Histopathological Evaluation of a Hydrophobic Terpolymer (PTFE-PVD-PP) as an Implant Material for Nonpenetrating Very Deep Sclerectomy.

PURPOSE: The purpose of the study was to assess the biocompatibility of porous terpolymer (polytetrafluoroethylene-co-polyvinylidene fluoride-co-polypropylene, PTFE-PVDF-PP) membranes as an implant material to be placed during nonpenetrating very deep sclerectomy (NPVDS). Another study objective was to determine whether the polymer membrane under investigation could be used to manufacture a new-generation implant, which would actively delay the process of fistula closure and facilitate aqueous humor drainage. METHODS: Histological response and tissue tolerance of the implant material were assessed. The study was performed on 38 eyeballs of 19 New Zealand white rabbits (19 implanted, 19 control). Histological assessment was carried out between 2 and 52 weeks after surgery. We routinely assessed inflammatory infiltrate, neovascularization, hemorrhage, and stromal edema as well as connective tissue attachment to the implant and adjacent tissues. RESULTS: At 52 weeks of observation, a statistically significant difference was revealed between the study and control groups in terms of resorptive granulation, tissue, and the inflammatory infiltrate. No features of acute inflammatory response to the implant were observed, and there was an absence of histological features of acute inflammatory infiltrates and subsidence of chronic inflammatory infiltrates and resorptive granulation over time. CONCLUSIONS: Slight fibrotic response and insignificant changes in neighboring eye tissues all indicate good tolerance to bioimplant materials. This allows for some optimism regarding the use of hydrophobic terpolymer in the construction of new intrascleral implants. However, the ultimate decision regarding its usefulness and safety in the treatment of glaucoma requires further investigation.

Nonpenetrating very deep sclerectomy with hyaluronic acid implant vs trabeculectomy--a 2-year follow-up.

OBJECTIVE: To study and compare the efficacy and safety of nonpenetrating very deep sclerectomy (NPVDS) with the use of hyaluronic acid implant (SKGEL) to trabeculectomy (TB) in patients with with medically uncontrolled glaucoma. METHODS: Prospective, controlled study of patients with open-angle glaucoma was designed. Seventy-eight eyes of 68 patients with medically uncontrolled glaucoma were assigned either to the NPVDS or to the TB group of trial. Examinations were applied before and 7 days, 1, 3, 6, 12, 18, and 24 months after surgery. MAIN OUTCOME MEASURE: Best-corrected logMAR visual acuity, intraocular pressure, number of additional procedures, antiglaucoma medications, number of complications. RESULTS: At 24 months, success rate defined as IOP ≤ 21 mmHg with medication and additional procedures in NPVDS group was 92.31 %, and 94.88 % in control group (p = 0.64). There was no statistically significant difference between intraocular pressure in NPVDS (14.56 ± 4.07 mmHg ) and control (TB) (15.38 ± 3.38 mmHg) group (p = 0.34). Number of glaucoma mediations decreased from 2.18 ± 0.56 to 0.54 ± 0.56 in NPVDS and from 2.28 ± 1.41 to 0.61 ± 0.03 in TB group (p = 0.71). Early and late postoperative complications included two cases of hyphema, two of choroidal detachment, two of filtering bleb fibrosis, four of cataract progression in the NPVDS group; and five cases of hyphema, four of choroidal detachment, one of filtering bleb fibrosis, one of blebitis, and 12 of cataract progression in the control group. CONCLUSIONS: NPVDS is an effective surgical option for patients with medically uncontrolled glaucoma. NPVDS is associated with a lower risk of complications, and in particular cataract progression, compared to TB. APPLICATION TO CLINICAL PRACTICE: NPVDS is a modification of NPDS devised for patients with medically uncontrolled open-angle glaucoma.

In vivo biocompatibility assessment of (PTFE-PVDF-PP) terpolymer-based membrane with potential application for glaucoma treatment.

The aim of the work was to evaluate the in vivo biological behaviour of polymeric membrane materials for glaucoma implants. The base material was biostable synthetic terpolymer (PTFE-PVDF-PP) with proved biocompability (PN-EN ISO 10993). The samples manufactured in the form a membrane were subjected to chemical and physical treatment to create an open pore system within the polymer matrix. As a porogenic phase biodegradable natrium alginate in a fibrous form was employed. The non-perforating deep sclerectomy technique was performed in a rabbit model. The clinical observations were made after 14 and 30 days. During the study clinical symptoms of a moderate degree were observed, and histopathological changes were typical for foreign body implantation. At the end stage of the study no significant difference in histopathological assessment was found between control and experimental group. Similarities observed in both groups and relatively mild histopathological changes in the tissue surrounding the implant indicate that the observed symptoms come from a deep scleral trauma caused by surgery, and not by the presence of the implant itself.

Nonpenetrating very deep sclerectomy with reticulated hyaluronic acid implant in glaucoma treatment.

BACKGROUND: The purpose of our study was to assess intraocular pressure control (IOP) and postoperative complications in nonpenetrating very deep sclerectomy (NPVDS) with reticulated hyaluronic acid implant (SKGEL) and Mitomycin C (MMC). MATERIAL/METHODS: Fifty eyes from fifty patients with medically uncontrolled glaucoma were randomized to either the NPVDS or NPDS group. The NPVDS procedure was similar to traditional NPDS (control group); however, excision of sclera and exposure of ciliary body were also performed, and only a narrow scleral flap was retained at a distance of 0.5 mm from Schlemm's canal. Mitomycin-C 0.2 mg/ml was applied on and under the superficial flap of the sclera during both NPVDS and NPDS. Follow-up examinations were carried out at 1 week, and then at 1, 3, 6, and 12 months after surgery. Success was defined as IOP <22 mmHg with or without glaucoma medication and laser procedures. RESULTS: The 12-month success rate in the NPVDS group was 96%, not significantly higher than in the control group (88%, p=0.88). There was no statistically significant difference in IOP between the NPVDS (15.9+/-2.5 mmHg) and NPDS (16.3+/-3.6 mmHg) groups (p=0.57). Complications included four cases of hyphema, three of choroidal detachment (myopic eyes), and one of filtering bleb fibrosis in the NPVDS group, and three cases of hyphema, two of choroidal detachment (myopic eyes), and three of filtering bleb fibrosis in the NPDS group. CONCLUSIONS: NPVDS is an effective surgical modality for patients with glaucoma. The safety of NPVDS is comparable to that of NPDS.

[Non-penetrating deep sclerectomy in the treatment of advanced cases of open angle glaucoma]. / Zastosowanie nieprzenikajacej sklerektomii glebokiej w leczeniu zaawansowanych postaci jaskry pierwotnej otwartego kata przesaczania.

PURPOSE: The purpose of the paper was to examine the efficacy of non-penetrating deep sclerectomy (NPDS) with sodium hyaluronate implants and mitomycin C in the treatment of advanced cases of open angle glaucoma. MATERIAL AND METHODS: Thirty-five eyes of 35 patients with medically uncontrolled advanced open angle glaucoma were retrospectively analyzed. Visual acuity and intraocular pressure measurement were performed before and after surgery at 1 and 7 days and 1, 6 and 12 months. Visual field was analyzed before and 12 months after surgery. RESULTS: The mean preoperative intraocular pressure was 27+/-3.1 mm Hg and 18.1+/-1.5 at 12 month after surgery (p<0.05). Visual acuity decreased more than two rows on Snellen chart in 4 patients. Visual field analysis shows mean defect MD--17+/-5.2 before surgery and 20.1+/-6.2 after 12 month of follow up (p>0.05). Complete success rate defined as an IOP lower than 21 mmHg without medications was 51%. In 3 eyes we performed needling and in 8 goniopuncture. Postoperative complications included hyphaema in 3 eyes, choroidal detachment in 1 eye, bleb fibrosis in 2 eyes. CONCLUSIONS: 1. Deep sclerectomy with SK-GEL implant and antimetabolites provided good reasonable control of intraocular pressure. 2. In uncomplicated cases it let us achieve stabilization of the visual field.

[Cyclodestructive procedures in secondary glaucoma in children]. / Zabiegi cyklodestrukcyjne w jaskrze wtórnej u dzieci.

PURPOSE: Comparison of the effectiveness and safety of cyclocryocoagulation and transscleral contact cyclophotocoagulation with diode laser (TSCPC) in children. PATIENTS AND METHOD: Sixty nine eyes of 60 children at the age from 4 months to 16 years were examined. Majority of patients was aphakic after congenital, traumatic and complicated cataract extraction. Aniridia, Sturge-Weber disease and ROP complications were observed. In 40 eyes cyclocryotherapy (I group), in 29 eyes TSCPC (II group) were performed. Intraocular pressure (IOP) was assessed in the early and late postoperative period. The number of procedures per one eye, IOP, visual acuity, and complications after cyclodestructive procedures were estimated. Follow-up ranged from 3 months to 4 years, mean 23 months. RESULTS: Transscleral cyclocryocoagulations were performed once to 4 times in one eye with intervals from 1 month to 1 year, mean 1.3 procedures per eye. TSCPC was performed once in 29 eyes and twice in 4 cases, it was 1.14 procedures per eye. Before treatment IOP ranged from 21.3 to 50.6 mmHg, mean 29.18 mmHg in the I group and 24.4-54 mmHg mean 34.85 mmHg in the II group and in the early postoperative period were 10-25 mmHg, mean 17.7 and 2-26 mmHg, mean 14.65 mmHg relatively. Decreasing of IOP was observed in 39% of eyes after cryotherapy and 57.9% after TSCPC, p = 0.0003. In the long-term follow-up in IOP below 22 mmHg after cyclocryotherapy in 60% of eyes and after TSCPC in 79% was observed. Visual acuity ranged from no light perception to 0.5, mean 0.04. No changes of vision after cyclocryocoagulation were noted. After TSCPC transient visual function decreased from 0.2 to 0.04 in 1 eye but recovered after 2 weeks. After cyclocryotherapy only conjunctival oedema was observed in majority of cases. In the early postoperative period after TSCPC uveitis occured in 3 eyes (10.35%), transient hypotony in 2 eyes, hyphaema in one eye. CONCLUSION: Diode cyclophtocoagulation decreases IOP more effective than cyclocryocoagulation in children but complications after TSCPC are more severe than after cyclocryotherapy.

[Laser therapy in the treatment of glaucoma]. / Zastosowanie laseroterapii w leczeniu jaskry.

PURPOSE: The paper is presenting the possibility of laser surgery in the treatment of glaucoma, new operations, and laser equipment. In the treatment of primary open angle glaucoma, argon laser was replaced by diode laser with continuous wave and in recent years by Nd:YAG Q switch, second harmonic 532 nm. This laser allows ophthalmologists for selective photoablation of cells with pigment in trabeculum without thermal effect. The introduction of fibers to transport energy let us increase accuracy and efficacy of laser therapy. Application of excimer lasers 308 nm enables to perform trabeculectomy by internal (ELT) and deep sclerectomy. After NPDS we sometimes have to use Q switch Nd:YAG for goniopuncture, to prolong filtration function of trabeculum--Descemet membrane. In primary angle closure glaucoma the most often laser treatment is iridotomy and gonioplasty. Laser cyclodestructive procedures almost completely eliminated cyclodiathermy and cyclokriotherapy, which were performed so far. The main cyclophotocoagulative procedures are contact transscleral cyclophotocogulation, transpupillary cyclophotocoagulation and intraocular cyclophotocoagulation. CONCLUSIONS: 1. The introduction of lasers enables safer, quicker and more effective antiglaucoma operations. 2. New laser equipment increases efficacy of so far performed laser surgery. 3. Laser surgery allows for the resignation of patients hospitalization and thereby enables to decrease the cost of treatment, and to increase the comfort of patients.