Lack of Spontaneous Venous Pulsation: Possible Risk Indicator in Normal Tension Glaucoma?

PURPOSE: Recently, the absence of spontaneous venous pulsation (SVP) has been suggested as a vascular risk factor for primary open-angle glaucoma (POAG). As the mechanism behind this phenomenon is still unknown, the authors have studied this vascular component using colour Doppler imaging (CDI). METHODS: A total of 236 patients were divided into three diagnostic groups: healthy controls (81), POAG (86) and normal tension glaucoma (NTG; 69). All subjects were submitted to CDI studies of the retrobulbar circulation, intraocular pressure measurements and assessment of SVP existence. Mann-Whitney, chi-square contingency tables and Spearman correlations were used to explore differences and correlations between variables in the diagnostic groups. RESULTS: Eighty-two percent of healthy controls had SVP (66/81), while a smaller numbers were registered in both glaucoma groups: POAG - 50% (43/86); NTG - 51% (35/69). In NTG patients, but not in POAG patients, the prevalence of the SVP phenomenon decreases with increased glaucoma damage (p = 0.04; p = 0.55, respectively). Overall glaucoma patients from both groups had lower central retinal vein (CRV) velocities than the healthy controls (p < 0.05). NTG patients with SVP had less severe visual field defects (mean defect -6.92 versus -11.1, p < 0.05), higher [correction added after online publication 21 September 2012; the word 'higher' has been inserted to replace the word 'lower'] peak systolic and mean flow velocities in the central retinal artery (p < 0.01; p < 0.05, respectively) as well as higher [correction added after online publication 21 September 2012; the word higher has been inserted to replace the word lower] maximal velocities and RI of the CRV (p < 0.02; p < 0.05, respectively). CONCLUSIONS: Glaucoma patients have a decrease in CRV velocities. SVP is less prevalent in glaucoma patients than in healthy individuals. This phenomenon apparently reflects different hemodynamic patterns in the central retinal vessels. This variable may be of particular importance in NTG patients, where it may be associated with more advanced functional damage.

Ocular Pulse Amplitude and Doppler Waveform Analysis in Glaucoma Patients

PURPOSE: To determine the correlation between ocular blood flow velocities and ocular pulse amplitude (OPA) in glaucoma patients using colour Doppler imaging (CDI) waveform analysis. METHOD: A prospective, observer-masked, case-control study was performed. OPA and blood flow variables from central retinal artery and vein (CRA, CRV), nasal and temporal short posterior ciliary arteries (NPCA, TPCA) and ophthalmic artery (OA) were obtained through dynamic contour tonometry and CDI, respectively. Univariate and multiple regression analyses were performed to explore the correlations between OPA and retrobulbar CDI waveform and systemic cardiovascular parameters (blood pressure, blood pressure amplitude, mean ocular perfusion pressure and peripheral pulse). RESULTS: One hundred and ninety-two patients were included [healthy controls: 55; primary open-angle glaucoma (POAG): 74; normal-tension glaucoma (NTG): 63]. OPA was statistically different between groups (Healthy: 3.17 ± 1.2 mmHg; NTG: 2.58 ± 1.2 mmHg; POAG: 2.60 ± 1.1 mmHg; p < 0.01), but not between the glaucoma groups (p = 0.60). Multiple regression models to explain OPA variance were made for each cohort (healthy: p < 0.001, r = 0.605; NTG: p = 0.003, r = 0.372; POAG: p < 0.001, r = 0.412). OPA was independently associated with retrobulbar CDI parameters in the healthy subjects and POAG patients (healthy CRV resistance index: β = 3.37, CI: 0.16-6.59; healthy NPCA mean systolic/diastolic velocity ratio: β = 1.34, CI: 0.52-2.15; POAG TPCA mean systolic velocity: β = 0.14, CI 0.05-0.23). OPA in the NTG group was associated with diastolic blood pressure and pulse rate (β = -0.04, CI: -0.06 to -0.01; β = -0.04, CI: -0.06 to -0.001, respectively). CONCLUSIONS: Vascular-related models provide a better explanation to OPA variance in healthy individuals than in glaucoma patients. The variables that influence OPA seem to be different in healthy, POAG and NTG patients.

In vivo testing of a novel adjustable glaucoma drainage device.

PURPOSE: We report on the in vivo testing of a novel noninvasively adjustable glaucoma drainage device (AGDD), which features an adjustable outflow resistance, and assess the safety and efficiency of this implant. METHODS: Under general anesthesia, the AGDD was implanted on seven white New Zealand rabbits for a duration of 4 months under a scleral flap in a way analogous to the Ex-PRESS device and set in an operationally closed position. The IOP was measured on a regular basis on the operated and control eyes using a rebound tonometer. Once a month the AGDD was adjusted noninvasively from its fully closed to its fully open position and the resulting pressure drop was measured. The contralateral eye was not operated and served as control. After euthanization, the eyes were collected for histology evaluation. RESULTS: The mean preoperative IOP was 11.1 ± 2.4 mm Hg. The IOP was significantly lower for the operated eye (6.8 ± 2 mm Hg) compared to the nonoperated eye (13.1 ± 1.6 mm Hg) during the first 8 days after surgery. When opening the AGDD from its fully closed to fully open position, the IOP dropped significantly from 11.2 ± 2.9 to 4.8 ± 0.9 mm Hg (P < 0.05). CONCLUSIONS: Implanting the AGDD is a safe and uncomplicated surgical procedure. The fluidic resistance was noninvasively adjustable during the postoperative period with the AGDD between its fully closed and fully open positions.

Comparison of the efficacy and longevity of nonpenetrating glaucoma surgery with and without a new, nonabsorbable hydrophilic implant.

BACKGROUND AND OBJECTIVE: To compare the efficacy and longevity of nonpenetrating glaucoma surgery with and without the use of a nonabsorbable hydrophilic implant at the Oxford Eye Centre, Johannesburg, South Africa, and the Glaucoma Unit, Jules Gonin Ophthalmic Hospital, Lausanne, Switzerland. PATIENTS AND METHODS: In a nonrandomized, prospective study between March 1997 and December 2001, 48 eyes of 32 patients aged 18 to 86 years with primary open-angle glaucoma underwent nonpenetrating glaucoma surgery; 25 eyes with the implant and 23 eyes without it. Intraocular pressure (IOP) was recorded preoperatively and postoperatively at 1, 7, and 14 days, at 1, 3, and 6 months, and thereafter every 6 months. RESULTS: The mean preoperative IOP was 27.5 +/- 11.8 mm Hg (range, 20 to 64 mm Hg) in the implant group and 24.8 +/- 7.1 mm Hg (range, 16 to 38 mm Hg) in the control group. During the first 18 months of follow-up, both groups showed identical IOP progression and the mean IOP remained less than 14 mm Hg. After 2 years of follow-up, the IOP started to rise in the control group but remained stable in the implant group. After 30 months, the mean IOP was 12.4 +/- 2 mm Hg and the IOP decrease in percentage was 62% +/- 6% in the implant group (n = 13) versus 16.1 +/- 3 mm Hg and 34% +/- 13% in the control group (n = 15) (mean IOP, P = .0022; mean IOP decrease in percentage, P = .01). CONCLUSIONS: During the first 18 months, there was no difference in the outcomes between the two groups. After 2 years of follow-up, the mean IOP was lower and the IOP decrease in percentage was greater in the implant group compared with the control group.

Estudo do comportamento da PIO de 24 horas e frequência de glaucoma em pacientes com síndrome da apnéia obstrutiva do sono

Purpose: To determine the frequency of glaucoma and evaluate the behavior of 24-hour intraocular pressure in patients with the obstructive sleep apnea syndrome (OSAS). Methods: Eleven consecutive patients with OSAS, diagnosed by polysonography, were avaliated in a cross-sectional study. Demographic data were analyzed: age, sex, race/color, weight, height and associated diseases. The patients were submitted to complete ophthalmologic examination, including the visual field, as well as to 24-hour intra-ocular pressure (IOP) evaluation by an applanation tonometer at 9h, 12h, 15h, 18h, 24h and 6h in the lying and sitting positions. The diagnostic criterion for glaucoma was alteration of the visual field (VF) compatible with glaucoma and one or more of the following alterations: cup-disc ratio >= 0.7, hemorrhage, wedge-shaped defect, bayonet-shaped vessels, Hoyt's sign, asymmetry > than 0.2 between cup/disc ratio of the eyes. The angle should be opened without alterations. Results: 9 (82%) of 11 patients showed glaucoma or were suspected to have glaucoma, 9% of which exhibited normal tension glaucoma and 73% were suspected to have glaucoma for presenting alterations in the optic nerve or ocular hypertension. The mean for the IOP values of the 11 patients was observed to be the highest at 6 o'clock, when they were lying down. Variations of IOP >= 5 mmHg occurred in 7 (64%) of the patients, and variations of up to 14 mmHg and IOP peaks of up to 32 mmHg were observed. Conclusion: OSAS may be an important risk factor for the development of glaucoma, particularly that of normal tension glaucoma. Patients with OSAS must be referred to an ophthalmologist and those professionals must be attentive to the association of sleep disorders in patients with open-angle glaucoma.

The value of intraocular pressure asymmetry in diagnosing glaucoma

PURPOSE

Conjunctival inflammation in patients under topical glaucoma treatment with indication to surgery

PURPOSE: To compare the frequency of conjunctival HLA-DR expression (a surrogate marker for inflammation) in eyes treated with topical prostaglandin analogues versus eyes treated with other topical antiglaucomatous drugs. METHODS: Patients diagnosed with primary open-angle glaucoma presenting indication for trabeculectomy were divided in groups according to the use or not of prostaglandin analogues. All subjects were treated with the maximum tolerated dose of antiglaucomatous drugs until the date of the surgery. At the beginning of the surgical procedure, a 5 x 5 mm biopsy of the bulbar conjunctiva was collected, incubated with monoclonal anti-HLA-DR antibody and processed for histological analysis. RESULTS: Of the 31 eyes included (31 patients), 25 were under topical prostaglandin analogues (Group 1) and six under other topical pharmacological agents (Group 2). Fourteen eyes of Group 1 (56%) and three of Group 2 (50 %) were positive for the inflammatory marker HLA-DR (P=1.0). The percentage of stained cells ranged from 15.49 to 48.09% (median: 27.61) in Group 1, and from 18.35 to 28 (median: 20.71) in Group 2, with no differences statistically significant (p=0.33). CONCLUSION: The use of prostaglandin analogues did not increase conjunctival expression of HLA-DR compared to other topical antiglaucomatous agents.

Biocompatibility of an x-shaped zirconium implant in deep sclerectomy in rabbits.

BACKGROUND: The aim of this study was to evaluate the mid-term biocompatibility of a new x-shaped implant made of zirconium in an animal model of glaucoma surgery. METHODS: Preoperatively, ultrasound biomicroscopy (UBM), intraocular pressure (IOP) and outflow facility (OF) data were acquired. Upon surgery, one eye was chosen randomly to receive an implant, while the other received none. Ten rabbits went through a 1-, 2-, 3-, 4- and 6-month follow-up. IOP was measured regularly, UBM performed at 1, 3 and 6 months after surgery. At the end of the follow-up, OF was again measured. Histology sections were analyzed. RESULTS: For both groups IOP control was satisfactory, while OF initially increased at month 1 to resume preoperative values thereafter. Eyes with implants had larger filtration blebs which decreased faster than in eyes without the implant. Drainage vessel density, inflammatory cell number and fibrosis were higher in tissues near the implant. CONCLUSIONS: The zirconium implant initially promoted the positive effects of the surgery (IOP control, OF increase). Nevertheless, after several months, foreign body reactions and fibrosis had occurred on some implants that restrained the early benefit of such a procedure. Modifications of the zirconium implant geometry could enhance the overall success rate.

Descemet membrane detachment after nonpenetrating filtering surgery.

PURPOSE: To make surgeons performing nonpenetrating filtering surgery aware of an unusual complication namely Descemet membrane detachment. METHODS: We retrospectively reviewed nine eyes of nine patients seen in our hospital with Descemet membrane detachment occurring after nonpenetrating filtering surgery from January 1994 to December 2000. RESULTS: Both planar and nonplanar detachments were reported. Neither scrolls nor tears in the Descemet membrane were observed in any patient. After viscocanalostomy (four patients), the detachment was generally noticed shortly after the procedure and the cornea maintained its clarity. After deep sclerectomy with a collagen implant (five patients), it developed weeks to months postoperatively with adjacent corneal edema. Four patients had descemetopexy. None required more than one procedure. However, at the last visit, two detachments persisted although they had diminished in size: one after viscocanalostomy and conservative treatment and one after descemetopexy after deep sclerectomy with a collagen implant. To date otherwise, no signs of significant corneal damage could be observed clinically nor by specular microscopy and pachymetry. CONCLUSIONS: The diagnosis of Descemet membrane detachment can be easily overlooked or misdiagnosed. The clinical presentation, clinical course, and pathogenesis depend on the type of nonpenetrating filtering surgery performed. Ophthalmologists should be aware of this unusual complication, which is likely to be more common after nonpenetrating filtering surgery than after trabeculectomy. A period of observation before attempting descemetopexy is recommended.

Décollement de rétine rhegmatogène et hypertonie: penser au syndrome de Schwartz-Matsuo [Rhegmatogenous retinal detachment and hypertension: Schwartz-Matsuo syndrome]

PURPOSE: To assess the usefulness of electron microscopy of the aqueous cells when confronted with the clinical association of rhegmatogenous retinal detachment after trauma, high intraocular pressure (IOP) and aqueous cells. METHOD: We report a clinical history of a 50-years-old man who had ocular trauma with perforation in 1944, intraocular lens for traumatic cataract in 1988, Yag capsulotomy in 1993 and retinal detachment with oral dialysis, high IOP and aqueous cells in anterior chamber in 1995. During the surgical therapy we performed an anterior chamber puncture to analyse the aqueous cells. An electron microscopic study was performed on 0.2 ml of aqueous humor mixed in the same volume of 2.5% glutaraldehyde and fixed with 1% osmium acid. RESULTS: Electron microscopic ultrastructural study of the aqueous cells showed numerous photoreceptor outer segments, some of them appearing degenerated. CONCLUSION: The combination of rhegmatogenous retinal detachment with tears near the ora serrata, high IOP and aqueous cells in the anterior chamber should lead the physician to do an anterior chamber puncture and analyse the aqueous cells structure. The combination of those three clinical signs associated with the photoreceptor outer segments in the anterior chamber allowed to diagnose the Schwartz-Matsuo syndrome.

Ten years follow-up after deep sclerectomy with collagen implant.

PURPOSE: To evaluate the long-term success rate and complications of nonpenetrating deep sclerectomy with collagen implant in open-angle glaucoma. PATIENTS AND METHODS: Clinical, prospective, monocentric, nonrandomized, unmasked study on 105 patients with medically uncontrolled glaucoma. A standard procedure deep sclerectomy with collagen implant was performed. Complete examinations were performed before surgery and postoperatively at 1 and 7 days; 1, 2, 3, 6, 9, and 12 months and then every 6 months during the 10 following years. RESULTS: The mean follow-up was 101.5+/-43.1 (3 to 144) months [mean+/-SD, (range)]. The preoperative intraocular pressure (IOP) was 26.8+/-7.7 (14 to 52) mm Hg and the best-corrected visual acuity 0.71+/-0.33 (0.02 to 1.5). Ten years after surgery IOP was 12.2+/-4.7 (6 to 20) mm Hg and best-corrected visual acuity 0.63+/-0.34 (0.01 to 1.2) (number of remaining patients=52). The mean number of medications per patient went from 2.3+/-0.7 (1 to 4) down to 1.3+/-1.1 (0 to 3). An IOP <or=21 mm Hg without medication was achieved in 47.7% patients and in 89% with or without treatment. One major complication was reported. Goniopuncture was performed in 61 eyes (59.8%), 5-fluorouracil treatment given to 25 patients postoperatively and included needling (n=5). CONCLUSIONS: On the basis of a 10-year follow-up deep sclerectomy with collagen implant demonstrated its efficacy in controlling IOP with few postoperative complications.

Free conjunctival autologous graft for bleb repair and bleb reduction after trabeculectomy and nonpenetrating filtering surgery.

PURPOSE: To describe methods and outcomes of excisional revision of a filtering bleb (bleb revision) using free conjunctival autologous graft either for bleb repair or for bleb reduction after trabeculectomy and deep sclerectomy with an implant. METHODS: Retrospective medical records were reviewed for a consecutive non-comparative case series comprising patients who underwent excisional revision of a filtering bleb between May 1998-January 2001. Excisional revision using free conjunctival autologous graft (bleb revision) was performed either for bleb repair, to treat early and late leaks and hypotony with maculopathy, or for bleb reduction, to improve ocular pain, discomfort, burning, foreign body sensation, tearing, and fluctuations of visual acuity. The revision consisted of bleb excision and free conjunctival autologous graft. The bleb histopathology was analyzed in patients who underwent bleb repair. RESULTS: Sixteen patients were included in the study, consisting of nine patients who had a trabeculectomy and seven patients who had a deep sclerectomy with an implant. Bleb revision was necessary in 14 patients due to leaking filtering bleb (bleb repair), and in 2 patients due to bleb dysesthesia (bleb reduction). After a follow-up of 15.1 +/- 8.4 months, the mean intraocular pressure (IOP) rose from 7.8 +/- 6.3 mm Hg to 14.3 +/- 6.5 mm Hg, and the visual acuity from 0.4 +/- 0.3 to 0.7 +/- 0.3, with a P value of 0.008 and 0.03, respectively. The complete success rate at 32 months, according to the Kaplan-Meier survival curve, was 38.3%, and the qualified success rate was 83.3%. Four patients (25%) required additional suturing for persistent bleb leak. To control IOP, antiglaucoma medical therapy was needed for six patients (37.5%) and repeated glaucoma surgery was needed for one patient. CONCLUSION: Free conjunctival autologous graft is a safe and successful procedure for bleb repair and bleb reduction. However, patients should be aware of the postoperative possibility of requiring medical or surgical intervention for IOP control after revision.

Four years later: a clinical update on latanoprost.

PURPOSE: Almost five years have elapsed since the introduction of latanoprost on several markets and considering the large number of publications dealing with it, the authors felt that it was worth re-evaluating the drug. METHODS: The criterion used to select trials for inclusion in the review was: all articles mentioning the drug in common electronic data-bases; these were then screened and considered, on the basis of methodological quality. RESULTS: Experimental data suggest that latanoprost acts by remodeling the extracellular matrix in the ciliary muscle, thus increasing the flow of aqueous humor through the ciliary muscle bundles of the uveoscleral pathway. POAG: Latanoprost persistently improves the pulsatile ocular blood flow in primary open angle glaucoma (POAG). Recent trials confirmed the greater IOP-lowering efficacy of latanoprost vs. timolol, dorzolamide, brimonidine and unoprostone. Trials lasting up to 24 months showed that latanoprost is effective in long-term treatment of POAG and ocular hypertension (OH), with no signs of loss of efficacy when compared to timolol or dorzolamide. Latanoprost provides better control of circadian IOP. Non-responders to beta-blockers should preferably be switched to latanoprost monotherapy before a combination therapy is started. The possibility of a fixed combination of latanoprost and timolol has been explored, with promising results. NTG: Latanoprost is effective in normal tension glaucoma (NTG), lowering IOP, improving pulsatile ocular blood flow and increasing ocular perfusion pressure. OTHER GLAUCOMAS: Latanoprost may provide effective IOP control in angle-closure glaucoma after iridectomy, in pigmentary glaucoma, glaucoma after cataract extraction and steroid-induced glaucoma. However, latanoprost was effective in only a minority of pediatric cases of glaucoma and is contraindicated in all forms of uveitic glaucoma. SAFETY: In the articles reviewed, new or duration-related adverse events were reported.

Reconditioning of the trabeculo-descemet's membrane with the 532-nm Nd : YAG (SLT) laser after deep sclerectomy.

The purpose of this study was to evaluate the intraocular pressure (IOP)-lowering effect of modified goniopuncture with the 532-nm Nd : YAG selective laser trabeculoplasty (SLT) laser on eyes after deep sclerectomy with collagen implant (DSCI). This was an interventional cased series. The effects of modified goniopuncture on eyes with insufficient IOP-lowering after DSCI were observed. Goniopuncture was performed using a Q-switched, frequency-doubled 532-nm Nd : YAG laser (SLT-goniopuncture, SLT-G). Outcome measures were amount of IOP-lowering and rapidity of decrease after laser intervention. In all, 10 eyes of 10 patients with a mean age of 71.0±7.7 (SD) years were treated with SLT-G. The mean time of SLT-G after DSCI procedure was 7.1±10.9 months. SLT-G decreased IOP from an average of 16.1±3.4 mm Hg to 14.2±2.8 mm Hg (after 15 min), 13.6±3.9 mm Hg (at 1 day), 12.5±4.1 mm Hg (at 1 month), and 12.6±2.5 (at 6 months) (P<0.0125). There were no complications related to the intervention. Patients in this series achieved an average 22.5% of IOP reduction after SLT-G. The use of the SLT laser appears to be an effective and safe alternative to the traditional Nd : YAG laser for goniopuncture in eyes after DSCI, with potential advantages related to non-perforation of trabeculo-descemet's membrane (TDM).