Volume 57 · Issue 07 · 2021

Cataract is the main cause of treatable visual impairment in children. Children face more risks during the perioperative period of cataract surgery than adults because of their anatomical, physiological, behavioral, and developmental characteristics; therefore, special attention and management are required. This article comprehensively discusses the perioperative management of children′s cataract surgery on the base of relevant literatures and the authors′ clinical experience, including the indications and timing of surgery, preoperative examination, prevention and treatment of surgical complications, and postoperative visual function reconstruction. (Chin J Ophthalmol, 2021, 57: 481-486)

In recent years, intraocular lenses (IOLs) have been increasingly used in the correction of aphakia after congenital cataract extraction. But IOL implantation in infants and young children, especially under 1 year old, is still controversy. Large-scale, multi-center, randomly controlled clinical observations on this issue have been conducted. The mid-and long-term results have shown that infantile cataract extraction combined with primary IOL implantation can achieve the same or better visual outcome as aphakic contact lens correction. For infants over 7 months of age and young children, primary implantation of IOLs is relatively safe, with a low complication and secondary operation rate. Compared to the way of aphakic contact lens correction, which could be with more inconvenience, high demand of coordination, a higher infection risk, high cost and the need of a secondary IOL implantation surgery, primary implantation of IOLs at over 7 months of age is worth exploring, with appropriate understanding of the surgical indications and adequate surgical techniques.(Chin J Ophthalmol, 2021, 57: 487-491)

Posterior capsular opacification (PCO) is the most common complication that leads to vision loss after cataract surgery. It is classically divided into fibrotic type and regenerative type according to clinical manifestations or pathological mechanisms. The widely used technique for preventing PCO is to mechanically polish anterior and posterior capsules after an uneventful phacoemulsification surgery. However, the efficacy of polishing anterior capsules on prevention of PCO is debatable. It has been found that polishing anterior capsules has an inhibitory or no effect on fibrotic PCO, but a stimulating effect on regenerative PCO. Therefore, whether to polish anterior capsules is dependent on the condition of individual patients and the type of intraocular lenses.(Chin J Ophthalmol, 2021, 57: 492-494)

In recent years, with the popularization of refractive cataract surgery and the concept of precision surgery, the material, shape and function of intraocular lenses are constantly improved, updated and diversified. To unify the classification standard of intraocular lenses in China, Chinese Cataract Society has reached a consensus based on the current medical situation in China after thorough discussions. This work is devoted to providing ophthalmologists and relevant departments with personalized selection and management in clinical practice, and providing guidance for clinical and basic research. (Chin J Ophthalmol, 2021, 57: 495-501)

To compare the accuracy of 6 intraocular lens power calculation formulas based on the new swept-source optical coherence tomography biometry and to analyze the prediction error.

Retrospective case series study. Clinical data were collected from 599 patients (599 eyes) who had underwent uncomplicated phacoemulsification and the IOLMaster 700 examination at the Eye Hospital of Wenzhou Medical University between November 2018 and November 2019. Among the patients, there were 208 males and 391 females with an age of (69±10) years. According to the axial length (AL), eyes were divided into the short AL group (≤22.5 mm, n=100), the normal AL group (>22.5 mm and<25.5 mm,n=375); and the long AL group (≥25.5 mm, n=124). Eyes were also grouped based on the mean keratometry (Km) as flat (≤42.00 D, n=47), normal (>42.00 D to<46.00 D,n=461), and steep (≥46.00 D, n=91), and by anterior chamber depth (ACD) as shallow (≤2.5 mm, n=71), normal (>2.5 mm to<3.5 mm,n=436), and deep (≥3.5 mm, n=92). The median absolute errors (MedAEs) of the Barrett Universal Ⅱ, Haigis, Hoffer Q, Holladay Ⅰ, Holladay Ⅱ, and SRK/T formulas in different AL, Km, and ACD groups were compared using the Friedman test.

The differences in MedAE among the 6 formulas of 599 patients (599 eyes) were statistically significant (χ²=120.549, P<0.001). The MedAE of the Barrett Universal Ⅱ formula was smallest (0.35 D), followed by the SRK/T formula (0.36 D). There was no significant difference between the MedAEs of the Barrett universal Ⅱ and Haigis, SRK/T formula (allP=1.000), but there were statistically significant differences among the other formulas (all P<0.01). In different AL groups, the MedAE of each formula was statistically different (χ²=38.307, 38.779, 112.997; allP<0.01).The Barrett Universal Ⅱ formula resulted in the lowest MedAE in the short AL group (0.40 D) and the long AL group (0.31 D). The MedAE of the SRK/T in the normal AL group was lowest (0.35 D). The 6 formulas showed significant differences in MedAE values in different Km groups (χ²=12.284, 90.924, 39.387; allP<0.05).The Haigis formula achieved the lowest MedAE in the flat Km group (0.26 D) and the steep Km group (0.34 D). The Barrett UniversalⅡ formula achieved the lowest MedAE in the normal Km group (0.33 D). The differences in MedAE values of the 6 formulas in different ACD groups were statistically significant (χ²=37.389, 57.643, 52.845; allP<0.01), and the MedAE values of the Barrett Universal Ⅱ in different ACD groups were smallest (0.46, 0.33, 0.31 D).

The Barrett Universal Ⅱ formula perform the best over the entire AL range, followed by the Haigis and SRK/T formulas. The Barrett Universal Ⅱ formula result in the lowest prediction error in the short AL group, the long AL group, and all ACD groups. The Haigis formula may be more accurate when the Km was ≤42.00 D or ≥46.00 D. (Chin J Ophthalmol, 2021, 57: 502-511)

To analyze the cause of late postoperative opacification of hydrophilic acrylic intraocular lenses (IOLs) and the effect of IOL replacement surgery.

This retrospective case series study comprised 15 eyes of 15 patients who were diagnosed as late postoperative opacification of hydrophilic acrylic IOLs from January 2019 to June 2020 at Qingdao Eye Hospital of Shandong First Medical University. The clinical data of patients were reviewed, and two IOLs were examined by scanning electron microscopy and energy dispersive X-ray spectroscopy. The intraoperative and postoperative complications of IOL replacement surgery were evaluated, and best corrected visual acuity was compared before and after surgery. Preoperative and postoperative data were compared using the paired t test.

The interval between the first IOL implantation and the detection of IOL opacification in 15 patients was (27.3±5.9) months. All the 15 patients had unilateral IOL opacification, and 9 patients had hypertension. Glycosylated hemoglobin A1c was significantly higher than the normal value in 4 of the 10 patients who underwent cataract surgery at our hospital. Confocal microscopy disclosed coralliform deposits on the superficial IOL optic. Scanning electron microscopy and energy dispersive X-ray spectroscopy showed the presence of calcium and phosphorus crystals in the opacification region of IOLs. Visual acuity in all 13 eyes receiving IOL exchange was significantly improved from 1.03±0.64 (logarithm of the minimum angle of resolution) to 0.39±0.21 (P<0.05). Posterior capsule rupture (4 eyes), new IOL implanted in the ciliary sulcus (3 eyes) and zonule breaking (1 eye) occurred during IOL replacement.

IOL opacification is related with the IOL material and calcium ion concentration on the IOL surface. IOL replacement surgery can improve visual acuity safely and effectively. (Chin J Ophthalmol, 2021, 57: 512-518)

To investigate the influencing factors on the vaulting one month after implantable collamer lens (ICL) implantation, and to develop and verify a prediction formula.

The first half of this study was retrospective case series study, and the second half was cross-sectional stydy. A total of 83 eyes of 83 patients who underwent ICL implantation in the Lixiang Eye Hospital of Soochow University were included in the first half of the study, with an average age of (27±5) years, from August 1, 2019 to December 30, 2019. All patients underwent a complete preoperative examination, including axis length, anterior chamber depth, comprehensive optometry, intraocular pressure, central corneal thickness, white-to-white diameter, horizontal and vertical sulcus-to-sulcus diameter (STS), crystalline lens thickness (LT), corneal curvature, and bright and dark pupil diameter. Multiple linear regression (stepwise) was used to develop a prediction formula. In the validation part, a total of 65 people (65 eyes) were included, with an average age of (26±5) years, from March 1, 2020 to June 1, 2020. The accuracy and reliability of the formula were verified by the intergroup correlation coefficient and Bland-Altman consistency test.

At 1 month after surgery, ICL size had the greatest impact on the vaulting (β=0.942, P<0.001), followed by horizontal STS (β=-0.517,P<0.001), LT (β=-0.376,P<0.001), and vertical STS (β=-0.257,P=0.017). The influence of other factors was not statistically significant (all P>0.05). The regression equation was as follows: the vaulting (μm)=-1 369.05+657.12×ICL size-287.41×horizontal STS-432.50×LT-137.33×vertical STS (the fitting degreeR=0.813, R²=0.660, and corrected R²=0.643). In the verification part, the predicted average vaulting was (497.31±102.75) μm, while the actual vaulting was (514.62±152.99) μm. About 96.92% (63/65) of the patients were fitted in the moderate vault, and 3.08% (2/65) were in the high vault. The intergroup correlation coefficient was 0.581. According to the Bland-Altman test, the actual vaulting was 17.31 μm, higher than the predicted value, and the 95% confidence interval of the difference was -260.28 to 294.90 μm.

The ICL size, horizontal and vertical STS and LT are the factors that affect and predict the vaulting one month after ICL implantation, and our prediction formula has good accuracy and reliability. (Chin J Ophthalmol, 2021, 57: 519-525)

To analyze the clinical features and fundus performance of patients with retinocytoma.

Retrospective case series study. Ten patients (12 eyes) diagnosed with retinocytoma were enrolled in Department of Ophthalmology of Eye & ENT Hospital of Fudan University from January 2006 to December 2019. Clinical data were reviewed, including gender, age, initial symptoms, tumor size and location, fundus manifestations and regression patterns.

There were 7 males and 3 females aged from 5 to 39 years, with a median age of 14 years. Eight patients had unilateral retinocytoma, while 2 patients had bilateral retinocytoma. The most common complaints were strabismus (4 patients) and blurred vision (3 patients). The average maximum base diameter of the tumor was 5.70 mm (2.69 to 8.69 mm), and the average thickness was 2.28 mm (0.61 to 3.76 mm). Tumors in 12 eyes were all of a single focus, 5 in the posterior pole, 5 in the midperiphery and 2 in the periphery. Ophthalmoscopic features of retinocytoma included a translucent retinal mass in 10 eyes, a calcification mass in 11 eyes, with well-defined retinal pigment epithelial alteration in 12 eyes and a zone of chorioretinal atrophy in 6 eyes. The regression patterns were type 1 in 2 eyes, type 2 in 1 eye and type 3 in 9 eyes. The gene test showed RB1 mutation in 1 patient. During the average follow-up of 28.7 months, all of the tumors were stable without malignant transformation.

Retinocytoma is a rare benign retinal tumor with characteristic fundus manifestations. Patients with retinocytoma should be monitored closely.(Chin J Ophthalmol, 2021, 57: 526-530)

To analyze the protein expression differences of lacrimal gland adenoid cystic carcinoma (LACC) with high-grade transformation (HGT).

Experimental study. A total of 8 paraffin tissue samples were collected in Tianjin Medical University Eye Hospital from December 2012 to January 2019. According to pathological examination, the samples were divided into the LACC group and the LACC-HGT group, with 4 cases in each group. The LACC group included 2 male samples and 2 female samples, with an average age of 53 years. The LACC-HGT group included 2 male samples and 2 female samples, with an average age of 44 years. Primary cells were cultured from fresh tumor tissue. Isobaric tags for relative and absolute quantification techniques were used to screen the differentially expressed proteins between the two groups, and bioinformatics analysis was conducted for the differentially expressed proteins. Microarray was used to screen differentially expressed mRNAs between LACC and LACC-HGT primary cells. The mass spectrum data were intersected with mRNA microarray data, and quantitative real-time (qRT) PCR was performed to verify the results. Proteomics and microarray data were compared using the independent samplet test. The qRT-PCR data were compared pairwise by one-way analysis of variance.

A total of 105 HGT-related differential proteins were detected in this study, including 50 up-regulated proteins and 55 down-regulated proteins. The significantly up-regulated proteins included hemoglobin subunit beta, hemoglobin subunit alpha 1, and collagen type Ⅵ alpha 2 chain; the significantly down-regulated proteins included Cereblon, adenosylhomocysteinase like 2, and ribosomal protein L39 pseudogene 5. Gene ontology analysis results showed that the LACC-HGT differential proteins were mainly located in the cytoplasm, vesicle cavity, and extracellular matrix, had organic acid binding and molecular carrier activity, and participated in the regulation of extracellular matrix composition, immunity, inflammation, apoptosis, and other biological processes. Pathway analysis showed that the LACC-HGT differential proteins were mainly involved in signal pathways such as mitogen-activated protein kinase signal pathway and extracellular matrix proteoglycans and glycan metabolism signal pathway. Protein complex prediction analysis screened out 4 up-regulated protein complexes and 1 down-regulated protein complex. There were 15 LACC-HGT differential proteins that overlapped with mRNA chip differential genes, of which 6 were tumor-related proteins including collagen type alpha 1 chain (COL14A1), EMAP like 4 (EML4), inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4), NDRG family member 2 (NDRG2), osteoglycin (OGN) an Ras homolog family member C (RhoC). The main function was the movement and migration of tumor cells. The qRT-PCR results showed that the relative expression levels of COL14A1, EML4, ITIH4, NDRG2, OGN, and RhoC in primary LACC-1, LACC-2, LACC-HGT-1, and LACC-HGT-2 cells were significantly different (F=1 675.98, 38.53, 27.37, 16.47, 13.38, 25.22, all P<0.01). For example, the relative expression of COL14A1 in primary LACC-HGT-1 (16.09±0.51) and LACC-HGT-2 (9.96±0.34) cells was significantly higher than that in primary LACC-1 (1.00±0.13) and LACC-2 (0.67±0.08) cells (all P<0.05).

There are differentially expressed proteins between LACC-HGT and LACC, among which COL14A1, EML4, ITIH4, NDRG2, OGN, and RhoC may play an important role in LACC-HGT and can be used as potential targets of LACC-HGT in further study. (Chin J Ophthalmol, 2021, 57: 531-539)

A pair of 16-year-old twin brothers presented to our hospital. The younger brother had been losing vision in his left eye for 6 months, and the older brother had been losing vision in both eyes for 6 months. Both patients were 2.05 meters tall and lean with spider-like fingers (toes). They had lens subluxation and a leopard-shaped fundus in both eyes. Their ocular manifestations, including anterior and posterior corneal curvature, total corneal refractive power, anterior and posterior and total corneal astigmatism, corneal thickness, and axial length, were relatively consistent. The twin brothers were both diagnosed with Marfan syndrome and bilateral lens subluxation, which is a relatively rare clinical condition. The younger brother underwent posterior scleral reinforcement for retinal foveoschisis in the left eye, and the retina was basically attached after surgery. The older brother was treated with optometry and frame glasses. (Chin J Ophthalmol, 2021, 57: 540-543)

Surgeon Introduction Liu Yizhi, Professor, PhD Supervisor; Director of Sun Yat-sen Ophthalmology Center of Sun Yat-sen University, Dean of Eye Hospital, Director of State Key Laboratory of Ophthalmology. Academic Leader of Innovation Group of National Natural Science Foundation of China, Chief Scientist of 973 Program, Vice Chairman of Ophthalmology Branch of Chinese Medical Association, and Chairman of Ophthalmology Branch of Guangdong Medical Association. It has made breakthroughs in the fields of precision cataract treatment and regenerative medicine, and undertaken major national scientific research programs, key projects of the National Natural Science Foundation of China and major international cooperation projects of the National Natural Science Foundation of China. He won the Ho Leung Ho Lee Science and Technology Progress Award, and won the second prize of the National Science and Technology Progress Award, the first prize of China Medical Science and Technology Award, the Guangdong Science and Technology Outstanding Contribution Award and many other awards as the first person to complete, as well as the Arthur Lim Award of the Asia-Pacific Ophthalmology Annual Conference, APACRS Gold Medal, etc.

The patient was a 30-year-old female. After the left eye was injured, his visual acuity decreased for 1 d, and he went to the Ophthalmology Center of Qingdao Municipal Hospital for treatment. Past physical health, denied genetic history. Eye examination: visual acuity was 0.2 (-9.00 DS =1.0) for the right eye and 0.01 (-9.00 DS =0.8) for the left eye; IOP was 16 mmHg (1 mmHg =0.133 kPa) in the right eye and 16 mmHg in the left eye; No obvious abnormalities were observed in the anterior segment of both eyes; The retina of the right eye is flat, with a leopard print fundus; Leopard-shaped fundus in left eye, normal retinal artery and vein deformation, hemorrhage in macular area, yellow lesion in the center (A in Quintessence Picture 1）。 Indocyanine green fundus angiography examination: A large number of tortuous choroidal veins in the left eye converged into thick branches and slightly contracted to form ampulla, showing a spider-like appearance. The super-large vortex vein passed through the sclera at the temporal edge of the optic disc, and the corresponding lesions in the macular area showed low fluorescence, with slight high fluorescence between them (B in Quintessence Picture 1）。 Clinical diagnosis: Large vortex vein near optic disc of left eye; Fundus lesions in binocular highly myopic eyes.

Cataract surgery can increase the risk of diabetic macular edema (DME) and Irvine-Gass syndrome postoperatively in nonproliferative diabetic retinopathy (NPDR) patients. An accurate distinction between DME and Irvine-Gass syndrome in NPDR patients after cataract surgery is significantly important for the selection of subsequent treatment plans and guarantee of long-term vision quality. This article elaborates the differential diagnosis and prevention of DME, in order to provide a theoretical basis for the timely prevention, accurate diagnosis and standardized treatment of DME in NPDR patients after cataract surgery.(Chin J Ophthalmol, 2021, 57: 546-551)

In refractive cataract extraction surgery, the ideal intraocular lens (IOL) location is within the capsular pocket and the center overlaps the visual axis. However, due to factors such as eye anatomy, IOL characteristics and surgical procedures, IOL may occur eccentricity and tilt, which may affect postoperative visual acuity and visual quality. Accurate measurement of lens and IOL eccentricity and tilt status can help guide IOL selection before surgery, evaluate IOL stability in the eye after surgery, and explore the relationship between IOL eccentricity and tilt and visual quality. In this paper, the influence of IOL eccentricity and tilt on visual quality and its related factors, lens and IOL position measurement methods are summarized in combination with relevant research results at home and abroad, in order to provide reference for clinical work and research, and improve the level of precise refractive cataract extraction surgery.(Chinese Journal of Ophthalmology, 2021, 57:552-556)