激光虹膜切开与周边虹膜切除术治疗瞳孔闭锁继发青光眼的临床观察

目的 观察Nd:YAG激光虹膜切开术(LI)与虹膜周边切除术(PI)治疗瞳孔闭锁继发青光眼的临床疗效.方法 选取因葡萄膜炎引起瞳孔闭锁继发青光眼患者62例67只服,随机分为LI组和PI组.观察手术前后眼压、前房深度、炎症及虹膜切口通畅情况并进行统计学处理.平均随访时间(21.5±4.6)个月.结果 (1)LI组33只眼均能一次性击穿虹膜,前房深度由术前(0.67±0.31)mm加深为(2.58±0.26)mm,前后比较差异具有统计学意义.术后24h眼压南术前(28.22±7.12)mmHg降至(20.06±3.59)mmHg,前后比较差异具有统计学意义.术后26只眼(78.8%)发生激光孔闭合,未行再次激光治疗,22只眼行PI,4只眼行滤过手术.(2)PI组34只眼均形成通畅的周切口,术后结膜充血、前房炎症反应明显减轻.前房深度由术前(0.71±0.48)mm加深为(2.61±0.33)mm,前后比较差异具有统计学意义.眼压由术前(27.54±6.69)mmHg降至最未次随访(15.79±3.67)mmHg,前后比较差异具有非常统计学意义,手术成功率79.4%.结论 PI不仅能有效解除瞳孔闭锁、控制眼乐,而且有利于控制炎症、缩短疗程.     

Deconstructing the mechanisms of angle closure with anterior segment optical coherence tomography

Background: To illustrate the common mechanisms of angle closure by observing the changes following a laser iridotomy and then cataract surgery with anterior segment optical coherence tomography. Design: Retrospective interventional case series. Participants: Four patients with iridotrabecular contact. Methods: The anterior chamber was imaged in different lighting conditions prior to and following a laser iridotomy and then cataract surgery. The images were superimposed on each other, using the interscleral spur line as a common baseline. Main Outcome Measures: Qualitative and quantitative analysis of the changes of the iris and the drainage angle. Results: Iridotrabecular contact was seen in dark conditions in all patients. Iridotrabecular contact related to pupil block was abolished after a laser iridotomy. Persistent iridotrabecular contact following a laser iridotomy, due to a lens‐induced mechanism, was abolished after cataract surgery. Iridotrabecular contact that persisted after a laser iridotomy and cataract surgery was due to a ‘pure’ plateau iris syndrome or peripheral anterior synechiae. These treatments lowered the height of the iris plane in the region posterior to the trabecular meshwork. Conclusion: Following a laser iridotomy and cataract surgery, there is posterior movement of the iris plane away from the trabecular meshwork, but iridotrabecular contact can persist due to the ciliary processes or peripheral anterior synechiae. These changes show that the risk of iridotrabecular contact depends on the height of the iris plane relative to the trabecular meshwork and the degree of physiologic pupil dilation, and that angle closure can be a multi‐mechanism disease rather than a pure one.     

Ultrasound biomicroscopic features of spherophakia

Background: Spherophakia is an uncommon diagnosis. This is the first case report of spherophakia evaluated by ultrasound biomicroscopy.
Methods: Ultrasound biomicroscopy is a new diagnostic technique developed by one of the authors and provides images with microscopic resolution of the anterior segment. A patient with spherophakia was evaluated by ultrasound biomicroscopy (Zeiss-Humphrey, 50MHz) before and after YAG laser iridotomy.
Results: Ultrasound biomicroscopic assessment revealed a shallow anterior chamber, a very steep anterior lens curvature, iridolenticular contact, elongated zonules, and an increased distance between the lens equator and the ciliary processes. Angle closure glaucoma was due to a pupil block mechanism. The pupil block was relieved by YAG laser iridotomy.
Conclusions: Ultrasound biomicroscopy is a useful technique to confirm the diagnosis of spherophakia. The pupil block in spherophakia is relieved by YAG laser iridotomy.     

Iris and trabecular meshwork pigment changes after posterior chamber phakic intraocular lens implantation

PURPOSE: To evaluate the changes in laser iridotomies, intraocular pressure (IOP), angle structures, and pupil diameter after implantable contact lens (ICL) (Version 4 Staar Surgical) implantation in myopic Asian eyes. SETTING: Department of Ophthalmology, Chung-Ang University Yongsan Hospital, Seoul, Korea. METHODS: The ICL was implanted in 81 eyes of 43 patients with spherical equivalent greater than -6.00 diopters. Gonioscopy examination was performed 1 day after laser iridotomy and 6 and 12 months after ICL implantation. The changes in laser iridotomy sites, IOP, and pupil diameter were also evaluated. RESULTS: Ten eyes (12.3%) had occlusion or narrowing of the laser iridotomy sites. The angle width was more than 30 degrees in all cases preoperatively but narrowed to less than 20 degrees in 16 eyes (19.8%) 6 months postoperatively. The mean pigment, measured by the semiquantitative method (grade 0 to 4), was 2.03 in the inferior angle, 0.18 in the nasal angle, 0.12 in the temporal angle, and 0.00 in the superior angle 12 months postoperatively. The pigment in all quadrants increased temporally as a result of the laser iridotomy or iris rubbing by the ICL; however, the pigments absorbed gradually and decreased to values before laser iridotomy 12 months postoperatively. There was a temporary increase in IOP from the instillation of steroid eyedrops 1 week and 1 month postoperatively; IOP returned to the preoperative level and remained there 12 months postoperatively. There was a significant decrease in pupil diameter 1 and 3 months postoperatively; the diameter returned to the preoperative size at 6 and 12 months. Pigment dispersion syndrome and pigmentary glaucoma were not seen. CONCLUSION: Implantation of the ICL narrowed the angle width but did not increase trabecular pigmentation compared with values after laser iridotomy, indicating ICL implantation is safe regardless of the pigmentary changes in the trabecular meshwork.     

Effect of neodymium:YAG laser iridotomy on number of aqueous melanin granules in primary pigment dispersion syndrome

PURPOSE: Increased numbers of aqueous melanin granules have been reproducibly demonstrated in eyes with pigment dispersion syndrome using the cell count mode of the laser flare-cell meter. It was the aim of this study to measure the exact number of aqueous melanin granules in eyes with pigment dispersion syndrome and pigmentary glaucoma before and after Nd:YAG laser iridotomy. METHODS: Nine eyes of seven patients with a clinical diagnosis of primary pigment dispersion syndrome and secondary open-angle glaucoma (mean age 41.1 +/- 10.8 years) were included in this study. Aqueous cells were quantified using the cell count mode of the laser flare-cell meter (Kowa FC-1000) before and 30 min after medical pupillary dilation. Measurements were performed before and 15 +/- 7 weeks after Nd:YAG laser iridotomy. The main outcome measure was the number of aqueous melanin granules before and after Nd:YAG laser iridotomy. RESULTS: The number (mean and quartiles) of aqueous melanin granules/0.075 microl aqueous humor (normal/dilated pupil) before antiglaucoma treatment was 4.5 (4.0, 7.25)/ 9.0 (5.0, 13.0) and was significantly reduced after iridotomy [1.5 (0.75, 3.25)/4.0 (1.6, 6.25), P=0.016]. CONCLUSION: Nd:YAG laser iridotomy results in significant (65%) decrease of aqueous melanin granules in eyes with primary pigment dispersion syndrome. This finding appears to confirm the concept of reverse pupillary block in primary pigment dispersion syndrome and may indicate that laser iridotomy is a useful treatment option in this condition.     

Influence of argon laser treatment of glaucoma on corneal endothelium

The morphometric study of the corneal endothelium was carried out by means of specular microscopy prior to and for one year following laser trabeculoplasty (LTP) or laser iridotomy. A significant increase in the endothelial cell size was demonstrated in 6 months after trabeculoplasty and in 3 months following iridotomy. The magnitude of increase in cell size following laser iridotomy was significantly correlated with the amount of laser energy delivered to the eye. However, such correlation was not demonstrated following LTP where the applied energy was kept fairly constant among the present treated cases. The increase in cell size failed to correlate with clinical factors including IOP before and after laser therapy, age and the presence or absence of endothelial burn. The treatment protocols using reduced energy are indicated to minimize endothelial damage induced by LTP or laser iridotomy.     

The effects of iridotomy size and position on symptoms following laser peripheral iridotomy

PURPOSE: To evaluate visual disturbances following laser peripheral iridotomy (LPI). Patients sometimes note visual disturbances following laser peripheral iridotomy. The purpose of this study was to provide what we believe to be the first systematic evaluation of these visual disturbances, including a determination of whether or not they are associated with characteristics of a primary patent laser peripheral iridotomy, such as lid position and size of the iridotomy. PATIENTS AND METHODS: This was a case series of 93 consecutive (172 eyes) glaucoma patients who had had an Nd: YAG laser peripheral iridotomy. Patients returning for a follow-up visit after laser peripheral iridotomy were selected. A standardized questionnaire was prospectively administered to the study patients at least 1 month after their laser peripheral iridotomy had been performed, inquiring if they experienced any of the following either before or after the iridotomy: halo, lines, crescent, ghost image, glare, spots, shadows, blurring, or other unlisted visual disturbances. On the same visit when they answered the questionnaire, the patients were examined at the slit lamp to assess the location, lid coverage status, and size of the laser peripheral iridotomy. Selection for the performance of the LPI was not prospective. A series of 93 consecutive patients served as controls. RESULTS: Seven (4%) of the 172 study eyes had postoperative visual symptoms of shadows, ghost images, crescents, or lines. Ninety (52.3%) of the laser peripheral iridotomies were covered by the upper lid, 40 (23%) were completely exposed, and 42 (24%) were partially exposed. Visual disturbances (those listed above plus glare, blurring, haloes, spots, and miscellaneous) occurred in 8 of the 90 (8.9%) eyes with completely covered laser peripheral iridotomies, in 11 of the 42 (26%) with partially covered laser peripheral iridotomies, and in 7 of the 40 (17.5%) with fully exposed LPIs. CONCLUSION: Visual symptoms following laser peripheral iridotomy are more likely to occur in patients who have partially or fully exposed laser iridotomies than in those in whom the iridotomy is completely covered by the lid.     

Intraocular pressure spike after YAG iridotomy in patients with pigment dispersion

BACKGROUND: The role of laser peripheral iridotomy to break a suspected reverse pupil block in the long-term control of pigment dispersion is promising, but the usefulness of this procedure has not been completely established. The author examined whether patients with pigment dispersion are at higher risk for an intraocular pressure (IOP) spike after laser peripheral iridotomy due to possible compromise of trabecular meshwork function, compared with patients undergoing prophylactic peripheral iridotomy for an occludable angle. METHODS: Data were collected prospectively on the first eye of 87 patients with occludable angles and 13 patients with pigment dispersion treated with peripheral laser iridotomy between November 1995 and October 1996 at the glaucoma service of a university-affiliated hospital in Toronto. All patients received one drop of 0.5% apraclonidine before the procedure. IOP was measured before and 1 and 24 hours after the procedure. RESULTS: There was no difference between the two groups in the distribution of right vs. left eyes, sex, race, the mean total energy required to produce a patent iridotomy, the mean number of medications used or the mean IOP before the procedure. The patients with pigment dispersion were significantly younger than those with occludable angles (mean age [and standard deviation (SD)] 40.5 [9.45] years vs. 66.4 [10.78] years) (p < 0.001). There was no difference between the two groups in mean IOP at 1 hour or at 24 hours. Twenty-nine patients (33%) in the occludable angle group and seven (54%) in the pigment dispersion group had an IOP spike greater than 2 mm Hg after the procedure (p = 0.001). Among these patients, the mean IOP (36.4 [SD 10.83] mm Hg vs. 30.3 [SD 7.04] mm Hg, p = 0.05) and the mean rise in IOP (14.0 [SD 10.63] mm Hg vs. 8.7 [SD 4.73] mm Hg, p = 0.04) were significantly higher in those with pigment dispersion than in those with occludable angles. Among the patients who used antiglaucoma medications before the procedure or had a prelaser IOP level greater than 22 mm Hg, those with pigment dispersion were more likely than those with occludable angles to have an IOP spike at 1 hour (p < or = 0.005). INTERPRETATION: Patients with pigment dispersion undergoing iridotomy to break a reverse pupil block should be carefully assessed after the procedure, as significant pressure spikes requiring treatment may occur.     

YAG laser iridotomy treatment for primary angle closure in east Asian eyes

AIM: To assess the efficacy of Nd:YAG laser iridotomy as initial treatment for primary angle closure in a community setting in rural Mongolia. METHODS: Subjects with occludable drainage angles in two glaucoma prevalence surveys in Mongolia (carried out in 1995 and 1997) were treated with YAG laser iridotomy at the time of diagnosis. These patients were re-examined in 1998. Patency of iridotomy, intraocular pressure (IOP), visual acuity, and gonioscopic findings were recorded. Iridotomy was classified unsuccessful in eyes where further surgical intervention was required or in which there was a loss of visual acuity to <3/60 from glaucomatous optic neuropathy. RESULTS: 164 eyes of 98 subjects were examined. Patent peripheral iridotomies were found in 98.1% (157/160) of eyes that had not undergone surgery. Median angle width increased by two Shaffer grades following iridotomy. Iridotomy alone failed in 3% eyes with narrow drainage angles and either peripheral anterior synechiae or raised IOP, but normal optic discs and visual fields. However, in eyes with established glaucomatous optic neuropathy at diagnosis iridotomy failed in 47%. None of the eyes with occludable angles that were normal in all other respects, and underwent iridotomy, developed glaucomatous optic neuropathy or symptomatic angle closure within the follow up period. CONCLUSIONS: Nd: YAG laser iridotomy is effective in widening the drainage angle and reducing elevated IOP in east Asian people with primary angle closure. This suggests that pupil block is a significant mechanism causing closure of the angle in this population. Once glaucomatous optic neuropathy associated with synechial angle closure has occurred, iridotomy alone is less effective at controlling IOP.     

PERSISTENT SYMPTOMS AFTER PERIPHERAL IRIDECTOMY FOR ANGLE-CLOSURE GLAUCOMA

Symptoms that persist after oerations for angle-closure glaucoma arise from different causes. In the presence of open peripheral iridectomies miotics may be beneficial or may close angles; wide pupil dilatation by phenylephrine used to diminish posterior synechiae may close angles; cycloplegic mydriatics will close some angles and open others. Unexpected bizarre reactions to eye drops may occur. bersistent chronic glaucoma will be more common after laser iridotomy than after correctly assessed filtering operations. The importance of gonioscopy in diagnosis and management is emphasised.     

Persistent symptoms after peripheral iridectomy for angle-closure glaucoma

Symptoms that persist after operations for angle-closure glaucoma arise from different causes. In the presence of open peripheral iridectomies miotics may be beneficial or may close angles; wide pupil dilatation by phenylephrine used to diminish posterior synechiae may close angles; cycloplegic mydriatics will close some angles and open others. Unexpected bizarre reactions to eye drops may occur. Persistent chronic glaucoma will be more common after laser iridotomy than after correctly assessed filtering operations. The importance of gonioscopy in diagnosis and management is emphasised.     

周边虹膜切除术后合并小瞳孔极浅前房的残余青光眼治疗

 2例原发性闭角型青光眼老年人行虹膜周边切除（开）术后5年以上,就诊时眼压高,前房极浅、瞳孔较小,晶状体混浊。本讨论的目的是关注原发性闭角型青光眼患者作预防性虹膜周边切除（开）术后的长期随访,提倡残余青光眼的个体化治疗,介绍小瞳孔合并极浅前房的白内障手术体会。（眼科,2012,21：24-28）     

Argon laser trabeculoplasty for chronic angle-closure glaucoma uncontrolled by iridotomy

Nineteen eyes of 19 Japanese patients with medically uncontrollable chronic angle-closure glaucoma following laser iridotomy or surgical iridectomy underwent argon laser trabeculoplasty (ALT), applying low-power and a small number of laser burns over a small extent of the trabecular meshwork. All the eyes had glaucomatous optic disc damage, visual field loss, and intraocular pressure elevation before ALT. In each case, the extent of peripheral anterior synechiae was equal or less than 50% of the angle. The mean follow-up was 35 months. Life-table analysis (Kaplan-Meier method) showed that the probability of success was 66% at the end of three years after ALT. It is concluded that in the cases of uncontrollable chronic angle-closure glaucoma following laser iridotomy or surgical iridectomy, ALT should be tried before filtration surgery.     

Pupil block glaucoma after neodymium:YAG capsulotomy in a patient with a partially subluxated posterior chamber intraocular lens

A 73-year-old-woman presented following neodymium:YAG capsulotomy for posterior capsular opacification with acute glaucoma. Previous cataract surgery had left her with a subluxated lens. Cornea edema obscured detail of the anterior chamber, but the edge of the lens could be seen clearly within the pupillary space. This produced a diagnostic dilemma because no obvious cause for pupil block could be seen. She failed to respond to medical therapy and had a laser iridotomy, following which her symptoms resolved. We believe this case demonstrates the importance of a laser iridotomy to exclude pupil block glaucoma when adequate visualization of the pupillary space is obscured.     

Anterior segment morphology after laser iridotomy in primary angle closure suspects

Purpose

To evaluate and compare the changes in anterior segment parameters in primary angle closure suspects before and after laser peripheral iridotomy and intrasession repeatability of measurements before laser iridotomy as assessed by Scheimpflug‐Placido disc topographer.

Methods

Before laser iridotomy, 56 eyes of 56 primary angle closure suspect patients underwent anterior segment analysis with the Sirius Scheimpflug‐Placido disc topographer system using glaucoma analysis mode, which was repeated a week after iridotomy. Anterior segment parameters such as central anterior chamber depth, central corneal thickness, anterior chamber volume and iridocorneal angle were analysed before and after laser iridotomy and compared with paired t‐test. Three consecutive scans were obtained to assess the intrasession repeatability of measurements before iridotomy by a single examiner and intraclass correlation co‐efficient was calculated. Multivariate regression analysis was performed to evaluate the predictors associated with iridocorneal angle narrowing.

Results

Intraclass correlation co‐efficient values ranged from 0.982 for anterior chamber volume to 0.998 for the iridocorneal angle. After laser iridotomy, mean central anterior chamber depth increased from 2.14 ± 0.29 mm to 2.21 ± 0.28 mm (p = 0.04), mean anterior chamber volume increased from 96.2 ± 16.98 mm³ to 98.14 ± 15.87 mm³ (p < 0.0001) and mean iridocorneal angle widened from 33.38 ± 3.96° to 34.82 ± 4.27° (p = 0.01), compared with pre‐iridotomy status. There was no change in central corneal thickness, intraocular pressure or pupil diameter. Multivariate regression analysis model showed that at one week after iridotomy, iridocorneal angle opening was positively correlated with age (β = 0.773, p = 0.005) and anterior chamber volume (β = 1.308, p < 0.0001).

Conclusions

Laser peripheral iridotomy induces significant changes in the 3‐D anterior segment morphology in primary angle closure suspect patients. The Scheimpflug‐Placido disc topographer provides reproducible measurements of the iridocorneal angle and other parameters measured and hence, may become clinically useful for non‐invasive detection of potentially occludable angles. Predictors of iridocorneal angle widening after iridotomy were older age and anterior chamber volume.

     

Nd:YAG激光虹膜切除术治疗葡萄膜炎继发闭角型青光眼

目的 评价Nd：YAG激光虹膜切除术治疗葡萄膜炎继发闭角型青光眼的临床效果。方法 回顾性分析27例葡萄膜炎继发瞳孔阻滞闭角型青光眼经Nd：YAG激光虹膜切除术治疗的情况。随诊时间2月到4年。结果1)一次激光所有患眼均成功击穿虹膜。虽经术后积极抗炎治疗．12眼(44％)发生虹膜孔关闭。多次激光治疗后，最终89％的患眼获得了通畅的激光孔。2)在46次激光治疗中，击射点数为3～376点，激光能量为12～2077mJ。所用激光能量较原发闭角型青光眼高。3)75％的患眼激光治疗后眼压控制正常，6只眼(22％)眼压不能控制行滤过手术。4)激光手术的并发症主要是激光时虹膜的出血和暂时的眼压升高。5)术前有活动性炎症的患眼，发生激光孔闭合的比例更高。结论 Nd：YAG激光虹膜切除术是治疗葡萄膜炎继发闭角型青光眼的一种安全有效的方法。为提高手术的成功率，应在积极抗炎的同时，尽早行激光虹膜切除术。若激光后虹膜孔反复关闭，应考虑手术周边虹膜切除术。     

How large must an iridotomy be?

Four cases of acute angle closure glaucoma in eyes with a small but patent Nd-YAG laser iridotomy are presented, and similar cases in the literature are reviewed. Theoretically a 15 microns diameter iridotomy should be large enough to prevent angle closure glaucoma due to pupil block. Mechanisms by which larger iridotomies fail to prevent angle closure glaucoma, and the role of provocation tests following iridotomy, are discussed. An iridotomy should be at least 150-200 microns in diameter if acute angle closure glaucoma is to be reliably prevented.     

The effect of iridotomy on iris contour

With a recently developed technique for quantifying the geometry of the anterior chamber in optical cross section (slit-lamp photography using the Scheimpflug principle and computer correction for the optical effects of the cornea), we studied the iris contour before and after iridotomy in six patients with narrow anterior chamber angles and angle-closure glaucoma. Before iridotomy, the iris contour was convex anteriorly in all meridians. After iridotomy, the anterior lens surface position did not change perceptibly. The iris at the pupil margin settled backward onto the lens surface, no longer held forward by the narrow stream of aqueous passing from the posterior chamber to the anterior chamber. Next to the pupil there was often a perceptible mound, presumably representing the iris sphincter. From the point of support by the lens to the root of the iris, the contour of the iris surface was a straight line, except for the surface irregularities. The deepening of the anterior chamber at each point was the difference between the convex contour before iridotomy and the straight line after iridotomy.     

Corneal endothelial damage after neodymium:YAG laser iridotomy

BACKGROUND AND OBJECTIVE: This study examined the long-term effect of neodynium:YAG (Nd:YAG) laser iridotomy on the corneal endothelium. PATIENTS AND METHODS: A prospective study was designed. Patients with narrow and occludable angles or fellow eye of acute angle closure glaucoma attack were treated with Nd:YAG laser iridotomy. For one year, 31 eyes of 21 patients underwent complete follow-up. Corneal endothelial specular microscopy was performed before and after laser iridotomy at 1, 3, 6, and 12 months. RESULTS: The decrease of endothelial cell density after YAG laser iridotomy was statistically significant at 1 month (P = 0.036), 6 months (P = 0.004), and 12 months (P = 0.000), respectively. The decrease was not statistically significant at 3 months (P = 0.467). Linear regression analysis indicated no statistical correlation between the percentage change in endothelial cell density and the total energy used during the treatment (1 month: P=0.08, 3 months: P= 0.3, 6 months: P=0.9, 12 months: P=0.2). CONCLUSION: This study demonstrated significant endothelial cell loss in the 1-year follow-up. The result suggested that Nd:YAG laser iridotomy may pose a long-term hazard to the corneal endothelium.     

Prognostic Factors for the Success of Laser Iridotomy for Acute Primary Angle Closure Glaucoma

Purpose

To identify the prognostic factors for successful laser iridotomy for acute angle-closure glaucoma (AACG).

Methods

We retrospectively reviewed the medical records of 77 eyes of 77 patients with AACG with initial intraocular pressure (IOP) above 40 mmHg. All of the patients received maximum tolerable medical therapy (MTMT) followed by laser iridotomy. In order to comparatively analyze the factors affecting successful laser iridotomy, an increase in IOP on follow-up was defined as increase in IOP greater than 21 mmHg requiring medical or surgical treatment.

Results

Successful laser iridotomy was achieved in 59.7% (46/77 eyes). Thirty-one eyes (40.3%) exhibited increased IOP on follow-up, and of these, 30 eyes developed an increase in IOP within six months after the first attack. The success rate was higher (92.9%) in 42 patients who had greater than 30% IOP reduction by MTMT at the first attack compared to the 35 patients whose IOP reduction was less than 30%, of which 24 eyes (72.7%) showed more than 30% IOP reduction after intravenous hyperosmotic agent treatment (p=0.012). The success rate was higher in patients treated within seven days after the development of symptoms than in those treated after seven days (Odds ratio, 4.51; 95% confidence interval, 1.38 to 14.75).

Conclusions

Our data suggest that we can expect successful IOP control after laser iridotomy in eyes with AACG if the patient can be treated within seven days after the development of symptoms and if the IOP reduction was more than 30% by MTMT.