近视眼手术人群角膜直径的分析

目的：测量近视眼手术人群的角膜直径,探讨不同性别、眼别角膜直径的差别及角膜直径与等效球镜度数之间的相关性。

方法：对2013-03/08来我院近视门诊行准分子激光手术的近视眼126例252眼,男48例96眼,女78例156眼, 年龄18～45(平均24.23±5.35)岁,应用IOL Master测量角膜直径\〖white-to-white(WTW)\〗距离。对252眼都采用NIDEK RT-2100综合验光仪进行主觉验光,并换算成等效球镜\〖Spherical equivalent(SE)\〗,按照等效球镜度数分成3组：轻度近视(-3.00D结果：全部病例角膜直径平均值为11.52±0.41mm,其中男性角膜直径11.60±0.35mm,女性11.43±0.36mm,性别间角膜直径有统计学意义( t=0.021,P=0.009); 右眼平均角膜直径(11.53±0.40mm)与左眼(11.51±0.42mm)比较无显著统计学差异(t=-0.115,P=0.912); 低度、中度和高度近视者的角膜直径的平均值分别为11.59±0.39、11.48±0.40、11.45±0.41mm,角膜直径与屈光度间呈负相关性(R²=-0.001,P=0.001),且三组近视患者角膜直径之间存在显著统计学差异(F=4.487, P=0.004)。

结论：近视眼手术人群中男性角膜直径大于女性; 近视程度越高,角膜直径越短。     

与隐形眼镜相关的感染性角膜炎-埃及5年流行病学研究

目的：研究埃及Tanta大学医院与隐形眼镜相关的感染性角膜炎患者的不同流行病学特点,评估这类疾病各方面的特点,以提高患者对这类疾病的认识,找出可行的解决方案。

方法：选取我院2009-01/2013-12期间在眼科门诊就诊的所有角膜炎患者仔细检查,并对所有与隐形眼镜相关的感染性角膜炎患者进一步检查和调查。

结果：本研究期间,总共108 496位有不同主诉的患者中,1463例(1.3%)患有不同形式的角膜炎,其中151例(0.1%)为隐形眼镜相关感染性角膜炎。结果发现患有隐形眼镜相关感染性角膜炎常见的年龄群<30岁,大多数是学生(64%),家庭人数多且较为拥挤,农村居民高于城市居民,患者采用户外水源及污水处理不卫生。从病史分析发现：隐形眼镜相关感染性角膜炎通常为彻夜使用,储存或者配戴不卫生,或者隐形眼镜来源不安全,例如化妆品商店和理发店。结膜囊微生物培养结果提示阳性率92%,阴性率8%。大多数培养阳性的病例是由细菌和真菌混合感染引起,共53例(38.1%),单纯细菌感染43例(30.9%),真菌31例( 22.3%),阿米巴12例(8.6%)。

结论：与隐形眼镜相关的感染性角膜炎常见于学生群体,与农村生活、户外供水、不卫生的污水处理等危险因素有关。彻夜配戴、储存或配戴不卫生及隐形眼镜来源不安全都可增加隐形眼镜相关感染性角膜炎的发病率。     

骨髓间充质干细胞应用于角膜疾病的研究进展

随着干细胞科学的飞速发展,近年间充质干细胞(MSCs)的研究已成为热点。骨髓间充质干细胞(BMSCs)是来源于骨髓中的MSCs,具有免疫原性低、有多向分化潜能、促进损伤修复、性能稳定等生物学优点。研究发现,BMSCs是医学领域中极具前景的一种特殊细胞,几乎在各系统疾病的治疗方面都有广泛应用。眼科学者的研究也发现,BMSCs已经成为角膜疾病中一种兼具科研价值和临床价值的种子细胞,为角膜盲患者的康复带来了一线希望。本文就BMSCs对角膜损伤与角膜移植排斥反应治疗方面的研究做一综述。     

Effect of torsional mode phacoemulsification on cornea in eyes with/without pseudoexfoliation

AIM: To evaluate the effect of torsional mode phacoemulsification on central corneal thickness, corneal endothelial cell density, and morphology in eyes with/without pseudoexfoliation (PEX) syndrome. METHODS: Fourty-two consecutive patients with and 42 patients without PEX as a control group scheduled for cataract surgery was studied. Phacoemulsification, using OZiL IP system, was performed with quick chop technique. Using noncontact specular microscopy, the central endothelial cell density (ECD), coefficient of variation, percentage of hexagonal cells, and the central corneal thickness (CCT) were evaluated preoperatively and postoperatively at 1, 7 and 30d. RESULTS: The ECD in PEX syndrome was statistically significantly lower than that in the control group preoperatively and postoperatively (P≤0.001). Percentage change in ECD was statistically significantly higher in PEX than that in control group after surgery follow up (P≤0.04). There was no statistically significant difference between both groups comparing percentage of hexagonal cells and coefficient of variation in the cell size before and after the surgery. At 1 and 7d after surgery, percentage change in CCT was statistically significantly higher in PEX group than that in the control group (P≤0.041). CONCLUSION: Although torsional mode phacoemulsification and intraocular lens (IOL) implantation provided a safe and favorable surgical outcome in patients with/without PEX, torsional phacoemulsification led to significantly higher ECD loss in the PEX group than that in the control group during the whole follow up period. In addition, more corneal swelling in the PEX group than that in the control group during the early postoperative period has indicated that the corneal endothelium, in presence of PEX endotheliopathy, seems to be more susceptible to the effects of phacoemulsification surgery in eyes with PEX. The increased risk of anterior chamber manipulations in patients with PEX should be taken into account for an increased risk of bullous keratopathy.     

Comparison of corneal measurements in keratoconic eyes using rotating Scheimpflug camera and scanning-slit topography

AIM: To compare the anterior segment measurements obtained by rotating Scheimpflug camera (Pentacam) and Scanning-slit topography (Orbscan IIz) in keratoconic eyes. METHODS: A total of 121 patients, 71 males (58.7%) and 50 females (41.3%) (214 eyes) with the diagnosis of keratoconus (KC) were enrolled in this study. Following diagnosis of KC by slit-lamp biomicroscopic examination, central corneal thickness (CCT), thinnest corneal thickness (TCT), anterior chamber depth (ACD), and pupil diameter (PD) were measured by a single examiner using successive instrumentation by Pentacam and Orbscan. RESULTS: There was no significant difference between the two instruments for the measurement of CCT and TCT. In contrast, scanning-slit topography measured ACD (3.46±0.40 mm vs. 3.38±0.33 mm, P=0.019) and PD (4.97±1.26 mm vs 4.08±1.19 mm, P<0.001) significantly larger than rotating Scheimpflug camera. The two devices made similar measurements for CCT (95% CI: -2.94 to 5.06, P=0.602). However, the mean difference for TCT was -6.28 (95% CI: -10.51 to -2.06, P=0.004) showing a thinner measurement by Orbscan than by Pentacam. In terms of the ACD, the mean difference was 0.08 mm (95% CI: 0.04 to 0.12, P<0.001) with Orbscan giving a slightly larger value than Pentacam. Similarly, Orbscan measurement for PD was longer than Pentacam (95% CI: 0.68 to 1.08, P<0.001). CONCLUSION: A good agreement was found between Pentacam and Orbscan concerning CCT measurement while comparing scanning-slit topography and rotating Scheimpflug camera there was an underestimation for TCT and overestimation for ACD and PD.     

In vivo corneal confocal microscopic analysis in patients with keratoconus

AIM:To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in patients with keratoconus and control subjects.METHODS: Unscarred corneas of 78 keratoconic subjects without a history of contact lens use and 36 age-matched control subjects were evaluated with slit-lamp examination (SLE), corneal topography and laser scanning IVCM. One eye was randomly chosen for analysis. Anterior and posterior stromal keratocyte, endothelial cell and basal epithelial cell densities and sub-basal nerve structure were evaluated.RESULTS: IVCM qualitatively demonstrated enlarged basal epithelial cells, structural changes in sub-basal and stromal nerve fibers, abnormal stromal keratocytes and keratocyte nuclei, and pleomorphism and enlargement of endothelial cells. Compared with control subjects, significant reductions in basal epithelial cell density (5817±306 cells/mm² vs 4802±508 cells/mm², P<0.001), anterior stromal keratocyte density (800±111 cells/mm² vs 555±115 cells/mm², P<0.001), posterior stromal keratocyte density (333±34 cells/mm² vs 270±47 cells/mm², P<0.001), endothelial cell density (2875±223 cells/mm² vs 2686±265 cells/mm², P<0.001), sub-basal nerve fiber density (31.2±8.4 nerves/mm² vs 18.1±9.2 nerves/mm², P<0.001), sub-basal nerve fiber length (21.4±3.4 mm/mm² vs 16.1±5.1 mm/mm², P<0.001), and sub-basal nerve branch density (median 50.0 (first quartile 31.2 - third quartile 68.7) nerve branches/mm² vs median 25.0 (first quartile 6.2 - third quartile 45.3) nerve branches/mm², P<0.001) were observed in patients with keratoconus.CONCLUSION: Significant microstructural abnormalities were identified in all corneal layers in the eyes of subjects with keratoconus using IVCM. This non-invasive in vivo technique provides an important means to define and follow progress of microstructural changes in patients with keratoconus.     

Eye rubbing-induced changes in intraocular pressure and corneal thickness measured at five locations, in subjects with ocular allergy

AIM: To assess the effects of eye rubbing on corneal thickness (CT) and intraocular pressure (IOP) measurements obtained 0-30min after habitual eye rubbing in symptomatic patients. METHODS: Measurements of IOP and CT were obtained at five locations (central, temporal, superior, nasal and inferior) before, and every 5min for 30min interval after 30s of eye rubbing, for 25 randomly selected eyes of 14 subjects with ocular allergy and 11 age-matched normals. Differences in measurements were calculated in each group [Baseline measurements minus measurements recorded at each time interval after eye rubbing (for IOP), and for each corneal location (for CT)] and comparison were then made between groups (allergic versus control) for differences in any observed effects. RESULTS: Within groups, baseline mean IOPs in the allergic patient-group (14.2±3.0 mm Hg) and in the control group (13.1±1.9 mm Hg) were similar at all times, after eye rubbing (P >0.05, for all). The maximum reduction in IOP was 0.8 mm Hg in the control subjects and the maximum increase was also 0.8 mm Hg in the allergic subjects. Between groups (allergic versus control), the changes in IOP remained under 1 mm Hg at all times (P=0.2) after 30min of eye rubbing. Between 0 and 30min of CT measurements after eye rubbing, the mean central CT (CCT), inferior CT (ICT), superior CT (SCT), temporal CT (TCT) and nasal CT (NCT) did not vary significantly from baseline values in the control and allergic-subject groups (P>0.05, for both). Between both groups, changes in CT were similar at all locations (P>0.05) except for the TC which was minimally thinner by about 4.4 μm (P=0.001) in the allergic subjects than in the control subjects, 30min following 30s of eye rubbing. CONCLUSION: IOP measured in allergic subjects after 30s of habitual eye rubbing was comparable with that obtained in normal subjects at all times between 0 and 30min. Although, CT in the allergic subjects were similar to those of the control subjects at all times, it varied between +10 and -7.5 μm following eye rubbing, with the temporal cornea showing consistent reductions in thickness in the subjects with allergy. However, this reduction was minimal and was considered to not be clinically relevant.     

Dectin-1 agonist curdlan modulates innate immunity to Aspergillus fumigatus in human corneal epithelial cells

AIM: To explore the immunomodulatory effects of curdlan on innate immune responses against Aspergillus fumigatus (A. fumigatus) in cultured human corneal epithelial cells (HCECs), and whether C-type lectin receptor Dectin-1 mediates the immunomodulatory effects of curdlan.METHODS:The HCECs were stimulated by curdlan in different concentrations (50, 100, 200, 400 μg/mL) for various time. Then HCECs pretreated with or without laminarin (Dectin-1 blocker, 0.3 mg/mL) and curdlan were stimulated by A. fumigatus hyphae. The mRNA and protein production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined by real-timequantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The protein level of Dectin-1 was measured by Western blot.RESULTS: Curdlan stimulated mRNA expression of TNF-α and IL-6 in a dose and time dependent manner in HCECs. Curdlan pretreatment before A. fumigatus hyphae stimulation significantly enhanced the expression of TNF-α and IL-6 at mRNA and protein levels compared with A. fumigatus hyphae stimulation group (P<0.05). Both curdlan and A. fumigatus hyphae up-regulated Dectin-1 protein expression in HCECs, and Dectin-1 expression was elevated to 1.5- to 2-fold by curdlan pretreatment followed hyphaestimulation. The Dectin-1 blocker laminarin suppressed the mRNA expression and protein production of TNF-α and IL-6 induced by curdlan and hyphae (P<0.05).CONCLUSION:These findings demonstrated that curdlan pretreatment enhanced the inflammatory response induced by A. fumigatus hyphae in HCECs. Dectin-1 is essential for the immunomodulatory effects of curdlan. Curdlan may have high clinical application values in fungal keratitis treatment.     

Corneal collagen crosslinking in keratoconus and other eye disease

Keratoconus is a condition characterized by biomechanical instability of the cornea, presenting in a progressive, asymmetric and bilateral way. Corneal collagen crosslinking (CXL) with riboflavin and Ultraviolet-A (UVA) is a new technique of corneal tissue strengthening that combines the use of riboflavin as a photo sensitizer and UVA irradiation. Studies showed that CXL was effective in halting the progression of keratoconus over a period of up to four years. The published studies also revealed a reduction of max K readings by more than 2 D, while the postoperative spherical equivalent (SEQ) was reduced by an average of more than 1 D and refractive cylinder decreased by about 1 D. The major indication for the use of CXL is to inhibit the progression of corneal ecstasies, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photo ablation. This treatment has been used to treat infectious corneal ulcers with apparent favorable results. Most recent studies demonstrate the beneficial impact of CXL for iatrogenic ecstasies, pellucid marginal degeneration, infectious keratitis, bullous keratopathy and ulcerative keratitis. Several long-term and short-term complications of CXL have been studied and documented. The possibility of a secondary infection after the procedure exists because the patient is subject to epithelial debridement and the application of a soft contact lens. Formation of temporary corneal haze, permanent scars, endothelial damage, treatment failure, sterile infiltrates, bullous keratopathy and herpes reactivation are the other reported complications of this procedure.