Volume 58 · Issue 05 · 2022

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

Glaucoma following cataract surgery is one of the common complications after pediatric cataract surgery, and it is the main cause of "second blindness" in children. Since this atypical disease is difficult to diagnose and evaluate, it has been gradually paid more attention by clinicians. There are still some controversies and challenges related to the characteristics of the disease, diagnostic criteria, and treatment options. This article discusses the definition, diagnostic criteria, related risk factors, treatment strategies, follow-up, and prognoses of glaucoma following cataract surgery. Establishment of a diagnosis and treatment system can better improve the visual rehabilitation of pediatric cataract children.

Cataract is the main cause of preventable visual impairment in children. Children requires special perioperative management because of their anatomical, physiological, behavioral, and developmental characteristics. In order to strengthen the standardized perioperative management of cataracts in children, the Chinese Cataract and Refractive Surgery Society has conducted a comprehensive discussion on the timing of surgery, surgical techniques, perioperative medications, and postoperative visual rehabilitation in children. The consensus has been reached to provide clinical guidance for Chinese ophthalmologists.

To investigate the influence of residual astigmatism on the postoperative visual acuity in cataract patients with implantation of an extended depth of focus intraocular lens (IOL).

Retrospective cohort study. A total of 56 eyes of 56 cataract patients who underwent phacoemulsification combined with extended depth of focus IOL implantation from January 2019 to December 2020 at Eye & ENT Hospital of Fudan University were included. There were 29 males and 27 females in all patients, and the age was (65±9) years. Patients were divided into two groups according to their postoperative residual astigmatism: low astigmatism group (<0.75 D, 28 eyes) and high astigmatism group (0.75 to 1.50 D, 28 eyes). At 3 months after surgery, measurements were completed, including postoperative uncorrected distance (5 m) visual acuity, uncorrected intermediate (80 cm) visual acuity, uncorrected near (40 cm) visual acuity, best corrected visual acuity (all the visual acuity was converted to the logarithm of the minimum angle of resolution visual acuity), defocus curves, quick contrast sensitivity function, wavefront aberration, and VF-14 questionnaire scores. The independent samples t-test and Mann-Whitney U test were used for data analysis.

The low astigmatism group and high astigmatism group′s uncorrected distance visual acuity [M (Q₁, Q₃)] were 0.05 (-0.06, 0.10), 0.08 (0.00, 0.22), their uncorrected intermediate visual acuity were 0.11 (0.00, 0.20), 0.14 (0.10, 0.21), their uncorrected near visual acuity were 0.28 (0.20, 0.32), 0.26 (0.20, 0.30), and their best corrected visual acuity were 0.17 (0.05, 0.30), 0.14 (0.04, 0.22), respectively. The differences were not statistically significant (all P>0.05). No significant difference was found in the defocus curves from +1.00 to -4.00 D, at intervals of +0.50 D, between the two groups (all P>0.05). No significant difference was found in the quick contrast sensitivity of low, middle and high frequency of dark vision between the low astigmatism group and high astigmatism group (all P>0.05), and the area under Log contrast sensitivity function of the two groups were 0.87±0.28 and 0.77±0.30 (P>0.05). The total whole-eye aberrations were 0.59±0.18 and 0.74±0.51, and the total higher-order aberrations were 0.30±0.13 and 0.37±0.25 in the two groups at 4.0-mm pupil diameter. The differences were not statistically significant when the total whole-eye aberration, total higher-order aberration, coma, cloverleaf aberration, and spherical aberration were compared (all P>0.05). The differences of the total VF-14 visual scores, near visual acuity scores and the distance visual acuity scores of the two groups were not statistically significant (all P>0.05).

Cataract patients with residual postoperative astigmatism 0.75 to 1.50 D can obtain as good visual quality as those with postoperative residual astigmatism<0.75 D after implantation of an extended depth of focus IOL.

To understand the developmental characteristics of early ocular biological parameters in patients with congenital cataract.

Retrospective case series study. The ocular biometry data such as the axial length, corneal curvature, anterior chamber depth and central corneal thickness of 169 patients under 3 years old who were diagnosed with congenital cataract in Eye Hospital of Wenzhou Medical University (Hangzhou Branch) from June 2016 to June 2020 were reviewed, and they were analyzed by 3 age groups. There were 87, 41, and 41 patients in three age groups, 1 to 6 months, 7 to 12 months, and 13 to 36 months, respectively; 108 patients with bilateral affected eyes and 61 patients with unilateral affected eyes were included; 84 patients with partial opacity lens and 85 patients with total opacity lens were included. The right eyes of the patients with bilateral congenital cataract were selected for analysis. Statistical analysis of ocular biological parameters between groups was performed using the independent samples t-test and paired samples t-test. Statistical analysis of the relationship between age in months and biological parameters was performed using the Pearson′s correlation test.

The axial length at the age of 1 to 6 months in the affected eyes of patients with bilateral cataract was (17.59±1.19) mm, it was shorter than the affected eyes of patients with unilateral cataract [(18.18±1.34) mm], and the axial length in the affected eyes of patients with unilateral cataract were shorter than the healthy eyes [(19.01±0.93) mm]. At the age of 7 to 12 months, the axial length in the affected eyes of patients with unilateral cataract [(19.89±0.74) mm] was shorter than the healthy eyes [(20.48±0.43) mm]. The differences were statistically significant (t=-2.06, -5.62, -3.47, all P<0.05). The axial length in the affected eyes with partial opacity at the age of 1 to 6 months was shorter than those with total opacity [(17.43±1.14) mm vs. (18.06±1.29) mm; t=-2.38, P=0.020]. The difference in axial length (affected eyes vs. healthy eyes) was significantly correlated with the age in months in partial cataract (r=0.53, P=0.001). The corneal curvature in the affected eyes of patients with unilateral cataract was flatter than the healthy eyes at the age of 7 to 12 months [(42.41±1.82) D vs. (43.19±1.96) D; t=-2.29, P=0.038], but was steeper at the age of 13 to 36 months [(43.36±2.32) D vs. (42.55±1.88) D; t=2.17, P=0.043]. The anterior chamber depth in the affected eyes of patients with unilateral cataract was less than the healthy eyes at the age of 1 to 6 months [(2.44±0.37) mm vs. (2.58±0.33) mm; t=-2.08, P=0.048].The central corneal thickness in the affected eyes of patients with unilateral cataract was thicker than the healthy eyes both at the age of 1 to 6 months and 7 to 12 months [(555.26±46.95) μm vs. (541.85±40.78) μm, (542.93±27.63) μm vs. (530.93±30.36) μm; t=3.82, 2.26; P=0.001, 0.040].

Congenital cataracts maybe affect the early development of axial length, corneal curvature, anterior chamber depth and central corneal thickness. The degree of lens opacity maybe affecte the early axial length development. The axial length in eyes with partial opacity can be shorter than those with total opacity before the age of 6 months, and thereafter gradually outnumbered the latter.

To investigate the relationship between corneal refractive power and anterior chamber parameters in age-related cataract patients with normal axial lengths and shallow anterior chambers.

Retrospective case series study. Clinical data of 627 age-related cataract patients (627 eyes) with axial lengths between 22 mm and 24 mm and anterior chamber depths less than 2.20 mm treated in the Department of Ophthalmology of Peking University International Hospital from June 2018 to October 2021 were selected. There were 215 male patients and 412 female patients, with an average age of (75±10) years. According to the average corneal refractive power, eyes were divided into groups of keratometry (K)<42 diopters (D) (50 eyes), 42 D ≤K<45 D (398 eyes) and K ≥45 D (179 eyes). Axial length, anterior chamber depth, corneal diameter, anterior chamber volume and anterior chamber angle of 3 groups were recorded, and Spearman correlation analysis was used to analyze the correlation between parameters. The differences of parameters among different groups were compared by one-way analysis of variance or Kruskal-Wallis test, and multiple or pairwise comparisons using LSD-t test or Mann-Whitney U test.

There was a negative correlation between axial length and corneal refractive power in 627 eyes (r=-0.62, P<0.001). Corneal refractive power was positively correlated with anterior chamber depth (r=0.26, P=0.006), while in the K≥45 D group, corneal refractive power was also positively correlated with anterior chamber depth (r=0.23, P=0.025). Anterior chamber depth [M (Q₁,Q₃)] was 1.77 (1.64, 1.90) mm in the K<42 D group, 1.85 (1.70, 2.14) mm in the 42 D≤K<45 D group and 2.02 (1.81, 2.18) mm in the K≥45 D group. Multiple comparisons showed that there were significant differences in anterior chamber depth between the K<42 D group and the K≥45 D group, between the 42 D≤K<45 D group and the K≥45 D group (U=14 372.00, 18 226.00; both P<0.05). There was a negative correlation between corneal refractive power and corneal diameter in 627 eyes (r=-0.52,P<0.001), while in the 42 D≤K<45 D group and the K≥45 D group, corneal refractive power were also negatively correlated with corneal diameter (r=-0.20, -0.28; both P<0.05). Corneal diameter was (11.77±0.43) mm in the K<42 D group, (11.24±0.35) mm in the 42 D≤K<45 D group and (10.90±0.33) mm in the K≥45 D group, while there were significant differences in multiple comparisons (t=1.92, 2.96, 2.01; all P<0.05). There was no correlation between corneal refractive power and anterior chamber volume, or between corneal refractive power and anterior chamber angle in 627 eyes (all P>0.05). There was no significant difference both in anterior chamber volume and in anterior chamber angle among 3 groups (all P>0.05).

For age-related cataract patients with normal axial lengths and shallow anterior chambers, the anterior chamber depth increase and the corneal diameter decrease with the increase of corneal refractive power, but there is no significant change in anterior chamber volume and anterior chamber angle.

To investigate the possible role of pyroptosis of lens epithelial cells (LECs) in the occurrence of diabetic cataract.

Experimental research. A total of 70 cataract lens anterior capsule and aqueous humor samples were obtained from 70 eyes (70 patients) with cataracts in the operation room of Tianjin Medical University Eye Hospital between March 2020 and November 2020. Patients were divided into the non-diabetic and diabetic groups, with 35 patients (35 eyes) in each group. The expressions of Nod like receptor protein 3 (NLRP3), cysteine-aspartic proteases 1 (caspase-1) and Gasdermin D protein (GSDMD) in the lens anterior capsule were detected by Western blotting, real-time quantitative PCR and immunohistochemical staining. Interleukin (IL)-1β and IL-18 inaqueous humor were detected by enzyme-linked immunosorbent assay (ELISA). The independent sample t-test was used for statistical analysis.

The age was (70±9) years in the diabetic group and (71±8) years in the non-diabetic group. There was no significant difference in age and gender distribution between the two groups (both P>0.05). Western blotting analysis showed that the expression levels of NLRP3, caspase-1 and GSDMD protein in the LECs of anterior capsule were 1.11±0.06, 0.95±0.04 and 0.39±0.03 in the diabetic group, significantly higher than those of the non-diabetic group (0.81±0.04, 0.33±0.11 and 0.16±0.04; t=4.38, 5.36, 4.63; all P<0.05). Real-time quantitative PCR showed that the levels of NLRP3, caspase-1 and GSDMD mRNA in the LECs of anterior capsule were 1.98±0.07, 54.36±4.88 and 6.98±1.18 in the diabetic group, significantly higher than those of the non-diabetic group (1.38±0.16, 15.31±1.51 and 2.41±0.95; t=3.49, 7.64, 3.00, all P<0.05). Immunohistochemical staining showed that the average gray values of NLRP3, caspase-1 and GSDMD in the diabetic group were higher than those of the non-diabetic group (all P˂0.01). ELISA showed that the levels of IL-1β and IL-18 in the aqueous humor were (4.178±0.028) fg/L and (20.983±0.018) fg/L in the diabetic group, significantly higher than those of the non-diabetic group [(4.063±0.017) fg/L and (20.509±0.073) fg/L; t=20.63, 37.21; both P˂0.01].

Caspase-1-mediated pyroptosis of LECs and the release of inflammatory mediators induced by pyroptosis may be involved in the occurrence and development of diabetic cataract.

To review the application for funding of ophthalmologic projects from the National Natural Science Foundation of China (NSFC) and the current research progress, and to provide reference for the promotion of basic eye research in China.

The NSFC application and funding information of ophthalmology-related projects from 2010 to 2021 were collected as a database for further analysis. The main categories of the analysis included the number of application and funding, the funding ratio, the research directions and the funded organizations.

During the 12 years, 13 267 applications were received in the field of ophthalmology, with an increase of 157.21% (1 025/652) in 2021 compared with 2010, and the number of applications for the Youth Foundation grew significantly. There were 2 221 funded projects, with an increase of 81.51% (97/119) in 2021 compared with 2010. After 2017, the number of funded projects was basically around 200 per year, with a funding rate of 16.74%(2 221/13 267). The funding amount was 1 026.9 million yuan in total, with an average of 462 400 yuan. Sun Yat-sen University (1 060 applied and 265 funded projects), Fudan University (759 applied and 186 funded projects), Shanghai Jiaotong University (820 applied and 178 funded projects), Wenzhou Medical University (625 applied and 113 funded projects) and Capital Medical University (538 applied and 95 funded projects) were the top five institutions in terms of the number of application and funding.

From 2010 to 2021, the application number of ophthalmology projects increased rapidly, while the number of funded projects increased slowly, and the funding ratio decreased year by year. With the support of NSFC, the basic research of ophthalmology in China has made great progress. However, we still need to find and solve problems to promote the sustainable advance of ophthalmology. (This article was published ahead of print on the official website of Chinese Journal of Ophthalmology on January 21, 2022)

A 6-year-old boy with blurred vision for 18 months was diagnosed as bilateral spherophakia and ectopia lentis. He received lensectomy and implantation of an iris-claw intraocular lens in the posterior chamber in both eyes. Good visual results were achieved, and there were no complications during the two-year follow-up.

An eleven-year-old boy visited the Department of Ophthalmology due to visual acuity loss accompanied by high intraocular tension in the left eye for one year. Besides glaucoma, the typical ocular manifestations of neurofibromatosis type 1 such as bilateral Lisch nodules of the iris, multiple patchy choroidal nodules and retinal microvascular abnormalities were identified, and Cafe-au-lait macules appeared on the body skin. Based on the medical history, clinical presentation and auxiliary examination results, the diagnosis of neurofibromatosis type 1 with secondary glaucoma in the left eye was confirmed.

The proband was an 8-year-old boy, complaining of progressively decreased vision in both eyes for 3 years. The electroretinogram was characterized by supernormal rod response. While the responses of the rod and cone system were reduced, the amplitudes of dark-adapted electroretinogram responses at a high intensity were supernormal. A homozygous non-frameshift deletion variant c.1002-1004del (p. L335del) in KCNV2 was found by the Next Generation Sequencing using a custom designed panel. His father was a heterozygous carrier of this variant. In silico analysis indicated the variant was harmful. The proband was diagnosed as cone dystrophy type 3B which also known as cone dystrophy with supernormal rod response.

A 65-year-old patient was admitted to the hospital due to proptosis of the left eye accompanied with ophthalmodynia and toothache for two months. Ophthalmic examination revealed a palpable mass around the lateral orbit and temporal fossa, and maxillofacial CT suggested a malignant tumor invading the left orbital floor wall. One week later, the patient was diagnosed with left orbital cellulitis and septic shock due to peri-orbit redness, eyelid edema, chest tightness, nausea, vomiting, hypotension, and a marked increase in peripheral blood neutrophil count. The infection was well controlled after remission of shock, anti-infective therapy and surgical drainage. At 2 months after surgery, the surgical incision of the upper eyelid skin recovered well and the best corrected visual acuity of the left eye was 1.0.

Cataract is the leading cause of visual impairment and blindness on a global scale. The pathogenesis of cataract is not completely understood. Circular RNAs (circRNAs) are a special kind of non-coding RNAs with high stability and conservation. They are widely involved in a variety of biological processes and diseases. Abnormal expression of circRNAs can participate in the development of cataract, affecting the function of lens epithelial cells through interacting with proteins and sponging microRNAs. They are possible targets for cataract prevention and treatment. This article reviews the research progress on the role of circRNAs in the occurrence and development of cataract.

Retinal ganglion cells (RGCs) are the most important type of neurons in the visual pathway. RGC axons exit the eye to form the optic nerve, which connects with the brain. The visual signals carried by RGC axons establish the only link between the outside world and our internal perception of sight. Researches on the morphological, physiological, molecular, and mosaic features of RGCs are of great significance. This article reviews the research advances of RGC classifications, definitive types of RGCs, and selective vulnerability of specific RGC types after various injuries.

Cataract in high myopia occurs early and develops rapidly, which is one of the common causes of visual loss in patients with high myopia, and most of them need cataract extraction surgery. However, the eyes of patients with high myopia are often accompanied by special anatomical structures and pathological changes, and are more prone to surgical complications such as refractive state accident, posterior cataract, retinal detachment, etc. Therefore, the surgical risk is much higher than that of simple cataract. This article summarizes the timing, preoperative management, prevention of surgical complications and postoperative follow-up of cataract extraction in high myopia, so as to provide reference and guidance for clinical diagnosis and treatment of cataract in high myopia.