Age-related changes of lens thickness and density in different age phases

AIM: To explore the changes in lens thickness and density with age. METHODS: A Chinese population-based retrospective study was performed. A total of 497 individuals (490 right eyes and 495 left eyes), ranging from 3 to 69 years old were included. Lens images obtained from IOL Master 700 were used to measure lens thickness and density. Piecewise regression model was chosen to illustrate the relationship of lens thickness and density with age. RESULTS: The proportion of people aged 3-18, 19-40, over 40 was 38.6%, 50.9% and 10.5% respectively. The whole lens thickness decreased with age during the first 7 years of life, kept stable from 8 to 16 years old, and then increased at the rate of about 27 µm per year. The thickness of the lens cortex and nucleus tended to decrease first and then increase with age, which was dependent on age stages. The whole lens density also decreased with age until 7 years old. The increasing rate of lens density was different in different age groups. The whole lens density increased rapidly from 7 to 22 years old and slowed down after 22 years old. Similarly, the changing tendency of lens cortical and nuclear density differed in different age phases. CONCLUSION: Both lens thickness and density are significantly associated with age, whereas they do not change linearly with age. Moreover, it is necessary to increase the population over 40 years old and conduct further research.     

外伤性晶状体脱位合并周边隐匿性视网膜病变的临床特征及预后分析

目的观察分析眼球钝挫伤合并外伤性晶状体脱位患者周边隐匿性视网膜病变的临床特点及预后。 方法本研究纳入2013年1月至2020年1月在柳州市人民医院眼科住院诊断为眼球钝挫伤合并外伤性晶状体脱位，并行23G微创玻璃体切割联合白内障摘除手术的72例（72眼）患者。根据裂隙灯和超声生物显微镜（UBM）检查，将患者分为晶状体不全脱位组和全脱位组，详细记录2组患者的术中周边视网膜病变情况，并分析其临床特征及疗效。 结果眼球钝挫伤合并外伤性晶状体脱位患者中有周边隐匿性视网膜病变的占72.22%，其中晶状体不全脱位组发生率高达80.95%，显著大于晶状体全脱位组的60.00%（P＜0.05）。2组患者的周边隐匿性视网膜病变均以隐匿性视网膜裂孔、变性和出血为最常见。所有患者术后视网膜情况稳定，视力预后较好。 结论眼球钝挫伤合并外伤性晶状体脱位患者常出现周边隐匿性视网膜病变，最常见的是视网膜裂孔、出血、变性。23G微创玻璃体切割联合白内障摘除手术是有效治疗手段，具有创伤小、并发症少的优势。     

前节OCT评估V4c型后房型有晶体眼人工晶体植入术安全性的临床研究

目的探讨前节光学相干断层扫描(OCT)评估V4c型后房型有晶体眼人工晶体(ICL)植入术治疗超高度近视长期安全性的价值。方法 41例(78眼)>-9.0D的超高度近视进行V4c型ICL植入手术患者,测量术前及术后1、3、6、12个月的角膜内皮细胞计数,应用前节OCT及超声生物显微镜(UBM)检测患者术前睫状沟沟到沟距离(WTW)、中央前房深度(ACD)、小梁于虹膜夹角(TIA)及术后各时段拱高、ACD、TIA。分析手术安全性;比较患者术前及术后各时段角膜内皮细胞计数、前节OCT测量指标,术前不同测量方法各参数测量结果 , UBM与前节OCT各参数测量结果。结果所有患者手术顺利,术后4 h内13只眼(12例患者)一过性眼压升高,降眼压处理后至随访结束眼压均平稳,其余患者无其他手术并发症发生。术后1、3、6、12个月,患者角膜内皮细胞计数低于术前,差异具有统计学意义(P<0.05);术后1、3、6、12个月,患者前节OCT测量指标ACD低于术前、TIA小于术前,差异具有统计学意义(P<0.05);术后1、3、6、12个月,患者角膜内皮细胞计数及前节OCT测量指标ACD、TIA、拱高比较差异无统计学意义(P>0.05)。术前WTW应用卡尺手测、角膜地形图(ObscanⅡ)前节分析系统测量、Master、UBM及前节OCT测量结果分别为(11.80±0.36)、(11.75±0.37)、(12.26±1.17)、(11.94±0.41)、(11.91±0.38)mm, Master测量WTW与其他方式比较差异具有统计学意义(P<0.05);术前ACD应用ObscanⅡ前节分析系统测量、Master、UBM及前节OCT测量结果分别为(3.1±0.20)、(3.30±0.17)、(3.11±0.13)、(3.10±0.15)mm, Master测量结果与其他方式比较差异具有统计学意义(P<0.05);术前TIA应用UBM、前节OCT测量结果分别为(40.98±5.82)°、(40.92±5.65)°,比较差异无统计学意义(P>0.05)。术前及术后各时段,前节OCT及UBM测量ACD、TIA及拱高的测量结果比较差异无统计学意义(P>0.05)。结论 V4c型ICL植入术治疗超高度近视无论视力、ICL位置或是眼内情况稳定性均良好,无严重并发症,手术方式安全稳定。应用前节OCT观察术后ICL位置、前房深度及房角情况简易方便,准确无创。测量简单方便且精准,可作为术后常规随访的测量方式。     

Protection against corneal hyperosmolarity with soft-contact-lens wear

Hyperosmotic tear stimulates human corneal nerve endings, activates ocular immune response, and elicits dry-eye symptoms. A soft contact lens (SCL) covers the cornea preventing it from experiencing direct tear evaporation and the resulting blink-periodic salinity increases. For the cornea to experience hyperosmolarity due to tear evaporation, salt must transport across the SCL to the post-lens tear film (PoLTF) bathing the cornea. Consequently, limited salt transport across a SCL potentially protects the ocular surface from hyperosmotic tear. In addition, despite lens-wear discomfort sharing common sensations to dry eye, no correlation is available between measured tear hyperosmolarity and SCL-wear discomfort. Lack of documentation is likely because clinical measurements of tear osmolarity during lens wear do not interrogate the tear osmolarity of the PoLTF that actually overlays the cornea. Rather, tear osmolarity is clinically measured in the tear meniscus. For the first time, we mathematically quantify tear osmolarity in the PoLTF and show that it differs significantly from the clinically measured tear-meniscus osmolarity. We show further that aqueous-deficient dry eye and evaporative dry eye both exacerbate the hyperosmolarity of the PoLTF. Nevertheless, depending on lens salt-transport properties (i.e., diffusivity, partition coefficient, and thickness), a SCL can indeed protect against corneal hyperosmolarity by reducing PoLTF salinity to below that of the ocular surface during no-lens wear. Importantly, PoLTF osmolarity for dry-eye patients can be reduced to that of normal eyes with no-lens wear provided that the lens exhibits a low lens-salt diffusivity. Infrequent blinking increases PoLTF osmolarity consistent with lens-wear discomfort. Judicious design of SCL material salt-transport properties can ameliorate corneal hyperosmolarity. Our results confirm the importance of PoLTF osmolarity during SCL wear and indicate a possible relation between PoLTF osmolarity and contact-lens discomfort.