Treatment of malignant glaucoma with contact transscleral cyclophotocoagulation.
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Adult↗
Biomedical subjects
R G Carassa
Publications and source records attributed to R G Carassa.
Treatment of hyperfiltering blebs with Nd:YAG laser-induced subconjunctival bleeding.
PURPOSE: To assess the feasibility of a new technique to manage hyperfiltering blebs after penetrating glaucoma surgery. METHODS: Neodymium:yttrium-aluminum-garnet (Nd:YAG) laser bursts were used to induce bleeding in conjunctival and episcleral vessels in the bleb area to achieve local delivery of autologous blood. RESULTS: In the three cases reported here in which this technique was used, the treatment was successful and safe, leading to resolution of hypotony and reduction of the bleb with no complications. CONCLUSION: Subconjunctival bleeding can be achieved using Nd:YAG laser, and can represent a valuable alternative to autologous blood injection in cases of hyperfiltration after glaucoma surgery.
Adult↗
Nd:YAG laser iridotomy in pigment dispersion syndrome: an ultrasound biomicroscopic study.
AIMS: Ultrasound biomicroscopy was used to study the shape of the iris and the iridolenticular contact in pigment dispersion syndrome (PDS) eyes, to compare them with matched normal eyes, and to assess the morphological effects of laser iridotomy in PDS eyes. METHODS: 50 eyes of 50 patients suffering from PDS (group 1), and 15 normal eyes of 15 subjects matched for age and refraction (group 2), were studied by ultrasound biomicroscopy (UBM, Humphrey-Zeiss). Nd:YAG laser iridotomy was proposed to the 30 PDS patients with concave iris and 18 underwent the treatment. RESULTS: The iris was concave in 27 eyes in group 1, and three more eyes showed a concave iris during accommodation. Among normals, iris concavity was present in two eyes. The height of the iris convexity was -0.15 (0.24) mm (range -0.65 to +0.21), in the eyes of group 1, whereas it was +0.07 (0.10) mm (range -0.21 to +0.16) in group 2 (p < 0.0012). Group 1 had greater iridolenticular contact than group 2: 1.55 (0.78) mm (range 0.30-2.88) and 1.07 (0.61) (range 0.30-2.50; p = 0.0304). After laser iridotomy, only one eye still had a concave iris. Pre- and post-treatment deflections were -0.35 (0.18) mm (range -0.61 to -0.05) and +0.01 (0.06) mm (range -0.12 to +0.17), respectively (p < 0.0001). Pre- and post-treatment iridolenticular contact was 2.10 (0.65) mm (range 0.70-2.88) and 0.93 (0.38) mm (range 0.4-1.75), respectively (p < 0.0001). After laser iridotomy, the treated irises were flatter than normal (p = 0.0207), whereas the iridolenticular contact was not significantly different. CONCLUSIONS: Laser iridotomy can restore a normal iris shape and iridolenticular contact in eyes suffering from PDS.
Adult↗
Value of ultrasound biomicroscopy for ciliodestructive procedures.
Ciliodestructive procedures are commonly performed by the transscleral approach because ciliary processes are seldom visible. Thus the ablative energy is directed toward an "invisible" target whose position can only be estimated on the basis of experimental data. Ultrasound biomicroscopy has been recently introduced in ophthalmologic practice. This high-frequency ultrasound B-scan method gives real-time images of the subsurface structures of the anterior portion of the living eye at microscopic resolution. Ultrasound biomicroscopy perfectly visualizes the ciliary body and its surrounding structures and is a promising complementary tool for ciliodestructive procedures. The system has been used to image early and late ciliary body alterations after transscleral cyclophotocoagulation, to establish the position of the ciliary body to ensure correct laser probe placement, to locate ciliary body residuals for retreatment, and to rule out scleral damage after the procedure. An apparatus has been designed for simultaneous contact cyclophotocoagulation and ultrasound biomicroscopy analysis. A prospective randomized clinical trial is now needed to clarify the influence of ultrasound biomicroscopy on the success rate of ciliodestructive procedures.
Animals↗
Increased preferential optic disc asymmetry in ocular hypertensive patients compared with control subjects.
The authors determined asymmetrical differences in optic disc cupping and pallor between the right and left eyes of 57 control subjects and 75 patients with ocular hypertension. Photogrammetry was used to measure the optic disc cup, and computerized image analysis was used to measure the optic disc pallor for the total disc and its quadrants. Generally, for control and ocular hypertensive eyes, the median values of cupping and pallor were significantly larger in the left eye than in the right, except for depth in the inferior quadrant (right eye minus left eye = 9.3%, P = 0.000) and pallor in the nasal quadrant (right eye minus left eye = 21.3%, P = 0.01), which were preferentially larger in the right eye than in the left in ocular hypertensive eyes. Ocular hypertensive eyes also showed a greater difference between the right and left eyes compared with control eyes for inferior depth (P = 0.06) and nasal pallor (P = 0.02). Detection of optic disc differences as a sign of ocular hypertension between the right eye and the left should evaluate the inferior and nasal quadrants of the disc.
Aged↗
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-microns 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 degrees, 1.5 mm from the corneolimbal junction. RESULTS: In the seeing-eye group, the follow-up was 20.7 +/- 8.14 months, pre- and posttreatment IOPs were 37.1 +/- 11.27 and 19.5 +/- 8.73 mmHg respectively (p < 0.0001), and success (IOP > 2 and < or = 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 IOPs 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.
Anterior Eye Segment↗
Viscocanalostomy: a pilot study.
PURPOSE: Viscocanalostomy is a new, non-penetrating procedure for glaucoma surgery. We started a prospective study to assess the effectiveness and safety of the operation. Materials and methods. Up to March 1998 we enrolled 33 patients (33 eyes) suffering from glaucoma, uncontrolled despite maximum medical therapy, who underwent viscocanalostomy according to Stegmann's technique. A complete ophthalmological examination was performed the day before surgery and on days 1 and 7 postoperatively. Further visits were scheduled at months 1, 3, 6 and 12. RESULTS: In four eyes Schlemm's canal was either missed or not deroofed properly, and the procedure was converted into simple trabeculectomy. After a mean follow-up of 3.0 +/- 2.6 months (range 1-10), success defined as IOP > 2 and < 21 mmHg with no medication was obtained in 86.2% of the cases (25/29); 23 out of 29 eyes (79.3%) had IOP > 2 and < 16 mmHg. In the 25 successful eyes, mean IOP was 27.7 +/- 9.5 mmHg (range 13-48) preoperatively and 12.0 +/- 3.0 mmHg (range 7-18) (p < 0.0001) at the end of the follow-up period. Mean VA ranged from 0.35 +/- 0.34 to 0.32 +/- 0.32 (n.s.). Intraoperative complications included: Descemet rupture (7), with iris plugging in two cases; choroidal deroofing (3), irregular incision of Schlemm's canal (2). Postoperative complications included: self-resolving 2-mm hyphema (4); IOP spike (1); inadvertent filtering bleb (2); hypotony with choroidal detachment for one week (1). CONCLUSIONS: In this short-term study, viscocanalostomy proved effective and safe in lowering IOP in glaucomatous eyes.
Aged↗
Diode and Nd:YAG laser contact transscleral cyclophotocoagulation in a human eye: a comparative histopathologic study of the lesions produced using a new fiber optic probe.
We compared the contact cyclodestructive effects (both gross and histologic) achieved with diode and Nd:YAG laser wavelengths (810 and 1064 nm, respectively), using equivalent energy doses, released by means of a new optical delivery system in a human eye that was soon to be enucleated because of a choroidal melanoma. For both lasers, a fiber optic system (400 microns) with a focusing microlens placed at the end of the fiber was used. The center of the beam was placed 1.5 mm from the corneoscleral limbus. At medium (5.2 to 6.6 J) and higher (7.8 J) energy levels, the cyclodestructive thermal damage produced by the diode laser appeared more widespread than that created by the Nd:YAG laser. At lower levels (3.6 to 3.9 J), both laser treatments produced similar lesions. The new delivery system proved to be safe and effective in achieving the desired cyclodestructive effects at both wavelengths.
Choroid Neoplasms↗