准分子激光屈光性角膜切削术治疗近视及近视散光临床分析

目的评价准分子激光屈光性角膜切削术治疗近视及近视散光的临床效果。方法应用准分子激光（NIDEKEC—5000型）治疗24D以下．伴或不件5D以内散光的近视眼。214只治疗眼随诊6个月以上。结果随诊1年以上的病例显示术后3个月屈光度及视力基本稳定。术后6个月时，在等值球镜度低于6D的治疗眼中，裸眼视力≥1．0者占92．04％，≥0．5为100％，80．53％的裸眼视力≥术前最佳矫正视力，99．12％的眼屈光度在预定矫正度数的±1．00D以内。低于10D的高度近视眼也有近似的疗效。214只治疗眼中操眼视力≥1．0者占78．97％，≥0．5为90．65％，72．43％的裸眼视力≥术前最佳矫正视力，88．32％的眼屈光度在预定矫正度数的±1．00D以内。6只眼（2．80％）最佳矫正视力减少2行以上，有Ⅱ级以上Haze的有7眼间（3．27％）。结论准分子激光屈光性角膜切削术治疗近视及近视散光具有很高程度的精确性和安全性，在＜10D的近视眼中更显示了良好的预测性和稳定性。     

Transmission of corneal collagen during arf excimer laser ablation

The time-resolved transmission of collagen films and 10-μm sections of bovine cornea during ArF laser ablation has been investigated. The film studies were performed on thin layers of extracted bovine corneal collagen, the principal chromophore in 193 nm photoablation. Transmission measurements were made on both dry and water-saturated films to assess the sensitivity of the ablation process to hydration. Distinct transient optical changes were observed in both fully desiccated and rehydrated films. Dehydrated films exhibit rapid reduction in film absorption over the time-course of the ablating laser pulse, presumably due to chromophore bleaching or annihilation. In contrast, rehydrated films demonstrate a short-lived enhancement of the attenuation. In either case, a single ablative laser pulse increased the long-term transmission of the film, although this increase was a factor of five greater for dehydrated films than for rehydrated samples. Results obtained from corneal tissue sections were essentially identical to those derived from hydrated collagen films. © 1993 Wiley-Liss, Inc.     

Effect of oestradiol on mouse uterine epithelial cell tumour necrosis factor-alpha release is mediated through uterine stromal cells

Oestradiol-17beta (Oe(2)) stimulates uterine epithelial cell proliferation and is critical for normal uterine differentiation and secretory function. Oe(2) can act directly on the epithelium via the epithelial oestrogen receptor (OR) or indirectly via the OR-positive underlying stroma. A primary role for epithelial-stromal interactions has been established for mediating steroid hormone action in the uterus. This study was undertaken to determine the mode of Oe(2) action in regulating epithelial cell cytokine release in the uterus. Mouse uterine epithelial and stromal cells were isolated and cultured separately. Transepithelial resistance (TER) was monitored with an EVOM voltohmmeter to determine monolayer polarity and integrity. Epithelial cells grown alone or in coculture with stromal cells were treated with Oe(2). Supernatants collected were assayed for transforming growth factor-beta (TGF-beta) and tumour necrosis factor-alpha (TNF-alpha) by bioassay and enzyme-linked immunosorbent assay, respectively. While Oe(2) treatment of epithelial cells led to a significant decrease in TER, the amount of TNF-alpha released was not altered. However, when epithelial cells were cocultured with stromal cells and treated with Oe(2), apical TNF-alpha release was significantly decreased, compared to cells not treated with hormone. As determined by oestrogen receptor antagonist studies, Oe(2) primed epithelial cells for the action of the stromal paracrine factor(s). In contrast, TGF-beta release by epithelial cells was not affected by Oe(2) when grown alone or in the presence of stromal cells. These studies indicate that Oe(2) has both direct and indirect effects on the uterine epithelium. While epithelial monolayer integrity is directly influenced by Oe(2), TNF-alpha release in response to Oe(2) is dependent on the presence of stromal cells, indicating that paracrine communication is necessary for steroid regulation of some but not all cytokines.     

准分子激光屈光性角膜切削术治疗近视和近视散光3年疗效分析

目的 :评价准分子激光角膜切削术 (photorefoactivekeratecomy ,PRK)治疗近视、近视散光的远期疗效。方法 :按术前屈光度将 2 0 9例 (3 77例 )屈光度为 - 1 5 0～ 1 6 0D的患者分为二组 ,低中度组 (I组 )为 - 1 5 0～ - 6 0 0D(2 3 8眼 ) ,高度组 (II组 )为 - 6 2 5～ - 1 6 0 0D(1 3 9眼 )。应用美国Visx2 0 /2 0准分子激光仪对上述二组患者行PRK治疗 ,并对患者术后 3年的屈光度、视力、角膜屈光力、角膜厚度、并发症进行随访观察。结果 :I组、II组中屈光度 <± 1D者分别占 94 5 %和 6 1 9% ;≥± 2 0 0D分别占 0 % ,2 3 7%。术后裸眼视力≥ 0 5者在I组、II组中分别占 99 6 %和 79 9% ;≥ 1 0者分别占 85 3 % ,48 2 %。角膜屈光力两组均在术后 6个月稳定 ,角膜上皮下雾状混浊O级在I组、II组分别为1 0 0 %和 98 6 % ,术后眼压两组均正常。结论 :准分子激光屈光性角膜切削术治疗近视、近视散光效果肯定 ,尤对低中度患者疗效更佳     

Transepithelial Transport of Aliphatic Carboxylic Acids Studied in Madin Darby Canine Kidney (MDCK) Cell Monolayers

Transport of ¹⁴C-labeled acetic, propionic (PA), butyric, valeric, heptanoic (HA), and octanoic (OA) acids across the Madin Darby canine kidney (MDCK) epithelial cell monolayer grown on a porous polycarbonate membrane was studied in Hanks' balanced salt solution (HBSS) at 37°C in both apical-to-basolateral and basolateral-to-apical directions. At micromolar concentrations of solutes, metabolic decomposition was significant as evidenced by [¹⁴C]CO₂ production during the OA transport. The apparent permeability (Pe) indicates that as lipophilicity increases, diffusion across the unstirred boundary layer becomes rate limiting. In support of this notion, transport of OA and HA was enhanced by agitation, showed an activation energy of 3.7 kcal/mol for OA, and resulted in identical Pe values for both transport directions. Analysis of Pe changes with varying alkyl chain length resulted in a G of –0.68 ± 0.09 kcal/mol for –CH₂-group transfer from an aqueous phase to the MDCK cells. When the intercellular tight junctions were opened by the divalent chelator EGTA in Ca²⁺/Mg²⁺ -free HBSS, transport of the fluid-phase marker Lucifer yellow greatly increased because of paracellular leakage. PA transport also showed a significant increase, but OA transport was independent of EGTA. Although albumin also undergoes paracellular transport in the presence of EGTA and OA binds strongly to albumin, OA transport in EGTA solution was unchanged by albumin. These observations indicate that transmembrane transport is the major mechanism for lipophilic substances. The present study, together with earlier work on the transport of polar substances, shows that the MDCK cell monolayer is an excellent model of the transepithelial transport barrier.     

Phototherapeutic keratoectomy (PTK) after keratoconjunctivitis epidemica

Background: Persistent and recurrent nummuli after epidemic keratokonjunktivitis (EKC) often lead to reduced visual acuity and increased glare. In spite of long-term topical steroid therapy nummuli often recur. We tried to treat persistent nummuli with phototherapeutic keratectomy (PTK). Patients: PTK with an excimer laser (193 nm) was performed in 13 eyes of 9 patients with nummuli. The nummuli were observed over 3–72 months (mean: 36 months). Preoperatively, the visual acuity was 0.1–0.9 (mean: 0.39 ± 0.22) and the brightness acuity test (BAT) was 0.05–0.5 (mean: 0.25 ± 0.15). Prior to PTK all eyes had been treated with local steroids several times for recurrent nummuli. Results: During the follow-up from 15 to 56 months (mean: 33 ± 11.5 ms), 11 eyes had an increase in visual acuity: 0.3–1.0 (mean: 0.63 ± 0.26). The reduction of glare was especially beneficial for the patients: 0.3–0,9 (mean: 0.55 ± 0.21). One patient had a recurrence of nummuli in both eyes 6 weeks after PTK. The subjective-induced spheric refractive change was − 2.5 D to + 2.0 D. The astigmatic error changed between − 2.0 D to + 1.5 D. Conclusion: PTK seems to be an effective method of treating persistent, recurrent nummuli after EKC. The low rate of recurrence of nummuli after PTK is remarkable.      

Holladay法计算准分子激光角膜切削术屈光矫正效应的应用

目的　评价计算准分子激光角膜切削术（ＰＲＫ） 矫正近视性屈光不正的角膜屈光力变化量的Ｈｏｌｌａｄｙ 法。 方法　用Ｈｏｌｌａｄａｙ 法计算ＰＲＫ 术后与术前角膜屈光力的差值（ 角膜实矫屈光度） ,并与角膜预矫屈光度进行比较。 结果　（１）Ａ 组：复性近视散光眼术后６ 个月,角膜实矫球镜度欠矫（０ ．４８ ±０ ．１９）Ｄ;角膜实矫散光度过矫３８ ．５ ％ （２５／６５） ,散光欠矫６１ ．５ ％ （４０／６５） ,过矫和欠矫≥±０ ．５０ Ｄ 占４１ ．５ ％ （２７／６５） ;实矫与预矫散光的轴位的差值≤±１５°占６０ ．０ ％ （３９／６５） 。（２）Ｂ 组：单纯近视眼术后６ 个月时,角膜实矫等值球镜度欠矫（０ ．５５ ±０ ．２６） Ｄ;术后６ 个月时产生（０ ．５９ ±０ ．３８）Ｄ 的矫正近视散光的效应,其中≥０ ．５０ Ｄ 者占５１ ．２ ％ （２２／４３） ,实矫近视散光轴位均在１８０°－ ４４°～１８０°＋ ４４°之间。 结论　应用Ｈｏｌｌａｄａｙ 公式从球、柱镜度两方面计算ＰＲＫ 的角膜屈光变化效应值,是合理、客观和准确的     

RK术后严重眼球破裂伤的手术治疗：附3例报告

报告３例ＲＫ术后严重眼球破裂伤的手术效果。方法部分穿透性角膜移植及联合瞳孔孔成形,前段玻璃体切除,角膜裂伤修补及后段玻璃体切除视网膜复位术。结果３例均保存了眼球。结论ＲＫ术后眼球破裂伤虽然严重而复杂,但通过穿透性角膜移植术及联合手术治疗,仍有可能保存眼球和恢复部分视力。     

PRK治疗RK后残余近视散光二年疗效分析

目的： 评价准分子激光屈光性角膜切削术治疗放射状角膜切开术后残余近视散光的预测性、稳定性和安全性。方法： 对５２ 眼 Ｒ Ｋ 术后残余近视散光患者行再次 Ｐ Ｒ Ｋ 治疗, 并连续随访两年以上。术前残余球镜屈光度－ ３７５±１３２ Ｄ,残余柱镜屈光度－ ２３６±１２５ Ｄ, 最佳矫正视力均≥０８。结果： 术后 ６ 个月球镜屈光度－ ０３２±０２４ Ｄ, 柱镜屈光度－ ０７８±０５２ Ｄ, 裸眼视力≥１０ 者４６ 眼 （８８４６％ ）, 术后 ２４ 个月球镜屈光度－ ０３７±０４２ Ｄ, 柱镜屈光度－ ０５６±０３７ Ｄ, 裸眼视力≥１０ 者 ４２ 眼 （８０７６％ ）。最佳矫正视力下降 １ 行以上者 ３ 眼 （５７６％ ）, 实际球镜矫正度与预期矫正度相差１０ Ｄ 以内 ５０ 眼 （９０１５％ ）, 柱镜相差 １０ Ｄ以内５１ 眼 （９８０７％ ）。结论： Ｐ Ｒ Ｋ 治疗 Ｒ Ｋ 术后残余近视散光的两年随访结果表明, 该方法预测性强、稳定性好和安全性高, 特别在矫正残余散光方面, 其结果令人满意。