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后房型人工晶状体

谢晓兰 2012.8

人工晶状体的进展第一代 1949-1954 原始的 Ridley 后房型人工晶状体第二代 1952-1962 早期前房型人工晶状体第三代 1953-1973 白内障囊内摘除术后使用过的包

括 虹膜囊膜的虹膜支撑型人工晶状体 第四代 1963-1992 从早期前房人工晶状体过渡到新 型前房型人工晶状体 第五代 1977-1992 后房型人工晶状体的过渡和成熟 阶段 第六代 1992-2000 新型人工晶状体

但是 , 作为理想的人工晶状体应该具备哪些特征呢 ?

光学性能高 质量轻 生物相容性好 性能稳定 , 无生物降解作用 无刺激 , 无致癌性

( 一 ) 聚甲基丙烯酸酯 PMMA( 二 ) 硅胶 Silicone( 三 ) 水凝胶 Hydrogel( 四 ) 丙烯酸酯 Acrylic 是 PMMA 的衍生物 , 是苯乙基

丙烯酸酯和苯乙基烯酸甲酯大的聚合物。目前是临床上最常用、引起后发障最少的可折叠人工晶状体材料。

But ,how about the implantation of posterior chamber phakic intraocular lens with a central hole → (Hole ICL)

?

Slit-lamp photograph of the eye after implantation of animplantable collamer lens with a central hole (Hole ICL).

To prevent pupillary block, this surgical technique unavoidably requires two preoperative laser iridectomies, which

are frequently accompanied by some pain;

OR intraoperative peripheral iridectomy, which is sometimes complicated by iris haemorrhage, causing surgical difficulties.

EVEN

Implantation of a newly developed Hole

ICL offered good results for all measures of safety,efficacy, predictability and stability for the correction of moderate to high myopic errors, even without peripheral iridectomy, suggesting its viability as a surgical option for the treatment of such eyes.

the RISK of cataract formation,presumably resulting from direct physical contact between the ICL and the crystalline lens or from localised malnutrition causing poor circulation of the aqueous humour.

A new ICL with an artificial central hole (Hole ICL) in order to overcome these disadvantages is coming up

D

convetionalwith a hole

PIOL

advantanges ?

safety

efficacy

predictability

less adversity

without peripheraliridectomy

ICLICL

with a central hole

evaluated 20 eyes of 20 patients with spherical equivalents of 7.3662.13 D

(mean6SD) who underwent Hole ICL implantation.

Before surgery and at 1 week and 1, 3 and 6 months after surgery,

Safety outcomesEffectiveness outcomesPredictabilityStabilityIOPEndothelial cell densitySecondary surgeries/adverse events

Hole ICL implantation is safe and effective, and provides predictable and stable refractive results in the correction of moderate to high myopia throughout a 6-month observation period. Moreover, no visionthreatening complications occurred throughout the follow-up period.

A modified implantable collamer lens (ICL) with a central hole (diameter, 0.36 mm), a “Hole-ICL”, was created to improve aqueous humour circulation

?

Locations of aqueous humour inflow and outflow. 1: locationof aqueous humour outflow; 2: location of aqueous humour inflow

Flow distribution along the long axis of the cross-sectional surfaceof the Hole-ICL. The length of the arrow corresponds to the flow

velocity

Flow distribution along the long axis of the cross-sectionalsurface for the conventional ICL. The length of the arrow

corresponds to the flow velocity

Comparison of flow velocity along the long axis of the crosssectional surface of the Hole-ICL, conventional ICL, and the eye without an ICL. The solid line represents the flow velocity of the Hole-ICL, and the dotted line represents the flow velocity for

the conventional ICL

Comparison of flow velocity along the short axis of the crosssectional surface in the Hole-ICL, conventional ICL,

and the ey ewithout an ICL

Trajectory analysis in the Hole-ICL (left) andconventional ICL (right). Representative lines are

shown

The flow distribution between the anterior surface of thecrystalline lens and the posterior surface of the Hole-ICL washigher than that between the crystalline lens and the conventionalICL

The flow distribution between the anterior surface of the crystalline lens and the posterior surface of the Hole-ICL was higher than that between the crystalline lens and the conventional ICL

Therefore, the circulation of aqueous humour to the anterior surface of the crystalline lens in a Hole-ICL would be higher than that in a conventional ICL.

the importance of aqueous humour circulation

anterior chamber depth decrease

Your Tesurgical trauma

myopia

age

Many surgeons also perform peripheral laser iridotomy (LI) prior to ICL implantation to prevent a pupillary block. LI

may cause complications including iritis intraocular haemorrhage,elevation of intraocular pressure, posterior iris synechia, and corneal decompensation, such as bullous keratopathy.

Using of the Hole-ICL may improve

aqueous humour circulation, preventing secondary cataracts and eliminating the need for LI.

↓↓↓Hole-ICLs improve the circulation of

aqueous humour to the anterior surface of the crystalline lens.

IN all : ICL with a hole is a tendency .

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