Volume 58 · Issue 04 · 2022

This issue focuses on refractive error. The responsible editorial committee responsible for the planning, composition and review of this issue is Professor Chen Yueguo.

As one of the methods to correct ametropia, refractive surgery has been accepted by more and more patients for its good safety, effectiveness and long-term stability. The two major types of refractive surgery are corneal refractive surgery, which is mainly performed with excimer laser and/or femtosecond laser, and phakic intraocular lens implantation. Each type has its own advantages and disadvantages. Surgeons should choose the best method according to their own technical conditions and the individual situation of each patient. In the preoperative and postoperative evaluation, we should not only pay attention to uncorrected vision and refraction, but also carry out a comprehensive visual quality assessment from both subjective and objective aspects. The ultimate goal of refractive surgery is to maximize patient satisfaction.

With the rapid development of materials, equipment and technology related to refractive surgery, the number of people who choose refractive surgery to take off glasses keeps increasing. People at different ages have different needs for refractive surgery with varying effects. How to improve the long-term postoperative satisfaction of patients at different ages should be the focus of refractive surgeons. Age-related factors are not only among the key considerations in the preoperative design of refractive surgery, but also the focus of preoperative communication and education and postoperative follow-up. By analyzing and discussing the influence of age-related factors on the strategy of refractive surgery, this article emphasizes that it is important to pay attention to age-related factors and strengthen perioperative education in ametropic patients, so as to obtain long-term ideal postoperative visual quality and improve patient satisfaction throughout the life cycle.

To explore the interocular differences in both the increase of corneal higher-order aberrations (HOAs) and axial length elongation, and the correlation between them after orthokeratology lens (OK lens) wear in children with myopic anisometropia.

It was a prospective cohort study. From 2018 to 2019, 31 children with myopic anisometropia who were fitted with OK lenses initially in the Department of Ophthalmology of Peking University Third Hospital were enrolled, including 15 males (30 eyes) and 16 females (32 eyes). The age was (10.7±1.4) years. Before (baseline) and 12 months after wearing OK lenses, corneal aberrations, corneal relative refractive power (corneal RRP, the difference between peripheral corneal refraction and central corneal refraction) and axial length were measured using the Sirius combining a corneal topographer and a tomographer and an IOL-Master intraocular lens biometer in two eyes. Interocular differences in corneal aberrations, corneal RRP and axial length were analyzed by the paired t test and Wilcoxon rank sum test. The Pearson and Spearman correlation analyses were used to explore the correlation between the increase in corneal HOAs, corneal RRP and axial length elongation.

At 12 months after wearing OK lenses, 6 children were lost for follow-up, and the data of the remaining 25 children (50 eyes) were evaluated. With 3.0- and 6.0-mm measuring zones of the total cornea and the anterior surface, the increases in total corneal HOAs, coma, spherical aberration of higher myopic eyes were significantly more than fellow lower myopic eyes (all P<0.05). The corneal RRP with 2.0-mm and 2.5-mm radius in the upper cornea and 2.5-mm radius in the inferior cornea of higher myopic eyes were more than fellow lower myopic eyes (t=-2.06, -2.07, -2.42; P=0.05, 0.049, 0.023), but there was no significant interocular difference in corneal RRP in the horizontal meridian direction of the cornea (both the nasal and temporal sides of the cornea) (both P>0.05). The axial length elongation in higher myopic eyes was 0.14 (0.08, 0.20) mm, which was significantly less than that in the contralateral eyes [0.18 (0.14, 0.35) mm] (Z =-3.21, P= 0.001). The interocular difference in axial length decreased from 0.40 (0.34, 0.54) mm at baseline to 0.33 (0.24, 0.54) mm (Z =-3.21, P = 0.001). The increases in HOAs, coma and spherical aberration of the anterior corneal surface with 3.0-mm measuring zone and the increase in coma of the anterior corneal surface with 6.0-mm measuring zone were all negatively correlated with axial length elongation (r=-0.493, -0.606, -0.500, -0.307; P<0.05). But the corneal RRP had no significant correlation with axial length elongation (r=-0.092, -0.104, -0.230, -0.061; P>0.05).

After 12 months of OK lens wear, interocular difference in axial length reduced significantly in children with myopic anisometropia, which was related to the larger increase in corneal HOAs of higher myopic eyes than fellow lower myopic eyes, especially coma.

To analyze the influencing factors and the effect of myopia control in children treated with orthokeratology.

It was a retrospective case series study. Data of 137 children from June 2016 to July 2020 in the Optometry Hospital of Wenzhou Medical University who were fitted with orthokeratology lenses and kept wearing them for 24 months were retrospectively reviewed. These children were divided into the modeling group (n=91) and verification group (n=46). The baseline conditions were recorded before they wore the orthokeratology lenses, including age, spherical equivalent refractive power (SER) and pupil area. The decentration distance was measured with a tangential difference map. Axial length (AL) changes of all children during 24 months were calculated. The influencing factors and the effect of myopia control were analyzed, and a regression equation was formulated with the modeling group. Then the influencing factors were imported with the verification group to compare the AL change differences between prediction and measurement.

There was statistical difference in AL between baseline and after wearing orthokeratology lenses for 24 months both in the modeling group [(25.16±0.90) mm vs. (25.56±0.82) mm; t=-10.119, P<0.001] and verification group [(25.29±0.71) mm vs. (25.67±0.69) mm; t=-8.785, P<0.001]. The AL changes in the modeling group showed significant correlations with baseline age (r=-0.365, P<0.001), baseline SER (r=0.308, P=0.003), pupil area (r=-0.260, P=0.013) and decentration distance (r=-0.352, P=0.001). The regression equation was as follows: y=1.609-0.056a-0.315b-0.009c+0.054d (y: AL changes, a: baseline age, b: decentration distance, c: pupil area, d: baseline SER). There was no statistical difference between prediction and measurement [(0.40±0.20) mm vs. (0.40±0.32) mm; t=-0.036, P=0.971].

Baseline age, decentration distance, baseline SER and pupil area contributed to predict the effect of myopia control after orthokeratology treatment.

To analyze the changes in refractive status and prevalence of myopia in 6-to 14-year-old children at 2 time points in Zhuozhou, Hebei Province.

In the current cohort study, the visual acuity and refractive status of primary and secondary school students aged 6 to 14 years were examined from June to August 2019 and reexamined from June to August 2020. A total of 30 412 subjects with examination data were enrolled, including 15 861 males (52.2%) and 14 551 females (47.8%), with an average age of (10.0±2.7) years. The participants underwent autorefraction without cycloplegia and a naked eye visual acuity test with a standard logarithmic visual acuity chart. Myopia was screened by the standard of equivalent spherical refraction less than -0.75 diopter (D). The categorical data were analyzed by the Chi-square or Fisher′s exact test. Clopper-Pearson was used to estimate the 95% confidence intervals for the incidence of myopia.

After the 1-year interval, the change of equivalent spherical refraction was(-0.67±1.11) D and(-0.76±1.11) D, respectively, in male and female participants, and their visual acuity decreased by 0.11±0.19 and 0.12±0.21, respectively. There were significant inter-group differences in the annual change of spherical power in different age groups (χ²=276.23, P<0.001). The naked eye visual acuity reduction was greatest in the 10-year-old students. The incidence of myopia was 42.2% (95% confidence intervals of 41.47% to 42.93%) during the 1-year follow-up period. The incidence of myopia was highest at the age of 14 (52.0% in males and 54.2% in females) and lowest at the age of 6 (31.0% in males and 33.1% in females).

The 1-year follow-up revealed an obvious myopic shift in the refractive status of school students in Zhuozhou, with their naked eye visual acuity decreased. The incidence of myopia was higher in females than that in males.

To investigate the effect of corneal collagen cross-linking (CXL) for progressive keratoconus and to evaluate changes in the parameters of rigid gas permeable contact lens (RGPCL) fitting after surgery.

It was a prospective cohort study. Fifty-three eyes of 41 keratoconus patients received accelerated CXL in Qingdao Eye Hospital of Shandong First Medical University from May to December 2018. There were 31 males and 10 females, aged (20.46±4.15) years. According to the corneal thickness, de-epithelial CXL (33 eyes) or trans-epithelial CXL (20 eyes) was performed. The best spectacle-corrected visual acuity, refractive power and the thinnest corneal thickness at baseline and at 6 weeks were compared. Corneal topography was performed at baseline and at 6 weeks, 3, 6 and 12 months postoperatively. Rose K RGPCLs were used before and 6 weeks after surgery, and the fitting status was monitored until 12 months after surgery. The t test was performed to analyze the difference before and after the operation.

The best spectacle-corrected visual acuity, refractive power, and the thinnest corneal thickness were not significantly changed over 6 weeks of follow-up, but the Kf, Ks and Kmax values were significantly increased in all patients (all P<0.05). In the de-epithelial group, the Kmax values before the operation, at 3, 6 and 12 months after the operation were (55.00±5.51) diopters (D), (54.73±5.34) D, (54.58±6.15) D and (54.20±5.49) D, respectively, and the decrease at 12 months was significant [(0.80±2.05) D; t=2.25, P=0.001]. In the trans-epithelial group, the Kmax values were (59.43±8.98) D, (57.97±8.79) D, (58.19±8.37) D and (56.94±7.19) D at the four time points, respectively, and the decreases at 3, 6 and 12 months were all significant [(1.46±2.09) D, (1.25±1.82) D, (2.49±3.64) D; t=3.12, 3.06, 3.50; P=0.006, 0.006, 0.007]. The best RGPCL-corrected visual acuity, the diameter and the average diopters of RGPCLs showed no significant change in both groups. The RGPCL base curve decreased by 0.07 mm in the de-epithelial group and by 0.13 mm in the trans-epithelial group (both P<0.05). The design of edge lifting was used in 10 eyes postoperatively in the de-epithelial group compared with 8 eyes preoperatively, and in 4 eyes postopratively in the trans-epithelial group compared with 7 eyes preoperatively. The number of eyes using the toric peripheral design of the lens was increased to 3 compared with 2 preoperatively in the de-epithelial group and from 1 to 4 in the trans-epithelial group. The acceptance rate of RGPCL fitting in both groups increased at 6 and 12 months after surgery compared to 6 weeks after surgery.

The corneal curvature became steep slightly at 6 weeks after CXL and gradually recovered and flattened. The Kmax in the trans-epithelial group decreased earlier and more than that in the de-epithelial group. The base curve of the RGPCLs was slightly reduced after 6 weeks, and the toric peripheral design was increasingly needed, but the requirement for the design of the lifted edge was different between the two groups. A good RGPCL fitting can be achieved within 1 year after CXL.

To evaluate the preliminary efficacy and safety of ab interno canaloplasty (ABiC) combined with micro-incision cataract surgery for treating primary open angle glaucoma (POAG) combined with cataract.

Prospective case series study. Patients diagnosed with POAG and concurrent cataract were enrolled to receive ABiC combined with micro-incision phacoemulsification and intraocular lens implantation in the Eye Center of the Second Affiliated Hospital of Zhejiang University School of Medicine from June 2018 to October 2019. Intraocular pressure (IOP), use of hypotensive medications, visual acuity, visual field, and optic nerve at baseline as well as at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively were assessed. Subgroup analyses were further performed to evaluate these data between controlled and uncontrolled POAG, as well as among mild, moderate, and advanced POAG. Success rate and complications were analyzed.

A total of 68 eyes in 42 patients completed a follow-up of 12 months. Compared to the baseline IOP under medical control [(18.25±2.65) mmHg (1 mmHg=0.133 kPa)], the mean postoperative IOP at 1 month [(14.31±3.25) mmHg], 3 months [(14.00±3.09) mmHg], 6 months[ (14.58±2.93) mmHg], and 12 months[ (14.84±2.73) mmHg] was all significantly reduced (P<0.05). The median (upper quadrant, lower quadrant) of the hypotensive medication number was 2.5 (2, 3) at baseline, which was significantly reduced to 0 (0, 1) at 1 month, and 0 (0, 0) at 3, 6, and 12 months (P<0.05). The complete success rate and qualified success rate at 12 months were 80.88%(55/68) and 89.71%(61/68), respectively. No deterioration in the visual field or optical coherence tomography scan of the optic nerve was observed at 12 months compared to the baseline status. Hyphema (26 eyes, 38.24%) and transient IOP spike (23 eyes, 33.82%) were the most common complications, but no severe case was present.

ABiC combined with micro-incision cataract surgery is considerably effective and safe in the treatment of POAG combined with cataract in the Chinese population.

To investigate the effects of wearing soft contact lens on corneal epithelial subbasement membrane nerve (CSN) and dendritic cells (DC) in dry eye patients and the changes of the two after stopping wearing.

Prospective case series study. From September 2018 to February 2019, 31 myopic patients with no history of wearing contact lenses were recruited at Wenzhou Medical University and Affiliated Optometry Hospital, 10 males and 21 females; Age (23.4±1.4) years old, soft contact lenses were wearing for 6 months and then stopped wearing them. Confocal microscopy was performed before wearing the glasses, 1 and 6 months after wearing the glasses, and 3 months after wearing the glasses, and the DC and CSN of the central and peripheral cornea were obtained. At the same time, the ocular surface disease index questionnaire and dry eye were performed. Repeated measures analysis of variance and generalized estimation equation were used to analyze whether the changes of each index at different follow-up times were statistically significant. Generalized estimation equations were used to analyze the main factors affecting the variation of confocal related parameters.

The ocular surface disease index questionnaire index and corneal staining grade increased after 1 month of wearing glasses (P<0.05), after which it remained stable and returned to baseline after 3 months of discontinuation. Central corneal total DC density, activated DC density, and DC area were all higher than baseline at 1 month after wearing glasses (P<0.05), followed by a decrease in DC area and activated DC density, and only the total DC density remained higher than baseline at 3 months of discontinuation; Peripheral corneal total DC density, activated DC density, DC area, and dendritic length were higher than baseline at 1 month (P<0.05), followed by a decrease, with the exception of total DC density, the remaining parameters returned to baseline at 6 months (P>0.05), the total DC density remained higher than baseline at 3 months off wear; Central and peripheral CSN declined after wearing glasses (P<0.05), returned to the baseline level after 3 months of discontinuation (P>0.05）。

The increased ocular surface discomfort, the increase and activation of DC and the decrease of CSN density were observed in patients with dry eye after wearing soft contact lenses continuously, which indicated the peak of ocular surface inflammatory reaction after wearing lenses for one month. After 3 months of wearing, CSN basically returned to normal, but the total DC density was still higher than before wearing glasses.

A patient with chief complaint of bilateral progressive visual impairment was diagnosed with Fuchs corneal dystrophy (FECD) in both eyes, macular hole in the left eye, and intraocular lens eye in the right eye. After communication with the patient and his family, they agreed to receive Descemet′s stripping without endothelial keratoplasty (DWEK) in the left eye. One year after the operation, the cornea of the left eye was transparent, and the central posterior elastic layer was missing about 4.0 mm diameter. The naked vision of left eye was 0.1, and the correction was not improved. It can be seen that DWEK surgery has a good therapeutic effect on patients with mild FECD.

A 4-year-old patient with a left orbital mass was admitted to the Department of Ophthalmology of the First Affiliated Hospital of Zhengzhou University. After clinical and imaging examinations, the left orbital mass lesion was removed under general anesthesia. Postoperative pathological examination confirmed orbital cranial fasciitis. The appearance and imaging result of the patient were normal at postoperative 7 months.

Small incision lenticule extraction (SMILE) is a new technique that exhibits excellent efficacy, safety and predictability for the correction of myopia and myopic astigmatism. However, one potential limitation of this technique is that the centration during femtosecond laser cutting might be subject to the surgeon′s experience and patient′s cooperation. To achieve accurate centration in SMILE is the key to obtaining good postoperative visual outcomes. This review summarizes relevant research results and discusses the centration methods and the influencing factors in SMILE, so as to provide reference for clinical practice of SMILE.

Keratoconus is an ectatic corneal disorder and characterized by central and/or inferior temporal corneal thinning in a cone shape. Studies have shown that its pathogenesis is related to changes in tissue proteins, enzymes, immune functions and specific genes, but the exact pathogenesis has not been clearly clarified yet. Hormones such as sex hormones have been found to be associated with keratoconus. This review aims to summarize and analyze the research progress of the effect of hormones on keratoconus and its mechanism, so as to explore the role of hormones in the early diagnosis of keratoconus and find new targets in the treatment of keratoconus, providing reference for clinical work.

Presbyopia, which refers to the decline of regulatory function due to increasing age, has become a global public health problem. There are many treatment methods for presbyopia, including optical lenses, contact lenses, intraocular lens implantation, keratectomy, etc. The research of drug treatment is also an important exploration direction. Based on various research results, the drug treatment mechanism of presbyopia can be based on increasing the depth of field to improve the quality of eyeball optical imaging, or by improving the elasticity of the lens to recover partial regulation. Therefore, drugs for reducing the pupil size and drugs for restoring the elasticity of the lens have received attention in the field of drug treatment for presbyopia, and some drugs have entered the clinical trial stage. This article will introduce the mechanism of action, research progress and future trends of these two classes of drugs.

Ge Qi, a former member of the editorial board of Chinese Journal of Ophthalmology, passed away in Beijing on January 17, 2022, at the age of 88.