Ultra-high Myopia Research Articles

Tilt and decentration of the crystalline lens in ultra-high myopia with cataract and its influencing factors: A study based on CASIA2'.

This study aims to examine the characteristics and influencing factors of crystalline lens tilt and decentration in ultra-high myopic cataract patients, as measured by the CASIA2. 60 eyes scheduled for cataract surgery with an axial length (AL) ≥ 28 mm were included. The IOLMaster700 was utilized to measure AL and the white-to-white (WTW) distance. The CASIA2 was employed to measure front curvature radius (FCR), crystalline lens tilt, and crystalline lens decentration. The relationships between lens tilt, decentration, and related factors were evaluated. The degree of lens tilt was 4.62 ± 2.44°, and the decentration was 0.20 (Q1 0.13, Q3 0.28) mm. Among the 60 eyes, 11 (18.3%) had a tilt ≥7°, and 6 (10%) had a decentratiolens tilt ≥7° (P = 0.038, P = 0.018). Eyes with AL >30.00 mm and FCR <8.45 mm had a higher degree of lens tilt. Additionally, a tilt ≥7° was associated with a greater decentration (P = 0.032), n. Preoperative crystalline lenses in eyes with ultra-high myopia and cataract exhibit certain degrees of tilt and decentration. An AL >30 mm is a risk factor for a lens tilt ≥7° and an decentration ≥0.4 mm. An FCR <8.45 mm is a risk factor for increased lens tilt, and a tilt ≥7° is a risk factor for increased lens decentrati ≥ 0.4 mm. An increase in AL and FCR <8.45 mm were risk factors for a and eyes with AL >30.00 mm had a higher degree of decentration (P = 0.005).

Paying attention to the application of contact lenses in the treatment of special types of refractive abnormalities in children

Childhood vision is in the stage of development, and the incidence of ametropia is high. For special types of refractive abnormalities such as ultra-high myopia, ultra-high anisometropia and aphakia, conventional wearing of frame glasses can easily cause aberrations and peripheral visual deformations, affect the visual development of children, and even cause refractory amblyopia. In this article, the benefits of contact lenses are discussed from perspectives of ultra-high refractive error, refraction-related refractory amblyopia, and photosensitivity-related refractive error, so as to attract the attention of clinical physicians, expand the application scope of contact lens wear, give full play to the role of contact lenses, and improve the diagnosis and treatment of refractive abnormalities in children.

Аспекты макулярной хирургии у пациентов с патологической миопией

Patient with high and ultra-high myopia belong to the one of the most difficult categories for the vitreoretinal surgery because of the morphological features of choroid, retina and vitreomacular interface: axial length over 26 mm, the presence of posterior staphyloma, thinning of choroid, a combination of hypo- and hyperpigmentation of the retina pigment epithelium. Therefore, the improvement of the technique of vitreoretinal surgery in patients with pathological myopia remains relevant. Purpose. To optimize the technique of vitreoretinal surgery in patients with pathological myopia. Material and methods. There are 14 patients (14 eyes) with myopic traction maculopathy against the background of pathological myopia with clinical refraction from 10 to 26 D were under observation. The axial length of the eye averaged 31.23 ± 1.94 mm. All patients underwent microinvasive three-port vitrectomy 25G. In connection with the anatomical features of the myopic eye, special methods of surgical manipulations in the macular region were used. Results. The obtained positive anatomical and functional results of the treatment demonstrated their effectiveness and safety, which made it possible to develop a certain algorithm for surgical manipulations in macular surgery in patients with pathological myopia. Conclusion. The use of non-standard techniques of vitreoretinal surgery, highly specialized tools and methods for visualizing the structures of the central zone of the retina optimizes the results of the treatment of macular pathology in patients with pathological myopia. Keywords: high myopia, traction maculopathy, epiretinal membrane, vitrectomy, cataract

Comparison of the reverse chopper-assisted prechop and phaco-chop nucleotomy techniques during phacoemulsification for cataracts with grade III nuclei: a randomized controlled trial.

Phacoemulsification surgery is the standard treatment for cataract. However, excessive ultrasound (US) energy may cause injury to the corneal endothelium and other ocular tissues. Recently, a new prechop technique assisted with the reverse chopper is showed to be more efficient and safe, by splitting the nuclei in situ without using any US energy. However, it is verified only in treating some kinds of complex cataracts such as grade IV hard nuclei cataract, small-pupil cataract, and ultra-high myopia cataract. Since grade III nuclei cataract is the most common type of cataract, it is necessary to evaluate the efficacy and safety of prechop technique with reverse chopper in routine cataract surgery. This prospective, two-parallel, randomized controlled trial was conducted in Beijing Tongren Hospital from January 2022 to September 2022. A total of 89 cataract patients (89 eyes) were enrolled and then randomly assigned to either the reverse chopper-assisted prechop group (n=45) or the phaco-chop group (n=44). The patients were followed for 3 months postoperatively. The best-corrected visual acuity (BCVA), cumulative dissipated energy (CDE), corneal endothelial cell loss (ECL), and degree of corneal edema were evaluated and compared between these 2 groups. Data were analyzed using SPSS 23.0 and GraphPad Prism 8.0. The CDE of the reverse chopper-assisted prechop group was significantly less than that of the phaco-chop group (P=0.011). Compared with the phaco-chop group, the corneal edema in the reverse chopper-assisted prechop group was milder (P=0.026) and the BCVA was better (P=0.0012) at 1 day after surgery. No significant difference was found in the count or rate of corneal ECL between the 2 groups at 1 month after surgery (corneal ECL count: P=0.090; corneal ECL rate: P=0.053). The BCVA of the 2 groups at 1 week, 1 month, and 3 months after surgery was equivalent (P=0.052, 0.26, and 0.41, respectively). The prechop technique assisted with the reverse chopper in treating cataract with grade III nuclei enables less phaco energy consumption, milder ocular structural damage, and faster recovery of vision, compared with traditional phaco-chop technique.

Clinical efficacy of posterior chamber phakic refractive lens implantation in the treatment of ultra-high myopia

Clinical efficacy of posterior chamber phakic refractive lens implantation in the treatment of ultra-high myopia

Effect of myopia and astigmatism deepening on the corneal biomechanical parameter stress-strain index in individuals of Chinese ethnicity.

Purpose: To investigate the differences in corneal biomechanical parameter stress-strain index (SSI) among different degrees of myopic eyes in Chinese individuals and to analyze the relevant factors of the SSI. Methods: This study analyzed the right eyes of 240 participants (240 eyes) aged 18-34years. The participants were divided into low-, moderate-, high-, and ultra-high myopia groups according to their spherical equivalent (SE), with 60 eyes included in each group. Spherical, cylinder, and SE were measured via automatically integrated optometry. Intraocular pressure (IOP) was measured using a non-contact tonometer. AL was measured using an IOLMaster device. Corneal curvature and central corneal thickness (CCT) were measured using a Pentacam. SSI and biomechanical corrected IOP (bIOP) were measured via corneal visualization Scheimpflug technology (Corvis ST). The statistical analyses included one-sample Kolmogorov-Smirnov tests and normal distribution histogram methods, Levene variance homogeneity tests, Pearson's correlation analyses, multiple linear stepwise regression analyses, one-way ANOVA, and LSD t-tests. Results: The mean (±SD) age of the 240 participants was (24.97 ± 4.16) years. The SSI was positively correlated with spherical, cylinder, SE, CCT, IOP, and bIOP and negatively correlated with K1 and AL (r = 0.475, 0.371, 0.497, 0.169, 0.291, 0.144, -0.154, and -0.464, respectively; all p < 0.05), but were not correlated with age, K2, or Km (all p > 0.05). Multiple linear regression analysis performed with SSI as the dependent variable, and spherical, cylinder, K1, CCT, and IOP as independent variables produced the following regression equation: SSI = 0.989 + 0.017 spherical + 0.042 cylinder +0.018 IOP (R 2 = 0.402, F = 31.518, p < 0.001). The SSI values in the low-, moderate-, high-, and ultra-high myopia groups were 0.945 ± 0.135, 0.940 ± 0.128, 0.874 ± 0.110, and 0.771 ± 0.104, respectively. The values decreased sequentially, and the differences between pairs were statistically significant (all p < 0.05), except for that between the low- and moderate-myopia groups (p > 0.05). Conclusion: SSI decreased with increasing myopia and astigmatism in the Chinese participants. The SSI was significantly lower in high and ultra-high myopia, especially ultra-high myopia. These findings indicate that increased corneal elasticity may be related to the pathogenesis of high and ultra-high myopia.

Comparison of Postoperative Safety, Efficacy, and Visual Quality after SMILE for Myopic Patients with Different Corneal Thicknesses

Purpose To investigate the safety, efficacy, and visual quality of small incision lenticule extraction (SMILE) in different corneal thickness patients with myopia or myopic astigmatism. Methods This prospective cohort study included 191 right eyes of 191 patients. Eyes were divided into three groups according to preoperative central corneal thickness (CCT) (Preoperative central corneal thickness (CCT) was the group indicator.) There were 31 eyes in the thin cornea group (CCT ≤500 um (μm), TC), 94 eyes in the moderate corneal thickness group (CCT ≥501 um (μm) and ≤550 um (μm), MD) and 66 eyes in the thick cornea group (CCT ≥550 um (μm), TK). Comparisons in uncorrected (UDVA) and best-corrected distance visual acuity (BDVA), manifest refractive spherical equivalent (SE), preoperative mesopic/photopic contrast sensitivity (CS), ocular higher-order aberrations (HOAs) at a 6mm analytical pupil diameter, and visual quality questionnaires were made (performed) among the three groups during the postoperative six months. Subgroup analyses were made based on preoperative SE. Results The safety indices at six months were 1.15 ± 0.18, 1.14 ± 0.17, and 1.18 ± 0.17, respectively (p = 0.374), and the efficacy indices at six months were 1.07 ± 0.25, 1.12 ± 0.22, and 1.11 ± 0.21, respectively (p = 0.599). The postoperative SE was −0.07 ± 0.52D, −0.14 ± 0.38D, and −0.05 ± 0.46D after SMILE in the three groups, respectively (p = 0.376). No significant difference was found in mesopic/photopic CS, HOAs, and visual quality among different corneal thickness groups and SE groups. Postoperative SE and efficacy indices were the lowest in thin cornea eyes with ultra-high myopia (over −9.00 D). Conclusions SMILE provides comparable safety, efficacy, and visual quality results in different corneal thickness patients. Those with myopia higher than -9.00 D had less efficacy after surgery, especially in thin cornea patients.

Accuracy of segmented measurement of axial length in ultra-high myopia filled with silicone oil using immersion B-scan ultrasonography.

To evaluate the accuracy of segmented measurement of axial length (AL) in high myopia filled with silicone oil by immersion B-scan ultrasonography (immersion B-scan). From June 2016 to June 2020, a total of 67 ultra-high myopia inpatients (67 eyes) who underwent silicone oil removal combined with cataract extraction and intraocular lens (IOL) implantation were retrospectively enrolled. The preoperative axial length (AL) of 31 patients with severe cataract were segmented measured using immersion B-scan (B-scan group) and another 36 patients with mild or moderate cataract were measured using IOLMaster 500 (IOLMaster group). The post-operative ALs in two groups were both measured using IOLMaster 500. The IOL power was calculated with Haigis formula. The differences in ALs between pre- and post-surgery, as well as the postoperative refractive spherical equivalent, absolute refractive error, the prediction deviation of postoperative refraction and best corrected visual acuity (BCVA) were compared. The pre- and post-operative ALs were 30.46±1.63 mm (range 28.09-33.51 mm) and 30.42±1.70 mm (range 28.03-33.90 mm) in B-scan group (t=0.644, P=0.542) and 30.51±1.21 mm (range 28.03-33.90 mm) and 30.43±1.27mm (range 28.54-33.50 mm) in IOLMaster group (t=1.843, P=0.074), respectively. Three months after surgery, BCVA were 0.45±0.13 (range 0.3-0.9) and 0.44±0.20 (range 0.2-1.0) in B-scan and IOLMaster group respectively (t=0.086, P=0.932). There was no significant difference of the postoperative spherical equivalent (-3.11±0.65 D vs -3.21±0.51 D, t=0.671, P=0.505) and the absolute refractive error (0.589±0.340 vs 0.470±0.245 D, t=1.615, P=0.112) between two groups. In B-scan group, absolute refractive error within ±0.50 D was found in 18 eyes (58.1%), within ±1.00 D in 26 eyes (83.9%), and within ±1.50 D in 31 eyes (100%). In IOLMaster group, absolute refractive error within ±0.50 D was found in 23 eyes (63.9%), within ±1.00 D in 34 eyes (94.4%), and within ±1.50 D in 36 eyes (Z=0.757, P=0.449). The segmented measurement of ALs by immersion B-scan shows comparable measurement accuracy with that of IOLMaster 500 in ultra-high myopia patients with severe cataract secondary to silicone oil filling and can obtain an ideal postoperative refractive state.

Predictive factors for postoperative visual acuity improvement with ICL-V4c for ultrahigh myopia above - 10 D.

The purpose of this study is to evaluate the predictive factors for postoperative visual acuity improvement (PVAI) in subjects who underwent phakic intraocular lens implantation with a central hole (ICL-V4c) for ultrahigh myopia above - 10 D. This was a retrospective study. Eyes with ultrahigh myopia above - 10 D undergoing ICL-V4c implantation were studied. Univariable linear regression models were used to assess the association between PVAI and preoperative parameters. Myopic maculopathy was classified into 5 categories by fundus photography. After the 1-month follow-up, the PVAI was compared within different age and preoperative spherical degree groups. This study included 726 eyes from 419 patients (111 men and 308 women), and the mean age, spherical refraction, and axial length were 28.67 ± 7.93years, - 13.61 ± 3.44 D, and 28.59 ± 1.50mm, respectively. At baseline, myopic maculopathy was classified (grades C0-C4) as follows: C0 was observed in 200 eyes (27.5%), C1 in 297 eyes (40.9%), C2 in 147 eyes (20.2%), C3 in 22 eyes (3.0%), and C4 in 60 eyes (8.3%). The PVAI was significantly negatively associated with age and positively associated with SD-pre(-Sph), but no significant association between myopic maculopathy classification and axial length was found. After 1month, 417 eyes (57.4%) gained more than 1 line at BCVA, 250 eyes (34.4%) remained the same, and 59 eyes (8.13%) lost 1 line. The postoperative visual acuity of 52 eyes was improved by more than 3 lines, and 42.3% were grade C4. The ICL performed well for the correction of ultrahigh myopia above - 10 D. Younger patients and those with a higher preoperative spherical degree had greater postoperative satisfaction. Chinese Clinical Trial Registry (ChiCTR2000036335). Date of registration: 2020/8/22.

Транс-ФРК: Компромисс?

Purpose. A statement of the fact of the presence of abnormally high visual acuity after the first stage of Trans-PRK and a proposal to use this information when planning laser correction of high and ultra-high myopia. Material and methods. Eyes were selected after the first stage of Trans-PRK (581 eyes), in which the postoperative myopic sphere equivalent was at least 2 diopters. Visual acuity was compared with non-operated eyes with a similar myopic sphere equivalent. Results. The revealed effect is that patients with high residual myopic refraction after the first stage of Trans-PRK have significantly higher visual acuity than non-operated people with similar refraction. Postoperative keratotopograms do not give grounds for understanding this effect. Conclusion. The explanation can be the forced work of the visual analyzer of the brain. With this in mind, it is possible to achieve and widely use a compromise between the desired and possible result in the practice of laser correction of myopia. Key words: myopia correction, first-stage, Trans-PRK, residual myopia, sphere equivalent, sight acuity, keratotopogram, visual analyzer of the brain, Ambliocor.

Femtosecond Laser-Assisted Small Incision Allogeneic Endokeratophakia Using a Hyperopic Lenticule in Rabbits.

PurposeTo investigate the morphologic and histopathologic changes in allogeneic endokeratophakia using hyperopic lenticules derived from small-incision lenticule extraction (SMILE).MethodsSix New Zealand rabbits (12 eyes) were included in this experiment and randomly and evenly divided into donor and recipient groups. The donor group underwent bilateral hyperopic SMILE surgery, and the concave lenticules were implanted into eyes in the recipient group. Corneal topography and anterior segment optical coherence tomography (OCT) examinations were performed at 1 day, 1 week, 1 month, and 5 months after surgery. All eyes were enucleated 5 months after surgery. Hematoxylin and eosin (HE) staining and transmission electron microscopy (TEM) were used to observe the corneal morphology in the recipient group.ResultsNo complications were observed, and the corneas remained transparent in the follow-up period. There was mild corneal edema within 1 week after surgery. Slit-lamp microscopy and OCT showed that the lenticules were gradually integrated with the surrounding corneal stroma. HE staining showed that the arrangement of corneal collagen was regular. The boundary between the lenticules and surrounding tissue could be identified with HE staining and TEM, and no inflammatory cells were found under TEM. The corneal Km values were significantly lower at 5 months postoperatively compared to preoperatively (P < 0.05).ConclusionsThis pilot study showed that allogeneic hyperopic SMILE lenticule endokeratophakia seems to be safe and feasible.Translational RelevanceAllogeneic hyperopic SMILE lenticule endokeratophakia may be applicable for the correction of corneal regression, ectasia, ultra-high myopia, or keratoconus.

Особенности витреомакулярной хирургии у пациентов со сверхвысокой миопией

Особенности витреомакулярной хирургии у пациентов со сверхвысокой миопией

Re-Evaluation of the Safety of Laser-Assisted Subepithelial Keratectomy

Purpose: Additional analyses of outcomes of laser-assisted subepithelial keratectomy (LASEK) are still necessary to improve the safety of LASEK. Therefore, in our study, outcomes were assessed retrospectively in 561 eyes that underwent LASEK treatment. Methods: Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA) and residual spherical equivalent were analyzed at 3 and 6 months postoperatively. We assessed four subgroups based on the degree of preoperative myopia considering mean BSCVA and loss of two or more lines. Results: Mean UCVAs and BSCVAs were obtained at 3 and 6 months postoperatively (1.23/1.35 and 1.23/1.37, respectively). The mean predictability was within ±0.125 diopters. Conversely, the safety indexes were 0.94 and 0.96 respectively, and the efficacy indexes were 0.86 and 0.86 at 3 and 6 months postoperatively, respectively. 8.4% eyes and 5.2% eyes lost two or more lines of BSCVA at 3 and 6 months postoperatively, respectively. The mean BSCVAs of the high or ultra-high groups were significantly lower than those of the low or mild groups both 3 months and 6 months postoperatively. The incidence rates of losing two or more lines of BSCVA in the high or ultra-high myopia groups were significantly greater than in the low or mild groups at 3 months and 6 months postoperatively. Conclusion: LASEK predictably corrected myopia achieving >1.2 in UCVA and BSCVA. However, the safety and efficacy indexes were

Effect of the zone-division LASIK for ultrahigh myopia

目的 评价对角膜相对较薄的超高度近视,应用分区切削模式进行LASIK治疗的临床效果.方法对95例(185眼)超高度近视,因选择6.0mm直径的切削区,剩余角膜厚度小于250μm,而进行LASIK分区切削治疗,分区切削分为2～3区,切削光区4.7～6.0 mm.随访时间6～20月,观察手术前后的屈光状态、裸眼视力、矫正视力、角膜地形图及并发症的发生情况.结果 术后1月视力达到最好并趋于稳定,所有患者的裸眼视力均较术前提高,术后3月183眼(98.92%)裸眼视力超过或等于术前最佳矫正视力.屈光回退47眼(25.41%),术后眩光51眼(27.57%),分析手术后角膜地形图,切削过度区光滑,无偏心切削.与标准手术相比可节省角膜厚度20%～25%,视力、屈光度变化与分区多少及近视度数有关.少数患者出现的眩光、夜视力下降等并发症,1个月后减轻或消失,角膜地形图均为正常负性形态.结论 LASIK分区切削模式是对角膜相对较薄的超高度近视进行激光治疗有效安全的方法.可节省角膜组织,具有安全可靠,稳定性、可预测性强的临床效果。