Pseudophakia and the pupil

Postoperative disturbances of the pupil are discussed on the basis of experience with more than 2500 intraocular lenses implanted after extracapsular cataract extraction (planned extracapsular or phacoemulsification). Apart from the changes to the pupil caused by an iris-fixed intraocular lens itself, the pupil may also be affected by blood, fibrinous inflammation, or remnants of cortex material or the anterior capsule after posterior chamber lens implantation. These conditions are frequently followed by synechiae between the pseudophakia and the iris. Mechanical damage to the iris or the sphincter muscle may also occur. Changes in the shape of the pupil often affect its function, and synechiae do so regularly. Secondary cataract necessitating treatment occurred in about 10% of our patients over a 7-year period. Today, YAG laser surgery represents the best means of restoring clarity to the pupil, though there are still a number of unresolved problems with the method. Neither primary nor secondary capsulotomy after pseudophakia implantation can be recommended. The methods of extracapsular cataract extraction with posterior chamber lens implantation are still at a stage of development which is not altogether satisfactory, since optic irregularities of the pseudophakia or the central posterior capsule may result in glare, disturbing the patient in spite of good visual acuity.     

Capsulorhexis phimosis in retinitis pigmentosa despite capsular tension ring implantation.

A 56-year-old man with retinitis pigmentosa presented with dense nuclear sclerosis and scattered zonular loss with laxity confirmed by ultrasound biomicroscopy. He had extracapsular cataract extraction with a 6.0 mm continuous curvilinear capsulorhexis and implantation of a capsular tension ring (CTR) and a single-piece poly(methyl methacrylate) (PMMA) intraocular lens (IOL) in the capsular bag in his left eye. Severe anterior capsule fibrosis and contracture of the capsulorhexis opening with nasal decentration of the IOL were noted 4 months after surgery. A neodymium:YAG (Nd:YAG) laser anterior capsulotomy was performed to prevent further zonular stress and IOL decentration. The centripetal forces of capsular fibrosis after cataract surgery may exceed the centrifugal resistance of the standard CTR and PMMA IOL in patients with retinitis pigmentosa. Such patients must be carefully monitored postoperatively. An Nd:YAG laser anterior capsulotomy is a safe and effective option to manage anterior capsule fibrosis.     

Propionibacterium acnes endophthalmitis: an unusual manner of presentation

An unusual clinical presentation of Propionibacterium acnes endophthalmitis as a solitary nodule on the corneal endothelial surface at the superior limbus in association with granulomatous uveitis is reported. The patient had previous extracapsular cataract surgery with intraocular lens implantation and two subsequent YAG laser capsulotomies. The organism was grown from a microbiopsy of the nodule after a negative anterior chamber tap. The patient was treated with systemic antibiotics, his condition worsened, and the implant, lens capsule, and anterior vitreous were surgically removed. No additional organisms were found and there was no evidence of coexistent phacoanaphylaxis. The patient had no further inflammation and attained 20/25 aphakic vision.     

Secondary cataract treatment with laser YAG-ND

The purpose of the study is to present the favorable results of YAG: Nd laser capsulotomy for the treatment of secondary opacification of the posterior capsule, in our department. A 3 years retrospective study was performed. For 1440 cataract operations, most of them extracapsular extractions with PMMA IOL placed in the posterior chamber (ciliary sulcus or capsular bag), 285 laser capsulotomies were done. The results are presented statistically, including sex and age distribution, type of cataract surgery and implant, treatment protocol (number of sessions, number of impulses per session, energy per impulse) and complications. The frequency of secondary capsular opacification in our study is 19.78%. It is most important in the age group 60-70 years, where the surgery for cataract is performed more often. Capsulotomy was done after extracapsular extraction with IOL placed in the posterior chamber, but especially after extracapsular extraction without implant placement or with complications that have permitted only the use of an anterior chamber implant. Capsulotomy is performed in only one session in 88% of the cases. The energy per impulse is usually 3-5 mJ and the mean number of impulses per session is 10-30. There are few complications: transient elevation of intraocular pressure in 14.73%, discrete laser marks on the implant in 8.77% and moderate iritis in 1% of the cases. YAG: Nd laser capsulotomy appears to be a safe and efficient method of treating secondary cataract; it improved visual acuity in all cases, if different ocular pathology had not influenced it.     

Post-traumatic endocapsular blood effusion

A rare complication after extracapsular surgery of the cataract, blood effusion is often a fortuitous discovery when a drop in visual acuity occurs. The subject reported herein is a 76-Year-old patient who presented an endocapsular blood effusion with no liquid level 1 Year after the extracapsular surgery of the cataract, discovered while examining a decrease in visual acuity. Questioning led to the discovery of eye trauma due to Nd: YAG laser posterior capsulotomy 3 Months before, which had progressed spontaneously and favorably for 2 Months, with a reduction of the effusion and better visual acuity. The bleeding seems to have come from a vascular injury due to a direct contusion, with blood possibly coming from the ciliary body, the iridocorneal angle, or the vitreous. The liquid effusion may have been caught at the back by the implant and enclosed in the area located between the capsular bag and the anterior hyaloid, without intravitreous diffusion. Most of reported cases in the literature discuss observations made on an intact posterior capsule, which appeared during or after close surgery. The treatment was simple supervision. Some Authors propose a Nd: YAG laser capsulotomy in case resorption is too slow.     

Preoperative anterior capsulotomy using YAG laser in cataract extraction by the envelope method. Preliminary report]

The envelope technique was used in 50 patients with cataract. In 25 patients anterior capsulotomy was performed by YAG laser before surgery (in 5 persons 1 day, in the remaining 20 1 hour before operation). The sole complications connected with laser capsulotomy was the raise in the intraocular pressure in 2 patients. In these woman-patients the laser surgery was performed a day before operation. In all the patients in whom the cataract operation was preceded by laser capsulotomy the removal of the anterior capsule did not produce any difficulty. The experience obtained during the study enable to state that laser capsulotomy simplifies considerably the operation and in connection with the envelope technique diminishes to a minimum the possibility of postoperative complications.     

Incomplete capsular bag distension syndrome after neodymium:YAG capsulotomy

We report a 60-year-old man with incomplete capsular bag distension syndrome 2 years after neodymium:YAG (Nd:YAG) laser capsulotomy for capsule opacification, which developed from extracapsular cataract extraction with intraocular lens (IOL) implantation performed 4 years before presentation to our clinic. The patient reported floaters of 15 days duration. Slitlamp examination showed shallowing of the inferior and medial anterior chamber. Dilated pupil examination showed a peripheral capsular bag inferiorly and medially behind the IOL. The bag was distended and filled with turbid fluid. The central and superior capsule was absent as a result of the previous Nd:YAG treatment. The IOL lie over the anterior capsule, and peripheral capsule leaves' edges were adhered. An Nd:YAG laser puncture of the incomplete capsular bag resolved the condition.     

Corneal endothelial damage after Nd:YAG laser anterior capsulotomy

The Nd:YAG laser is used primarily in the management of posterior capsular opacification in patients who have had extracapsular cataract extraction. Despite wide clinical use little is known about its damaging effects on the ocular tissues particularly on the corneal endothelium. To evaluate the pathologic changes caused by high powered Nd:YAG laser pulses on the anterior segment of the eye we focused the beam of this laser on the anterior lens capsule in rabbit eyes. Six eyes underwent anterior capsulotomy and three power settings were used (3.4 mJ, 5.8 mJ, 8.6 mJ). The fellow eyes served as controls. We studied acute corneal endothelial changes 6 hours after the capsulotomy using transmission electron microscopy. Results indicate that especially in the high setting the laser energy can cause injury and destruction of endothelial cells and alterations in the Descement membrane. These effects may be crucial of patients with corneas in critical cell number after a cataract surgery.     

Secondary surgical and neodymium-YAG laser discissions

Between November 1978 and June 1984, 161 surgical and 102 neodymium-YAG laser discissions were performed. The incidence of discission in patients with a mean three-year follow-up after extracapsular surgery was 22.1% (39 of 176 eyes) after extracapsular cataract extraction alone and 14.5% (81 of 558 eyes) after extracapsular cataract extraction with intraocular lens implantation (P less than .02); the incidence was 25.5% (47 of 184 eyes) with the transiridectomy clip lens and 9.1% (33 of 364 eyes) with the posterior chamber lens (P less than .001). The average interval between cataract surgery and the discission was 2.4 years. The intraocular pressure was increased in 51% (48 eyes) of the eyes two to five hours after YAG laser discission and was unpredictable in most patients. After surgical discission, the intraocular pressure was increased on the first postoperative day in 13% (18 eyes) of the eyes. With surgical discission, significant complications included vitreous manipulation, wound leak, and intraocular inflammation. Intraocular lens pitting occurred in 20 patients undergoing YAG laser discission. Complications with both procedures included cystoid macular edema, retinal detachment, glaucoma, and closure of a previously adequate discission opening.     

Effect of anterior capsule contraction on visual function after cataract surgery

PURPOSE: To examine the effect of contraction of the anterior capsule opening after cataract surgery on visual acuity and contrast sensitivity. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHODS: Thirty-two eyes of 32 consecutive patients who showed marked contraction of the anterior capsule opening after implantation of an intraocular lens were recruited. The area of the anterior capsule opening was measured by Scheimpflug videophotography before and after neodymium:YAG (Nd:YAG) laser anterior capsulotomy and was correlated with visual acuity and contrast sensitivity. RESULTS: After Nd:YAG laser anterior capsulotomy, the mean area of the anterior capsule opening increased significantly from 8.2 mm(2) to 18.0 mm(2) (P<.0001). Contrast sensitivity at most visual angles also improved significantly after Nd:YAG anterior capsulotomy, although visual acuity did not. The area of the anterior capsule opening before anterior capsulotomy was correlated significantly with contrast sensitivity but not with visual acuity, whereas there was no correlation between the opening area after anterior capsulotomy and visual acuity or contrast sensitivity. CONCLUSIONS: Contraction of the anterior capsule opening after cataract surgery significantly diminished contrast sensitivity in proportion to the opening area but did not markedly worsen visual acuity. Neodymium:YAG laser anterior capsulotomy improved contrast sensitivity.     

Effect of the laser ridge on posterior capsule opacification

The most common complication of extracapsular cataract extraction is posterior capsule opacification, which appears to result from the proliferation of anterior lens epithelium onto the posterior capsule. The presence of a posterior chamber intraocular lens has been shown to decrease the incidence of posterior capsule opacification, possibly by a barrier mechanism. This retrospective clinical study compares the effect of two different lens designs (with and without a laser ridge) on posterior capsule opacification requiring Nd:YAG laser posterior capsulotomy. Twenty-one of 101 patients (20.8%) with nonridged lenses required Nd:YAG laser posterior capsulotomies versus 13 of 86 patients (15.1%) with ridged lenses. Although these data showed a clinical benefit from using a ridged lens, no statistical difference in the incidence of posterior capsulotomy was noted. Further evaluation of capsular-optic surface apposition is needed.     

Ciliary block (malignant) glaucoma after cataract extraction with lens implant treated with YAG laser capsulotomy and anterior hyaloidotomy.

An 84-year-old woman developed high intraocular pressure with a shallow anterior chamber 2 months after an extracapsular cataract extraction with posterior chamber lens implant. The condition did not respond to peripheral iridectomy and removal of the implant but was treated successfully with YAG laser capsulotomy and anterior hyaloidotomy.     

Ocular irritative response to YAG laser capsulotomy in rabbits: release of calcitonin gene-related peptide and effects of methysergide.

The Neodymium (Nd):YAG laser is commonly used in ophthalmology mainly for the posterior capsulotomy in patients with secondary cataract after extracapsular cataract extraction. A frequent side-effect following different kinds of YAG laser treatments is an acute increase in the intraocular pressure (IOP). The present study addresses the role of calcitonin gene-related peptide (CGRP) in the ocular irritative response following YAG laser anterior capsulotomy in rabbits. The YAG laser anterior capsulotomy caused an irritative response in the eye, which consisted of an increase in the IOP, miosis and breakdown of the blood-aqueous barrier. Following YAG laser capsulotomy, CGRP-immunoreactivity was found in the aqueous humour in different molecular weight forms as revealed by gel-permeation chromatography. One of the peaks coeluted with synthetic human CGRP. Methysergide attenuated the increase in the IOP and disruption of the blood-aqueous barrier, but not the miosis, following YAG laser anterior capsulotomy. The present study demonstrates the release of CGRP into the aqueous humour following YAG laser capsulotomy, and suggests that CGRP is partly causing the increase in IOP and disruption of the blood-aqueous barrier in this irritative response.     

The effect of neodymium: YAG laser capsulotomy on aqueous humor dynamics in the monkey eye

The creation of a posterior capsulotomy utilizing a neodymium:YAG (Nd:YAG) laser is often followed by an increase in the intraocular pressure (IOP). In order to study the cause of this pressure rise, six eyes of three cynomolgus monkeys underwent extracapsular cataract extraction followed 2 to 3 months later by Nd:YAG laser capsulotomy. Eyes were evaluated clinically and examined histopathologically at 1 hour, 3 hours, 1 day, 3 days, 1 week, and 1 month after laser treatment. Although IOP did not increase after laser capsulotomy, outflow facility was decreased 80% from baseline levels at 3 hours, at 3 hours, 1 day, and 3 days. After laser treatment, the anterior chamber and meshwork contained fibrin, lens material, inflammatory cells, pigmented macrophages, erythrocytes, and free pigment. Most of these elements had cleared the meshwork by 1 month.     

Histological characteristics of ocular structures after YAG-laser exposure of various sections of the crystalline lens in experimental studies]

This work was aimed at analysis of all the aspects, pathomorphologic included, of short-pulsed YAG laser exposure of the lens. Experiments were carried out with 79 rabbit eyes. After laser exposure the eyes were enucleated in 1-24 h and in 7-10 days. Thirty-one eyes were subjected to YAG laser ++capsule puncture. Fragmentation of intracapsular structures was carried out in 23 eyes. Combined operations were performed on 25 eyes. Every series comprised two groups, differing by the energy of laser exposure: 3-5 mJ. Histologic analysis has lead the authors to the following conclusions. The pattern and severity of pathomorphologic changes were directly related to the energy and time of laser exposure and site of the focal plane of irradiation. The major destructive shifts after YAG laser fragmentation of the cortical layer and capsulotomy are focussed at the site of exposure and involve the adjacent sections of the lens. Laser exposure of 3-5 mJ may be used to open the anterior capsule of the lens and to facilitate the cataract mass discharge in extracapsular cataract extraction. Use of combined method helps enhance induration and fragmentation of the cortical layers of the lens, rules out surgical discission of the anterior capsule of the lens, and facilitates removal of the nucleus and wash out of the lens mass.     

Nd:YAG激光在白内障前囊膜切开与透明皮质乳化术中对眼前节组织的生物学效应

报告在白内障囊外摘除与后房人工晶体植入术中应用Nd∶YAG激光辅助手术30例。16例成熟期白内障在囊外摘除术前做激光前囊膜切开术。14例未成熟期白内障在做前囊膜切开的同时做透明皮质乳化术。结果表明激光辅助手术在缩短手术时间、减少合并症、提高疗效方面有显著效果。并对治疗中激光对眼前节组织的生物学效应及其机理进行了讨论。     

Sudden decrease in vision caused by liquefied after-cataract

We report a case of sudden decrease to unilateral visual acuity in a 39-year-old patient who had extracapsular cataract surgery 5 years earlier. The decrease was caused by involvement of the visual axis because of a rare complication known as liquefied after-cataract. Treatment with a neodymium:YAG (Nd:YAG) laser was successfully performed. Although there was no rupture in the posterior capsule, the opacity disappeared and the visual acuity improved to 20/20. This new form of after-cataract can cause a sudden decrease in vision, and Nd:YAG laser treatment, even without a posterior capsule rupture, can be performed successfully.     

Effect of preoperative YAG laser anterior capsulotomy on the incidence of posterior capsule opacification: ten year follow-up.

One hundred twenty-two patients, who were followed for ten years, had bilateral extracapsular cataract surgery with implantation of J-looped posterior chamber lenses between 1980 and 1981. On the first eye an anterior capsulotomy was performed with a pico-second YAG laser 12 to 20 hours before surgery; on the second eye a capsulotomy was performed manually at the time of surgery. Four of the eyes (3.27%) with laser capsulotomies had opacified posterior capsules after ten years; 61 of the eyes (50.00%) with manual capsulotomies had opacified capsules that had to be opened with a YAG laser.     

Posterior Capsule Opacification in Pseudophakic Eyes

Posterior capsule opacification following extracapsular cataract extraction is a manifestation of proliferation of anterior lens epithelium onto the posterior capsule. In addition to Elschnig pearl formation, vision is decreased in two ways. Multiple layers of proliferated epithelium produce a frank opacity. Also, the lens cells show myofibroblastic differentiation and their contraction produces numerous tiny wrinkles in the posterior capsule resulting in visual distortion. Because the cells that proliferate are anterior lens epithelial cells and because proliferation begins at the site of apposition of anterior capsular flap and the posterior capsule, a wide anterior capsulectomy should help reduce the risk of and delay the onset of visual loss from this complication of extracapsular surgery. Polishing the posterior capsule at the time of surgery will not help in this regard unless there is a complicated cataract with pre-existing posterior migration of lens epithelium. The presence of a potential cleavage plane between the proliferating epithelium and the posterior capsule provides a therapeutic alternative to surgical or laser discission.     

Prospective analysis of laser photophacofragmentation

Several recent reports have discussed the potential benefits of using the Nd:YAG laser to photofragment the nucleus prior to cataract extraction. We attempted to determine the efficacy and safety of photophacofragmentation prior to cataract surgery. We selected 32 patients for the laser photofragmentation category and 37 patients for the control group. We compared these patients with both phacoemulsification and extracapsular cataract extraction. There was no apparent difference between the four subgroups in endothelial cell loss postoperatively. There was a significant decrease in the amount of ultrasonic time required to remove the cataract for patients who had prior treatment with the YAG laser. However, although this was statistically significant, it did not alter the patient's total surgical time nor the outcome of surgery. We feel that photophacofragmentation introduces needless increased risk to the patient and recommend guarded use of this approach.