Volume 58 · Issue 07 · 2022

This issue focuses on the research progress of cataract and intraocular lens (IOL) diagnosis and treatment. The responsible editorial committee responsible for the planning, composition and review of the key contents of this issue is Professor Lu Yi.

Refractive cataract surgery has evolved considerably in recent years owing to the rapid development in precise ocular biometry, surgical technique and instrumentation, and various astigmatism-correcting and multifocal intraocular lenses. However, inherent defects of these premium intraocular lenses should not be underestimated and neither should imperfections of measuring devices. Cataract surgery complications such as posterior capsular opacification and dry eye, which were originally infrequent or minor, are becoming increasingly prominent. Surgeons must properly understand and conduct refractive cataract surgery and there is still a long way to go before perfection.

Infectious endophthalmitis after ophthalmic surgery refers to postoperative endophthalmitis associated with pathogen infection. The incidence of infectious endophthalmitis after ophthalmic surgery has been reduced, but there are still many controversial issues in its diagnosis, treatment and prevention. The Chinese Vitreo-Retina Society of Chinese Medical Association, together with domestic experts in cataract, trauma and glaucoma, has synthesized all the current research evidences available at home and abroad and reached consensus opinions after careful discussion, in order to provide reference for preventing and managing infectious endophthalmitis after ophthalmic surgery safely and effectively, and thus to improve its cure rate and patients′ visual function.

Fuchs uveitis syndrome is a chronic, non-granulomatous, and unilateral anterior uveitis. It is one of the most under-diagnosed or misdiagnosed uveitis entities. A number of factors are involved in its etiology, which has not been completely understood. Misdiagnosis of this disease may result in over-treatment and facilitate the development of complicated cataract and secondary glaucoma. An extensive investigation and literature review on this disease have been performed by the experts in the Ocular Immunology Group of Ophthalmology Society of Chinese Medical Association and the Uveitis and Ocular Immunology Group of Chinese Ophthalmologist Association. Consensus opinions on Fuchs uveitis syndrome have been developed in an attempt to provide general guidance and reference in the diagnosis and treatment of this disease.

To investigate the effect of phacoemulsification on the Berger space (BS).

A prospective cohort study. Patients with cataract who underwent phacoemulsification and intraocular lens implantation in the Department of Ophthalmology, Affiliated Hospital of Nantong University from May 2021 to October 2021 were enrolled. The BS was observed by slit-lamp microscopy and anterior segment optical coherence tomography (AS-OCT) before and 1 month after operation. Intraoperative optical coherence tomography with a 25G optical fiber was performed to observe the BS. The number of eyes with the BS and materials in the BS (MIB) detected perioperatively was counted, and the width of the BS was measured. Statistical analysis was carried out by the Chi-square test, generalized estimating equations, Mann-Whitney U test and binary logistic regression analysis.

A total of 119 patients (119 eyes) were included [44 males, 75 females; mean age, (65±12) years]. Preoperatively, the BS was identified in only 4 eyes (3.4%), and no MIB was found. Intraoperatively, the BS was identified in 47 eyes (39.5%), and the MIB was observed in 20 eyes (16.8%). At one month postoperatively, the BS was identified in 33 eyes (27.7%), of which 16 eyes (13.4%) still had MIB. There were significant differences in the detection rates of the BS and MIB between intraoperative and preoperative groups (both P<0.001). The difference in the detection rate of the BS postoperatively compared to intraoperatively was statistically significant (P=0.001), while the difference in the detection rate of MIB was not statistically significant (P>0.05). The intraoperative and postoperative width of the BS [M (Q₁, Q₃)] was 160.3 (61.6, 273.1) μm and 106.8 (0, 259.4) μm, respectively, and the difference was statistically significant (Z=-2.28, P=0.023). In addition, the detection rate of the BS and MIB in patients with a high risk of zonular fiber weakness [60.7% (17/28) and 42.9% (12/28)] was significantly higher than that in patients without this risk factor [33.0% (30/91) and 8.8% (8/91)] (χ²=6.90, P=0.009; P<0.001). In the multivariable model, weakness of zonular fibers (OR=0.214, 95%CI: 0.081 to 0.561) and higher cumulative dissipated energy (OR=1.255, 95%CI: 1.047 to 1.504) were the main risk factors for structural changes of the BS intraoperatively.

Phacoemulsification can damage the normal anatomical structure of the BS, resulting in intraoperative entrance of fluid and particulates to the BS.

To compare decentration and tilt tolerances between continuous range intraocular lens (IOL) and bifocal IOL in myopia during the early stages post intraocular implantation.

A retrospective cohort study was conducted using follow-up data of 145 patients (145 eyes) who underwent phacoemulsification combined with IOL implantation in the Eye & ENT Hospital of Fudan University from January 2018 to December 2020. According to whether the axial length was less than 24.5 mm, patients were divided into non-myopic and myopic groups. According to IOL type, patients were divided into extend depth of focus (EDOF) ZXR00 IOL group (myopic 38 eyes, non-myopic 41 eyes) and bifocal ZMB00 IOL group (myopic 23 eyes, non-myopic 43 eyes). The distance and near visual acuity (log of the minimum angle of resolution visual acuity), IOL tilt and decentration, intraocular high-order aberration (HOA), coma, trefoil, spherical aberrations, modulation transfer function (MTF), as well as VF-14 index and the incidence of dysphotopsia were compared between the 2 groups at 3 months after surgery. Statistics were performed using Student′s t-test, χ² test, Pearson correlation analysis and multiple linear regression analysis.

In either the myopic or non-myopic group, no significant differences were found in age, gender, eye laterality, axial length and IOL degree between eyes with the two different types of IOLs (all P>0.05). At 3 months after surgery, there was no significant difference in uncorrected and best-corrected distance visual acuity between the ZXR00 IOL group and the ZXR00 IOL group, while uncorrected near visual acuity was better in the ZMB00 IOL group than the ZXR00 IOL group (t=10.41, P<0.01). The total postoperative IOL decentration in the ZXR00 IOL group and ZMB00 IOL group in myopic eyes were (0.32±0.17) and (0.38±0.16) mm, respectively, which were greater than those in non-myopic eyes [(0.22±0.12), (0.28±0.12) mm; t=3.16, 2.57; both P<0.05]. However, there were no significant differences in IOL tilt between myopic and non-myopic eyes in the 2 groups (both P>0.05). There were no significant differences in postoperative IOL tilt and decentration between the 2 groups regardless of myopia or non-myopia (all P>0.05). In myopic eyes, HOA, coma aberration and spherical aberration in the ZXR00 IOL group were significantly lower than those in the ZMB00 IOL group, while the total ocular MTF (38.15±10.12) was significantly higher than that in the ZMB00 IOL group (30.46±10.53) (all P<0.05). Pearson correlation analysis and multiple linear regression analysis showed a positive correlation between postoperative HOA and both IOL tilt and decentration in the ZMB00 IOL group (r=0.627, 0.726; β=0.446, 0.587; all P<0.01). However, no such relationship was found in the ZXR00 IOL group (all P>0.05). In myopic eyes, when the IOL tilt aberration and decentration were greater than the median, the HOAs in the ZXR00 IOL group [(0.33±0.14), (0.27±0.11) μm] were lower than those in the ZMB00 IOL group [(0.88±0.56), (0.96±0.45) μm], while the total ocular MTF (42.87±10.97, 40.22±9.30) were higher than those in the ZMB00 IOL group (25.02±8.99, 29.87±10.19) (all P<0.05). In myopic eyes, the proportion of patients with visual interference symptoms in the ZXR00 IOL group [42.11% (16/38)] was significantly lower than that in the ZMB00 IOL group [78.26%(18/23), χ²=7.59, P<0.05].

During the early stages after IOL implantation in myopic eyes, EDOF IOL is more tolerant to decentration and tilt than bifocal IOL.

To compare the difference of decentration and tilt among 4 kinds of aspherical intraocular lenses (IOLs), and to analyze their objective visual quality.

Prospective non-randomized controlled clinical trial. Age-related cataract patients who planned to undergo phacoemulsification and IOL implantation in the Affiliated Hospital of North Sichuan Medical College from April to June in 2020 were divided into ZCB00 group, SN60WF group, A1-UV group, and AO group according to IOL types. Thirty right eyes and thirty left eyes were selected in each group. Before operation and at 1 day, 1 week and 1 month postoperatively, decentration and tilt values were measured by a new swept-source anterior-segment optical coherence tomography device (CASIA2), and wavefront aberrations, objective scatter index (OSI), modulation transfer function cut off frequency (MTF cut off) and Strehl ratio (SR) were also examined. Values of decentration, tilt and visual quality compared among 4 groups were took from the right eye. One-way analysis of variance was used for inter-group comparison, and repeated measurement one-way analysis of variance was used for intra-group comparison. Data between right eyes and left eyes from all the individuals were compared by independent sample t-test.

A total of 181 patients (240 eyes) were enrolled, and 169 patients (224 eyes) completed the follow-up (114 right eyes and 110 left eyes). There were 77 males and 92 females, with an age of (69±9) years. There was no significant difference in gender, age, axial length, decentration and tilt of crystalline lens and IOL power among 4 groups (all P>0.05). At 1 day, 1 week and 1 month postoperatively, there was significant difference in decentration value among 4 groups (F=7.11, 6.12, 4.66; all P<0.05). For further pairwise comparison, the decentration value of SN60WF group was higher than that of the other 3 groups at 1 day and 1 week postoperatively, and the decentration value of SN60WF group was (0.259±0.101) mm at 1 month postoperatively, which was higher than that of ZCB00 group (0.177±0.099) mm and AO group (0.163±0.122) mm, and the differences were statistically significant (using SNK-q test, both P<0.05). The IOL tilt value in the ZCB00 group, SN60WF group, A1-UV group, and AO group at 1 month postoperatively were (4.806±1.129)°, (5.080±1.309)°, (4.586±1.338)°, (5.112±1.406)°, respectively. No significant difference in tilt value among 4 groups was found at any time after surgery (all P>0.05). In each group, there was no significant difference in decentration and tilt value at different postoperative time points (all P>0.05). At 1 month postoperatively, there was no significant difference in decentration and tilt at horizontal and vertical directions respectively among 4 groups (all P>0.05), and in each group, there was no significant difference in decentration and tilt value between right eyes and left eyes (all P>0.05), and IOLs tended to tilt towards the inferonasal or inferotemporal direction in both eyes. With 4-mm and 6-mm pupil diameter, there was significant difference in internal (F=131.32, 85.17) and ocular (F=46.64, 47.55) spherical aberration among 4 groups (all P<0.01). For further pairwise comparison, the spherical aberration of AO group was higher than that of the other 3 groups, and the difference was statistically significant (using SNK-q test, all P<0.05). There was no significant difference in OSI, MTF cut off and SR among 4 groups (all P>0.05).

The four types of IOLs show decentration and tilt in varying degrees after implantation in the capsular bag, but this difference do not lead to clinical significance. Human eyes have tolerance to mild decentration and tilt of aspheric IOLs, showing good visual quality.

To analyze the clinical characteristics and survival of Chinese uveal melanoma (UM) patients.

It was a retrospective case series study. Clinical data and demography characteristics of 1 166 UM patients who were diagnosed in Beijing Tongren Hospital from January 2004 to January 2020 were collected. The disease was followed up after informed consent was obtained. Kaplan-Meier plots were used to visualize survival outcomes, and the different risk groups were compared using the Log-rank test. The multivariate Cox proportional hazards model was used to select independent prognostic risk factors.

A total of 1 166 individuals (598 men, 568 women) were included in this study. The average age was (47.6±12.2) years. Median follow-up time was 38 months. Treatment included episcleral brachytherapy in 881 (75.6%) patients, local tumor resection in 38 (3.2%) patients, laser therapy in 115 (9.9%) patients and primary enucleation in 119 (10.2%) patients. In 120 patients out of the 881 patients with primary brachytherapy, enucleation was performed due to an increasing tumor size or uncontrolled neovascular glaucoma. The Kaplan-Meier survival analysis showed the 5-and 10-year metastasis rates were 18.5% and 26.8%, and the melanoma-related mortality rates were 13.6% and 22.2%, respectively. The Log-rank test showed that patient age (χ²=5.01) and gender (χ²=7.19), as well as tumor grade (χ²=49.11), shape (χ²=34.73), location (χ²=18.60), pathological type (χ²=8.07), presence of subretinal fluid (χ²=15.71) and ciliary body involvement (χ²=19.72) were factors influencing patient prognoses (all P<0.05). In the multivariate Cox analysis, the T2, T3, T4 tumors (compared with the T1 tumor, HR=4.41, 6.82, 10.49), subretinal fluid (HR=1.98), ciliary body involvement (HR=1.79), being male (HR=1.53) and advanced age (greater than 53 years old) (HR=1.83) were independent risk factors for poor prognoses (all P<0.05).

UM occurs at a significantly earlier age and non-pigmented tumors represent smaller proportion in Chinese patients. Higher T-stage, presence of subretinal fluid, ciliary body involvement, advanced age, and being male are independent risk factors for poor outcomes.

To evaluate the perfusion features of the anterior segment in patients with different types of strabismus.

A cross-sectional study. Sixteen strabismus patients (16 eyes) who received the examination of iris indocyanine green angiography (ICGA) in Tianjin Eye Hospital from November 2016 to December 2021 were enrolled and divided into two groups according to whether they had a history of extraocular muscle injury/rectus muscle surgery. All patients underwent routine ophthalmic examinations. Angiographic images were obtained by the anterior segment camera, and indicators such as arm to iris circulation time, whole iris filling time, regression onset time, and complete regression time were recorded. The independent sample t test or Mann-Whitney U test was used to compare iris perfusion aspects of the two groups, and the Pearson/Spearman correlation tests was used to analyze the correlation of arm to iris circulation time and whole iris filling time with age and course of strabismus.

Among the 16 patients, there were 10 males and 6 females. The mean age was (49.2±13.2) years, and the course of strabismus ranged from 2 to 31 months. There were 7 patients in the group of without extraocualr muscle injury and 9 patients in the extraocular muscle injury/surgery group. There was no significant difference in age and course of strabismus between the two groups (both P>0.05). The arm to iris circulation time [M (Q₁, Q₃)] of the group without extraocular muscle injury and the group with extraocular muscle injury/surgery were 18 (18, 21) and 22 (20, 24) s, respectively. The average whole iris filling time was (13.86±1.95) and (12.22±3.60) s, respectively. There was no statistical significance between the two groups (both P>0.05). Correlation analysis showed that arm to iris circulation time was not correlated with age and course of strabismus (r=-0.033, -0.079; both P>0.05). And the whole iris filling time was not correlated with age and course of disease (r=0.057, -0.119; both P>0.05). The matrix scatter plots showed that in the group of extraocular muscle injury/surgery, there were three patients who were older than the average (49.2 years) and above the median of arm to iris circulation time (20 s) (two cases with the vertical muscle involved), meanwhile, there were three patients (all with the vertical muscle involved) whose course of strabismus was longer than 6 months and above the median of arm to iris circulation time, which were more than those in the group of without extraocular muscle injury (1 case, respectively).

ICGA in patients with strabismus show that a history of injury to the extraocular muscle or surgical treatment beyond 2 months had no effect on iris perfusion. Age and course have no correlation with iris reperfusion. The vertical muscle involvement has more effects on the blood supply to the anterior segment.

A patient complained of ophthalmology with poor vision in both eyes for more than 30 years and aggravation for more than 2 years. The central anterior lens capsule was found to have a conical protrusion under a slit-lamp microscope after pupil dilation in both eyes. The diagnosis was bilateral cataract and congenital anterior lenticonus. Phacoemulsification cataract extraction combined with intraocular lens implantation was performed. The visual acuity in both eyes was significantly better after surgery.

With the development of the technology of phacoemulsification and intraocular lens (IOL) implantation, the calculation formula of IOL power has been optimized. The existing formulas are still not accurate enough for some special cases, such as patients with short or long axial length and previous corneal refractive surgery, because the calculation of IOL power is a nonlinear function, and these mathematical formulas based on an optical model can not show the nonlinear relationship well. Therefore, new IOL calculation formulas developed by using an artificial intelligence nonlinear mathematical model have come into being. This review demonstrates the development and application of new IOL calculation formulas, in order to provide guidance for improving the visual quality and clinical application of each calculation method in cataract patients.

Presbyopia is a physiological phenomenon that ocular regulation function gradually declines with age. The aging of the global population is increasing day by day, and at present, nearly 1/4 of the population is affected by presbyopia. Lens surgery can correct presbyopia and includes phakic intraocular lens implantation and lens replacement. This paper summarizes and analyzes the clinical application and progress of various intraocular lenses for correction of presbyopia, such as monofocal, multifocal, extended depth of field and adjustable intraocular lenses, in order to provide reference for clinical correction of presbyopia.