Ocular biometric characteristics of Han ethnicity in Tianjin and Uyghur ethnicity in Xinjiang undergoing cataract surgery.

AIM: To analyze and compare the differences among ocular biometric parameters in Han and Uyghur populations undergoing cataract surgery. METHODS: In this hospital-based prospective study, 410 patients undergoing cataract surgery (226 Han patients in Tianjin and 184 Uyghur patients in Xinjiang) were enrolled. The differences in axial length (AL), anterior chamber depth (ACD), keratometry [steep K (Ks) and flat K (Kf)], and corneal astigmatism (CA) measured using IOL Master 700 were compared between Han and Uyghur patients. RESULTS: The average age of Han patients was higher than that of Uyghur patients (70.22±8.54 vs 63.04±9.56y, P<0.001). After adjusting for age factors, Han patients had longer AL (23.51±1.05 vs 22.86±0.92 mm, P<0.001), deeper ACD (3.06±0.44 vs 2.97±0.37 mm, P=0.001), greater Kf (43.95±1.40 vs 43.42±1.69 D, P=0.001), steeper Ks (45.00±1.47 vs 44.26±1.71 D, P=0.001), and higher CA (1.04±0.68 vs 0.79±0.65, P=0.025) than Uyghur patients. Intra-ethnic male patients had longer AL, deeper ACD, and lower keratometry than female patients; however, CA between the sexes was almost similar. In the correlation analysis, we observed a positive correlation between AL and ACD in patients of both ethnicities (rHan =0.48, rUyghur =0.44, P<0.001), while AL was negatively correlated with Kf (rHan =-0.42, rUyghur =-0.64, P<0.001) and Ks (rHan =-0.38, rUyghur =-0.66, P<0.001). Additionally, Kf was positively correlated with Ks (rHan =0.89, rUyghur =0.93, P<0.001). CONCLUSION: There are differences in ocular biometric parameters between individuals of Han ethnicity in Tianjin and those of Uyghur ethnicity in Xinjiang undergoing cataract surgery. These ethnic variances can enhance our understanding of ocular diseases related to these parameters and provide guidance for surgical procedures.

Time trends in myopia and high myopia prevalence in young university adults in China.

AIM: To investigate time trends in myopia and high myopia prevalence over 6y among young university adults in China. METHODS: This is a 6-year series cross-sectional study from 2016 to 2021. Totally 4910 freshmen were enrolled and completed a questionnaire concerning age, gender, and disease history. Students with eye diseases were excluded after a detailed eye examination. The refractive status was measured by non-cycloplegic objective refraction and ocular parameters were measured by Lenstar 900. The examination followed the same protocol each year. Trends over time in myopia and high myopia prevalence, as well as ocular biometry parameters, were analyzed. RESULTS: From 2016 to 2021, the axial length (AL) and corneal radius (CR) increased significantly (P=0.002 for AL; P=0.04 for CR). However, the spherical equivalent (SE) and the ratio of axial length to the corneal radius (AL/CR) did not change significantly (P=0.59 for SE; P=0.24 for AL/CR). The frequency of AL ≥26.0 mm increased from 26.6% in 2016 to 29.3% in 2021 (P=0.05 for trend). The prevalence of myopia and high myopia did not change significantly in our study (P≥0.18). Compared to a similar cross-sectional study conducted 10 years ago, the prevalence of myopia decreased significantly (94.9% vs 91.8%, P<0.001). Whereas the prevalence of high myopia increased largely (18.12% vs 27.6%, P<0.001). CONCLUSION: The prevalence of high myopia increases in young university adults during 10y period. Myopia control should begin earlier in childhood. However, these interventions are still needed for high myopia even in young adulthood.

Prevalence and inconformity of refractive errors and ocular biometry of 3573 medical university freshman students for 4 consecutive years.

AIM: To evaluate the prevalence of refractive errors and ocular biometry in 3573 freshman students at Tianjin Medical University for 4 consecutive years. METHODS: In this university-based, cross-sectional study, comprising 3573 students, visual acuity (VA), slit-lamp examination, non-cycloplegic auto-refraction, and ocular biometry were recorded. RESULTS: The prevalence of myopia increased annually, from 2017 to 2020 were 93.5%, 94.5%, 95.9%, and 96.2%, respectively (P=0.03), and the prevalence of high myopia was 25.7%, 26.9%, 28.6%, and 28.6%, respectively. Males tended to have a higher percentage of total astigmatism than females, with astigmatism ≥0.75 and ≥1.0 D criteria. The percentage of with-the-rule astigmatism, against-the-rule astigmatism, and oblique astigmatism was 90.3%, 5.8%, and 3.9%, respectively, with astigmatism ≥1.00 D criteria. The mean spherical equivalent, axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), corneal radius (CR), and lens position (LP) were 4.37±2.52 D, 25.28±1.24 mm, 539.49±34.98 µm, 3.31±0.34 mm, 3.47±0.21 mm, 7.8±0.28 mm, and 5.04±0.32 mm, respectively. With diopter increase in myopia, the AL became longer, CR became steeper, ACD became deeper, LT became thinner, and LP became more posterior (all P<0.01). Females had a shorter AL, thinner CCT, smaller CR, shallower ACD, thicker lens, and more anterior LP than males (P<0.01). The 64% of high myopia had AL≥26 mm, meanwhile, 5.8% mild myopia and 21.1% moderate myopia had AL≥26 mm. With AL≥26 mm, mild and moderate myopia compared to high myopia, AL was shorter (26.51±0.46 vs 26.87±0.70 mm), CR was larger (8.10±0.3 vs 7.85±0.23 mm) and LT was thinner (3.39±0.19 vs 3.45±0.19 mm, P<0.001). CONCLUSION: The prevalence of myopia and high myopia is significantly high in freshman students. The majority of astigmatism is with-the-rule. Inconformity of refractive errors and ocular biometry existed in some students. Attention should be paid to the ocular biometry of myopia.

Comparative study of objective visual quality between FS-LASIK and SMART in myopia.

AIM: To compare the changes in the objective visual quality of patients with low and moderate myopia postoperatively after transepithelial photorefractive keratectomy using the smart pulse technology (SMART) and femtosecond laser in situ keratomileusis (FS-LASIK). METHODS: Corneal higher-order aberrations (HOAs), horizontal coma, vertical coma and spherical aberration were measured using Pentacam, and cutoff for modulation transfer function (MTF cutoff), objective scatter index (OSI) and Strehl ratio (SR) was measured using an optical quality analysis system (OQAS-II), before and after operation at 1, 3, and 6mo, and data were analyzed by repeated measurement two-way analysis of variance. RESULTS: The difference in uncorrected distance visual acuity between SMART and FS-LASIK was statistically significant only 1wk postoperatively. Approximately 86.36% and 80.69% of patients with spherical equivalent (SE) in ±0.50 D were observed in the SMART and FS-LASIK groups, respectively. No significant difference was observed in SE between the two groups (P=0.509). The HOAs increased postoperatively compared with those before surgery in both groups (P<0.05). No significant difference in HOA, corneal horizontal coma, spherical aberration, ΔHOA, Δhorizontal coma, and Δspherical aberration were observed between the two group (P>0.05). Corneal vertical coma and Δcorneal vertical coma in the FS-LASIK group were higher than those in the SMART group (P<0.05). The OSI of both groups at 1mo after surgery was higher than that before surgery (P<0.05). At 3 and 6mo postoperatively, the OSI in the FS-LASIK group was slightly higher than that in the SMART group (P=0.040 and 0.047, respectively). At 6mo after surgery, the MTF cutoff was statistically significant different between the two groups (P=0.026). No significant difference in SR between the FS-LASIK and SMART groups was observed at 1, 3, and 6mo postoperatively (P>0.05). CONCLUSION: The HOAs increase and visual quality is delayed in both groups postoperatively, and the long-term objective visual quality after SMART is slightly better than that after FS-LASIK.

Alteration of EIF2 Signaling, Glycolysis, and Dopamine Secretion in Form-Deprived Myopia in Response to 1% Atropine Treatment: Evidence From Interactive iTRAQ-MS and SWATH-MS Proteomics Using a Guinea Pig Model.

Purpose: Atropine, a non-selective muscarinic antagonist, effectively slows down myopia progression in human adolescents and several animal models. However, the underlying molecular mechanism is unclear. The current study investigated retinal protein changes of form-deprived myopic (FDM) guinea pigs in response to topical administration of 1% atropine gel (10 g/L). Methods: At the first stage, the differentially expressed proteins were screened using fractionated isobaric tags for a relative and absolute quantification (iTRAQ) approach, coupled with nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) (n = 24, 48 eyes) using a sample pooling technique. At the second stage, retinal tissues from another cohort with the same treatment (n = 12, 24 eyes) with significant ocular changes were subjected to label-free sequential window acquisition of all theoretical mass spectra (SWATH-MS) proteomics for orthogonal protein target confirmation. The localization of Alpha-synuclein was verified using immunohistochemistry and confocal imaging. Results: A total of 1,695 proteins (8,875 peptides) were identified with 479 regulated proteins (FC ≥ 1.5 or ≤0.67) found from FDM eyes and atropine-treated eyes receiving 4-weeks drug treatment using iTRAQ-MS proteomics. Combining the iTRAQ-MS and SWATH-MS datasets, a total of 29 confident proteins at 1% FDR were consistently quantified and matched, comprising 12 up-regulated and 17 down-regulated proteins which differed between FDM eyes and atropine treated eyes (iTRAQ: FC ≥ 1.5 or ≤0.67, SWATH: FC ≥ 1.4 or ≤0.71, p-value of ≤0.05). Bioinformatics analysis using IPA and STRING databases of these commonly regulated proteins revealed the involvement of the three commonly significant pathways: EIF2 signaling; glycolysis; and dopamine secretion. Additionally, the most significantly regulated proteins were closely connected to Alpha-synuclein (SNCA). Using immunostaining (n = 3), SNCA was further confirmed in the inner margin of the inner nuclear layer (INL) and spread throughout the inner plexiform layer (IPL) of the retina of guinea pigs. Conclusion: The molecular evidence using next-generation proteomics (NGP) revealed that retinal EIF2 signaling, glycolysis, and dopamine secretion through SNCA are implicated in atropine treatment of myopia in the FDM-induced guinea pig model.

Lag of accommodation predicts clinically significant change of spherical equivalents after cycloplegia.

AIM: To evaluate related factors with the change of spherical equivalents (ΔSE) and determine the suitable predictor of clinically significant ΔSE (≥0.50 D) with cyclopentolate hydrochloride on Chinese children. METHODS: A total of 145 right eyes of 145 children aged 4 to 15y were enrolled. Intraocular pressure, axial length and lag of accommodation (LOA) were assessed before cycloplegia induced by 3 drops of 1% cyclopentolate at 5-minute intervals. SE was measured before and 1h after the first drop of cyclopentolate. ΔSE was compared between different gender groups and among refractive groups. Multivariate linear regression analysis was performed to find related factors with ΔSE. ROC analysis was used to figure out the suitable predictor of clinically significant ΔSE. RESULTS: For the total 145 eyes, the mean SE reached up to -0.70±1.86 D from -1.30±1.62 D, with the mean ΔSE of 0.60±0.55 D. The mean ΔSE were 0.63±0.55 D and 0.57±0.56 D respectively in the male and female group (P=0.40). The mean ΔSE was significantly different among different refractive groups (P<0.0001), with the ΔSE of hyperopia group (1.12±0.64 D) larger than that of the emmetropia (0.56±0.43 D, P=0.001) and myopia group (0.32±0.28 D, P<0.0001). The ΔSE was correlated with LOA (B=-0.54, P<0.0001), cycloplegic SE (B=0.10, P<0.0001) and age (B=-0.04, P=0.015). ROC curve indicated that LOA predicted clinically significant ΔSE by 82% [area under the curve (AUC)=0.82] alone, while the value was slightly improved to 85% (AUC=0.85) in combination with axial length and 86% (AUC=0.86) in association with axial length as well as age. CONCLUSION: After cycloplegia with cyclopentolate, the ΔSE decreases with larger LOA, longer axial length and older age. Specifically, LOA plays a more vital role in predicting clinically significant ΔSE.

Commentary review on peripapillary morphological characteristics in high myopia eyes with glaucoma: diagnostic challenges and strategies.

The incidences of open angle glaucoma (OAG) and high myopia are increasing concomitantly. Considering the aging population and concurrent rapid increase in the number of individuals with myopia, the risk of visual defects caused by highly myopic OAG is likely to increase dramatically over the next few decades. However, precise screening and diagnosis of OAG is challenging because of the tilt and rotation of the optic disc, as well as extensive ß-zone parapapillary atrophy in highly myopic eyes. Recent advances in optical coherence tomography (OCT) and OCT angiography (OCTA) technologies imply that both modalities are promising tools for the detection of highly myopic OAG. Notably, the diagnosis of OAG remains to be determined with the longitudinal changes of functional damages (e.g. visual field defect, visual electrophysiological changes). We herein describe some aspects of microvascular and microstructural pathology in patients with highly myopic OAG and proposes a framework for the development of novel diagnostic and therapeutic strategies.

Protective effects of riboflavin-UVA-mediated posterior sclera collagen cross-linking in a guinea pig model of form-deprived myopia.

AIM: To evaluate the effect of posterior sclera collagen cross-linking induced by riboflavin-ultraviolet A (UVA) on form-deprived myopia in guinea pigs. METHODES: Twenty-five pigmented guinea pigs of 3-week-old were randomly assigned into 4 groups that included normal control (NOR, n=7), form-deprived (FDM, n=7), normal with riboflavin-UVA cross-linking (NOR+CL, n=5) and form-deprived with cross-linking (FDM+CL, n=6). The NOR+CL group and the FDM+CL group received the riboflavin-UVA induced cross-linking at day 0. FDM was induced by monocularly deprived with facemask in the right eyes. The refraction, axial length and corneal curvature were measured by retinoscopy, A-scan and keratometer respectively in scheduled time points (day 0 and 1, 2, 3, 4wk after form-deprivation). At the end of 4 weeks' experiment, stress-strain tests of sclera were measured and morphological changes of sclera and retina were examined. RESULTS: After 4wk, the interocular difference of refractive error were -0.11±0.67, -2.93±0.56, 1.10±0.58, and -1.63±0.41 D in the NOR, FDM, NOR+CL, and FDM+CL groups respectively. Mixed-effect linear model revealed significant effect of FDM (P<0.01) and CL (P<0.001). Also, after 4wk, the interocular difference of axial length were 0.01±0.04, 0.29±0.07, -0.13±0.06, and 0.11±0.05 mm in the NOR, FDM, NOR+CL, and FDM+CL group. Mixed-effect linear model revealed significant effect of FDM (P<0.001) and CL (P<0.01). As for corneal curvature, significant interocular difference have not found between any of the two groups. At the end of this experiment, the ultimate stress and elastic modulus were found significantly increased in both CL groups. But no difference was found in the groups without cross-linked. There was no abnormality observed in the retina and RPE cells of the treated eyes. CONCLUSION: The posterior sclera collagen cross-linking induced by riboflavin-UVA can slow down the progress of myopia and increase the sclera biomechanical strength in the guinea pig model of form-deprived myopia.

Comparison between two autorefractor performances in large scale vision screening in Chinese school age children.

AIM: To evaluate the effectiveness of Grand Seiko Ref/Keratometer WAM-5500 compared to Topcon KR800 autorefractor in detecting refractive error in large scale vision screening for Chinese school age children with the WHO criteria. METHODS: A total of 886 participants were enrolled with mean age of 9.49±1.88y from Tianjin, China. Spherical equivalent (SE) was obtained from un-cycloplegic autorefraction and cycloplegic autorefraction. Topcon KR 800 (Topcon) and Grand Seiko WAM-5500 (WAM) autorefractors were used. Bland-Altman Plot and regression were generated to compare their performance. The overall effectiveness of detecting early stage refractive error was analyzed with receiver operating characteristic (ROC) curves. RESULTS: The mean SE was -0.98±1.81 diopter (D) and the prevalence of myopia was 48.9% defined by WHO criteria according to the result of cycloplegic autorefraction. The mean SE of un-cycloplegic autorefraction with Topcon and WAM were -1.21±1.65 and -1.20±1.68 D respectively. There was a strong linear agreement between result obtained from WAM and cycloplegic autorefraction with an R2 of 0.8318. Bland-Altman plot indicated a moderate agreement of cylinder values between the two methods. The sensitivity and specificity for detecting hyperopia were 90.52% and 83.51%; for detecting myopia were 95.60% and 90.24%; for detecting astigmatism were 79.40% and 90.21%; for detecting high myopia were 98.16% and 98.91% respectively. CONCLUSION: These findings suggest that both Grand Seiko and Topcon autorefractor can be used in large-scale vision screening for detecting refractive error in Chinese population. Grand Seiko gives relatively better performance in detecting myopia, hyperopia, and high myopia for school age children.

The prevalence of vision impairment and refractive error in 3654 first year students at Tianjin Medical University.

AIM: To determine the prevalence of vision impairment (VI) and refractive error in first year university students at the Tianjin Medical University. METHODS: This is a cross-sectional observational cohort study of VI and refractive error among first year university students at the Tianjin Medical University. The first year university students were involved in this study and were given a detailed questionnaire including age, birth date, and spectacle wearing history. A standardized ophthalmologic examination including visual acuity (VA), slit-lamp examination, non-cycloplegic auto-refraction, objective refraction, fundus photography, and examination of their spectacles were recorded. RESULTS: A total of 3654 participants were included in this study. Totally 3436 (94.03%) individuals had VI in this population. Totally 150 (4.10%) individuals had VI due to ocular disease, including amblyopia, congenital cataract, retinal atrophy or degeneration, strabismus, congenital nystagmus, refractive surgery orthokeratology. Totally 3286 (89.93%) subjects had VI due to refractive error. Only 218 (5.97%) students were emmetropia. Moreover, refractive error was the main cause for the VI (95.63%). Totally 3242 (92.52%) students were myopia and the prevalence of mild, moderate, and high myopia subgroup was 27.05%, 44.35%, and 21.26% respectively. Totally 44 (1.29%) subjects were hyperopic. The rates of uncorrected visual acuity (UCVA), presenting visual acuity (PVA) and best corrected visual acuity (BCVA) which better than 20/20 in both eyes were 5.65%, 22.32% and 82.13% respectively. The rates of correction, under correction and well correction in myopia subjects were 82.73%, 84.39% and 15.61%, respectively. CONCLUSION: We present a high prevalence of refractive errors and high rates of under correction refractive error among first year university students. These results may help to promote vision protection work in young adults.

Clinical evaluation of surgery-induced astigmatism in cataract surgery using 2.2 mm or 1.8 mm clear corneal micro-incisions.

AIM: To evaluate corneal astigmatism after phacoemulsification using 2.2 mm or 1.8 mm clear corneal micro-incisions and its effects on visual function. METHODS: Sixty cases (60 eyes) with cataract were randomly divided into groups A (n=30) and B (n=30) respectively underwent 2.2 mm and 1.8 mm clear corneal tunnel incision phacoemulsification combined with folding intraocular lens implantation from the time direction of 11:00. On day 1 and at 1, 4, and 6wk after operation, patients' vision was measured and both the corneal curvature and corneal thickness (CT) were recorded using Pentacam. RESULTS: The measured surgery-induced astigmatism (SIA) in both groups A and B peaked on day 1 after operation, and then gradually decreased and eventually stabilized in week 4. No statistically significant difference was found in corneal astigmatism between two groups (P>0.05). The measured corneal astigmatism at 4wk and 6wk postoperatively were 0.28±0.09 D and 0.27±0.10 D for groups A and 0.27±0.09 D and 0.25±0.10 D for groups B without statistically significant difference (P>0.05). In addition, no significant differences in visual acuity and CT were found between groups A and B before or after operation. CONCLUSION: Both 2.2 mm and 1.8 mm micro-incision cataract surgeries result in relatively small SIA with no difference in visual function and corneal astigmatism between two surgery approaches. Thus, the two types of surgical systems are safe and efficient for cataract treatment, by which satisfactory uncorrected visual acuity can be regained early postoperatively.

α-Melanocyte-stimulating hormone ameliorates ocular surface dysfunctions and lesions in a scopolamine-induced dry eye model via PKA-CREB and MEK-Erk pathways.

Dry eye is a highly prevalent, chronic, and multifactorial disease that compromises quality of life and generates socioeconomic burdens. The pathogenic factors of dry eye disease (DED) include tear secretion abnormalities, tear film instability, and ocular surface inflammation. An effective intervention targeting the pathogenic factors is needed to control this disease. Here we applied α-Melanocyte-stimulating hormone (α-MSH) twice a day to the ocular surface of a scopolamine-induced dry eye rat model. The results showed that α-MSH at different doses ameliorated tear secretion, tear film stability, and corneal integrity, and corrected overexpression of proinflammatory factors, TNF-α, IL-1ß, and IFN-γ, in ocular surface of the dry eye rats. Moreover, α-MSH, at 10(-4) µg/µl, maintained corneal morphology, inhibited apoptosis, and restored the number and size of conjunctival goblet cells in the dry eye rats. Mechanistically, α-MSH activated both PKA-CREB and MEK-Erk pathways in the dry eye corneas and conjunctivas; pharmacological blockade of either pathway abolished α-MSH's protective effects, suggesting that both pathways are necessary for α-MSH's protection under dry eye condition. The peliotropic protective functions and explicit signaling mechanism of α-MSH warrant translation of the α-MSH-containing eye drop into a novel and effective intervention to DED.

Anti-VEGF treatment for myopic choroid neovascularization: from molecular characterization to update on clinical application.

Choroidal neovascularization (CNV) secondary to pathologic myopia has a very high incidence in global, especially in Asian, populations. It is a common cause of irreversible central vision loss, and severely affects the quality of life in the patients with pathologic myopia. The traditional therapeutic modalities for CNV secondary to pathologic myopia include thermal laser photocoagulation, surgical management, transpupillary thermotherapy, and photodynamic therapy with verteporfin. However, the long-term outcomes of these modalities are disappointing. Recently, intravitreal administration of anti-VEGF biological agents, including bevacizumab, ranibizumab, pegaptanib, aflibercept, and conbercept, has demonstrated promising outcomes for this ocular disease. The anti-VEGF regimens are more effective on improving visual acuity, reducing central fundus thickness and central retina thickness than the traditional modalities. These anti-VEGF agents thus hold the potential to become the first-line medicine for treatment of CNV secondary to pathologic myopia. This review follows the trend of "from bench to bedside", initially discussing the pathogenesis of myopic CNV, delineating the molecular structures and mechanisms of action of the currently available anti-VEGF drugs, and then systematically comparing the up to date clinical applications as well as the efficacy and safety of the anti-VEGF drugs to the CNV secondary to pathologic myopia.

Nerve growth factor expression and nerve regeneration in monkey corneas after LASIK.

PURPOSE: To determine whether changes in cornea nerve growth factor (NGF) protein and gene expression correlate with corneal nerve regeneration after LASIK in rhesus monkeys. METHODS: Ten rhesus monkeys underwent randomly assigned LASIK procedures to correct -8.0 diopters of myopia in both eyes and two additional monkeys (with no surgery) served as controls. The central corneas of the experimental animals were excised 3 and 7 days and 1, 3, and 6 months after the surgery. Nerve regeneration, NGF mRNA, and protein expression were analyzed by gold chloride staining, real-time polymerase chain reaction, and enzyme-linked immune sorbent assay analysis, respectively. RESULTS: Compared to controls, the LASIK-treated animals had a significantly diminished nerve plexus in the sub-basal region of the cornea at all times after the surgery (P < .001). NGF protein levels decreased significantly on days 3 and 7 after LASIK (P < .001), but returned to control levels 1 month later. NGF mRNA levels increased 5.4-fold on day 3 after the surgery (P < .001), then reduced to two-fold (P < .05) above control levels on day 7 and were back to normal at 3 months and beyond. After LASIK, the changes of early NGF protein and NGF mRNA levels correlated with the density of the corneal nerve plexuses. CONCLUSIONS: The results showed that the LASIK procedure in non-human primates was associated with changes in NGF protein and mRNA levels in the cornea. Such changes may be related to the initiation of nerve regeneration and the final recovery of nerve plexuses in the cornea.

Evaluation of corneal cell growth on tissue engineering materials as artificial cornea scaffolds.

The keratoprosthesis (KPro; artificial cornea) is a special refractive device to replace human cornea by using heterogeneous forming materials for the implantation into the damaged eyes in order to obtain a certain vision. The main problems of artificial cornea are the biocompatibility and stability of the tissue particularly in penetrating keratoplasty. The current studies of tissue-engineered scaffold materials through comprising composites of natural and synthetic biopolymers together have developed a new way to artificial cornea. Although a wide agreement that the long-term stability of these devices would be greatly improved by the presence of cornea cells, modification of keratoprosthesis to support cornea cells remains elusive. Most of the studies on corneal substrate materials and surface modification of composites have tried to improve the growth and biocompatibility of cornea cells which can not only reduce the stimulus of heterogeneous materials, but also more importantly continuous and stable cornea cells can prevent the destruction of collagenase. The necrosis of stroma and spontaneous extrusion of the device, allow for maintenance of a precorneal tear layer, and play the role of ensuring a good optical surface and resisting bacterial infection. As a result, improvement in corneal cells has been the main aim of several recent investigations; some effort has focused on biomaterial for its well biological properties such as promoting the growth of cornea cells. The purpose of this review is to summary the growth status of the corneal cells after the implantation of several artificial corneas.

[Clinical research of the phakic foldable angle-supported intraocular lens for the correction of high myopia].

OBJECTIVE: To assess the safety, efficacy, predictability and stability of the phakic foldable angle-supported intraocular lens (IOL) (CACHET IOL, Alcon Inc., USA.) for correction of high-to-extremely high myopia in adults. METHODS: In this prospective study, 29 eyes of 15 patients were implanted with CACHET phakic angle-supported IOL and followed for 1 year postoperatively. Preoperative manifest refractive sphere was -12.08 ± 2.44 diopters (D). Visual acuity(uncorrected visual acuity, UCVA; best spectacle-corrected visual acuity, BSCVA), predictability and stability of manifest refraction spherical equivalent (MRSE), adverse events, and endothelial cell density were analyzed primarily during 1-year of follow-up. RESULTS: After 1 year of follow-up, a BSCVA of 0.6 or better was achieved by 100% of eyes; 9.7% (26/29) had a BSCVA of 1.0 or better; no eyes lost ≥ 1 line BSCVA, 62.1%(18/29) had no change in lines of BSCVA, 31.0% (9/29) gained 1 line of BSCVA, 3.4% (1/29) gained 2 line of BSCVA, and 3.4% (1/29) gained more than 2 line of BSCVA; the safety index was 1.13 (1.08/0.96); UCVA of 1.0 or better was achieved by 58.6% (17/29), 100% had an UCVA of 0.5 or better, 86.2% (25/29) of eyes achieved a UCVA of 0.8 or better, and 93.1% (27/29) of eyes achieved a UCVA of 0.6 or better; the efficacy index was 1.03(0.99/0.96). The overall mean percentage change in endothelial cell density 1 year after surgery was -0.23% ± 4.80%. Five eyes (17.2%) had increased intraocular pressure (IOP) on the day of surgery. No pupil ovalization, pupillary block, or retinal detachment events were observed. Glare (6.9%, 2/29) and halo (13.8%, 4/29) mainly appeared in the first month after surgery, and had no influence on driving in night. CONCLUSIONS: After 1 year of follow-up, the implantation of phakic foldable angle-supported IOL was proved to be safe, effective and predictable with minimal complications in patients with high myopia. Due to the limitation of visiting time, long-term of clinical investigation is necessary to verify the safety and efficacy of this IOL.

[Research status of photodynamic therapy for corneal neovascularization].

Pathological corneal neovascularization is an important reason of visual impairment. Research outcomes showed that angiogenesis mechanism is similar in all the tissues of the body and photodynamic therapy demonstrate a useful effect in blocking tumor and choroidal neovascularization. This method is currently being tried for the treatment of corneal neovascularization. This paper will review the research status of photodynamic therapy in corneal neovascularization using various photosensitizers.