Thieltges Fabian, Liu Zengping, Brinken Ralf, Braun Norbert, Wongsawad Warapat, Somboonthanakij Sudawadee, Herwig Martina, Holz Frank G, Stanzel Boris V
Department of Ophthalmology, University of Bonn, Bonn, Germany.
Department of Ophthalmology, University of Bonn, Bonn, Germany ; Present address: Zengping Liu, Department of Ophthalmology, National University of Singapore, Singapore.
Transl Vis Sci Technol. 2016 Jun 1;5(3):11. doi: 10.1167/tvst.5.3.11. eCollection 2016 Jun.
We developed a surgical method for localized and atraumatic removal of the retinal pigment epithelium (RPE) with a novel instrument.
Bleb retinal detachments (bRD) were raised with balanced salt solution (BSS) following vitrectomy in 27 rabbits. The RPE was scraped with 3 loop variants (polypropylene [PP], 0.1 mm; PP, 0.06 mm; metal, 0.1 mm) of a custom-made instrument. Stabilization of bRDs with BSS or various concentrations (0.1%-0.5%) of hyaluronic acid (HA) was video analyzed. Perfusion-fixed samples of scraped areas and controls were studied by light and transmission electron microscopy.
The bRDs were sufficiently stabilized by ≥0.25% HA. Using the PP 0.1 mm loop with a single forward/backward stroke, an area of ca. 2.5 × 1.5 mm was nearly devoid of RPE, yet did show occasional Bruch's membrane (BM) defects combined with choriocapillaris hemorrhages in 13% of the bRDs. A single scrape with PP 0.06 mm resulted in unsatisfactory RPE denudement, while repeated scraping maneuvers caused more BM defects and hemorrhages. The metal loop resulted in incomplete RPE removal and massive intraoperative subretinal hemorrhages. Histologically, intact photoreceptor outer segments (POS) were observed above the RPE wounds in bRDs. Controls with bRDs alone showed an intact RPE monolayer with microvilli, with few engulfed remains of POS.
Localized removal of RPE in HA stabilized bRD can be achieved by a PP 0.1 mm loop instrument.
Removal of degenerated RPE may aid RPE cell replacement strategies.
我们开发了一种使用新型器械对视网膜色素上皮（RPE）进行局部无创伤切除的手术方法。
在27只兔子玻璃体切除术后，用平衡盐溶液（BSS）引发水泡性视网膜脱离（bRD）。用定制器械的3种环变体（聚丙烯[PP]，0.1毫米；PP，0.06毫米；金属，0.1毫米）刮除RPE。对用BSS或不同浓度（0.1%-0.5%）透明质酸（HA）稳定的bRD进行视频分析。通过光镜和透射电子显微镜研究刮除区域和对照的灌注固定样本。
≥0.25%的HA能充分稳定bRD。使用0.1毫米PP环单次前后刮擦，约2.5×1.5毫米的区域几乎没有RPE，但在13%的bRD中偶尔出现Bruch膜（BM）缺陷并伴有脉络膜毛细血管出血。用0.06毫米PP单次刮擦导致RPE剥脱不充分，而反复刮擦操作会导致更多BM缺陷和出血。金属环导致RPE切除不完全且术中出现大量视网膜下出血。组织学上，在bRD的RPE伤口上方观察到完整的光感受器外段（POS）。仅bRD的对照组显示RPE单层完整，有微绒毛，很少有吞噬的POS残余物。
使用0.1毫米PP环器械可在HA稳定的bRD中实现RPE的局部切除。
去除退化的RPE可能有助于RPE细胞替代策略。
