Volume 60 · Issue 06 · 2024

Posterior chamber phakic intraocular lens implantation is a type of intraocular surgery. With advancements in implant materials and design, this procedure has seen rapid adoption and widespread use in ophthalmology clinics in recent years. However, the changes in surgical techniques and the occurrence of postoperative complications have raised safety concerns that require significant attention in clinical practice. This paper aims to address the key factors influencing the safety of posterior chamber phakic intraocular lens implantation, exploring relevant characteristics, mechanisms, and current challenges. By emphasizing the importance of this surgery and proposing effective measures, it aims to provide guidance for clinical practice, enhance the safety of posterior chamber phakic intraocular lens implantation, and foster the healthy advancement of this surgical technique.

In recent years, artificial intelligence (AI) technologies have experienced substantial growth across various sectors, with significant strides made particularly in medical AI through advancements such as large models. The application of AI within the field of ophthalmology can enhance the accuracy of eye disease screening and diagnosis. However, the deployment of AI and its large models in ophthalmology still encounters numerous limitations and challenges. This article builds upon the transformative achievements in the medical AI sector and discusses the ongoing challenges faced by AI applications in ophthalmology. It provides forward-looking insights from an ophthalmic perspective regarding the era of large models and anticipates research trends in AI applications in ophthalmology, so as to foster the continuous advancement of AI technologies, thereby significantly promoting eye health.

Multifocal intraocular lenses (MIOLs) have demonstrated efficacy and safety in adult cataract surgery, yet they encounter many challenges in pediatric applications. This article elaborates on the difficulties in biometric measurements in children, the unpredictability of postoperative refraction outcomes, the lack of long-term spectacle independence in children with MIOLs, the absence of significant advantages in correcting childhood amblyopia, and the potential increase in the rate of secondary surgeries. Due to the insufficient clinical evidence supporting the use of MIOLs in children at present, it is proposed that MIOLs be cautiously applied to children with congenital cataracts in clinical practice. Further research in this area is encouraged.

To evaluate the in vitro optical performance of three types of non-diffractive extended depth-of-focus (EDoF) intraocular lenses (IOLs).

Experimental study. Three Vivity IOLs, three Eyhance IOLs, and three ES60 IOLs were included. The professional optical bench OptiSpheric^® IOL PRO 2 and an ISO-2 corneal model were applied. The through-focus modulation transfer function (MTF) and predicted visual acuity (logarithm of the minimum angle of resolution) of different spatial frequencies and different focuses under apertures of 3.0 mm and 4.5 mm were recorded. The aspheric monofocal (Tecnis ZCB00), diffractive EDoF (Tecnis Symfony), and trifocus (STF1) IOLs, as well as the lowest visual requirement criteria of EDoF IOLs of American Academy of Ophthalmology served as assessment controls.

For the 3.0-mm aperture, the peak value of the MTF was highest with ZCB00, followed by Eyhance, ES60, Vivity, Symfony, and STF1. All experimental non-diffractive EDoF IOLs had two MTF peaks, and the distance between both peaks was longest with Vivity (1.76 D), followed by ES60 (1.43 D) and Eyhance (1.36 D). Among the control IOLs, Symfony had two MTF peaks, and the peak MTF of the intermediate focus was highest. STF1 had three MTF peaks, and the peak MTF of the near focus was highest. For the 4.5-mm aperture, the ranking of the MTF peak of the six types of IOLs was the same as that for the 3.0-mm aperture. Vivity had an increased MTF peak of the distance focus, but a decreased intermediate focus MTF peak, while the MTF peaks of the distance, intermediate, and near focuses in the other IOLs decreased, compared to those for the 3.0-mm aperture. The predicted visual acuity of the distance focus of the three types of non-diffractive EDoF IOLs was all better than 0.0. The predicted visual acuity of the intermediate focus of the Vivity IOL and the ES60 IOL was 0.11 and 0.05 better than that of the Eyhance IOL, respectively. Based on the predicted visual acuity of 0.2, Vivity and ES60 had a depth of focus of at least 0.50 D exceeding ZCB00, while Eyhance had a depth of focus of 0.40 D exceeding ZCB00.

In the experiments in vitro, the three types of non-diffractive EDoF IOLs exhibited varying degrees of intermediate to near focus optical performance while maintaining distance focus optical performance. The Eyhance IOL showed better distance focus optical performance than ES60 and Vivity IOL. The Vivity IOL and the ES60 IOL showed better depth of focus extensions than the Eyhance IOL and met the lowest visual requirement criteria of EDoF IOLs of American Academy of Ophthalmology.(This article was published ahead of print on the Online-First Publishing Platform for Excellent Scientific Researches of Chinese Medical Association Publishing House on April 29, 2024)

To evaluate the efficacy of sutureless intrascleral intraocular lens (IOL) fixation with the modified Yamane technique.

It was a retrospective case series study. Patients undergoing sutureless intrascleral IOL fixation with the modified Yamane technique were included at Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University from January 2022 to September 2023. Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), recorded as the logarithm of the minimum angle of resolution (logMAR), were measured before surgery and at 1 day, 3 days, 1 week, 1 month, and 3 months postoperatively. Refractive error and intraocular pressure were also checked. Anterior segment examination with a slit lamp microscope, fundus examination, anterior segment and posterior segment optical coherence tomography were performed. Intraoperative and postoperative ocular complications were documented.

A total of 53 patients (53 eyes) were included in this study, comprising 40 males and 13 females, with a median age of 60 (49, 68) years. Among them, the proportion of a history of trauma was 22.6% (12/53). There was 1 eye with intraoperative vitreous hemorrhage (1.9%). All eyes had no obvious hypotony, no obvious inflammation in the anterior chamber, and no pupillary abnormalities at 1 week after surgery. The mean follow-up time was (8.0±3.3) months (range, 3 to 16 months). There was no iris capture, re-dislocation, or haptic exposure of the IOL during the follow-up. The corneal endothelial cell density was (2 236±704) cells/mm² preoperatively and (1 964±628) cells/mm² at 1 month, with significant difference (P<0.001). The UCVA (logMAR) was 1.53±0.75 preoperatively, 0.18±0.17 at 1 month, 0.15±0.14 at 3 months, and 0.14±0.13 at the final visit (P<0.001). The UCVA (logMAR) at 1 month was significantly different from that at 3 months and the final visit (both P<0.05). At 1 month, 50.9% (27/53) of the eyes had an UCVA (logMAR)≤0.1, and the rate was 56.6% (30/53) at 3 months. The BCVA (logMAR) was 0.25±0.21, 0.03±0.06, 0.02±0.06, and 0.02±0.06 before surgery, at postoperative1 month, 3 months, and the final visit, respectively (P<0.001). The BCVA (logMAR) at 1 month was not significantly different from that at 3 months and the final visit (both P>0.05). The rate of the eyes with a BCVA (logMAR)≤0 was 81.1% (43/53) at 1 month and 83.0% (44/53) at 3 months. The IOL tilt was (5.18±2.60)° at postoperative 1 month and (5.08±2.48)° at postoperative 3 months, without statistically significant difference (P>0.05). The IOL decentration was (0.35±0.24) mm at postoperative 1 month and (0.32±0.24) mm at postoperative 3 months, without statistically significant difference (P>0.05).

Sutureless intrascleral IOL fixation with the modified Yamane technique is simpler and more minimally invasive to achieve a stable and centered IOL implantation with fewer complications and good visual prognosis.

To assess the impact of femtosecond laser-assisted phacoemulsification on corneal endothelial characteristics and prognosis among patients with type 2 diabetes and age-related cataracts, considering varying nuclear hardness.

This non-randomized controlled trial involved 161 patients (161 eyes) with type 2 diabetes undergoing cataract extraction at Weifang Eye Hospital between March 2020 and December 2022. The cohort comprised 73 males and 88 females, with an average age of (65.9±5.23) years. Based on patient preference, 101 individuals underwent conventional phacoemulsification (group A), while 60 chose femtosecond laser-assisted phacoemulsification (group B). Patients were further stratified based on Emery-Little grade of lens nuclei into A1/B1 (grade Ⅰ and Ⅱ), A2/B2 (grade Ⅲ), and A3/B3 (grade Ⅳ) subgroups. The study compared effective phacoemulsification time (EPT), cumulative energy release of phacoemulsification (CDE), central corneal thickness (CCT), endothelial cell density (ECD), coefficient of variation (CV), and hexagon cell ratio (HEX) before and after surgery at 1 day, 1 week, 1 month, and 3 months.

The intraoperative EPT of patients in groups A and B were (6.52±4.93) and (5.63±4.31)s, respectively, and the CDE were 11.57%±5.21% and 10.68%±6.02%, respectively. The differences between them were not statistically significant (all P>0.05).There were no significant differences in EPT and CDE between groups A1 and B1 (all P>0.05), and there were statistically significant differences between groups A2 and B2, A3 and B3 (all P<0.05).The postoperative CCT was increased in both groups.There were no statistically significant differences in CCT between A1 and B1 groups at different time after surgery (all P>0.05), and there were statistically significant differences in CCT between A2 and B2, A3 and B3 groups at 1 day and 1 week after surgery (all P<0.05), and group B was significantly lower than group A.There was no significant difference between 1 month and 3 months after surgery (P>0.05).ECD was reduced in both groups.There was no statistically significant difference in ECD at different time of operation between A1 and B1 groups (all P>0.05), while there was statistically significant difference in ECD at 1 day, 1 week, 1 month and 3 months after operation in A2 and B2, A3 and B3 groups (all P<0.05). Group B was significantly better than group A. There was no significant difference in coefficient of variation and HEX between the two groups at different time after surgery (P>0.05).

Femtosecond laser-assisted phacoemulsification demonstrates benefits in preserving corneal endothelial cells, reducing early postoperative corneal edema, and minimizing corneal injury in type 2 diabetes patients with cataracts of high nuclear hardness.

To explore the differences in metabolites and metabolic pathways in the aqueous humor between patients with presenile cataracts and senile cataracts.

This metabolomic study was conducted at Tianjin Medical University Eye Hospital from August 2020 to September 2022. Eight patients with presenile cataracts (8 eyes) and 8 patients with senile cataracts (9 eyes) were included. Data were collected, including age, gender, preoperative uncorrected visual acuity, intraocular pressure, lens dysfunction index, and axial length. Aqueous humor and anterior capsule tissue samples were obtained during cataract surgery. Metabolites in the aqueous humor were detected using Liquid Chromatography-Mass Spectrometry in a non-targeted approach. The principal component analysis, differential analysis, clustering analysis, and correlation analysis were performed to identify differentially expressed metabolites. These metabolites were ranked based on the fold change (FC). The receiver operating characteristic (ROC) curve analysis and metabolic enrichment analysis were used to identify differential pathways and potential biomarkers for presenile cataracts. Immunohistochemistry was conducted on anterior capsule tissues, and pyruvate levels were measured by colorimetry to validate metabolomic results.

Patients with presenile cataracts included 7 males and 1 female, with a mean age of (37.50±4.90) years. Patients with senile cataracts were 7 males and 1 female, with a mean age of (73.44±5.22) years. Except for age, there were no significant differences in baseline data (P>0.05). A total of 347 differential metabolites were identified, 10 of which were potential biomarkers for presenile cataract according to the ROC curve analysis (all P<0.05), including propoxycaine (log₂FC=7.26), 2-methyl-2, 3, 4, 5-tetrahydro-1, 5-benzodiazepine-4-ketone (log₂FC=6.35), l-pyroglutamic acid (log₂FC=-1.72), leanly-proline (log₂FC=-0.77), and choline (log₂FC=-0.56) in the positive ion mode, and N-phenylacetyl glutamine (log₂FC=-1.84), pyruvate (log₂FC=1.07), ascorbic acid (log₂FC=0.92), pseudouracil nucleoside (log₂FC=-0.68), and palmitic acid (log₂FC=-0.51) in the negative ion mode. The metabolic enrichment analysis identified 72 differential pathways (32 cationic and 40 anionic), with significant differences in glutathione metabolism, cysteine and methionine metabolism, glycolysis or gluconeogenesis, pyruvate metabolism, and the citric acid cycle (P<0.05). The experimental validation showed reduced lactate dehydrogenase and increased pyruvate levels in patients with presenile cataracts (P<0.05).

Pyruvate and nine other metabolites may serve as potential biomarkers for presenile cataracts. Pathways involving glutathione metabolism, cysteine and methionine metabolism, glycolysis or gluconeogenesis, pyruvate metabolism, and the citric acid cycle are notably dysregulated in patients with presenile cataracts.

To explore the changes in gray matter volume of the cerebral cortex in patients with intermittent exotropia (IXT) using the voxel-based analysis and to analyze the correlation between these changes and clinical manifestations.

This was a cross-sectional study. A collection of 15 consecutive patients diagnosed with IXT at Tianjin Eye Hospital from March 2021 to May 2022 formed the exotropia group, which comprised 8 males and 7 females, with an average age of (23.5±5.2) years. Ten healthy individuals, 3 males and 7 females, with an average age of (27.0±7.5) years, were selected as the control group. All participants underwent assessments of exotropia severity and Titmus stereoacuity. Three-dimensional high-resolution brain images were obtained through MRI scans. Voxel-based morphometry was employed to preprocess the MRI data, and the SPM toolbox in MATLAB was utilized to analyze differences of images between the two groups. Regions of interest (ROI) with structural abnormalities in the gray matter volume analysis were selected, and the ratio of gray matter voxel values in the ROI to the mean gray matter voxel values of the whole brain for each participant was calculated using the MarsBaR software. The correlation between this ratio and exotropia severity as well as the common logarithm of Titmus stereoacuity was analyzed.

The differences in age, gender distribution, and refractive error between the two groups were not statistically significant (all P>0.05). However, there were statistically significant differences in the degree of strabismus and Titmus stereoacuity (both P<0.001). Compared to the control group, patients in the strabismus group exhibited decreased gray matter volume in several brain regions, including the wedges of the medial surface of the cerebral hemisphere (decreased by 89 voxels), the left lingual gyrus (decreased by 176 voxels), the left calcarine sulcus V3 area (decreased by 30 voxels), the central anterior gyrus of the right frontal lobe (decreased by 192 voxels), the gray matter of the left hippocampal gyrus (decreased by 20 voxels), and the bilateral lateral geniculate nuclei (decreased by 100 and 40 voxels on the left and right sides, respectively). These differences were all statistically significant (all P<0.001). Additionally, there was an increase in gray matter volume in several brain regions, including the bilateral caudate nuclei (increased by 60 and 76 voxels on the left and right sides, respectively) and the left precentral gyrus (increased by 36 voxels). These differences were also statistically significant (all P<0.001). A group-level analysis identified 10 brain regions with structural differences between the two groups, which were used as ROI. The gray matter volume ratio was negatively correlated with the degree of exotropia (all P<0.05) in the ROI of the left wedges (r=-0.670), left calcarine sulcus V3 area (r=-0.610), and left lingual gyrus (r=-0.684). The gray matter volume ratio was negatively correlated with lgTS (all P<0.05) in the ROI of the left wedges (r=-0.568) and the central anterior gyrus of the right frontal lobe (r=-0.563).

Patients with IXT exhibit decreased gray matter volume in the horizontal connection areas between the primary visual cortices V1 and V2. The reduction in gray matter volume of the lingual gyrus and the dorsal visual pathway V3 area becomes more pronounced with increasing exotropia severity, while the gray matter volume of the precentral gyrus (BA6 area) decreases with worsening stereoacuity.

The patient was a 26-year-old female. Because of blurred vision in his left eye after being stung by a bee for more than one year, he went to the Department of Ophthalmology, the Fifth Affiliated Hospital of Jinan University. He was diagnosed as "penetrating corneal injury of left eye" in an external hospital, and underwent "deep corneal foreign body removal" with anti-infection and anti-inflammatory treatment after operation. Eye examination: left eye naked visual acuity of 0.6 (uncorrectable), intraocular pressure of 20 mmHg (1 mmHg =0.133 kPa); No conjunctiva congestion; A round white opacity of 2 mm in diameter can be seen in the cornea in the pupil area, and a dense gray area can be seen in the center of the opacity, reaching the whole thickness of the cornea; The central depth of the anterior chamber is acceptable, the iris texture is clear, the pupil is round, about 3 mm in diameter, and the light response is normal; The cortex of the lens is feathery white and cloudy, and the anterior capsule of the lens can be seen in a pattern similar to a colored butterfly under mirror reflection irradiation (Quintessential Picture 1). Clinical diagnosis: traumatic cataract of left eye; Postoperative corneal foreign body removal after penetrating corneal injury of the left eye.

A 21-year-old female patient presented to the Ophthalmology Department of Yunnan University Affiliated Hospital with complaints of "bilateral blurred vision accompanied by diplopia for 3 weeks". The patient′s main symptoms included intermittent visual blurring, diplopia, headaches, and ocular discomfort. Ocular examination revealed intermittent exotropia, sometimes accompanied by esotropia or orthotropia, along with signs of pupillary constriction and pseudomyopia. Based on the clinical presentation, a diagnosis of intermittent exotropia complicated by spasm of the near reflex (SNR) was made. The patient underwent bilateral exotropia surgery, which corrected the ocular alignment and resolved the symptoms and signs of SNR postoperatively.

The increasing incidence of myopia has become a global public health concern. Exploring the mechanisms underlying the onset and progression of myopia is crucial for prevention and control. This paper reviews the role of peripheral retinal defocus mechanisms in the development of myopia, with particular emphasis on the interaction between accommodation lag and peripheral retinal defocus, as well as the impact of optical intervention on myopia control effectiveness. In recent years, researchers have developed various optical tools for myopia prevention and control based on the peripheral retinal defocus theory, such as peripheral defocus spectacle lenses, orthokeratology lenses, and peripheral defocus soft contact lenses. This paper aims to provide clinicians with the latest research findings to deepen their understanding of the mechanisms involved in myopia development and to guide the future development and clinical application of myopia prevention and control products.

With the increasing prevalence of myopia among adolescents, the pathogenesis of this condition has garnered significant attention. Studies have discovered the expression of various hormone receptors in ocular tissues of both animals and humans. Additionally, changes in hormone levels accompany the development of myopia, although the exact relationships remain inconclusive. This article reviews the potential influences and mechanisms of action of endogenous hormones such as melatonin, serotonin, insulin, glucagon, sex hormones, vitamin D, and prostaglandins in ocular tissues including the retina, choroid, and sclera. It elaborates on the relationship between fluctuations in these hormone levels and the progression of myopia, aiming to provide guidance for exploring targets for myopia prevention and control.