 0.05 µm, group C), and more positive SA (0.20 µm, group D), respectively. Subjective visual acuity and contrast sensitivity, and objective optical quality and ocular aberrations were analyzed 3 months postoperatively. Results: There was no significant difference in baseline measurements across all groups. Postoperatively, no statistically significant differences were found in visual acuity between groups (P > .05), while differences reached statistical significance in mesopic contrast sensitivity at 12 and 18 cpd (P < .01). There were significant differences in ocular SA and higher-order aberrations at 6 mm pupil, as well as in optical quality parameters (P < .05). Group C showed a minimum value of objective scatter index (1.17 ± 0.55) but maximum values of modulation transfer function cutoff (31.94 ± 9.18) and optical quality value OV 100% (1.07 ± 0.31), indicating lower intraocular scattering and superior optical quality. Conclusions: This comprehensive evaluation is conducive to deepening the understanding of visual and optical performance of pseudophakic eye. A modest amount of positive ocular SA seemed to be a more preferable option for enhancing visual quality after aspheric ntraocular lense (IOL) implantation.