Giuseppe Trabucchi

Contact transscleral cyclophotocoagulation with diode laser in refractory glaucoma.

Objective To evaluate the clinical effectiveness of contact transscleral cyclophotocoagulation (CTCP) with diode laser. Design and Patients Forty-eight seeing eyes and 20 blind and painful eyes of 68 patients suffering from refractory glaucoma were treated using a diode laser (EOS3000, Laser Science) coupled with a 400-μm optic fiber ending in a 3-mm focusing tip. Sixteen to twenty 3.9-J (2.6 W x 1.5 to 2.5 s) laser spots were placed over 360°, 1.5 mm from the corneolimbal junction. Results In the seeing-eye group, the follow-up was 20.7 ± 8.14 months, pre- and posttreat-ment lOPs were 37.1 ± 11.27 and 19.5 ± 8.73 mmHg respectively (p < 0.0001), and success (IOP > 2 and < 21 mmHg) was 70.8%. No significant visual acuity change was found in the successful eyes, whereas a significant visual acuity reduction was found in the unsuccessful cases (p=0.03). In the blind-eye group, the follow-up was 20.5 ± 8.54 months, pre- and post-treatment lOPs were 50.7 ± 15.05 and 20.6 ± 13.99 mmHg respectively (p < 0.0001), and success (remission of pain) was 100%. As for complications, one seeing eye developed a spontaneously-resolved vitreous hemorrhage and one seeing and one blind eye became hypotonic, though no phthysis was observed. No conjunctival or lens damage was detected, and no scleral thinning was revealed by ultrasound biomicroscopy. No case of sympathetic ophthalmia was found. Conclusions Diode laser can be successfully employed for CTCP in refractory glaucoma.

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.

Fluorescein and Indocyanine Green Angiography in Vascular Chorioretinal Diseases

Fluorescein angiography allows visualization of blood flow in retinal and choroidal tissues, permitting diagnostic support in many ocular diseases. Particularly, fluorescein angiography has become a very important tool in the study and treatment of chorioretinal diseases. Because of the limitations of fluorescein angiography in imaging the choroidal circulation and associated pathologies, investigators have searched for alternative dyes to improve choroidal angiography, the most promising of which has been indocyanine green dye. The usefulness of indocyanine green angiography to aid in the diagnosis and treatment of a variety of chorioretinal diseases was reported during the last years. The goal of this article is to make an overview on the most frequent Fluorescein and ICGA patterns of vascular diseases of the chorioretina.

ICGA-GUIDED LASER PHOTOCOAGULATION OF OCCULT CHOROIDAL NEOVASCULARIZATION IN AGE-RELATED MACULAR DEGENERATION

Purpose: To evaluate the efficacy of indocyanine green angiography (ICGA)‐guided laser photocoagulation in eyes with fluorescein angiographic evidence of occult choroidal neovascularization (O‐CNV) in patients with age‐related macular degeneration (ARMD) with or without pigment epithelium detachment (PED). Methods: Eighty eyes of 79 consecutive patients with O‐CNV underwent laser treatment of a clearly outlined extrafoveal ICGA hyperfluorescent area, presumed to be focal CNV. Four types of presumed CNV were treated: Group 1 (20 eyes), CNV beneath the PED; Group 2 (23 eyes), CNV at the margin of the PED; Group 3 (10 eyes), parapapillary CNV and PED; and Group 4 (27 eyes), macular CNV without PED. Median follow‐up was 17.5 months (range, 6‐24 months). Results: After 1 year, 15% of the eyes in Group 1, 30% in Group 2, 100% in Group 3, and 52% in Group 4 had obliteration of the presumed CNV. After 1 year, visual acuity was stable or improved in 18% of Group 1, in 37.5% of Group 2, in 100% of Group 3, and in 73% of Group 4. The remaining eyes worsened. Conclusions: Indocyanine green angiography‐guided laser treatment may improve or stabilize visual acuity in some eyes with O‐CNV. The best outcome is seen in eyes with presumed parapapillary CNV, probably made up of choroidal telangiectases in many cases. The type and location of the presumed CNV influence prognosis after laser treatment considerably. A randomized, controlled clinical study appears necessary to investigate the efficacy of ICGA‐guided laser treatment in different types of presumed CNV. The inclusion criteria for further trials need to be defined with precision, as data from patients with different choroidal vascular abnormalities have been pooled until now.

Indocyanine green angiography in enlarged blind spot syndrome.

PURPOSE To report the indocyanine green angiography findings in a case of acute idiopathic blind spot enlargement syndrome. METHOD The patient underwent ophthalmologic examination with fluorescein angiography and indocyanine green angiography. RESULTS A monocular enlarged blind spot was found on automated perimetry; fluorescein angiography showed a hypofluorescent peripapillary atrophic area and indocyanine green angiography highlighted diffuse, small hypofluorescent spots scattered throughout the posterior pole. Visual field defects and indocyanine green angiography abnormalities resolved over 4 weeks. CONCLUSION Indocyanine green angiography in acute idiopathic blind spot enlargement syndrome showed many lesions not visible with fluorescein angiography, indicating a choroidal involvement reaching not only the peripapillary area but the entire posterior pole.

Indocyanine green angiography (ICGA) in pathological myopia.

One hundred and fifty patients (300 eyes), mean age 49±15 years, with degenerative myopia underwent fluorescein and indocyanine green angiography (ICGA). Fluorescence of choroidal neovascularization (CNV) on ICGA was less evident than with fluorescein angiography (FA). FA revealed CNV in 98 eyes; ICGA showed CNV with different angiographic patterns in 82 eyes. ICGA permitted CNV diagnosis when retinal hemorrhages were present. ICGA allowed a more precise evaluation of lacquer cracks which appeared more numerous than the ones identified by FA. ICGA visualized the retrobulbar vasculature. This study shows that ICGA has a useful role for diagnosing and managing pathological myopia.

Double‐frequency Nd:YAG laser vs. argon‐green laser in the treatment of proliferative diabetic retinopathy: Randomized study with long‐term follow‐up

A randomized clinical trial using the argon‐green (514 nm) and the double‐frequency Nd:YAG (532 nm) lasers was carried out on 42 eyes with proliferative diabetic retinopathy (PDR), with the aim of assessing the long‐term effects of double‐frequency Nd:YAG panretinal photocoagulation (PRP).

The erodible mask in photorefractive keratectomy for myopia and astigmatism.

This paper reports a new approach for performing photorefractive keratectomy (PRK) that uses an erodible mask to control shape transfer processes. The advantages of this technique, when compared to conventional PRK performed with mechanical diaphragm, are 1) the possibility of transferring almost any shape onto corneal surface; 2) a smoother corneal surface following photoablation; 3) easier eye fixation; and 4) a controlled humidified environment over ablation zone. We report our experimental study on scanning electron microscopy of polymethylmethacrylate (PMMA) plates ablated using conventional technique versus erodible mask technique; the results showed a smoother surface in the PMMA plate ablated using the erodible mask. We also report our preliminary clinical results of four eyes treated for the correction of myopia combined with astigmatism. Myopia ranged from -2.00 to -10.00 D, and astigmatism ranged from -1.50 to -2.50 D. Three months after surgery, all four eyes were within +/- 1.00 D of myopic attempted correction, but astigmatism was completely corrected only in one eye. No complications or scarring have been reported. We believe the erodible mask could be effective in the correction of myopia and myopic astigmatism, but further improvements are necessary to allow easier alignment of the mask over the eye. All commonly available excimer laser devices produce photorefractive keratectomy as a concentric ablation of the corneal stroma, deeper in the center than in the peripheral part; this is produced by means of an iris or diaphragm which, depending on the type of laser, progressively opens or closes, allowing a greater laser beam delivery in the center.(ABSTRACT TRUNCATED AT 250 WORDS)

Comprehensive study of damage to intraocular lenses by single and multiple nanosecond neodymium: YAG laser pulses

ABSTRACT The results of an extensive study of the probability of damage induced in implant quality intraocular lenses (IOLs) by a commercially available nanosecond Nd:YAG photodisruptor are presented. These results were compared with the morphology of damage seen on scanning electron microscopy. The differences in the shape of the damage probability curves derived for the different lens groups demonstrate that a single threshold value does not characterize the threshold for IOL damage. We suggest that a standard method using a clinical photodisruptor be used by all workers to derive these curves for all IOLs in clinical use. The clinical relevance of our findings is emphasized.

Intraocular measurements of pressure transients induced by excimer laser ablation of the cornea.

The evolution of pressure waves induced by argon‐fluoride laser ablation of the cornea in the typical operative conditions of clinical laser keratectomy has been studied experimentally and analyzed.