Duration Of Hypotony Research Articles

Risk factors and management of choroidal effusions.

Choroidal effusions are recognized as a common early postoperative complication of glaucoma surgery, and although often benign, they may cause significant ocular morbidity. This article aims to summarize current research on the risk factors and management of choroidal effusions. Glaucoma drainage device (GDD) implantation and trabeculectomy are the most commonly performed surgeries for the management of moderate to severe glaucoma. Common postoperative complications of these procedures include hypotony and the development of choroidal effusions. Choroidal effusions have recently been associated with the oral administration of certain drugs, including select monoclonal antibody, antiseizure and bisphosphonate medications. Risk factors for effusion development include specific patient characteristics such as pseudoexfoliative glaucoma, older age and hypertension. Although choroidal effusions typically resolve with medical therapy alone, surgical intervention may be required. Various methods of surgical intervention, such as surgical drainage or GDD tube ligation, can be utilized to treat choroidal effusions when conservative management with medical treatment fails, but themselves carry alternative risks that must be considered. Minimizing the incidence and duration of hypotony following ophthalmic surgery and careful monitoring of patients starting certain oral medications are important in limiting the occurrence of choroidal effusions. Risk factors for choroidal effusions have been recently identified in the literature. A better understanding of these risk factors, as well as the outcomes of choroidal effusion management, can help to reduce the occurrence of effusions overall and minimize ocular morbidity.

Exploring literature-based definitions of hypotony following glaucoma filtration surgery and the impact on clinical outcomes.

To highlight the variations in published definitions of hypotony and their impact on reported clinical outcomes. To propose a revised definition, focusing on clinically significant hypotony (CH). Literature review of hypotony definitions published between January 2010 and December 2015 was carried out. Numerical definitions for hypotony, its onset, duration and associated clinical signs were recorded. Each definition was applied to surgical outcomes data collected prospectively from a cohort of 300 glaucoma patients treated at a single centre. The sensitivity and specificity of each definition in identifying CH [defined as low intraocular pressure (IOP) with signs of maculopathy hypotony and choroidal detachment] were calculated. A total of 128 eligible papers were identified, and 14 different definitions for hypotony were extracted. In 53 (41.4%), hypotony was not defined. In the remaining 75 (58.6%), the numerical definitions varied between 4 and 8mmHg, and of these, 24 (32%) included the onset and duration of hypotony as part of the definition. Definition-dependent hypotony rates within the cohort varied between 1% and 59.3%. No statistical differences were found between the groups based on corneal thickness or axial length. Clinically significant hypotony (CH) was identified in 37 (12.3%), with large differences in the sensitivity and specificity among published definition. Variations in defining postoperative hypotony can have a large impact on the reported success and failure rates among studies. There is a need for a more robust universal definition, focusing on clinically important signs, to allow better comparison between different treatment modalities.

Ultrasound biomicroscopy in chronic ocular hypotony: its impact on diagnosis and management.

To determine the value of ultrasound biomicroscopy (UBM) in the assessment of ocular hypotony in cases where the underlying pathologic mechanism remains unclear after extensive clinical examination. In a retrospective study, the records of 60 patients who had undergone UBM to elucidate the underlying structural abnormalities of chronic ocular hypotony (intraocular pressure of 0-8 mmHg) were evaluated. Most patients (47 of 60 eyes) had a history of intraocular surgery or of other ocular diseases (e.g., uveitis), and after careful clinical examination, the cause had remained unclear. All patients were observed up for a minimum of 12 months. The associated pathoanatomy of the hypotony was demonstrated by UBM in 95% of the cases. Ciliary body abnormalities were present in 80% of the eyes. Therapeutic intervention was associated with restoration of normal ocular pressure in 50% of the cases. Often more than one intervention was necessary. A long duration of hypotony did not impede reaching the therapeutic goal of normalizing intraocular pressure and preventing phthisis. Ultrasound biomicroscopy is a new tool for detecting the underlying structural abnormalities in ocular hypotony. In cases where clinical examination is not sufficient it can be of great help in deciding on a course of treatment.

Typical Ultrasound Biomicroscopic Findings Seen in Ocular Hypotony

Detailed imaging of the ciliary body region by means of ultrasound biomicroscopy can provide information that is crucial for further treatment whereas clinical evaluation and 10-MHz standard B scan are less helpful. Background: To evaluate the suitability of ultrasound biomicroscopy (UBM) for elucidating the causes of ocular hypotony. Patients and Methods: A retrospective chart review was performed to determine the usefulness of UBM in the evaluation of ocular hypotony. UBM, B scan, and a detailed clinical examination had been performed. Sixty patient charts with prolonged ocular hypotony of different causes were reviewed from January 1994 to December 1998. The information obtained by the UBM was classified into three groups: ‘diagnostic’ (group 1), ‘helpful’ (group 2), ‘not helpful’ (group 3). Results: Of the 60 eyes, 45 UBM examinations (75%) were in group 1, 9 eyes (15%) were assigned to group 2 and 6 eyes (10%) were in group 3. The duration of hypotony had no influence. Conclusion: In cases of ocular hypotony, the cause was related to ciliary body pathologies in 80%. Only UBM could distinguish tractional from dehiscence ciliary body detachment which required a different management approach. UBM with its high resolution imaging of the anterior segment – including the ciliary body – is highly suitable for diagnostic clarification.

Effects of early postfiltration ocular hypotony on visual acuity, long-term intraocular pressure control, and posterior segment morphology.

To determine whether hypotony after filtration surgery has any influence on visual acuity and intraocular pressure (IOP) lowering. We prospectively investigated 43 eyes of 43 patients undergoing trabeculectomy without the use of antimetabolites for 12 months. The lowest postoperative IOP valued 4.9 +/- 3.6 mm Hg (range, 0-14 mm Hg). It correlated statistically significant with the IOP 6 weeks (P = 0.016), 6 months (P = 0.009), and 1 year after surgery (P = 0.027). Eyes with a deterioration of visual acuity 6 weeks after surgery had undergone a stronger postoperative hypotony (correlation with lowest postoperative IOP, P = 0.035). The mean period with an IOP less than 5 mm Hg was 3.5 +/- 8.0 days, and the mean period with an IOP less than 10 mm Hg lasted 45.4 +/- 68.8 days (range, 0-276 days). A hypotony score based on IOP and duration of hypotony was introduced. A correlation was detected between morphologic signs of hypotony, such as tiny retinal folds, at the 6-month follow-up and the duration of hypotony (P = 0.029) and hypotony score (P = 0.001). Hypotony after filtration surgery may decrease visual acuity in the early postoperative period. Conversely, early postoperative hypotony correlated with better long term IOP control. There was no deleterious effect on visual acuity after 6 months.

Direct cyclopexy in the treatment of the persistent hypotony syndrome due to traumatic cyclodialysis (author's transl)

Persisting hypotony in 8 eyes due to traumatic cyclodialysis extending from 75 degree - 240 degree was cured by a modified technique of "direct cyclopexy". Our approach consists of the following elements: 1.4 mm lamella limbal based scleral window in the area of the cyclodialysis. 2. Incision of the basal scleral lamella directly behind and parallel to the scleral spur. 3. Bipolar cautery of the ciliary muscle. 4. Under direct visual control, suture of the insertion of the ciliary muscle to the scleral spur with 10/0 nylon. In all cases intraocular pressure was normalized, no anterior synechiae and no secondary glaucoma ensued. Postoperative tonographic C-values were below the upper normal limit. The degree of functional improvement depends on the duration of hypotony and other contusional changes. Early "direct cyclopexy" is recommended.