小梁和巩膜切除术联合睫状体上腔引流治疗无晶状体和人工晶状体青光眼

目的探讨联合睫状体上腔引流的小梁和巩膜切除（LSEVDS）治疗无晶状体和人工晶状体眼青光眼的效果。方法采用回顾性方法观察103例（109眼）无晶状体和人工晶状体眼的青光眼患者。26例（26眼）无晶状体眼和34例（36眼）人工晶状体眼患者行LSEVDS，另外19例（20眼）无晶状体眼和24例（27眼）人工晶状体眼患者行传统小梁切除术。平均随访12．6个月，比较了术后视力、眼压（IOP）、视野、前房深度、滤过泡形态、脉络膜脱离、前房出血等情况。结果术后12个月，LSEVDS使无晶状体眼和人工晶状体眼的眼压明显下降，降眼压效果比小梁切除术更显著，其差异有统计学意义（P〈0．05）。LSEVDS的并发症包括前房积血（11．2％）、脉络膜脱离（6．5％）、低眼压（19．2％）和浅前房（11．2％），均于2周内好转。术后患者视力的变化无统计学意义。结论在治疗无晶状体和人工晶状体眼青光眼方面，LSEVDS的效果优于传统小梁切除术。     

Use of Gamma-Irradiated Cornea to Plug Sclerostomy Site During Tube Shunt Revision

Tube shunt implantation is a common procedure for control of intraocular pressure (IOP). However, tube revision and repositioning must sometimes be performed, and this involves removing the tube from its sclerostomy site. This site is prone to leaking and this may cause postoperative hypotony. We describe a novel and cosmetically acceptable technique of plugging and covering the sclerostomy site with gamma-irradiated corneal tissue.     

扁平部造瘘术治疗角膜葡萄肿

探讨睫状体扁平部造瘘术治疗角膜葡萄肿的效果。方法 16例16眼角膜葡萄肿施行了扁平部造瘘术,并对术后临床效果进行了分析、评价。结果 经随访观察3个月－1年,16眼中15眼角膜葡萄肿消失,4眼视力有不同程度提高,12眼眼压保持正常范围。结论 扁平部造瘘术是治疗角膜葡萄肿、保留眼球、挽救部分视力的有效方法之一。     

Rate-dependent,nonlinear photoablation of ocular tissue at 308 nm

To quantify the dependence on pulse repetition rate of 308 nm laser ablation in ocular tissue and elucidate the photoablation mechanisms involved, 85 full-thickness ab interno sclerostomies were created in six human donor eyes using an 800-μm-diameter quartz optical fiber. A laser pulse duration of 135 ns, fluence of 31 mJ/mm², and a fixed repetition rate between 5 and 40 Hz were used for 38 sclerostomies; the remaining 47 sclerostomies were completed at various laser settings during initial experimentation. Surprisingly, the numbers of pulses required for complete penetration of the optical fiber through the fixed tissue thickness were not constant as expected but decreased nonlinearly with increasing repetition rate. This demonstrates that the 308 nm excimer laser cuts ocular tissue significantly more rapidly per pulse at higher repetition rates. To explain this nonlinearity, we propose a composite ablation mechanism composed of photochemical, thermal, mechanical, and optical effects in varying proportions. © 1994 Wiley-Liss, Inc.     

Laser sclerostomy ab interno using continuous wave and pulsed lasers in a rabbit model

Purpose: This experimental study was designed to find an optimal combination of parameters for a gonioscopic ab interno approach to laser sclerostomy.Methods: Laser sclerostomy ab interno was performed delivering the laser energy via a slit lamp and a gonioscopic contact lens to the iridocorneal angle. The laser energy is required to be well transmitted by the cornea and at the same time to be maximally absorbed by the sciera at the iridocorneal angle. For local enhancement of absorption the sciera was stained with the biocompatible dyes Fluorescein (absorption maximum at 480 nm) and Methylene blue (absorption maximum at 668 nm) applied by iontophoresis. A continuouswave (cw)-Argon laser and a cw-dye laser produced relatively long pulses (200 ms) at wavelengths matching with these respective maxima. Additionally a pulsed dye laser emitting shorter pulses (2s) was successively adapted to the wavelengths of the two maxima. In some cases a Q-switched Nd: YAG laser had to be used for perforation of Descemet's membrane. A total of 44 rabbit eyes was treated to compare the results for these four different laser/dye combinations.Results: While no successfull perforation of the sciera could be achieved using the cw-dye laser with scleral staining by Methylene blue, the intraoperative success rate ranged between 59% and 75% for the other three laser/dye combinations. Histological examinations of the eyes on the first postoperative day showed smaller thermal necrosis zones, but more often fibrin reactions when using the shorter pulse length. Although we often found iris adherences to the internal fistula ostium, no major complications were observed.Conclusion: Further improvement of intraoperative success rates is needed, before clinical application of the approach can be considered.     

IOP-lowering effects for the application of human umbilical vein in non-penetrating deep sclerostomy in rabbits

AIM: To estimate the effects of human umbilical vein (HUV) implanted under the sclera of glaucoma model on intraocular pressure (IOP) lowering and to investigate its related mechanisms METHODS: A total of 20 human umbilical veins (HUV) were collected from healthy fetus umbilical core. After the establishment of glaucoma model in rabbits, human freeze-dried umbilical vein was implanted under the sclera during NPDS, while for control group, sclerostomy was performed without implant. The formation of the filtration bleb and IOP were detected every 24 hours before surgery and on day 3, 7, 10 and 14 after surgery. Handheld pen-type Tono-penⅡtonometer was used to measure IOP after topical anesthesia treatment. Each measurement has three duplicates. The incision recovery, filtration, conjunctiva congestion and anterior chamber inflammation were observed everyday after surgery. RESULTS: IOP was decreased dramatically with less inflammation than traditional sclerostomies with the application of HUV. The significant differences of IOP between the NPDS with and without HUV implant groups were shown up from 10 days after surgery. The average IOP in NPDS without HUV implant was 14.25mmHg, while for NPDS with HUV implant group, it was 12.30mmHg. This structure of filtration bleb, which allowed the aqueous humor to leave the eye, was formed for any type of surgery. However, 1-2 weeks later, filtration bleb was still existed in the group of sclerostomy with HUV implant and more stable than that of the surgery without HUV implant. Histological observations were performed on day 3, 7 and 14 after surgery. For the eyes under sclerostomy with HUV implant, HUV lumina was shown up on 3 days after surgery with few fibroblast cells near the sclera. On 7 days after surgery, HUV lumina was stably maintained but with obvious fibroblast cells and inflammatory cell. On 14 days after surgery, HUV lumina was still clearly observed but with scarring formation, which suggests that the IOP lowering effects might result from an effective drainage structure formation. CONCLUSION: HUV might be an alternative material to make the drainage pathway for non-penetrating deep sclerostomy.     

Clinical characteristics and surgical treatment of idiopathic uveal effusion syndrome

AIM: To investigate the clinical characteristics of idiopathic uveal effusion syndrome (IUES) and to identify effective surgical modalities for its treatment. METHODS: This retrospective analysis included clinical data of 33 eyes from 26 patients with IUES at Beijing Tongren Hospital. Records of eye examinations, ocular ultrasound, ocular ultrasound biomicroscopy (UBM), and follow-up surgical treatment were reviewed and analyzed. RESULTS: Of 26 patients, 17 (65.4%) were male and 9 (34.6%) were female. The average age of disease onset was 46.8y (range: 22-64y). Seven patients (26.9%) showed retinal detachment in both eyes at presentation. B-ultrasound showed the presence of retinal detachment in one eye or both eyes. All patients had binocular ciliary leakage and detachment. Eyes with retinal detachment underwent four-quadrantic partial-thickness sclerectomy and sclerostomy. Subretinal fluid resolution was achieved within 6mo. Recurrence was observed in three eyes and was resolved with re-operation. CONCLUSION: Ophthalmic ultrasound and UBM, among others, can be helpful in the diagnosis of IUES. Sclerectomy and sclerostomy are surgical modalities that can successfully treat the disease. Some patients may experience recurrence after surgery; reoperation remains safe and effective for them. Long-term follow-up is essential in such settings.     

Ab-interno erbium (Er):YAG laser sclerostomy with iridotomy in Dutch cross rabbits

An ab-interno technique using a pigmented rabbit model has been developed that uses a pulsed erbium:YAG laser to create an iridotomy with a sclerostomy through the same corneal incision. Laser energy was delivered with an articulated arm terminating in side-firing (850 or 650 μm OD) or end-firing (850 or 400 μm OD) fiber optic endoprobes, which allowed iridotomies and sclerostomies, respectively, to be created. Initially, sclerostomies (8–10, 8 mJ/300 μs pulses) and basal iridotomies (1–3, 4 mJ/200 μs pulses) were created with the larger probes. Problems encountered with this technique included corneal decompensation and rapid formation of peripheral anterior synechiae with occlusion of sclerostomies. The smaller endoprobes were then used to create midperipheral iridotomies and sclerostomies utilizing the same energy parameters. Sclerostomies created in this manner remained patent in the first postoperative week until the animals were sacrificed to obtain material for histologic study. © 1993 Wiley-Liss, Inc.     

Uveal Effusion Syndrome

The terms uveal effusion, choroidal effusion, ciliochoroidal effusion, ciliochoroidal detachment, and choroidal detachment have been used interchangeably in the literature. These labels all describe an abnormal collection of fluid that expands the suprachoroidal space, producing internal elevation of the choroidal. There are various inflammatory and hydrostatic conditions that can cause uveal effusion, but in some cases no obvious cause exists. In this setting, patients are thought to have a distinct, primary abnormality of the choroid or sclera, called uveal effusion syndrome (UES). UES may be idiopathic, or associated with hypermetropia, and should be considered a diagnosis of exclusion. Histological studies show amorphous glycosaminoglycan-like material filling the interfibrillary spaces of excised scleral tissue, with disruption of collagen fibers. In some patients there may be reduced macromolecular diffusion that interferes with the normal transscleral egress of albumin out of the eye, perhaps causing choroidal fluid retention due to altered osmotic forces. An alternative, and perhaps complementary hypothesis, is that swollen sclera compresses the transscleral vessels with resulting fluid retention. Patients with UES are most typically middle-aged men who have a relapsing remitting clinical course. There is often co-existing, shifting subretinal fluid that may involve the macula. Chronic disease may lead to secondary retinal pigment epithelial (leopard spot) changes and permanently reduced visual acuity. Treatment with systemic steroids does not appear to be effective. Surgical decompression of the vortex veins as they pass through the sclera has been described, but the most common treatment is full-thickness sclerectomies to provide an exit for choroidal fluid. The largest case series suggests that this produces an anatomic improvement in approximately 83% of treated eyes after a single procedure and in about 96% after one or two procedures. Final visual acuity improves by two or more lines in 56% of the eyes, is stable in 35%, and worsens in 9%. Although extremely rare, UES is a serious condition that is difficult to treat and can lead to severe and permanent visual loss in both eyes.     

Transconjunctival Application of Mitomycin C in Combination with Laser Sclerostomy ab interno: A Long-Term Morphological Study of the Postoperative Healing Process

The precise mechanism whereby mitomycin C enhances IOP reduction in glaucoma filtering surgery still eludes us. Ten rabbits received full-thickness Nd:YAG laser sclerostomy ab interno and adjunctive intraoperative treatment with mitomycin C (MMC) applied topically over the intact conjunctiva (0.5 mg ml⁻¹for 5 min). A systematic ultrastructural analysis of the fistulas and surrounding tissue was then conducted in conjunction with clinical observations, over the ensuing 10 weeks. In order to investigate also the extent to which MMC impedes fistula occlusion in the absence of percolating aqueous humour, we created non-perforating (‘half-thickness’) sclerostomies ab interno in three additional rabbits, one with and two without MMC therapy. Transconjunctival MMC application resulted in no serious complications. Eight of the ten full-thickness fistulas remained patent throughout the study, maintaining significant IOP reduction; the other two sclerostomies were compromised by iris incarceration. The MMC-treated, half-thickness canal remained as a tissue-free cul de sac; the two non-treated ones became completely occluded within one week without having recourse to extraocular cell populations. MMC suppressed the migration and proliferation of fibroblasts, macrophages and clump cells from the episclera, sclera, ciliary body and iris root. Repolymerization of heat-damaged collagen was abortive; neosynthesis was not observed. Myofibroblasts were encountered in the vicinity of the sclerostomy canals, and, after the fifth week, these cells were also found to be deployed as a canal-lining layer, delimiting the lumen from the surrounding stroma along most of the fistula length. Towards the external ostium, this layer of myofibroblasts was incomplete or absent. Near the internal ostium, lining cells were derived from the corneal endothelium.The transconjunctival mode of applying MMC appears to be efficient. This antifibrotic drug exerts its inhibitory influence by suppressing not only cell migration and proliferation, but also phagocytic and synthetic activities. However, exposed tissues are not acellular, and amongst the populations present, myofibroblasts are found to dominate the scene. The canal-delimiting cellular lining may play a role in maintaining fistula patency in MMC-treated eyes.