Paolo Bettin

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 Stegmanns 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 Schlemms 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 Schlemms 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.

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.

Viscocanalostomy in patients with glaucoma secondary to uveitis: Preliminary report

Purpose: To assess the efficacy of viscocanalostomy in eyes with uncontrolled glaucoma secondary to uveitis. Setting: Immunology and Uveitis Service, Department of Ophthalmology and Visual Sciences, University Hospital San Raffaele, Milan, Italy. Methods: All consecutive patients with glaucoma secondary to uveitis and inadequate intraocular pressure (IOP) control (IOP >21 mm Hg) under maximum‐tolerated medical therapy had viscocanalostomy. Patients with active uveitis at the time of surgery, peripheral anterior synechias in the upper quadrant, previous ocular surgery, or sight in only 1 eye were excluded. Eleven eyes of 11 patients with a mean age of 52.2 years ± 19.9 (SD) were operated on. The etiology of the uveitis was recorded. The ocular variables were IOP, best corrected visual acuity, number of antiglaucoma medications, and complications. Success was defined as an IOP between 6 mm Hg and 21 mm Hg (inclusive) without medication (complete success), or with 1 or more antiglaucoma medications and/or goniopuncture (qualified success). The mean follow‐up was 45.9 ± 11.6 months (range 23 to 56 months). Results: Viscocanalostomy significantly reduced IOP from a mean baseline value of 35.1 ± 7.0 mm Hg (range 23 to 48 mm Hg) to a mean final value of 18.1 ± 4.9 mm Hg (range 12 to 30 mm Hg) (P<.0001). Complete success was achieved in 6 eyes (54.5%) and qualified success, in 10 eyes (90.9%). The mean number of preoperative and final antiglaucoma medications was 3.4 ± 0.8 (range 2 to 4) and 0.7 ± 1.2 (range 0 to 3), respectively (P = .0004). Complications were minor and included transient hyphema and postoperative IOP spike. Conclusion: This preliminary study suggests that viscocanalostomy is a safe, effective surgical alternative for treating glaucoma in patients with uveitis.

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.

Optical Coherence Tomography Angiography Macular and Peripapillary Vessel Perfusion Density in Healthy Subjects, Glaucoma Suspects, and Glaucoma Patients

Purpose To evaluate macular and peripapillary vessel perfusion density (VD) in glaucoma suspects (GS) and glaucoma patients; to correlate ganglion cell-inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) thicknesses with macular and peripapillary VD; and to evaluate the diagnostic accuracy of the structural and vascular parameters. Methods A consecutive series of GS, glaucoma patients, and healthy subjects was prospectively recruited from July 1, 2016, to January 31, 2017. All subjects underwent standard automated perimetry, spectral-domain optical coherence tomography (OCT), and 6 × 6-mm optical coherence tomography angiography (OCT-A) centered on the fovea and optic nerve. Results Forty controls, 40 GS, and 40 glaucoma patients were enrolled. Peripapillary RNFL, GCIPL, and macular RNFL thicknesses significantly decreased in the glaucoma group compared to controls and GS (P < 0.01). Peripapillary VD in average and in the superior and inferior quadrants decreased in the glaucoma group (P ≤ 0.001); conversely, macular VD was not statistically different across groups (P > 0.05). At the peripapillary area, a correlation between RNFL thickness and VD was found; conversely, no statistically significant correlation was found between GCIPL thicknesses and macular VD (all P > 0.05) in all groups. Peripapillary RNFL and GCIPL showed higher diagnostic capacity compared to peripapillary and macular VDs. Conclusions Structural damage is evident both in the peripapillary and in macular areas. Vascular damage seems to be less prominent, as it was seen only for the glaucoma group and at the radial peripapillary plexus. Diagnostic abilities are excellent for structural variables, less so but still good for peripapillary VD, and poor for macular VD.

Deep Sclerectomy With Mitomycin C and Injectable Cross-linked Hyaluronic Acid Implant: Long-term Results

Purpose:To evaluate the long-term efficacy and safety of deep sclerectomy (DS) augmented with mitomycin C (MMC) and injectable cross-linked hyaluronic acid implant (Healaflow) in medically refractory glaucoma patients. Materials and Methods:Our study included 96 eyes of 83 consecutive patients with open-angle glaucoma undergoing MMC-DS with injectable cross-linked hyaluronic acid implant. Mean follow-up was 28.6±20.0 months. Variables analyzed were: intraocular pressure (IOP), best-corrected visual acuity, mean number of antiglaucomatous drugs, execution of postoperative maneuvres (goniopuncture, bleb needling, and laser lysis of scleral flap sutures). Tonometric success was defined by 2 different thresholds, specifically IOP⩽21 mm Hg (criterion A) and ⩽15 mm Hg (criterion B). The procedure was defined as a qualified success if reached with medication and as a complete success if reached without. Results:For criterion A, qualified and complete success rates were 96% and 94%, respectively, at 12 months, 95% and 92% at 24 months, and 92% and 89% at 36 months. For criterion B, qualified and complete success rates were 75% and 75%, respectively, at 12 months, 62% and 60% at 24 months, and 59% and 58% at 36 months. Goniopuncture was performed in 56 eyes (58%), bleb needling with 5-fluorouracil injection in 4 eyes (5.1%), and laser release of scleral flap sutures in 4 eyes (4%). Six eyes required additional filtering surgery. Conclusion:DS with Healaflow and MMC seems to be an effective and safe technique to lower IOP in patients affected by open-angle glaucoma, with few postoperative complications.

Delayed suprachoroidal hemorrhage following Nd:YAG laser goniopuncture: a case report.

Purpose To report a delayed suprachoroidal hemorrhage following Nd:YAG laser goniopuncture (LGP) in an eye with a previous deep sclerectomy. Methods Case report. Results A 75-year-old woman with advanced primary open-angle glaucoma underwent LGP due to unsatisfactory intraocular pressure (IOP) in her left eye, 1 month after undergoing deep sclerectomy in the same eye. Delayed suprachoroidal hemorrhage occurred the day after LGP execution. Conclusions Nd:YAG laser goniopuncture is often performed to enhance IOP control following deep sclerectomy. Although LGP is usually effective and safe, severe complications, such as delayed suprachoroidal hemorrhage, may occur after its execution.

Anterior Chamber Angle Assessment Techniques

The anterior chamber angle is the actual anatomical angle created by the root of the iris and the peripheral corneal vault. Within it lie the structures involved in the outflow passage of the aqueous, namely the trabecular meshwork and the Schlemm’s canal (figure 1). The depth of the angle in a healthy eye is approximately 30°, with the superior part usually less deep than the inferior half. However the depth is influenced by gender, age and refractive error. Female gender has the greatest influence on iridocorneal angle reduction, followed by age and spherical equivalent (Rufer et al.). The relationship of the iris plane to the cornea has a significant effect on the aqueous humor’s accessibility to its outflow drainage system. In eyes where the iris and corneal endothelium are “closed”against one another, the aqueous will not be drained causing an increase of the intraocular pressure (angle closure glaucoma) (Lens, 2008).

Comparison of methods to quantify macular and peripapillary vessel density in optical coherence tomography angiography

Purpose To compare macular and peripapillary vessel density values calculated on optical coherence tomography angiography (OCT-A) images with different algorithms, elaborate conversion formula, and compare the ability to discriminate healthy from affected eyes. Methods Cross-sectional study of healthy subjects, patients with diabetic retinopathy, and glaucoma patients (44 eyes in each group). Vessel density in the macular superficial capillary plexus (SCP), deep capillary plexus (DCP), and the peripapillary radial capillary plexus (RCP) were calculated with seven previously published algorithms. Systemic differences, diagnostic properties, reliability, and agreement of the methods were investigated. Results Healthy eyes exhibited higher vessel density values in all plexuses compared to diseased eyes regardless of the algorithm used (p<0.01). The estimated vessel densities were significantly different at all the plexuses (p<0.0001) as a function of method used. Inter-method reliability and agreement was mostly poor to moderate. A conversion formula was available for every method, except for the conversion between multilevel and fixed at the DCP. Substantial systemic, non-constant biases were evident between many algorithms. No algorithm outperformed the others for discrimination of patients from healthy subjects in all the retinal plexuses, but the best performing algorithm varied with the selected plexus. Conclusions Absolute vessel density values calculated with different algorithms are not directly interchangeable. Differences between healthy and affected eyes could be appreciated with all methods with different discriminatory abilities as a function of the plexus analyzed. Longitudinal monitoring of vessel density should be performed with the same algorithm. Studies adopting vessel density as an outcome measure should not rely on external normative databases.

22q11.2 microduplication syndrome and juvenile glaucoma

ABSTRACT Background: 22q11.2 microduplication is a relatively recently recognized syndrome. Findings in affected individuals range from apparent normality to a wide variety of systemic and ocular conditions. We describe the association between 22q11.2 microduplication and juvenile glaucoma in two brothers. Materials and Methods: We reviewed ophthalmological, genetic, and hematological medical records of two patients and their unaffected mother. Results: A 2.07 Mb interstitial duplication in 22q11.21 and a smaller 182 kb duplication in 22q11.23 were identified in both subjects. Patient 1 showed an initial intraocular pressure (IOP) of 15 mmHg in right eye (RE) and 32 mmHg in left eye (LE) under maximum medical treatment. Deep sclerectomy surgery in LE was converted to trabeculectomy due to a macroperforation of the trabeculo-descemetic membrane. Postoperatively, the patient developed persistent hypotony with retinal folds, while IOP in RE increased to 28 mmHg. Trabeculectomy in RE was also complicated by persistent hypotony. Autologous blood injection was performed, resulting in an increase in both visual acuity and IOP. Patient 2 presented with an IOP of 29 mmHg in RE and 33 mmHg in LE. We planned an elective trabeculectomy and added orally administered acetazolamide. The patient developed bilinear cytopenia that contraindicated the surgical procedure. After hematologic normalization, the patient underwent trabeculectomy in LE, causing persistent hypotony. We performed deep sclerectomy surgery in RE, without any significant intra- or post-operative complications. Conclusions: 22q11.2 microduplication syndrome can be associated with juvenile glaucoma. Trabeculectomy may be complicated by persistent hypotony. Deep sclerectomy appears to be a better surgical option, although the presence of a thin sclera may result in conversion to trabeculectomy.