Ultrastructural analysis of collagen fibrils and proteoglycans in keratoconus

Purpose: To investigate ultrastructural alterations in the distribution of collagen fibrils (CFs) and proteoglycans (PGs) in the keratoconus cornea. Methods: Four normal corneas (donor age 24–75 years) and four severe and one mild keratoconus corneas (donor age 24–47 years) were fixed in 2.5% glutaraldehyde containing 0.05% cuprolinic blue dye for electron microscopy. Analyses were carried out on approximately 39 000 CF and 66 000 PG filaments in the anterior, middle and posterior stroma, using analySIS^® soft imaging software. Results: In severe keratoconus, stromal lamellae were seen to undulate in most regions, whereas in mild keratoconus only the middle and posterior lamellae were affected. In keratoconus corneas the mean diameter and interfibrillar spacing of CFs was reduced in all zones (p < 0.0001) and the CF and PG number density and area fractions were significantly increased (p < 0.0001) compared with in normal corneas and were higher (p < 0.0001) in the corneas with severe keratoconus than in that with mild keratoconus. The lamellae contained microfibrils (8–9 nm wide) and, in addition, PGs embedded within CFs. Degenerate keratocytes containing PGs were found in all keratoconus corneas. Conclusions: These studies suggest that as keratoconus progresses, the PG content of the stroma increases, whereas fibril diameter is reduced. The altered stromal content of PGs may influence CF diameters and their organization in keratoconus, weakening lateral cohesion and resulting in significant disorder of CF packing.     

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.     

国内外圆锥角膜文献增长规律及主要影响因素的比较分析

目的：对国内外圆锥角膜文献进行分析,以确定其文献增长规律和主要影响因素。

方法：以圆锥角膜(keratoconus)为检索词,检索PubMed(1911-01-01/2013-11-10)和CNKI(1960-01-01/2013-11-10)中收录的圆锥角膜文献数量,对文献量进行直线或曲线回归分析以确定文献增长规律及主要影响因素。

结果：国外圆锥角膜逐年累积文献量呈递增趋势,其趋势图呈指数曲线分布(y1=0.8824e^0.7937X,R²=0.9533)。国内圆锥角膜逐年累积文献量呈递增趋势,其趋势图也呈指数曲线分布(y2=0.2441e^1.6073X,R²=0.9957)。PubMed数据库中10种眼科学核心期刊收录文献1 932篇,CNKI数据库中10种眼科学核心期刊收录文献409篇。

结论：国内外圆锥角膜研究的文献量均呈上升趋势,表明圆锥角膜的研究仍是一个热点。影响国外圆锥角膜文献增长的主要因素是学科发展自身固有的规律,影响国内圆锥角膜文献增长的主要因素是学科发展所处的环境。     

Topographic Keratoconus is not Rare in an Iranian population: The Tehran Eye Study

Abstract

Purpose: To determine the prevalence of topographic keratoconus in an Iranian population, selected from Tehran districts 1 to 4.

Methods: In a cross-sectional study, samples were selected from four districts of Tehran through stratified cluster sampling. Participants underwent ophthalmic and optometric examinations and Orbscan topography maps were acquired from 442 people. Based on Orbscan topography maps, cases of keratoconus were categorized.

Results: In the study sample, 263 people (61.7%) were female, and the participants’ mean age was 40.8?±?17.1 years (range 14–81 years). Age- and sex-standardized prevalence of keratoconus was 3.3% (95% confidence interval, CI, 0.1–5.5%. The standardized prevalence of bilateral keratoconus was 1.8% (95% CI 0.2–3.5). The age-standardized prevalence of keratoconus was 3.9% and 2.6% in men and women, respectively (p?=?0.341). The prevalence of keratoconus was 0.8% in the 14–29-year-old age group and 7.5% in those ≥60 years; the prevalence of keratoconus significantly increased with age (odds ratio, OR, 1.05, 95% CI 1.01–1.08). The prevalence of keratoconus was 2.5% (95% CI 0.5–4.6) in the Persian ethnic group and 7.9% (95% CI 1.6–15.7) among non-Persians (p?=?0.063 and OR 3.33).

Conclusions: This study provides the first population-based estimate of the prevalence of keratoconus in Iran. The prevalence of topographic keratoconus was high among citizens of Tehran districts 1 to 4. To confirm the hypothesis of a high rate of keratoconus in Iran, more extensive studies are needed which would examine the role of genetics and the environment.     

放射状角膜切开术在轻中度圆锥角膜病例中视觉康复的疗效

目的：探讨放射状角膜切开术在轻中度圆锥角膜治疗中光学和视力康复的效果。
　　方法：回顾性分析应用放射状角膜切开术治疗圆锥角膜的病例22例31眼并进行了至少12 mo的随访。测量并分析术前术后裸眼视力,最佳矫正视力,自动屈光计值,角膜曲率,角膜不规则指数以及并发症。
　　结果：在最后一次随访中,平均裸眼视力( logMAR)由0.86±0.34显著提升至0.30±0.29(P<0.0001),平均最佳矫正视力由0.47±0.21提升至0.17±0.23(P<0.0001)。平均角膜曲率由48.69±3.68 D 降低至44.33±3.09 D ( P<0.0001)。自动屈光计测得平均等效球镜值由-5.61±2.85D显著提升至-2.29±1.95D(P<0.0001)。在整个随访过程中,中央角膜厚度和3mm,5mm区域的角膜不规则指数均无变化。术中和术后没有观察到严重并发症。
　　结论：在本组病例中,放射状角膜切开术是轻中度圆锥角膜视觉康复的有效治疗方法。     

使用Oculus Keratograph 5M测量圆锥角膜患者NITBUT和TMH

目的:比较圆锥角膜患者和正常人使用Oculus Keratograph 5M(K5M)测得的非侵入性泪膜破裂时间(NITBUT)和泪河高度(TMH),以确定这两项指标和圆锥角膜的关系.方法:50例100眼圆锥角膜患者和50例100眼正常人参加了这项研究.圆锥角膜组患者的年龄为15~60(平均28.33±8.60)y.对照组为18~60(平均26.25±1.11)岁.使用K5M测量所有受试者的NITBUT和TMH.结果:两组之间的NITBUT和TMH平均值差异无统计学意义(P=0.58,0.69).两参数的相关性研究显示,两组中NITBUT和TMH之间均无相关性(圆锥角膜组: r=0.053, P=0.721;对照组: r=-0.0501, P=0.7098).结论:研究显示圆锥角膜对泪液质量和数量都没有显著的临床影响.     

Keratoconus in Asians: demographics, clinical characteristics and visual function in a hospital-based population

Background: To describe the demographics, clinical characteristics and visual function of Asian patients with keratoconus managed in a tertiary eye centre. Design: Prospective cross‐sectional study. Participants: 116 patients with clinically evident or suspected keratoconus (on videokeratography) recruited over 11 months. Methods: A standardised interview, full ophthalmic examination, refraction and corneal topography were performed. Visual function was assessed with the VF‐14 questionnaire. Main Outcome Measures: Demographics, clinical characteristics and visual function. Results: Mean age of our patients was 29.5 ± 9.40 years on enrolment, 62.9% were male, and the ethnic distribution was 60.3% Chinese, 13.8% Malays and 9.5% Indians. Clinically evident keratoconus was present bilaterally in 65 patients (56.0%) and unilateral keratoconus in five patients (4.3%). Five patients (4.3%) had a family history of keratoconus. The majority of patients were managed with contact lenses (60.8%) or glasses (24.5%). Eye rubbing was common (68%) as were asthma (26.3%) and eczema (18.4%). Conical protrusion was the commonest sign (75.3%). The mean cylinder was higher in keratoconus eyes compared with keratoconus suspect eyes (?4.01 vs. ?1.27, P < 0.001), and best‐corrected visual acuity was poorer (0.19 vs. 0.05, P < 0.001). Unaided visual acuity was significantly worse with increasing age (P = 0.016). On the VF‐14, 32% scored 90 or less (out of 100), reflecting difficulties with vision‐related daily activities. Conclusions: Our Asian patients with keratoconus had similar demographic and clinical characteristics to patients in Western populations. Even with apparently good visual acuity, some patients still experience substantial impairment in vision‐related activities.     

A New Case of Keratoconus Associated with Williams-Beuren Syndrome

ABSTRACT

Background: Williams-Beuren syndrome is a multisystemic genetic disorder caused by a contiguous gene deletion at 7q11.23. Keratoconus is a complex disease and it is suspected to have a genetic origin, although the specific gene responsible for keratoconus has not been identified. Although there are several ocular features in Williams-Beuren syndrome, keratoconus is not regularly described as part of this syndrome.

Purpose: To report a new patient with keratoconus and Williams-Beuren syndrome.

Discussion: This is the third case of an association between Williams-Beuren syndrome and keratoconus. The authors believe that the Williams-Beuren syndrome chromosome region can be a possible target for further investigation as the genetic basis of keratoconus.     

Association of Lysyl oxidase (LOX) Polymorphisms with the Risk of Keratoconus in an Iranian Population

Background: Keratoconus is a connective tissue-related eye disease with unknown etiology that causes the loss of visual acuity. Lysyl oxidase (LOX) is an amine oxidase that catalyzes the covalent cross-link of collagens and elastin in the extracellular environment, thus determining the mechanical properties of connective tissue. The current study aimed to investigate the possible associations between two LOX polymorphisms, rs1800449 and rs2288393, and susceptibility to keratoconus.

Methods: A total of 262 Iranian subjects including 112 patients with keratoconus and 150 healthy individuals as controls were recruited. Genotyping for the LOX variants was performed using allele-specific PCR.

Results: A significant difference was found between two groups regarding allelic and genotyping distribution of LOX polymorphism at position rs1800449 G>A. The frequency of AA and GA?+?AA genotypes were increased in patients compared to controls (17% versus 8% and 62.5% versus 50%, respectively), showing a statistically significant difference (OR?=?2.827, 95% CI: 1.251–6.391, p?=?0.012). The A allele was associated with an increased risk for keratoconus, with the frequency of 39.9% and 29% in patients and controls, respectively (OR?=?1.614, 95% CI: 1.119–2.326, p?=?0.011). Furthermore, the haplotype analysis revealed that the rs1800449G/rs2288393C is a protective factor against keratoconus (OR?=?0.425, 95% CI?=?0.296–0.609, p?=?0.001). Conversely, the +473A/rs2288393C (OR?=?3.703, 95% CI?=?2.230–6.149, p?=?0.001) and +473G/rs2288393G (OR?=?15.48, 95% CI?=?3.805–63.03, p?=?0.001) haplotypes were identified as risk factors for keratoconus.

Conclusion: Our study demonstrated that the LOX rs1800449 genotypes (AA and GA?+?AA) and allele (A) appears to confer risk for susceptibility to keratoconus.     

The effects of changed biomechanical parameters on measurements of intraocular pressure in keratoconus patients

Background: Keratoconus is associated with changes in the corneal structure, such as defects of Bowman's layer, a decrease of corneal thickness etc. They result in alterations of some of the biomechanical parameters of the cornea, namely, rigidity and elasticity. The present study was performed to examine how impression tonometry and applanation tonometry for determination of intraocular pressure (IOP) are affected by the changed biomechanical parameters associated with keratoconus. Patients and methods: We examined 20 normal subjects (40 eyes) and 17 keratoconus patients (25 eyes). The corneal thickness was measured by ultrasound pachymetry in the corneal center. In the keratoconus patients, an additional measurement was made at the conus peak. The corneal curvature was determined using the TMS keratoscope. The IOP measurements were made with the Schi?tz tonometer (10 g). For comparison, additional IOP measurements in the corneal center and, in the keratoconus group, on the conus peak were made with the applanation tonometer. Results: The normal subjects had a central corneal thickness of 548 ± 30 μm, compared to 505 ± 42 μm in the corneal center and 425 ± 41 μm on the conus peak in keratoconus patients. The average corneal curvature was 43.3 ± 1.8 D in the normal subjects and 47.8 ± 4.1 D in keratoconus patients. Applanation tonometry produced results on 11.33 ± 1.43 mm Hg in the normal group (corneal center) compared to values of 12.00 ± 2.55 mm Hg (corneal center) and 7.30 ± 1.95 mm Hg (conus peak) in the keratoconus cohort. The coefficient of rigidity was 0.0236 ± 0.0026 μl⁻¹ in the normal subjects, compared to 0.0173 ± 0.0050 μl⁻¹ in the keratoconus patients. Conclusion: The morphological changes associated with keratoconus may cause tonometry errors.      

不同进展期圆锥角膜生物力学研究

目的:探讨可视化角膜生物力学分析仪(Corvis ST)测量正常角膜、顿挫期圆锥角膜、亚临床期圆锥角膜、临床期圆锥角膜的生物力学变化,分析不同进展期圆锥角膜生物力学特征,为更早期地诊断圆锥角膜提供临床依据.方法:病例对照研究.选取顿挫期圆锥角膜15眼为顿挫组,亚临床期圆锥角膜23眼为亚临床期组,临床期圆锥角膜40眼为圆锥角膜组,欲行近视激光手术和正常角膜志愿者40眼为正常组(对照组),应用Corvis ST测定各组的生物力学参数,并进行比较分析,绘制受试者工作曲线(ROC).结果:正常角膜与顿挫期圆锥角膜生物力学各参数差异均无统计学意义(P>0.05).正常角膜与亚临床期组第二压平长度(AL2)、第一压平速率(AV1)、最大压陷曲率半径(HC-radius)、最大压陷深度(DA)间的差异有统计学意义(P<0.05).正常角膜与圆锥角膜组除第二压平速度(AV2)、最大压陷时间(HC-time)、最大压陷屈膝峰间距(PD)差异无统计学意义外,其余生物力学数据差异均有统计学意义(P<0.05),ROC曲线分析DA对于圆锥角膜诊断效率最高(曲线下面积0.891±0.028).结论:顿挫期圆锥角膜生物力学较正常角膜无改变,亚临床期圆锥角膜生物力学较正常角膜部分参数有改变,但其参数单独诊断圆锥角膜特异性和敏感性均较差.临床期圆锥角膜生物力学较正常角膜明显改变,DA诊断效率最高.     

Investigation of the Efficacy of the Cone Location and Magnitude Index in the Diagnosis of Keratoconus

Purpose: The aim of this study was to investigate the sensitivity, specificity, and accuracy of The Cone Location and Magnitude Index (CLMI) in keratoconus diagnosis. Methods: 301 eyes of 159 keratoconus patients and 394 eyes of 265 refractive surgery candidates as a control group were enrolled in this retrospective clinical study. CLMI was compared with keratometric corneal topography parameters, wavefront aberrations, and pachymetry data derived from optical coherence tomography using independent sample t-tests and ROC curves. Logistic regression analysis was applied to determine the most accurate parameter in keratoconus diagnosis. Pearson’s correlation analysis was used to determine the correlation between CLMI and the other measurements. Results: Average axial CLMI (aCLMI) was 8.19?±?6.15 D in the keratoconus group and 0.83?±?0.62 D in the control group (p?=?0.001). aCLMI had the greatest sensitivity (89%), specificity (94%), and accuracy (92%) for the keratoconus diagnosis at the best cut-off point of 1.82 according to the ROC curve. Logistic regression analysis selected aCLMI as the most accurate measurement among the other parameters (accuracy 92.8%). aCLMI showed strongest correlations with coma-like aberrations (r?=?0.881), total high-order aberrations (r?=?0.858), and vertical coma (r?=??0.814), respectively. Conclusion: CLMI is a robust index for screening keratoconus with high sensitivity, specificity, and accuracy.     

Prevalence of Orbscan II corneal abnormalities in relatives of patients with keratoconus

Background: To determine the prevalence of Orbscan II‐derived keratoconus traits in relations of individuals with keratoconus and a control group and to apply these to a pedigree analysis. Methods: In a controlled, prospective, observational case series, four Orbscan II‐derived corneal parameters were examined in relations of individuals with keratoconus and a control group of low myopes (<2.5 D). The four parameters and thresholds for abnormality (derived from a literature review) were as follows: average keratometry (≥47.2 D), I‐S value (≥1.2 D), posterior float apex (≥42 µm) and thinnest pachymetry (≤463 µm). Results: Forty‐four unrelated controls (88 eyes) and eight families with 90 members without known (178 eyes) and 11 members with keratoconus (19 eyes) were analysed. One of 88 (1.14%) control eyes had a single keratoconus trait, and none had more than one trait. Of 178 eyes from relatives of patients with keratoconus, 45 (25.3%) had one or more keratoconus traits. Relatives of patients with keratoconus had an elevated risk of possessing a keratoconus trait (relative risk 14.67, CI 2.07–104.07, P < 0.001) compared with controls. Approximately 53.3% of relatives with a keratoconus trait were evident on either pachymetric or posterior elevation indices alone. Six of eight families suggested dominant inheritance. Conclusions: Keratoconus traits are common in relatives of patients with keratoconus. There prevalence may have been previously underestimated by using placido image‐based topography alone where corneal pachymetry and posterior elevation are not assessed. This study suggests an autosomal dominant pattern of inheritance with variable expressivity in some families.     

Pentacam眼前节分析仪诊断早期圆锥角膜的临床应用

目的：探讨Pentacam眼前节分析仪在早期圆锥角膜诊断中的临床应用。

方法：选取2019-02/12于我院就诊的早期圆锥角膜患者49例49眼纳入研究,参照Rabinowitz诊断标准,将其分为临床期圆锥角膜组27例27眼和亚临床期圆锥角膜组22例22眼,另选取20例20眼有近视、散光史的正常眼作为对照组。采用Pentacam眼前节分析仪分别测定3组受检者角膜表面变异指数(ISV)、圆锥角膜指数(KI)、垂直不对称指数(IVA)、中央圆锥角膜指数(CKI)、高度离心指数(IHD)、高度不对称性指数(IHA)、不规则指数(ABR)、最小曲率半径(Rmin)、角膜散光(CYL)、角膜前表面高度(AE)、角膜前表面最大屈光力(Kmax)、角膜后表面高度(PE)变化,比较三组受检者各指标检测值,绘制ROC曲线,分析各指标诊断圆锥角膜的临床价值。

结果：三组受检者ISV、KI、IVA、CKI、IHD、IHA、ABR、Rmin、CYL、AE、Kmax、PE检测值比较有差异(P<0.05); 临床期圆锥角膜组受检者ISV、KI、IVA、CKI、IHD、IHA、ABR、Rmin、CYL、AE、Kmax、PE检测值与对照组比较有差异(P<0.05); 亚临床期圆锥角膜组受检者ISV、KI、IVA、CKI、IHD、IHA、ABR、Rmin、CYL、AE、Kmax、PE检测值与对照组比较有差异(P<0.05); ROC曲线分析结果显示,IVA、KI、AE、PE、Rmin、IHD、Kmax、ISV、ABR诊断临床期圆锥角膜的敏感度和特异度均较高; IVA、Rmin、AE、PE诊断亚临床期圆锥角膜的敏感度和特异度均较高。

结论：Pentacam眼前节分析仪可精确测量角膜前后表面形态学参数,其在圆锥角膜早期临床诊断中发挥重要作用。     

使用Pentacam检测亚临床期和早期圆锥角膜患者角膜体积和前房容积

目的:使用Pentacam检测健康、亚临床期和早期圆锥角膜患者角膜体积和前房容积。方法:流行病学研究。共纳入63例屈光手术患者。根据Amsler-Krumeich标准,将患者分为正常、亚临床期和早期三组。收集了包括年龄和性别在内的人口统计信息,并获得了患者的完整病史。所有患者进行完整的视力检查。随后,使用Pentacam测量三组患者的角膜体积和前房容积。结果:对照组角膜体积明显高于亚临床期组和早期组(P<0.05),但两组间前房容积无显著性差异(P>0.05)。结论:测量角膜体积有助于鉴别亚临床期圆锥角膜和早期圆锥角膜与正常眼。亚临床圆锥角膜患者、早期圆锥角膜患者和正常人的前房容积无显著差异。     

The Effect of Corneal Epithelium on Corneal Curvature in Patients with Keratoconus

Abstract

Objective: To investigate the effects of corneal epithelium on corneal curvature in patients with keratoconus. Design: This is a prospective, nonrandomized study. Participants: Fifty-nine eyes of 47 patients diagnosed as keratoconus and for whom corneal collagen crosslinking (CXL) was recruited in this study. Methods: This study is a single-center clinical trial. Pregnancy, lactation, connective tissue disease, corneal thickness below 350?μm, severe dry eyes, or scar of corneal surgery were exclusion criteria. Before and during CXL procedure after removing the corneal epithelium, maximum values of corneal apical curvature, simulated keratometry 1 (Sim-K1), simulated keratometry 2 (Sim-K2), temporal and inferior curvature values, all of which are 1.5?mm from the corneal center, were calculated. These values before and after removal of epithelium were compared statistically. Results: Mean age of patients was 23.30?±?5.5 (12–38) years. Twenty-eight (59%) were male while 19 (41%) were female. Mean values measured before and after removing the corneal epithelium were: apical curvature; 59.19?±?7.2 (47.06–82.40) diopter (D) and 61.70?±?8.8 (49.19–92.66) D (p?=?0.001), SimK1; 47.57?±?4.3 (39.14–64.57) D and 48.23?±?4.3 (41.89–66.70) D (p?=?0.001), SimK2; 52.04?±?5.3 (43.56–69.34) D and 53.34?±?5.6 (43.73–70.89) D (p?=?0.001), inferior curvature; 53,85?±?5.2 (43.47–76.56) D and 55.05?±?5.8 (44.56–81.93) D (p?=?0.002), temporal curvature 49.49?±?5.1 (41.50–71.03) D and 51.53?±?5.4 (41.58–73.34) D (p?=?0.001), respectively. Conclusions: In keratoconus patients during CXL treatment, after removing the corneal epithelium, more steepness is detected in the curvature of the steeper area of the cornea. When evaluating patients with keratoconus, the masking effect of corneal epithelium on values of curvature should be taken into consideration.     

A Case of Unusual Coexistence of Keratoconus and Optic Disc Pit

Abstract

Purpose: To report a case of unusual coexistence of keratoconus and optic disc pit. Methods: A 29-year-old male patient followed up because of the left established and right subclinical keratoconus presented with blurred vision on the left eye that occurred within days. In addition to a comprehensive ophthalmic examination, computerized corneal topography (CT), corneal pachymetry, and optical coherence tomography (OCT) examination were performed. Results: The corneal CT showed a mild keratoconus pattern, with a minimum corneal pachymetry of 472 in the right eye and moderate keratoconus pattern with a minimum pachymetry of 435 micron in the left eye. The OCT scans showed the presence of the optic disc pit and related maculopathy. Conclusions: This is the second report of the coexistence of keratoconus and optic disc pit in the literature. The association of these two entities is therefore less likely to be accidental. Further histopathological studies will be necessary to explain this relationship between two entities.     

圆锥角膜的遗传模式研究

目的：探讨遗传因素在圆锥角膜发病中的作用及圆锥角膜的遗传模式。

方法：采用遗传流行病学方法对2020-07/2023-04就诊于河南省立眼科医院的圆锥角膜患者100例的一级亲属280例的患病情况进行调查，采用Falconer回归法进行遗传度的估算，采用Penrose法进行一般遗传模式估计，采用Falconer公式、Edwards近似公式及江三多阈值模型推导公式进行遗传模式的确认。

结果：纳入的圆锥角膜患者一级亲属中患有圆锥角膜者16例(5.714%)，圆锥角膜遗传度为(86.100±7.400)%。Penrose法计算得出同胞患病率(S)/一般人群患病率(q)为35.348，接近1/(q)^1/2，提示圆锥角膜符合多基因遗传模式。Falconer公式、Edwards近似公式及江三多阈值模型推导公式计算圆锥角膜患者一级亲属预期患病率分别为5.900%、7.714%、5.700%，与圆锥角膜患者一级亲属实际患病率(5.714%)均无显著差异，提示圆锥角膜为多基因遗传病。

结论：遗传因素在圆锥角膜的发病中占有重要作用，圆锥角膜是一种多基因遗传病。     

Double Jeopardy: Blepharophimosis Syndrome with Congenital Nasolacrimal Duct Obstruction in Twins

ABSTRACT

Purpose: Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) is an autosomal dominant disorder characterized by bilateral ptosis with poor levator function, epicanthus inversus and shortened horizontal palpebral fissures. Method: Eighteen -month -old twin sisters presented with history of watering from their left eyes since birth. Examination revealed features of BPES with left congenital nasolacrimal duct obstruction in both. Result: the twins underwent therapeutic probing, which was successful in one and failed in the other. the second child was subsequently managed by external dacryocystorhinostomy. Conclusion: To our knowledge, this is the first report of Blepharophimosis syndrome with congenital nasolacrimal duct obstruction occurring in twin sisters.     

圆锥角膜患者长期配戴硬性透气性角膜接触镜后眼表变化分析

目的： 分析圆锥角膜患者长期配戴硬性透气性角膜接触镜(RGPCL)后眼表相关参数的变化。

方法： 采用前瞻性病例研究。纳入2018-01/2022-01在我院眼视光学中心门诊确诊并验配RGPCL的原发性圆锥角膜患者113例213眼,根据圆锥角膜严重程度分为轻度圆锥角膜组42例80眼,中度圆锥角膜组54例102眼,重度圆锥角膜组17例31眼。采用Keratograph眼表综合分析仪观察三组患者戴镜前,戴镜后1 wk,1、3、6、12 mo的非侵入性泪膜破裂时间(NIBUT)、非侵入性泪河高度(NITMH)、眼红指数、脂质层厚度、角膜荧光染色、睑板腺分泌功能,Schirmer I试验及眼表疾病指数量表(OSDI)评分变化。

结果：三组患者戴镜前性别、年龄、NIBUT、NITMH、脂质层厚度、睑板腺分泌功能、Schirmer Ⅰ试验均无差异(P>0.05),而球镜、柱镜、等效球镜(SE)、BCVA、IOP_NCT、角膜前、后表面Kmax、最薄点角膜厚度、眼红指数、角膜荧光染色、OSDI评分均有差异(P<0.05)。低度圆锥角膜组NIBUT戴镜3、6、12 mo 较戴镜前有差异(P<0.05); NITMH戴镜6、12 mo较戴镜前有差异(P<0.05); 眼红指数、角膜荧光染色、OSDI戴镜1 wk,1 mo较戴镜前有差异(P<0.05); 脂质层厚度和睑板腺分泌功能戴镜12 mo较戴镜前有差异(P<0.05)。中度圆锥角膜组NIBUT戴镜6、12 mo较戴镜前有差异(P<0.05); NITMH、脂质层厚度、睑板腺分泌功能戴镜12 mo较戴镜前有差异(P<0.05); 眼红指数戴镜1 wk,1、3 mo较戴镜前有差异(P<0.05); 角膜荧光染色戴镜后1 wk较戴镜前有差异(P<0.05); OSDI评分戴镜1 wk,1 mo较戴镜前有差异(P<0.05)。高度圆锥角膜组NIBUT、NITMH、眼红指数戴镜1 wk,1、3、6、12 mo较戴镜前有差异(P<0.05); 脂质层厚度戴镜6、12 mo较戴镜前有差异(P<0.05); 角膜荧光染色和OSDI评分戴镜1 wk,6、12 mo较戴镜前有差异(P<0.05); 睑板腺分泌功能戴镜6、12 mo较戴镜前有差异(P<0.05); Schirmer Ⅰ试验戴镜12 mo较戴镜前有差异(P<0.05)。

结论： 圆锥角膜患者长期配戴RGPCL会不同程度影响眼表微循环,从而影响患者的主观舒适度,但对患者的视觉质量无明显影响,长期规范配戴RGPCL控制圆锥角膜进展具有良好的安全性。