Thomas Klink

In vivo confocal microscopy of failing and functioning filtering blebs: Results and clinical correlations.

PurposeTo correlate clinical filtering bleb function with characteristics as detected by in vivo confocal microscopy. MethodsIn a case-matched cross-sectional study, 52 eyes of 48 patients were examined 1 day to 12.8 years after primary trabeculectomy (mean 375 d). The patients were examined clinically and by in vivo confocal microscopy (Rostock Cornea Module/Heidelberg Retina Tomograph II, Heidelberg Engineering, Inc, Heidelberg, Germany). Nine early and 17 late functioning blebs were pair-matched with malfunctioning blebs. Stromal fiber patterns, the number of intraepithelial and stromal cystic spaces, and the amount of cellular infiltrates were evaluated. ResultsFour stromal patterns (trabecular, reticular, corrugated, compacted) invisible to slit-lamp biomicroscopy could be distinguished by in vivo confocal microscopy. The trabecular pattern occurred only in functioning blebs, particularly early postoperatively. Intraepithelial cystic spaces were associated with functioning late blebs, whereas they were equally distributed in early blebs. In contrast, stromal cystic spaces indicate function in early blebs, whereas in late blebs the number of these cavities was similar in both groups. The density of intraepithelial and stromal round cells was higher in functioning late blebs compared with malfunctioning late blebs. ConclusionsIn vivo confocal microscopy allows to assess filtering bleb structures that are invisible biomicroscopically. Some morphologic features detected by this technique seem to indicate filtering bleb function and time after surgery. The predictive value of these features deserves further clarification in a prospective longitudinal study.

Comparison of phacotrabeculectomy versus phacocanaloplasty in the treatment of patients with concomitant cataract and glaucoma

BackgroundCataract and glaucoma are both common comorbidities among older patients. Combining glaucoma surgery with minimal invasive phacoemulsification (phaco) is a considerable option to treat both conditions at the same time, although the combination with filtration surgery can produce a strong inflammatory response. Combined non-penetrating procedures like canaloplasty have shown to reduce intraocular pressure (IOP) comparable to trabeculectomy without the risk of serious bleb-related complications. The purpose of this retrospective study was to compare the outcomes of phacotrabeculectomy and phacocanaloplasty.MethodsThirty-nine eyes with concomitant cataract and glaucoma who underwent phacotrabeculectomy (n = 20; 51.3%) or phacocanaloplasty (n = 19; 48.7%) were included into this trial on reduction of IOP, use of medication, success rate, incidence of complications and postsurgical interventions. Complete success was defined as IOP reduction by 30% or more and to 21 mmHg or less (definition 1a) or IOP to less than 18 mmHg (definition 2a) without glaucoma medication.ResultsOver a 12-month follow-up, baseline IOP significantly decreased from 30.0 ± 5.3 mmHg with a mean of 2.5 ± 1.2 glaucoma medications to 11.7 ± 3.5 mmHg with a mean of 0.2 ± 0.4 medications in eyes with phacotrabeculectomy (P < .0001). Eyes with phacocanaloplasty had a preoperative IOP of 28.3 ± 4.1 mmHg and were on 2.8 ± 1.1 IOP-lowering drugs. At 12 months, IOP significantly decreased to 12.6 ± 2.1 mmHg and less glaucoma medications were necessary (mean 1.0 ± 1.5 topical medications; P < .05). 15 patients (78.9%) with phacotrabeculectomy and 9 patients (60.0%) in the phacocanaloplasty group showed complete success according to definition 1 and 2 after 1 year (P = .276). Postsurgical complications were seen in 7 patients (36.8%) of the phacocanaloplasty group which included intraoperative macroperforation of the trabeculo-Descemet membrane (5.3%), hyphema (21.1%) and bleb formation (10.5%). Although more complications were observed in the phacotrabeculectomy group, no statistically significant difference was found.ConclusionsPhacocanaloplasty offers a new alternative to phacotrabeculectomy for treatment of concomitant glaucoma and cataract, although phacotrabeculectomy yielded in better results in terms of IOP maintained without glaucoma medications.

Trabeculectomy versus canaloplasty (TVC study) in the treatment of patients with open-angle glaucoma: a prospective randomized clinical trial.

To compare the outcomes of canaloplasty and trabeculectomy in open‐angle glaucoma.

Corneal thickness after overnight wear of an intraocular pressure fluctuation contact lens sensor.

Purpose:  To assess the effect of overnight wear of a contact lens‐based sensor (CLS) for monitoring of 24‐hr intraocular pressure (IOP) fluctuations on central corneal thickness (CCT).

Are there filtering blebs after canaloplasty

PurposeAim of the study was to assess the development of filtering blebs after canaloplasty. MethodsTwenty eyes of 20 consecutive patients receiving canaloplasty were included. All eyes were examined clinically (slit lamp), and by anterior segment optical coherence tomography and high-frequency ultrasound biomicroscopy to detect filtering blebs. Preoperative and postoperative intraocular pressure (IOP) and medications were recorded. No antimetabolites were used at any time. Two success criteria were defined to assess a possible correlation of bleb formation and success: (1) IOP ⩽21 mm Hg and minimum 20% IOP reduction without medication and (2) IOP <18 mm Hg without medication. ResultsNo filtering blebs were detected clinically. One patient had a filtering bleb-like structure as detected by anterior segment optical coherence tomography and ultrasound biomicroscopy. Mean IOP decreased significantly from 22.15±9.5 mm Hg preoperatively to 13.3±9.9 mm Hg at last follow-up (at 245±120.0 d). The number of medications was reduced significantly from 3.15±1.2 preoperatively to 0.55±0.94 postoperatively. Complete success rate was 65% for both success criteria. ConclusionsFiltering blebs occur rarely after canaloplasty. In canaloplasty, IOP reduction seems to be independent of subconjunctival aqueous drainage, thus, avoiding the problems of conjunctival scarring.

Transvenous embolization of carotid cavernous fistulas via the superior ophthalmic vein.

Abstract.Background: Treatment of choice for symptomatic carotid–cavernous and cavernous–dural fistulas is neuroradiologic intervention via the femoral artery. Owing to the location of the fistula and/or to anatomic variations, a direct surgical approach via the superior ophthalmic vein may be necessary for embolization. Methods: Three patients presented with exophthalmos, episcleral venous congestion, chemosis, restricted eye movement, and secondary glaucoma. One patient had visual impairment and scotoma due to compression of the optic nerve by the fistula. The tentative diagnosis of an arteriovenous fistula was confirmed in two cases by color Doppler imaging and in all three cases with cerebral arterial angiography (two carotid–cavernous fistulas, one cavernous–dural fistula). After an unsuccessful transarterial attempt, embolization via the superior ophthalmic vein was chosen. Results: In all three patients the preparation of the superior ophthalmic vein was performed without any complications. In two cases the fistula could be embolized completely with platinum coils. In one patient the placement of the microcatheter was impossible, because of an abnormal vascular pattern. Later on the fistula was successfully embolized by an approach via the femoral vein. All three patients had complete resolution of symptoms. There were no recurrences. Conclusion: Embolization of carotid–cavernous and cavernous–dural fistulas by a surgical approach via the superior ophthalmic vein represents safe and effective treatment when standard transarterial access is impossible. The cooperation of an orbital surgeon and an invasive neuroradiologist can be of benefit for this rare group of patients.

Large-area versus small-area application of mitomycin C during trabeculectomy.

Purpose To compare 2 different application methods of mitomycin C (MMC) in patients undergoing trabeculectomy. Methods This retrospective trial compared outcomes of 191 eyes that underwent trabeculectomy with small-area (96 eyes; 50.3%) and large-area (95 eyes; 49.7%) MMC application. Main outcome measures were changes in intraocular pressure (IOP), required glaucoma medications, the frequency of complications, and postsurgical interventions. Results Within both treatment groups, a highly significant IOP reduction was seen during follow-up (p < 0.0001). Statistical analyses revealed a significant difference in IOP between both groups. Patients treated with a larger size of surface area had a higher IOP reduction within the first postoperative year. Choroidal detachment, shallow anterior chamber, and bleb leak were seen more often in the large-area group with more aggressive MMC use. In contrast, complications associated with bleb failure such as bleb scarring were higher in the small-area group. Success rate was higher in the large-area MMC application group after 12 months. Conclusions Large-area treatment seems to be a more efficient application method of MMC during trabeculectomy.

Postoperative subconjunctival bevacizumab injection as an adjunct to 5-fluorouracil in the management of scarring after trabeculectomy.

Purpose Scarring after glaucoma filtering surgery remains the most frequent cause for bleb failure. The aim of this study was to assess if the postoperative injection of bevacizumab reduces the number of postoperative subconjunctival 5-fluorouracil (5-FU) injections. Further, the effect of bevacizumab as an adjunct to 5-FU on the intraocular pressure (IOP) outcome, bleb morphology, postoperative medications, and complications was evaluated. Methods Glaucoma patients (N = 61) who underwent trabeculectomy with mitomycin C were analyzed retrospectively (follow-up period of 25 ± 19 months). Surgery was performed exclusively by one experienced glaucoma specialist using a standardized technique. Patients in group 1 received subconjunctival applications of 5-FU postoperatively. Patients in group 2 received 5-FU and subconjunctival injection of bevacizumab. Results Group 1 had 6.4 ± 3.3 (0–15) (mean ± standard deviation and range, respectively) 5-FU injections. Group 2 had 4.0 ± 2.8 (0–12) (mean ± standard deviation and range, respectively) 5-FU injections. The added injection of bevacizumab significantly reduced the mean number of 5-FU injections by 2.4 ± 3.08 (P ≤ 0.005). There was no significantly lower IOP in group 2 when compared to group 1. A significant reduction in vascularization and in cork screw vessels could be found in both groups (P < 0.0001, 7 days to last 5-FU), yet there was no difference between the two groups at the last follow-up. Postoperative complications were significantly higher for both groups when more 5-FU injections were applied. (P = 0.008). No significant difference in best corrected visual acuity (P = 0.852) and visual field testing (P = 0.610) between preoperative to last follow-up could be found between the two groups. Conclusion The postoperative injection of bevacizumab reduced the number of subconjunctival 5-FU injections significantly by 2.4 injections. A significant difference in postoperative IOP reduction, bleb morphology, and postoperative medication was not detected.

[Non-penetrating glaucoma surgery].

Patients at high risk of developing complications (e.g. high myopia, aphakia, advanced visual field defects) benefit from non-penetrating glaucoma surgery (NPGS). Neovascular glaucoma, traumatic glaucoma or patients with a narrow angle (a scleral spur must at least be visible) are not suitable for NPGS. The aim of deep sclerectomy (DS) is mainly external subconjunctival drainage. Modified with mitomycin C and intrascleral implants, intraocular pressure (IOP) and success of DS are comparable to trabeculectomy. Viscocanalostomy and the further development to canaloplasty aim for blebless IOP control. Viscocanalostomy has an extremely low complication profile but only a slight reduction in IOP. Canaloplasty creates much more favourable results. Combined with phacoemulsification canaloplasty appears to lower IOP comparable to phacotrabeculectomy and demonstrates a more sustainable success compared to canaloplasty alone.

Erbium-YAG laser-assisted preparation of deep sclerectomy

Abstract Background: Deep sclerectomy and viscocanalostomy are becoming more and more popular as non-penetrating filtering procedures. The purpose of the present study was to simplify the technique of this procedure and to reduce the rate of unintended perforations during the preparation of the deep lamella. Methods: 20 enucleated porcine eyes were used. A superficial lamellar scleral flap with an area of 5×5 mm as for trabeculectomy was surgically prepared. Using a pulsed erbium:YAG laser the deep lamella (220±40 µm) with an area of 4×3 mm was removed. Ablation was performed with an energy of 40–100 mJ, a frequency of 1–10 Hz and a spot size of 500 µm and 1 mm (divergent beam). During the procedure the intraocular pressure was kept constant by continuous infusion. Finally the eyes were analyzed histologically. Results: After initial trials it was possible to ablate the remaining deep corneoscleral lamella with the erbium:YAG laser without perforating into the anterior chamber. Starting with an energy of 70–85 mJ and a reduction to 40–60 mJ when reaching deeper layers, a spot size of 500 µm and a 10 Hz repetition rate gave the highest safety and efficiency in preparation. After a learning curve it was possible to preserve Descemet’s membrane and intact trabecular meshwork in 10 consecutive operations as demonstrated by histology. Conclusion: Erbium:YAG laser- assisted deep sclerectomy offers an alternative to microsurgical preparation of the deep scleral lamella. The thermal damage is minimal (10–40 µm) and scarring may therefore not be stimulated.