Argon Laser Group Research Articles

Amniotic membrane transplantation with intra-stromal Voriconazole versus amniotic membrane transplantation with argon laser photocoagulation for treatment of resistant fungal keratitis

Background Fungal keratitis is a serious problem that may affect vision. Many procedures like argon laser, voriconazole injection, and amniotic membrane transplantation (AMT) may be used to control infection. Aim To compare between intrastromal voriconazole injection with AMT and argon laser photocoagulation with AMT as treatment for fungal keratitis. Patients and methods Mycotic keratitis cases were divided in two groups, with 15 cases each. In one group, intrastromal voriconazole injection and AMT in the same setting was done, and in the other group, argon laser photocoagulation and AMT in the same setting was done. The studied cases included 21 cases with mixed infection and nine cases were pure fungal keratitis according to culture results. In the voriconazole group, intrastromal injection followed by AMT was done, whereas in the argon group, the corneal ulcer was irradiated with argon after fluorescein staining followed by AMT in the same settings. Results Healing was achieved in both groups in 2–6 weeks in all cases. Less than 50% of cases of the voriconazole group healed by the third week, whereas 80% of cases of the argon laser group healed by the third week. Vision was increased in four (26.7%) patients in the voriconazole group, whereas in six (40%) cases in the argon laser group. Conclusions Argon laser with AMT gives better results than intrastromal voriconazole injection with AMT for the treatment of resistant mycotic keratitis.

Long-term Visual and Refractive Outcomes of Argon Laser-treated Retinopathy of Prematurity.

PurposeIn this case–control study, we measured visual acuity, objective refraction, ocular biometric parameters, and strabismus in premature cases classified according to the following categories: argon laser-treated retinopathy of prematurity (ROP), untreated spontaneously regressed ROP, no ROP, and full-term controls.MethodsCases with a history of prematurity at six years of age were categorized into the following groups: patients with a history of treated type 1 ROP using argon laser (group I), untreated spontaneously regressed ROP (group II), and no history of ROP (group III). Group IV included age-matched healthy full-term controls. Funduscopy was performed for all the cases and the control group.Results In total, 24 eyes of 12 laser-treated ROP cases, 186 eyes of 93 spontaneously regressed ROP patients, 74 eyes of 37 premature cases with no history of ROP, and 286 eyes of 143 controls were included in the study. The mean spherical equivalent in the treated cases was not significantly different from that in the untreated cases and patients in group III. However, the average cylindrical power was significantly different among the groups (P 0.004). Furthermore, anisometropia (1.5 diopters) was diagnosed with a higher rate in the treated cases (P = 0.03). The corneal curvature of the laser-treated eyes was significantly steeper and the axial length was significantly shorter than those in the other groups (P 0.002 and P 0.001, respectively, for multivariate analysis). Strabismus was found in three treated patients (25%). Additionally, there were three treated eyes (12.5%) diagnosed with macular dragging.ConclusionPremature cases including those who had a history of argon laser-treated ROP and those with untreated spontaneously regressed ROP showed acceptable long-term visual and refractive outcomes along with a fairly low rate of ocular disorders.

Effect of Different Formulations and Application Methods of Coral Calcium on its Remineralization Ability on Carious Enamel

BACKGROUND: Coral calcium is a new biomimetic product and dietary supplement which consists mainly of alkaline calcium carbonate.
 AIM: The aim of the current study is to compare the remineralization effect of coral calcium in different formulations and application methods.
 METHODS: A total of 35 extracted molars was collected, examined, and sectioned to obtain 70 sound enamel discs, all specimens were examined for calcium mineral content using energy dispersive analysis of X-rays (EDAX) coupled with scanning electron microscope. Hydroxyapatite (HA) nanoparticles were synthesized through wet chemical precipitation approach and characterized by transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) analysis. Teeth specimens were subjected to demineralization, and mineral content was measured, specimens were divided into ten groups according to the remineralizing agent used, where Groups 1–3 used 10, 20, and 30 weight % (wt.%) coral calcium gel, respectively, Groups 4–6 used 10, 20, and 30 wt.% coral calcium and nanohydroxyapatite mix gel, and Groups 7–9 used 10, 20, and 30 wt.% coral calcium with argon laser activation and Group 10 (control group) without a remineralizing agent. All groups were re-examined by EDAX after remineralization.
 RESULTS: The TEM and FT-IR analysis confirmed the formation of rod shape HA in nanoparticles size range. All groups showed a statistically significant decrease in calcium level after demineralization, all groups showed a statistically significant increase in calcium content after remineralization except for the control group. Moreover, Groups 2 and 8 showed the highest increase in calcium level after remineralization.
 CONCLUSION: Coral calcium showed a significant remineralizing effect on carious enamel (demineralization) with an optimum concentration of 20 wt.%.

PASCAL Laser Produces Less Pain Responses Compared to Conventional Laser System During the Panretinal Photocoagulation

Background: Majority of patients experience pain during complete the panretinal photocoagulation (PRP). Laser photocoagulation delivery progressed with the introduction of pattern-scanning laser systems (PASCAL). Shorter pulse duration and choroidal penetration are believed to reduce pain during laser treatment. Objective: The purpose of this study was to assess pain response in patients with proliferative diabetic retinopathy (PDR) who underwent either PASCAL or conventional laser. Subjects and Methods: Eighty eyes with newly diagnosed proliferative diabetic retinopathy were randomly divided in to two groups each composed of 40 eyes: group (A) in which patients were received standard argon laser panretinal photocoagulation and group (B) in which patients were received pattern scan multispot panretinal photocoagulation. Results: Mean pain scores were 0.515 ±0. 834 in the PASCAL laser and 0.128 ±...1 in the conventional laser group. Numerical pain score was statistically significant higher in conventional group than in PASCAL group (p<0.001). Conclusion: It could be concluded that pattern scan multispot laser PRP was associated with more patient comfort compared to conventional PRP.

PASCAL Laser Produces Less Pain Responses Compared to Conventional Laser System During the Panretinal Photocoagulation

Background: Majority of patients experience pain during complete the panretinal photocoagulation (PRP). Laser photocoagulation delivery progressed with the introduction of pattern-scanning laser systems (PASCAL). Shorter pulse duration and choroidal penetration are believed to reduce pain during laser treatment. Objective: The purpose of this study was to assess pain response in patients with proliferative diabetic retinopathy (PDR) who underwent either PASCAL or conventional laser. Subjects and Methods: Eighty eyes with newly diagnosed proliferative diabetic retinopathy were randomly divided in to two groups each composed of 40 eyes: group (A) in which patients were received standard argon laser panretinal photocoagulation and group (B) in which patients were received pattern scan multispot panretinal photocoagulation. Results: Mean pain scores were 0.515 ±0. 834 in the PASCAL laser and 0.128 ±...1 in the conventional laser group. Numerical pain score was statistically significant higher in conventional group than in PASCAL group (p<0.001). Conclusion: It could be concluded that pattern scan multispot laser PRP was associated with more patient comfort compared to conventional PRP.

Effect of Diabetes Duration on Proliferative Disease Regression after Panretinal Photocoagulation Using a Conventional Laser Versus Pattern Scan Multispot Laser

Background: Panretinal photocoagulation (PRP) is considered the gold standard for first line therapy in proliferative diabetic retinopathy (PDR). The aim of PRP is to prevent visual loss following vitreous hemorrhage, tractional retinal detachment, and neovascular glaucoma, by leading to regression of neovascularization. Objective: The purpose of this study was to compare the effect of diabetes duration on proliferative disease regression after pan-retinal photocoagulation using a conventional green laser versus a multispot pattern scan laser. Subjects and Methods: Eighty eyes with newly diagnosed proliferative diabetic retinopathy were randomly divided in to two groups each composed of 40 eyes: group (A) in which patients were received standard argon laser panretinal photocoagulation and group (B) in which patients were received pattern scan multispot panretinal photocoagulation. Changes in central macular thickness and BCVA at 1st, 4th, 12th week and 6th month follow-up were compared to baseline measurements. Fundus fluorescein angiography was performed at 4 weeks, 12 weeks and 6 months to assess regression of PDR. Results: by the end of the study, complete regression occurred in 37 (92.5%) of patients in conventional laser group and 36 (90%) patients in PASCAL group, while persistence of the disease occurred in 3 (7.5%) patients in each group and recurrence occurred 1 (2.5%) in PASCAL group. There was no statistically significant correlation in each study group between clinical outcome and age or duration of DM. Conclusion: There was no statistically significant correlation in each study group between duration of DM and proliferative disease regression.

Comparison of encirclage and cryotherapy with argon laser in the management of traumatic cyclodialysis cleft.

The study compared anatomical and functional outcome of a novel technique of encirclage and cryotherapy with the conventional argon laser in the management of traumatic cyclodialysis cleft in 19 patients (10: encirclage and 9: argon laser). The postoperative anatomical success was taken as rise in intraocular pressure (IOP) more than 6 mm Hg or the closure of cleft on gonioscopy or ultrasound biomicroscopy (UBM). Visual outcome was measured as change in logMAR visual acuity. Traumatic cataract and hypotony were present in majority. IOP>6 mm Hg was noted in 90% of encirclage group and in 77.70% of argon laser group. Two cases had non-closure of cleft. Encirclage is comparable to argon laser in terms of anatomical and functional success with possible advantage of single procedure and use in cases with failed laser.

Retinal Nerve Fiber Layer Thickness Post-Laser Treatment in Diabetic Retinopathy: Argon versus Pattern Scanning Laser

Conventional argon laser causes transient thickening of retinal nerve fibre layer (RNFL). The effect of pattern scanning laser (PASCAL) has not been well described. We compared the immediate changes in peripapillary RNFL thickness post-panretinal photocoagulation between conventional argon lasers and PASCAL in patients with diabetic retinopathy changes. A total of 32 subjects were recruited. There were 16 patients in the argon group and 16 patients in PASCAL group. Diabetic patients were recruited from Ophthalmology Clinic, Universiti Kebangsaan Malaysia Medical Centre (UKMMC). Complete eye examinations and fundus photographs were performed at baseline prior to laser treatment, and post-laser treatment at two and four months. RNFL thickness was measured using time domain optical coherence tomography. Both groups were comparable with respect to clinical characteristics and demographics. There was no significant difference in average RNFL thickness between the two groups prior to treatment (p= 0.323). RNFL post-laser treatment for patients receiving conventional argon laser remained unchanged with no significant differences in all quadrants at any time-point (two and four months). However, for the PASCAL group, significant thickening occurred at four months for average RNFL and the inferior quadrant (p <0.05). The other quadrants similarly demonstrated increasing thickness at four months but this did not reach statistical significance. Transient RNFL thickening occurs in both conventional and PASCAL laser patients. The PASCAL laser induces a greater increase in RNFL thickness than the argon laser group. Important events, such as laser eye treatments and even type of laser used, are worthy of consideration when evaluating RNFL.

Amniotic Membrane Graft with Argon Laser Photocoagulation Versus Amniotic Membrane Graft with Tissue Debridement for Treatment of Mycotic Keratitis

ABSTRACTAim: To compare augmented therapy with argon laser and amniotic membrane graft (AMG) versus AMG and tissue debridement for resistant mycotic corneal ulcers. Methods: This study included 40 cases of resistant fungal corneal ulcers in two groups. In one group, argon laser photocoagulation and AMG were done while AMG with tissue debridement was done as adjunctive therapy for the specific antifungal agents. Results: Complete healing with no adverse effects was achieved in argon laser group in duration ranging from 2-3 weeks in all cases. In the AMG group, duration of healing ranged from 3-5 weeks. Visual acuity was improved with one or more line gain in eight cases (40%) in the laser group, while in six cases (30%) only in the AMG group. Conclusions: Augmented therapy with argon laser and AMG is superior to AMG with tissue debridement for treatment of resistant fungal corneal ulcers.

Argon laser photocoagulation versus intrastromal voriconazole injection in treatment of mycotic keratitis.

To compare argon laser photocoagulation and intrastromal injection of voriconazole as adjunctive treatment modalities in cases of resistant mycotic corneal ulcers. Two groups each of them included 20 cases of resistant mycotic corneal ulcers. Both groups treated with local and systemic specific antimicrobial drugs guided with culture and sensitivity results. In one group argon laser photocoagulation was used as an adjunctive therapy to the specific antifungal drugs and in the other group, intrastromal injection of voriconazole was done besides the specific antifungal drugs. The 40 cases included in the study were proven according to culture and sensitivity to be 28 cases with pure fungal results and 12 cases with mixed (fungal and bacterial). In argon laser group, argon laser irradiation of the corneal ulcer was performed using argon laser 532 nm wavelength (Carl Zeiss LSL 532s AG; Meditec, Inc.) after fluorescein staining. In the other group, voriconazole solution (500 µg/mL) was prepared and injected in the corneal stroma. All cases were followed up for 3mo after healing was achieved. Complete healing of the epithelial defect and resolution of stromal infiltration with no adverse effects were achieved in argon laser group in duration ranged from 2-4wk in 90% of cases. In voriconazole group 4 cases needed amniotic membrane graft due to thinning and 16 cases healed in duration ranged from 2-6wk (80% of cases). Argon laser photocoagulation is superior to intrastromal voriconazole injection in treatment of resistant fungal corneal ulcers.

Does Pattern Scan Laser (PASCAL) photocoagulation really induce less VEGF expression in murine retina than conventional laser treatment?

To investigate the differences in the mRNA and protein expression levels of vascular endothelial growth factor (VEGF) in murine retina between mice subjected to conventional laser (AG) and those subjected to Pattern Scan Laser (PASCAL) system. Male C57BL/6 mice were randomly assigned to one of three groups: Group 1 (G1) receiving retinal scatter laser photocoagulation using with AG photocoagulator (n=16), Group 2 (G2) receiving retinal scatter laser photocoagulation using with PASCAL (n=16) and Group 3 (G3) served as an untreated control group (n=6). Molecular and morphological analyses of VEGF were performed on days 1, 2 and 5 by ELISA, real-time PCR and immuno-histochemical analysis. In samples which underwent AG (G1), when compared with the control group (G3), VEGF mRNA level increased 2.4 folds on day 2, whereas it decreased on day 5 (p□0.001). In samples which underwent PASCAL (G2), on the other hand, VEGF mRNA level increased 1.8 folds on day 1 and 2.2 folds on day 5 when compared with the control group (G3). In samples which underwent AG (G1), when compared with the control group (G3), VEGF protein level increased significantly on day 2, whereas it decreased on day 5 (p□0.001). In group G2, the VEGF levels in the sensory retina significantly increased as compared to control groups at both 2 and 5days after laser photocoagulation using PASCAL laser (p=0.012, both time points). The peak expressions of VEGF protein in samples which underwent PASCAL and conventional laser were found on day 5 and day 2 respectively. In retinas of PASCAL-treated mice, VEGF immunoreactivity gradually increased during the 5-day follow-up. However, in argon laser group, the strongest VEGF immunoreactivity was detected on day 2, then started to decrease on day 5. In summary, the expression of VEGF protein and mRNA gradually increase during a 5-day follow-up period in PASCAL-treated mouse eyes, whereas in AG group they reach their peak levels on the second day of follow-up and started decreasing after then. These results may also explain why the PASCAL system is less effective in regressing neovascularization in the clinic.

A Comparison of Argon Laser and Radiofrequency in Trichiasis Treatment

The aim of this study was to find concrete clinical evidence for determination of the best method of treatment for trichiasis and the location that responds best to treatment with radiofrequency and argon laser. This study was performed in 2007 and 2008 on 100 patients, involving a total of 1,181 lashes in contact with the globe. Patients were randomly assigned to 2 groups of treatment: the radiofrequency group (group 1; 2 watts, 2- to 3-mm depth, cut-coagulating mode) and the argon laser group (group 2; spot size 50 μm, 760 mW, 930-nm wavelengths, continuous). After complete ophthalmic examination and photography, the eyelid was divided into 3 segments (medial, central, and lateral) and treated. The patients were examined 3 months later in terms of response to treatment, pain, and complications. The mean age of the patients was 57.1 ± 24, ranging from 14 to 98 years. Of the 100 patients included, 56% were women and 44% were men. The results revealed the successful treatment of 472 (82.4%) lashes in the radiofrequency group and 383 (62.9%) in the argon laser group. Responses were significant in the central regions of the upper and lower lids (p = 0.001). Similarly, notching was observed in 4 cases, 3 of which (75%) belonged to the radiofrequency group. However, this trend was not statistically significant. The radiofrequency method was found to be superior in comparison to argon laser in the central regions of both upper and lower eyelids.

Argon laser induced changes to the carbonate content of enamel

Argon laser irradiation can be used to cure orthodontic brackets onto teeth in significantly less time than conventional curing lights. In addition, it has been shown that the argon laser seems to impart a demineralization resistance to the enamel. The purpose of this study was to use surface science techniques to ascertain if this demineralization resistance is possibly a result of a decrease in the carbonate content of enamel. Eleven mandibular third molars previously scheduled for extraction were collected and used in the present study. The teeth were sectioned in two and randomly assigned to either the argon laser (457–502 nm; 250 mW cm −2) or the control (no treatment) group. The sections assigned to the argon laser group were cured for 10 s and analyzed. To exaggerate any potential changes the experimental sections were then exposed to a further 110 s of argon laser irradiation. Surface analysis was performed using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results showed no statistically significant change in the carbonate content of enamel after argon laser irradiation ( p > 0.05). Thus, it is suggested that any demineralization resistance imparted to the enamel surface by argon laser irradiation is not due to alterations in carbonate content.

Argon laser vs conventional visible light-cured orthodontic bracket bonding: An in-vivo and in-vitro study

Many advantages of argon lasers have been reported, including high-speed orthodontic adhesive curing and less enamel demineralization. The purpose of this study was to compare bond strengths after curing with the argon laser (10 seconds) and the conventional curing light (40 seconds) in vivo and in vitro. Four premolars from each of 23 volunteers were randomly assigned to either the argon laser group or the conventional light group for the in-vivo study. Shear bond strengths were measured after 14 days with custom-designed debonding pliers. In-vitro bond strengths were measured by using 4 premolars from each of 25 volunteers. Shear bond strength was measured after 14 days of thermocycling with the same protocol as the in-vivo study. Adhesive remnant index scores (ARI) were determined. No significant differences were found in bond strengths according to curing method, dental arch, or sex. In-vivo results were significantly lower (P < .05) than in-vitro results. A significant (P < .05) difference in ARI scores between the curing methods was determined; no significant correlation between mean bond strengths and ARI scores was determined. Bond strength for argon laser curing is comparable to conventional light curing and is sufficient for clinical applications. Although the argon laser left more adhesive on the tooth surfaces on debonding, there was no increase in enamel surface fractures.

Five-year results of a randomized, prospective, clinical trial of diode vs argon laser trabeculoplasty for open-angle glaucoma

PURPOSE: To evaluate the safety and efficacy of laser trabeculoplasty (LTP) with a semiconductor diode laser (810 nm, [DLT]) vs an argon blue-green laser (488 to 514 nm, [ALT]). METHODS: In a prospective, randomized clinical trial, 50 eyes of 46 patients with uncontrolled open-angle glaucoma on maximally tolerated medical therapy were treated and followed at regular intervals for 5 years. Fifty laser spots were applied over 180 degrees using either maximal laser power or sufficient power to produce blanching or a small bubble (570 to 850 mW, DLT; 400 to 1,100 mW, ALT). We performed DLT using a 100-μm spot size, a 0.5-second exposure, and a Ritch lens; we conducted ALT with a 50-μm spot, a 0.1-second exposure, and a Goldmann lens. Patients in the study were followed until trabeculectomy was required. RESULTS: The mean follow-up times ± SD for all eyes were 38.6 ± 5.4 months, DLT (n = 22; range, 1 to 68 months) and 35.5 ± 4.8 months, ALT (n = 28; range, 1 to 66 months). Those in the diode laser group (n = 16) who had more than 1 year of follow-up were tracked for 49.4 months, and those in the argon laser group (n = 21) were tracked for 45.8 months. There were no significant differences in the mean pretreatment intraocular pressures (IOPs): 21.2 mm Hg, DLT (n = 22) and 21.5, ALT 21.5 mm Hg (n = 28); P = .81] or in mean final IOPs (15.7 mm Hg, DLT and 17.1 mm Hg, ALT; P = .19). Time to surgical failure showed no significant differences, with 50% of the DLT eyes and 58% of the ALT eyes surviving at 5 years ( P = .59). CONCLUSION: In eyes with open-angle glaucoma and unsatisfactory IOP control on maximally tolerated medical therapy, DLT and ALT are equally effective in lowering IOP over a 5-year period.

Argon vs Diode Laser Trabeculoplasty

To compare the efficacy of diode laser and argon laser trabeculoplasty in a randomized prospective study of 11 paired fellow eyes. Fellow eyes of 11 patients, having had no prior laser trabeculoplasty and requiring laser trabeculoplasty to lower intraocular pressure, were randomly assigned prospectively to diode laser trabeculoplasty in one eye and argon laser trabeculoplasty in the other eye. In the diode laser group, the average baseline intraocular pressure was 21.6 +/- 2.0 mm Hg before trabeculoplasty and 19.6 +/- 2.1 mm Hg (or a 7.7% +/- 11.5% mean pressure reduction) at 1 month, 19.3 +/- 2.6 mm Hg (or a 6.9% +/- 13.5% mean reduction) at 2 months, and 19.0 +/- 3.3 mm Hg (or a 2.4% +/- 16.9% mean reduction) at 3 months postoperatively. In the argon laser group, the average intraocular pressure was 24.4 +/- 3.5 mm Hg before treatment and 17.6 +/- 1.7 mm Hg (or a 24.7% +/- 11.4% mean pressure reduction) at 1 month, 16.8 +/- 2.5 mm Hg (or a 26.7% +/- 15.3% mean reduction) at 2 months, and 15.5 +/- 1.2 mm Hg (or a 30.0% +/- 16.5% mean reduction) at 3 months after laser trabeculoplasty. The difference between argon and diode laser intraocular pressure reduction was statistically significant at 1 month (P < .01), 2 months (P < .01), and 3 months (P < .05) after treatment. Argon laser trabeculoplasty appears to be more effective than diode laser therapy in lowering intraocular pressure during the first 3 months after treatment.

Diode Laser Compared With Argon Laser for Trabeculoplasty

A randomized prospective study on two groups of ten patients compared the efficacy of diode laser and argon laser trabeculoplasty. In the diode laser group the intraocular pressure was 23.0 +/- 3.97 mm Hg before the treatment, 20.2 +/- 4.49 mm Hg at two hours, 16.3 +/- 3.13 at six months, and 16.9 +/- 2.80 mm Hg at one year. The differences from baseline were statistically significant at six months (P = .0001) and at one year (P = .0001) but not at two hours. In the argon laser group the intraocular pressure was 23.4 +/- 3.6 mm Hg before the treatment, 22.7 +/- 4.35 mm Hg at two hours, and 17.6 +/- 4.53 mm Hg at six months. One patient had uncontrolled mean high intraocular pressure and underwent surgery. In the nine patients who completed the study the intraocular pressure at one year was 16.7 +/- 3.00 mm Hg. The differences from baseline were significant at six months (N = 10; P = .0001) and 12 months (N = 9; P = .0001) but not at two hours. Differences between the two groups were not significant at two hours, six months, and one year. Laser trabeculoplasty may be effectively with a diode laser.

Argon laser versus microscissors for hysteroscopic incision of uterine septa

We performed hysteroscopic metroplasty in 21 women with repeated abortion and subseptate uterus. The patients were randomly allocated to septal incision with the argon laser (group I, 10 subjects) or microscissors (group II, 11 subjects) to compare these instruments in terms of surgical feasibility and anatomic results. The mean operating time was 57% longer in group I than in group II (p = 0.001), the intra- and postoperative morbidity of the whole series was negligible, and the anatomic results at abdominal ultrasonography and hysteroscopy performed 2 months postoperatively were similar in the two groups. This study confirms that microscissors are the simplest, fastest, most effective, and least expensive instrument to correct a septate uterus. The complete agreement of the findings at follow-up hysteroscopy and ultrasonography suggest the use of the latter as the method of choice to check the surgical results.

Comparison of Xenon Arc and Argon Laser Photocoagulation in the Treatment of Choroidal Melanomas

We analyzed the follow-up data in 38 consecutive patients with selected choroidal melanomas that were treated by photocoagulation between 1971 and 1980. Indications for treatment included photographic documentation of tumor growth or an unequivocally positive radioactive phosphorus uptake test, or both. Xenon arc photocoagulation was used in 22 patients (58%) and argon laser was used in 16 patients (42%). At the time of data analysis, the length of follow-up was at least 58 months in all patients. Although all treated tumors were initially eradicated according to ophthalmoscopic and fluorescein angiographic criteria, there was subsequent regrowth in three of the 22 patients (14%) treated with xenon photocoagulation and in ten of the 16 patients (64%) treated with argon laser. The recurrences were observed on an average of 71 months after completion of treatment in the xenon-treated group and on an average of 30 months in the argon-treated group. More treatment sessions were required in the argon laser group to achieve tumor control. Complications of vitreous hemorrhage, cystoid macular edema, and retinal detachment were greater in the xenon photocoagulation group.

Laser Iridectomy: A Controlled Study Comparing Argon and Neodymium:YAG

Laser peripheral iridectomies were performed on both eyes of 38 patients with acute or chronic primary angle-closure glaucoma or with narrow angles capable of closure. The right eye was treated with the neodymium YAG laser (Nd:YAG) and the left eye with the argon laser. Patients were followed for a minimum of eight months. The mean number of applications to produce iris penetration was six with the Nd:YAG laser and 73 with the argon laser. Visual acuity, postoperative intraocular pressure (IOP), corneal changes, and pigment dispersion were similar in the two groups. Microhyphema was more prevalent in the Nd:YAG iridectomy group. Pupillary distortion, iritis, and late failure of patency were more frequent in the argon laser group. Nd:YAG laser iridectomies require fewer applications and produce less inflammation. This controlled study demonstrates that when properly and carefully performed, the Nd:YAG laser is at least as effective and appears to be as safe as the argon laser for performing peripheral iridectomies.