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At least 19 recordsLinked to original sources
PubMed1980

[Results of peripheral iridectomy in narrow-angle glaucoma and of prophylactic iridectomy (author's transl)].

During a period of three years 79 eyes with narrow-angle glucoma were operated on, and prophylactic iridectomy was performed in 55 eyes. In this way, narrow-angle glaucoma in the fellow eye, which frequently occurs, was prevented. There are less postoperative complications with therapeutic and prophylactic peripheral iridectomy than with filtering operations. In view of the pathogenesis of narrow-angle glaucoma peripheral iridectomy is the most economical and effective procedure for preventing another attack and narrow-angle glaucoma in the fellow eye.

Adult↗
PubMed2002

Phacotrabeculectomy: peripheral iridectomy or no peripheral iridectomy?

PURPOSE: To study the effect of peripheral iridectomy (PI) in phacotrabeculectomy. SETTING: Academic private glaucoma practice with a primarily white patient population. METHODS: This retrospective study comprised 126 eyes of 117 patients randomized for PI or no PI during phacotrabeculectomy who were followed for 12 months. Postoperative parameters in both groups included intraocular pressure (IOP), bleb development, visual acuity, and complications. RESULTS: There were no statistically significant differences between the 2 groups in visual acuity or IOP. Bleb development required significantly more 5-fluorouracil therapy in the no-PI group than in the PI group; however, bleb failure and the need for laser suture lysis were not significantly different between groups. Complications were rare in both groups. CONCLUSION: Phacotrabeculectomy without PI may be an acceptable alternative to the surgical management of co-existing cataract and glaucoma.

Aged↗
PubMed1989

The effect of combined application of argon and Nd-YAG lasers on iridectomy in rabbits.

Recently iridectomy using an argon or Nd-YAG laser to treat narrow angle glaucoma has become popular, and is now the procedure of choice over the standard surgical technique. However, the shock wave of the Nd-YAG laser causes hemorrhage in almost all cases and the high energy level of the Nd-YAG laser, which is required for iridectomy, causes injury to the lens and cornea. Furthermore, there is a tendency toward closure of the iridectomy site after argon laser application. We performed iridectomies by a combined application of argon and Nd-YAG lasers in pigmented rabbits to improve iris bleeding, iridectomy patency, and lens and corneal damage. The iridectomy patency and the lens and corneal damage were examined with a scanning electron microscope. The rabbits that underwent laser iridectomies with only the Nd-YAG laser were used as a control group. Based on the results, it can be concluded that laser iridectomy by a combined application of argon and Nd-YAG lasers results in a lower rate of bleeding, a higher rate of patency, and less damage to the lens and cornea as compared with iridectomy performed by Nd-YAG laser only.

Animals↗
PubMed1998

[Apraclonidine prevents the acute increase of intraocular pressure in brown eyes with Nd:YAG laser iridectomy].

OBJECTIVE: To investigate if apraclonidine can effectively prevent the acute increase of intraocular pressure (IOP) in brown eyes with Nd:YAG laser iridectomy. METHODS: 48 eyes with primary angle closure glaucoma were divided into treatment and control groups, which were matched by age and sex. One drop of apraclonidine was applied into the conjunctival sac at one hour before laser iridectomy and immediately after laser iridectomy in treatment group, whereas one drop of antibiotic as placebo was applied in control group at the same time. IOP, pupil diameter were measured at 0.5, 1, 1.5, 2, 3.5 hours after laser iridectomy. RESULTS: The maximum increase of IOP after laser iridectomy was 0.62 +/- 0.67 kPa and 1.13 +/- 0.87 kPa in treatment and control group respectively, there was a significant difference (P = 0.03). The obvious decrease of IOP occurred at 0.5, 1 and 1.5 hours after laser iridectomy in treatment group. No ocular and systemic side effects were found in treatment group, except pupil diameter was obviously larger in treatment group than that in control group. CONCLUSION: 1% apraclonidine effectively prevents the acute increase of IOP in brown eyes with Nd:YAG laser iridectomy.

Clonidine↗
PubMed1994

Analysis of diode, argon, and Nd: YAG peripheral iridectomy in cadaver eyes.

We compared semiconductor diode, neodymium (Nd): YAG and argon laser iridectomies performed in 14 cadaver eyes using Miyake videographic, histologic and scanning electron analysis. We found that the diode laser created an iridectomy in < 10 applications in blue, hazel and brown irides using 1000-1200 mW over 0.5 seconds. In hazel and blue irides the argon laser created iridectomies at parameters similar to the diode, but required multiple low energy burns in brown irides. Scanning electron microscopy showed pigment epithelial loss with the diode and Nd:YAG laser, and heaped up epithelium at the iridectomy site with the argon laser. Nd:YAG laser had the greatest iridectomy size. This study suggests a possible clinical advantage of diode versus argon laser iridectomies in reduced applications in brown irides and in preventing postoperative pigment occlusion. However, diode laser demonstrated no definite advantage over Nd:YAG laser.

Cadaver↗
PubMed1985

Threshold for lens damage during Q-switched Nd:YAG laser iridectomy. A study of rhesus monkey eyes.

Clinical and pathologic examinations were performed after 18 iridectomies had been created in six eyes of three rhesus monkeys using increasing Q-switched neodymium (Nd):YAG laser energy, pulses per burst, and number of bursts. Treatment parameters bracketed the threshold for lens damage during iridectomy. Iridectomy with one or two bursts of one or two Q-switched pulses at 5 to 6.2 mJ per pulse was achieved without lens damage. Slight increase of pulse energy or an increase to three pulses per burst (without pulse energy increase) caused local damage to the underlying lens. Marked increase of any of the treatment parameters caused slightly larger iridectomies and slightly larger, localized damage of the underlying lens. Synechiae developed between the monkey posterior iris surface at the iridectomy and the damaged area in 80% of the lens lesions. In monkeys, the small pulsed laser iridectomies created with pulses of energies up to 6.5 mJ became occluded during the healing process.

Animals↗
PubMed1984

Argon laser iridotomy and surgical iridectomy in treatment of primary angle-closure glaucoma.

In an attempt to compare surgical peripheral iridectomy and laser iridotomy with regards to the long-term control of the intraocular pressure (IOP), analyses were carried out of the clinical records of 195 eyes of 149 primary angle-closure glaucoma patients who had undergone either peripheral iridectomy or laser iridotomy and were followed up for at least one year. One hundred and ten eyes underwent peripheral iridectomy and 85 eyes had laser iridotomy. The postoperative IOP not exceeding 20 mmHg was taken as the criterion for success. The iridectomized eyes showed no significant difference from those treated with laser iridotomy in 13 clinical factors, including age at treatment, sex, type of angle-closure glaucoma, preoperative mean IOP with medication, visual field, extent of peripheral anterior synechiae (PAS) and horizontal cup/disk (C/D) ratio. The rate of successful IOP control was obtained in 76.4% of the eyes in the peripheral iridectomy group and in 75.3% of the eyes in the laser iridotomy group. It appears that laser iridotomy is just as effective as surgical iridectomy in normalizing IOP. Discriminant analysis was done to derive a discriminant function consisting of a set of factors that will prognosticate the response of primary angle-closure glaucoma either to surgical iridectomy or to laser iridotomy. Four factors were demonstrated to be significant prognosticators. They were preoperative mean IOP with medication, visual field change, C/D ratio and PAS-index, in order of statistical significance. The discriminant function yielded the discriminant efficacy of 71.2% in overall cases.

Aged↗
PubMed1996

Combined argon and Nd: YAG laser peripheral iridectomy: A new approach in clinical practice.

PURPOSE: To evaluate the therapeutic effect of combined argon and Nd: YAG laser peripheral iridectomy. METHODS: 151 cases (200 eyes) of primary angle-closure glaucoma and combined glaucoma were treated by combined procedure. Argon laser was the first used to create partial iridectomy in 2/3-3/4 thickness without penetrating pigmented epithelium, and then Nd: YAG laser was required to complete a patent iridectomy. RESULTS: A successful iridectomy was achieved in all patients independent of any type of irides (100%). Iris penetration rate in one session presented in 95.0%. Complications appeared to be less common in our patients: iris bleeding was only seen in 5.0% cases; the postoperative inflammation was mild; corneal burns, localized lenticular opacities and closure of iridectomies were less frequent. The follow-up ranged from 3m to 6.5 years. The success rate in controlling IOP with/without medications were 99.0% except 2 eye failure. No attack occurred in 129 eyes with prophylactic laser therapy during the periods of follow-up. CONCLUSION: Combined procedure had much more advantage over either the argon or Nd: YAG laser iridectomy. It tended to be more preferable for Asian patients with heavily pigmented and thick irides.

Adult↗
PubMed2003

Latanoprost-induced iris darkening: a morphometric study of human peripheral iridectomies.

PURPOSE: This microscopic study was undertaken to compare the melanocytes of peripheral iridectomy specimens from two eyes that had latanoprost-induced iris darkening (LIID) with iridectomies taken from the fellow untreated eyes. METHODS: The two patients in this study were the ones who underwent LIID in the latanoprost treated eye from a series of 17 patients requiring bilateral trabeculectomy. The first trabeculectomy procedure provided a control peripheral iridectomy for each patient, whereas the second eye was treated with once daily 50 microg ml(-1) latanoprost drops for 6 months. The four peripheral iridectomy specimens from the two LIID patients were subjected to quantitative morphometric analysis by light microscopy of iris cellularity, and electron microscopy of iris melanocyte immature melanosomes and mature melanin granules. RESULTS: There was no significant difference in stromal cellularity between the LIIDs and their respective controls nor were there significant differences in the numbers of immature melanosomes or melanin granules in the melanocytes. However, there was a significant increase in the diameter of melanin granules that was more pronounced in the anterior border layer than the deeper stroma. With the anterior border melanocytes, the increase in melanin granule size was associated with significant increases in granule area and the percentage of cell cytoplasm occupied by melanin (granularity). CONCLUSIONS: The only morphological change identified in two peripheral iridectomies that had LIID when compared to untreated fellow eye specimens was a modest increase in the size of stromal melanocyte melanin granules that was more pronounced in the cells of the anterior border region.

Antihypertensive Agents↗
PubMed2003

Slit-lamp visualization of aqueous flow through an inferior iridectomy.

PURPOSE: To demonstrate how an inferior iridectomy prevents a pupillary block in aphakic patients with a silicone oil tamponade. DESIGN: Observational case series. METHODS: Photographs of two patients who had undergone vitrectomy, lensectomy, membrane peeling, silicone oil tamponade, and inferior iridectomy for a complex retinal detachment were evaluated. RESULTS: In the thin layer of erythrocytes covering the endothelium, we observed an arc clear of erythrocytes anterior to the inferior iridectomy. CONCLUSIONS: With silicone oil blocking the pupil, aqueous humor was channeled through the inferior iridectomy with sufficient force to sweep the endothelium anterior to the iridectomy clean of erythrocytes, thus visualizing the mechanism that prevents a pupillary block glaucoma.

Aqueous Humor↗
PubMed2002

[Drug therapy for residual angle-closure glaucoma after laser iridectomy].

OBJECTIVE: To observe and compare the effect of 0.005% latanoprost and 0.5% timolol solutions in the treatment of post-iridectomy residual angle-closure glaucoma. METHODS: Laser peripheral iridectomy was performed and 68 cases (68 eyes) of post-iridectomy residual angle-closure glaucoma were selected and treated with 0.005% latanoprost once at night as the study group and 0.5% timolol twice a day as the control group Intraocular pressure (IOP) was measured before treatment, on day 3, week 1, week 2, week 4, month 2, month 3 and month 6 in the follow-up, and visual acuity, visual field and C/D ratio were monitored. RESULTS: Of 68 patients, 56 (82.4%) complete the 6 month follow-up. The basic IOP for all subjects in two groups before treatment was not statistically different (t = 0.236, P = 0.814). After the treatment for three days, the efficiency in IOP reduction was statistically different between 2 groups with repeated measure ANOVA (F = 287.441, P < 0.001). In each group, the IOP after treatment was statistically different from that at baseline, with t = 14.103, P < 0.001 and t = 10.308, P < 0.001 in the latanoprost and timolol groups respectively. For those patients who finished 6 months' follow-up, the IOP difference between the 2 groups was statistically significant with repeated measure ANOVA (F = 74.259, P < 0.001). The IOP was statistically reduced in both the latanoprost and the timolol groups with F = 148.787, P < 0.001 and F = 54.875, P < 0.001 respectively. At each follow-up time, the IOP in latanoprost group was statistically different from that of the timolol group with t values to be -6.127, -5.930, -6.201, -5.931, -7.412, -6.640 and -6.756 (P < 0.001). The IOP was statistically different from that before treatment in each group with a mean difference to be -7.034 approximately -6.897 in the latanoprost group and -4.704 approximately -5.000 in the timolol group (P < 0.001). The IOP was not statistically different within each group in the follow-up with mean difference of 0.034 approximately 0.138 (P = 0.904 approximately 0.629) in the latanoprost group and a mean difference of 0.037 approximately 0.296 (P = 0.910 approximately 0.366) in the timolol group. The best-corrected visual acuity, visual field and C/D ratio were not significantly changed during follow-up. CONCLUSIONS: 0.005% latanoprost and 0.5% timolol can be used in the drug therapy of post-iridectomy angle-closure glaucoma and the efficiency of 0.005% latanoprost is better than of 0.5% timolol. Drug therapy of post-iridectomy angle-closure glaucoma is a practical strategy.

Adolescent↗
PubMed1984

Complications of extracapsular cataract surgery. The indications and risks of peripheral iridectomy.

With the increased popularity of extracapsular cataract surgery, the need for a peripheral iridectomy has been questioned. Some surgeons feel that the risks involved in performing the iridectomy are greater than when leaving the iris untouched. The indications and risks of iridectomy with cataract surgery are discussed. Four case reports are presented. In three cases, iridectomy was not performed with cataract surgery, and a pupillary block developed. In one of these three, a congenital cataract, secondary angle closure, developed requiring filtering surgery. In the fourth case, an iridectomy prevented serious complications from an unusual degree of postoperative inflammation with complete posterior synechia following uneventful cataract surgery.

Aged↗
PubMed1985

Shock-wave effect on anterior segment structures following experimental neodymium:YAG laser iridectomy.

The short-pulse laser may prove superior to the argon laser in producing noninvasive iridectomies. Little is known of the effects of the laser shock-wave on anterior segment structures adjacent to the iris. To investigate this question, iridectomies were produced in two owl monkeys using a neodymium (Nd):YAG laser and tissues were evaluated by light microscopy and scanning and transmission electron microscopy. For purposes of comparison, one eye received an iridectomy produced by an argon laser. Results indicate that while clean iris colobomas can be produced with a well-focused Nd:YAG laser, its shock-wave affects tissues in both the trabecular meshwork and corneal endothelium if the iridectomy is located within 0.8 mm of the limbus. No damage to the trabecular meshwork or corneal endothelium was evident after the argon laser iridectomy.

Animals↗
PubMed2001

Pigment vacuum iridectomy for phakic refractive lens implantation.

I present a technique designed to ensure an atraumatic patent basal iridectomy for phakic refractive lens implantation. The technique divides the iridectomy procedure into 2 steps. First, the stromal layer is removed by surgical excision. Then, the pigment layer is removed by gentle vacuum aspiration with a 25 gauge cannula. Atraumatic, small, basal peripheral iridectomies that are functional and cosmetically pleasing have been performed in 12 eyes. There were no cases of large amounts of pigment debris deposited in the trabecular meshwork as checked by gonioscopy. Pigment vacuum iridectomy may be a reliable procedure to ensure a proper basal iridectomy in any type of anterior segment eye surgery.

Drainage↗
PubMed1977

Laser iridectomy.

The laser energy required to achieve an iridectomy in the human eye is calculated as a function of laser beam radius and pulse duration. Two widely different models of the stromal pigment distribution are used in order to embrace the range of coloured irides encountered in practice. The attendant hazards to the cornea, lens and retina are also considered, resulting both from self absorption and also by thermal conduction from the heated iris. These calculations are used to interpret experimental iridectomies attempted over the last ten years and to provide a theoretical foundation for the specialized techniques of iridectomy currently employed. Finally, a new single pulse technique, suggested by these calculations, is formulated and results of preliminary dye laser experiments presented. These results are very encouraging because full-thickness iridectomies were formed in both blue- and brown-eyed rabbits with only 40 mJ of incident laser energy. It was found that the threshold laser energy required for iridectomy was sensibly constant over the visible spectrum for the brown-eyed rabbit. However, for the blue-eyed rabbit the energy had a pronounced minimum in the yellow portion of the spectrum.

Animals↗
PubMed1999

Optical sector iridectomy in corneal opacities.

PURPOSE: To evaluate the visual outcome after optical sector iridectomy in cases of corneal opacities. METHODS: Seventeen eyes of 17 patients with preoperative visual acuity of <6/60 in the affected eye underwent sector iridectomy in a prospective clinical study at a tertiary eye care center. Of 17 cases, 11 had corneal opacities after healed keratitis, four after trauma, and one each due to alkali burns or trachoma. The sector iridectomy was undertaken in cases in which one sector of the cornea and lens was fairly clear. Success was defined as attainment of ambulatory visual acuity of 6/60 or better. RESULTS: Mean age of the patients was 32+/-2.3 years. Most eyes had deep vascularized corneal scars (13 eyes). Optical sector iridectomy was performed most frequently in the lower nasal quadrant (11 eyes) followed by the lower temporal quadrant (four eyes). Of 17 eyes, 16 achieved a visual acuity of 6/60 or better. No intra-or postoperative complications were encountered. CONCLUSION: Optical sector iridectomy in cases of corneal opacities is a simple and safe procedure that can improve visual outcome and provide ambulatory vision to patients. It is a valuable alternative to penetrating keratoplasty if penetrating keratoplasty is not possible or not promising for various reasons.

Adolescent↗