YAG Laser Anterior Capsulotomy Research Articles

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.

Early capsular distension syndrome after sulcus implantation of intraocular lenses

Two cases of early capsular distension syndrome (cds) are presented. the first occurred after sulcus implantation of a 12.0 mm poly(methyl methacrylate) iol (5.0 mm optic, 10 degree anterior angulation). the second case occurred after sulcus implantation of a foldable silicone iol with optic capture (6.0 mm optic, no anterior angulation). both cases resolved after a neodymium:YAG laser anterior capsulotomy. Cataract surgeons should be aware of the possibility of CDS after sulcus implantation of an IOL in the presence of an intact capsulorhexis and posterior capsule. A small capsulorhexis and in-the-bag capture of the IOL optic are major predisposing factors in this setting.

Anterior capsule contraction and intraocular lens dislocation in eyes with pseudoexfoliation syndrome

AIMSTo examine the extent of anterior capsule contraction as well as intraocular lens (IOL) decentration and tilt following implant surgery in eyes with pseudoexfoliation syndrome (PE).METHODS53 eyes from 53 patients...

Delayed dislocation of foldable plate-haptic silicone lenses after Nd:YAG laser anterior capsulotomy

PURPOSE: To report two eyes (two patients) that had plate haptic silicone intraocular lenses that dislocated 4 weeks after Nd:YAG laser anterior capsulotomy to relieve capsular contraction. METHODS: Case reports. The clinical records of two patients were reviewed. RESULTS: After uncomplicated phacoemulsification with implantation of plate haptic silicone lenses in the capsular bag, two eyes of two patients developed visually notable early contraction of the capsulorhexis. Three radial-relieving incisions approximately 1 mm long were made with a Nd:YAG laser in each eye to enlarge the capsulotomy. Although vision improved, both patients experienced sudden further reduction of vision after approximately 4 weeks. Upon examination of both patients, we noted an extension of an anterior radial capsulotomy incision peripherally, and the intraocular lenses had dislocated from the capsular bag into the ciliary sulcus. CONCLUSIONS: Tears may extend after radial-relieving incisions have been used to enlarge a contracted anterior capsulotomy, possibly because of continued capsular fibrosis. This may allow extrusion of a foldable intraocular lens from the capsular bag.

Anterior capsule contraction and intraocular lens dislocation after implant surgery in eyes with retinitis pigmentosa

Objective The purpose of the study was to investigate the extent of anterior capsule contraction, intraocular lens (IOL) decentration, and tilt after implant surgery in eyes with retinitis pigmentosa (RP). Design A case-control study. Participants Forty-seven eyes from 47 patients with typical RP and 47 control eyes from 47 age-matched healthy patients were studied. Intervention Phacoemulsification surgery with polymethylmethacrylate IOL implantation with continuous curvilinear capsulorrhexis was performed. Main outcome measures The area of the anterior capsule opening obtained with capsulorrhexis and the amount of the decentration and tilt of the IOL were measured using a Scheimpflug photography system at 1 week and 1, 3, 6, 9, and 12 months after surgery. Results The mean area in the RP group was found to be significantly smaller than that in the control group at 1 month after surgery and later ( P < 0.0001). The percent area reduction in the RP group at 6 months was 45.2 ± 25.8% and 4.6 ± 13.5% in the control group. Both the decentration length and tilt angle were also greater in the RP group than in the control group. Fourteen (29.8%) of the 47 RP eyes had undergone a neodymium:YAG (Nd:YAG) laser anterior capsulotomy at 12 months after surgery, whereas none of the control eyes had undergone an Nd:YAG. Conclusions Anterior capsule contraction in the RP eyes was more extensive than in the control eyes, leading to a high Nd:YAG laser anterior capsulotomy rate. Both lens decentration and tilt also were greater in the RP eyes than in the control eyes.

Effect of Captopril on Ocular Irritative Response to Topical Neutral Formaldehyde and Yag-Laser Capsulotomy in the Rabbit

Angiotensin converting enzyme (ACE) -inhibitors inhibit degradation of inflammatory mediators substance P (SP) and bradykinin, which may further stimulate the synthesis of prostaglandins. The resulting increase in inflammatory mediators in tissues is suggested to be the reason for the dry cough, involving sensory C-fiber activation, among patients receiving ACE-inhibitor therapy. In the present study, the effect of an ACE-inhibitor, captopril, on ocular irritative responses was studied in the rabbit. Intravenous captopril decreased markedly the blood pressure and the intraocular pressure (IOP) modestly. Topical neutral formaldehyde elicits an irritative response in the eye mediated through sensory neuropeptides SP and calcitonin gene-related peptide (CGRP). Following topical neutral formaldehyde, the increase in IOP and breakdown of the blood-aqueous barrier were inhibited by captopril, while miosis was not affected. Cyclic AMP (cAMP) content in the aqueous humour was increased by captopril, and this increase was inhibited by indomethacin. Following YAG-laser anterior capsulotomy, captopril inhibited the increase in IOP, breakdown of the blood-aqueous barrier and miosis. The present study demonstrates that use of short-term administration of captopril prior to sensory nerve stimulation or YAG laser anterior capsulotomy does not enhance the ocular responses to these stimuli in the rabbit. In the present study, captopril inhibited these responses, at least partly by decreasing the blood pressure.

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.

Results of 87 cases of intraocular lens implantation at the front of the whole capsular bag

To prevent or delay Elschnig pearl formation, we performed an unusual surgical technique on 87 patients: intraocular lens implantation at the front of the whole capsular bag. We tried to obtain tight adhesion between the anterior and posterior capsules so the lens epithelial cells could not proliferate and form Elschnig pearls. In fact, the patients exhibited no Elschnig pearls or Soemmering's ring, but developed large anterior capsular folds and a multilayer cell membrane between both capsules after two (three cases), six (19 cases), and 12 months (14 cases). This led to a decrease in visual acuity, and a Nd:YAG laser anterior and posterior capsulotomy was required in most cases (83%). Several months later, these eyes developed enormous Elschnig pearls emanating centrifugally from the laser opening, strongly suggesting that lens epithelial cells require aqueous humor for Elschnig pearl transformation. Since it is not yet possible to obtain perfect adhesion between anterior and posterior capsules, our results confirm the need to remove the anterior capsule after extracapsular cataract extraction.

Capsular bag distension after endophacoemulsification and posterior chamber intraocular lens implantation

Six cases of capsular bag distension after capsulorhexis, endophacoemulsification, and posterior chamber intraocular lens (IOL) implantation are presented. Five cases bad prominent posterior subcapsular cataracts preoperatively. In three cases, the anterior chamber depths were shallower and the apparent refractive errors were more myopic than normal after surgery. All six cases exhibited an apparent early complete sealing of the anterior capsular remnant against the anterior IOL optic. In each case, the capsular bag contained moderate particulate debris and flare while the adjacent vitreous and anterior chambers were clear. I suspect the particles are epithelial cell and cortical debris suspended in a fluid comprising lens epithelial protein, cellular breakdown products, balanced salt solution, and water. Five cases have received no specific treatment. In one case, a neodymium:YAG laser anterior capsulotomy allowed a forward egress of fluid from the distended capsular bag and a return to normal pseudophakic anatomy.

Prostaglandin E 2 and Protein Release Following Nd: YAG Laser Application to the Anterior Capsule of Rabbit Lens

We compared the effects of Nd:YAG laser anterior capsulotomy and photophacofragmentation on the release of prostaglandin E2 (PGE2) and protein in the New Zealand rabbit aqueous humor. Following anterior capsulotomy, the concentration of PGE2 was significantly more elevated (P less than .025) than it was in the contralateral untreated eyes at intervals from one-half hour up to four hours, and rapidly decreased in 24 hours. The concentration of protein showed a relatively gradual increase which became significant (P less than .05) after two hours, and remained elevated 24 hours after anterior capsulotomy. In contrast, photodisruption into the lens without damaging the anterior capsule showed little effect on the release of PGE2 and protein in the aqueous humor.

Anterior capsulotomy with the neodymium:YAG laser: Results and opinions

Three series and a control group of patients have been analyzed to study the early and long-term complications of neodymium:YAG laser anterior capsulotomy. In the author's opinion, the results have been favorable, and the procedure is recommended. It is important that a limited number of punctures be made, especially if there is any delay in surgery.

Neodymium:YAG laser anterior capsulotomy and a possible new application.

Neodymium:YAG laser anterior capsulotomy performed in nine cases had a high incidence of complications. In 220 cases of Nd:YAG laser nucleus pretreatment, without opening the anterior capsule, the time required for emulsification of the nucleus was less than with standard techniques.