How to cite this article:
Ferreira J, Fernandes F, Patricio M, Brás A, Rios C, Stalmans I, Pinto LA. Magnetic Resonance Imaging Study on Blebs Morphology of Ahmed Valves. J Curr Glaucoma Pract 2015; 9 (1):1-5.
Purpose: To determine the morphometric parameters of filtration blebs of a valved aqueous humor drainage device.
Materials and methods: Orbital magnetic resonances imaging (MRI) was taken after implantation of an Ahmed valve (FP7 model). Outcomes of the analysis were intraocular pressure (IOP) and the bleb\'s morphometric analysis (volume, height, major and minor axis). Associations between IOP and the imaging-related study variables were explored by Spearman\'s correlation test.
Results: Eleven patients underwent orbital MRI examination. Recordings were taken after a mean of 2.7 months (1-6 months) after surgery. IOP was significantly lower than its preoperative values (17.6 ± 6.4 mm Hg vs 36.1 ± 6.4 mm Hg, p < 0.01). Mean bleb volume was 856.9 ± 261 mm3 and its height, major and minor axis were 5.77 ± 1.9, 14.8 ± 2.9 and 8.14 ± 3.6 mm, respectively. A positive correlation was detected between IOP and mean height (r = 0.77, p = 0.048) and major axis (r = 0.83, p = 0.03). Interestingly, the overall bleb volume was related to IOP levels immediately prior to surgery (r = 0.75, p < 0.01). Additionally, the posterior part of the plate was found to be displaced from the scleral surface in five cases (45%).
Conclusion: Ahmed valve\'s bleb morphology seems to correlate with both the pre- and postoperative IOP, which might suggest a clinical benefit of administering aqueous suppressants pre- as well as postoperatively. The plate of the device may show a significant dislocation from its initial surgical implantation site.
Carmen C Sánchez-Noguera,
How to cite this article:
Albis-Donado O, Sánchez-Noguera CC, Cárdenas-Gómez L, Castaneda-Diez R, Thomas R, Gil-Carrasco F. Achieving Target Pressures with Combined Surgery: Primary Patchless Ahmed Valve Combined with Phacoemulsification vs Primary Phacotrabeculectomy. J Curr Glaucoma Pract 2015; 9 (1):6-11.
Purpose: To evaluate the ability of phacoemulsification combined with either primary trabeculectomy (PT) or primary Ahmed glaucoma valve implantation (PAVI) to achieve target intraocular pressures (TIOP) in adults with primary open angle glaucoma.
Materials and methods: Chart review of 214 adult patients operated between January 2002 and June 2008 with a minimum follow-up of 6 months. Group 1 comprised 181 eyes of 166 patients undergoing PT while group 2 included 50 eyes of 49 patients in combination with primary AVI. Target lOPs were pre-determined for each patient and success was defined as an IOP at or lower than target with or without medications. An IOP above target, loss of light perception or need for additional procedures to lower IOP were considered a failure.
Results: Mean preoperative IOP was 17.2 mm Hg in group 1 and 17.3 in group 2. Mean postoperative IOPs were 10.2 and 9.2 on day 1, 12.2 and 11.6 at year 1, and 10.7 in both groups at year 5. Survival rates in groups 1 and 2 were 96.7 vs 96% at 6 months, 89 vs 96% at 12 months, 83.5 vs 96% at 24 months and 79.4 vs 89.1% at 36, 48 and 72 months. Transient bleb leaks were more frequent in group 1 (26 eyes, 14.4 vs 0%, p = 0.001) and transient choroidal detachments were more frequent in group 2 (7 eyes, 3.9 vs 6 eyes, 12%, p = 0.038).
Conclusion: Midterm results for achieving target pressures using combined phacoemulsification with either PT or PAVI are comparable. The profile of complications is different for the two procedures.
Purpose: To measure the rate of complications from chronic hypotony following trabeculectomy and clarify the definition of postoperative hypotony.
Materials and methods: In this retrospective case-control study, the rate of complications was compared between 34 eyes with chronic hypotony and 34 eyes without hypotony. Chronic hypotony was defined as those eyes with an intraocular pressure (IOP) of less than 6 mm Hg on two consecutive clinic visits at least 3 months after trabeculectomy. Cases were identified from a database of two glaucoma surgeons between 2010 and 2013. Outcomes measured included visual acuity, presence of choroidal effusion, hypotensive maculopathy and cataract development/progression. Factors associated with the development of hypotony were considered using analysis of variance (ANOVA) multivariate regression.
Results: Maculopathy was seen in 23.5% of hypotony eyes but not in controls (p < 0.01). No significant difference in the rate of choroidal effusion or cataract was documented between groups. Control eyes were more likely to remain complication free (58.8 vs 32.4%, p < 0.03). Spontaneous recovery from hypotony occurred in 32.4% of hypotony eyes.
Conclusion: Sight threatening complications occur more frequently in eyes with chronic hypotony following glaucoma surgery. However, not all eyes with chronic hypotony develop sight threatening complications. A definition of hypotony that combines IOP criteria with the presence of structural and/or functional changes is recommended.
Fabio N Kanadani,
Carlos R Figueiredo,
Rafaela Morais Miranda,
Patricia LT Cunha,
Tereza Cristina M Kanadani,
How to cite this article:
Kanadani FN, Figueiredo CR, Miranda RM, Cunha PL, M Kanadani TC, Dorairaj S. Ocular Perfusion Pressure and Pulsatile Ocular Blood Flow in Normal and Systemic Hypertensive Patients. J Curr Glaucoma Pract 2015; 9 (1):16-19.
Purpose: Glaucomatous neuropathy can be a consequence of insufficient blood supply, increase in intraocular pressure (IOP), or other risk factors that diminish the ocular blood flow. To determine the ocular perfusion pressure (OPP) in normal and systemic hypertensive patients.
Materials and methods: One hundred and twenty-one patients were enrolled in this prospective and comparative study and underwent a complete ophthalmologic examination including slit lamp examination, Goldmann applanation tonometry, stereoscopic fundus examination, and pulsatile ocular blood flow (POBF) measurements. The OPP was calculated as being the medium systemic arterial pressure (MAP) less the IOP. Only right eye values were considered for calculations using Student\'s t-test.
Results: The mean age of the patients was 57.5 years (36-78), and 68.5% were women. There was a statistically significant difference in the OPP of the normal and systemic hypertensive patients (p < 0.05). The difference in the OPP between these groups varied between 8.84 and 17.9 mm Hg.
Conclusion: The results of this study suggest that although the systemic hypertensive patients have a higher OPP in comparison to normal patients, this increase does not mean that they also have a higher OBF (as measured by POBF tonograph). This may be caused by chronic changes in the vascular network and in the blood hemodynamics in patients with systemic hypertension.
Purpose: To investigate diurnal intraocular pressure (IOP) fluctuation in eyes with angle-closure.
Materials and methods: Seventy-seven eyes of 77 newly diagnosed patients with angle closure [33 subjects with primary angle-closure suspects (PACS), 23 subjects with primary angle-closure (PAC), and 21 subjects with primary angle-closure glau-coma (PACG)] were enrolled after laser peripheral iridotomy for this prospective, cross-sectional study.
Goldmann applanation tonometry (GAT) was performed at 08:00, 12:00, 16:00, 20:00, and 04:00 hours. Mean diurnal IOP, peak IOP, trough IOP, and IOP fluctuation (peak-trough) were compared between groups.
Results: The mean age of the enrolled subjects was 56.8 ± 5.4 years, with 30 males and 47 females. Intraocular pressure fluctuation was significantly higher in the PACG (7.4 ± 2.8 mm Hg) and PAC (5.5 ± 2.3 mm Hg) groups compared with PACS subjects (4.4 ± 1.5 mm Hg). The highest IOP was recorded at 04:00 hours in all but two patients. Two PACS, 10 PAC and 8 PACG patients, with normal office hour IOP had IOP peaks > 21 mm Hg at night. Twenty-five percent patients (20/77) had abnormal IOP despite good office hour readings.
Conclusion: Primary angle-closure glaucoma and PAC eyes showed diurnal IOP fluctuations greater than 5 mm Hg in most subjects, with peak IOP recorded at 04:00 hours. Peak IOP was higher than office hour IOP recordings in subjects with angle-closure. A diurnal variation curve is recommended in these subjects, especially in cases with controlled IOP during office hours.
Subconjunctival and subscleral fibrosis are the major causes of failure of filtering surgery. Antiproliferative agents have been successfully used to improve the long-term success of this surgery. Recent advancement in the field of glaucoma surgery has been the use of bioengineered, biodegradable, porous collagen-glycosaminoglycan matrix implant in the subconjunctival and/or subscleral space to modify the wound-healing process and reduce scar formation, hence improving the surgical success without the need for anti-fibrotic agents.
Biodegradable, collagen implants have shown favorable results when used with deep sclerectomy. There have been variable results regarding the success of trabeculectomy when combined with these implants. These implants also decrease the dose of mitomycin C required with trabeculectomy and hence, decrease the side effect associated with these drugs.
The use of the biodegradable implants in glaucoma surgery is still evolving and further studies are needed to find the appropriate surgical technique, the ideal size and site of placement and determine their long-term impact on trabeculectomy outcomes and complications.
Camille Van Mierlo,
Luís Abegão Pinto,
Introduction: Iatrogenic pigment dispersion syndrome generally originates from a repetitive, mechanical trauma to the pigmented posterior epithelium of the iris. This trauma can arise after intraocular surgery, most commonly due to an abnormal contact between the intraocular lens (IOL) and the iris. Whether surgical removal of this primary insult can lead to a successful intraocular pressure (IOP) control remains unclear.
Methods: Case-series. Patients with IOP elevation and clinical signs of pigment dispersion were screened for a diagnosis of iatrogenic IOL-related pigment dispersion.
Results: Three patients in which the IOL or the IOL-bag complex caused a pigment dispersion through a repetitive iris chafing were selected. In two cases, replacement of a sulcus-based single-piece IOL (patient 1) or a sub-luxated in-the-bag IOL (patient 2) by an anterior-chamber (AC) iris-fixed IOL led to a sustained decrease in IOP. In the third case, extensive iris atrophy and poor anatomical AC parameters for IOL implantation precluded further surgical intervention.
Conclusion: IOL-exchange appears to be a useful tool in the management of iatrogenic pigment dispersion glaucoma due to inappropriate IOL implantation. This cause-oriented approach seems to be effective in controlling IOP, but should be offered only if safety criteria are met.