The use of intraluminal PRESERFLO stenting in avoiding early postoperative hypotony.

PURPOSE: Postoperative hypotony following PRESERFLO MicroShunt (PMS) implantation is a frequent cause of complications such as choroidal detachment and hypotony maculopathy. This study aims at evaluating the impact of intraluminal stenting of the PMS during the early postoperative period. METHODS: We retrospectively analyzed the data of 97 patients who underwent PMS implantation with intraoperative placement of a Nylon 10-0 suture as intraluminal stent (PStent) and compared the outcomes to those of an existing database of the traditional MicroShunt implantation technique (PTrad, n = 120). The primary outcome measure was the intraocular pressure (IOP) at one week postoperatively. As a secondary outcome measure, adverse hypotony, defined as an IOP ≤ 5 mmHg with significant choroidal effusion and/or anterior chamber shallowing or the presence of macular folds was also assessed. Additionally, the time to stent removal and the IOP one week after stent removal were reported. RESULTS: Preoperative median IOP was 25.0 (20.5-30.3) mmHg in PStent and 25.0 (19.3-32.0) mmHg in PTrad (p = 0.62). One week after surgery, the median IOP dropped to 10.0 (8.0-13.0) mmHg in PStent and 7.0 (5.0-9.0) in PTrad (p < 0.01). At one month, the IOP was 12.0 (10.0-14.0) mmHg in PStent and 10.0 (8.0-11.0) mmHg in PTrad (p < 0.01). After 3 months, both groups showed similar median IOP levels of 11.0 (8.0-13.5) mmHg and 10.0 (9.75-13.0) mmHg in PStent and PTrad, respectively (p = 0.66). The presence of adverse hypotony was significantly lower in PStent compared to PTrad (6.2% vs 15.8%, p < 0.05). In PStent the stent was removed after 30.0 (21.0-42.5) days. One week after stent removal the mean IOP drop was 6.1 ± 0.5 mmHg (p < 0.01). CONCLUSION: In the early follow-up period, intraluminal stenting of the PMS appears to be safe and effective in controlling the IOP while reducing early postoperative hypotony. Surgical success is not compromised by stent placement. Based on our data, it is recommended to remove the suture two to six weeks after surgery for most patients with uncomplicated postoperative clinical findings.

Risk factors for early and late retinal detachment after boston type I keratoprosthesis surgery.

PURPOSE: To determine the differential risk factors for retinal detachment (RD) after Boston Type 1 Keratoprosthesis (B1KPro) during the first year after surgery (early RD; ERD) and afterwards (late RD; LRD). METHODS: Retrospective cohort study of 94 eyes (90 patients) undergoing B1KPro implantation at Centro de Oftalmología Barraquer from June 2006 to July 2022 with a minimum follow-up of one year. RESULTS: The incidence of RD in the whole sample after B1KPro implantation was 29% (27/94), occurring in 21% of eyes (ERD; 20/94) the first year, and in 7% afterwards (LRD; 7/94). Hypotony was revealed as a significant risk factor for ERD (16/19 = 84%; OR = 14.5, P < 0.0001), together with aphakia (16/20 = 80%; OR = 5.9, P = 0.004), intraocular lens (IOL) removal (4/8 = 50%; OR = 6.2, P = 0.03), previous choroidal detachment (CD; 7/20 = 35%; OR = 35.5, P = 0.001) and previous pars plana vitrectomy (PPV; 15/20 = 75%; OR = 6.6, P = 0.006). Multivariate analysis included hypotony and PPV at any time as variables significantly associated with ERD occurrence. The occurrence of LRD was significantly related to peripheral retinal changes, detected few days before (4/6 = 66%; OR = 65, P < 0.0001). CONCLUSION: Hypotony emerged as one of the main factors influencing ERD occurrence after B1KPro implantation. Additionally, previous CD, PPV, aphakia, and IOL removal should be considered to estimate the risk of postoperative retinal detachment. In contrast, peripheral retinal changes after B1KPro seem to be significantly related to LRD occurrence. This study reinforces the need for frequent intraocular pressure evaluation, and comprehensive periodic retinal assessment over time. KEY MESSAGES: What is known Retinal detachment (RD) is a severe complication after Boston Type 1 Keratoprosthesis (B1KPro) implantation, resulting in a permanent reduction of visual acuity in a clinically relevant percentage of eyes. The time of RD occurrence after B1KPro implantation differs in the literature but is reported to be more common within the first year. Previous aphakia, choroidal detachment, or RD repair, intraocular lens removal, vitritis, or history of Nd-YAG laser have been described as risk factors for RD after B1KPro surgery in samples with varying follow-ups. WHAT IS NEW: Multivariate analysis in the first year after B1KPro surgery showed hypotony and pars plana vitrectomy at any time as significant risk factors for early RD. Late RD cases, occurring after one year following the B1KPro surgery, seem to be significantly related to peripheral retinal changes suffered a few days before loss of visual acuity and RD diagnosis. It is plausible to think that risk factors for RD after B1KPro differ in short and long postoperative times.

Concurrent ciliary body detachment in patients presenting with serous choroidal detachment following glaucoma surgery.

PURPOSE: To examine the rate of ciliary body detachment in patients with choroidal detachment following glaucoma surgery and its effect on the clinical course, management, and prognosis. METHODS: A prospective observational case-series study. Patients with choroidal detachment following glaucoma surgery in 2018-2019 were included. All underwent complete ophthalmological examination and ultrasound biomicroscopy for evaluation of the presence and extent of ciliary body detachment. Follow-up examinations including ultrasound biomicroscopy scans were performed at 1 week, 1 month, 3 months, and 6 months. RESULTS: Eight patients (8 eyes) were enrolled, 4 male and 4 female, of mean age 72 years (range 60-83). Five patients underwent trabeculectomy with mitomycin C (0.02%), which was combined with phacoemulsification cataract extraction in one; two underwent Ahmed glaucoma valve implantations, and one underwent ab-interno Xen45 gel stent implantation with mitomycin C (0.02%). The mean intraocular pressure was 26.0 ± 7.65 mmHg preoperatively, dropping to 6.9 ± 2.64 mmHg on first postoperative day one. Mean time from surgery to diagnosis of choroidal detachment was 11.6 ± 5.73 days. Ciliary body detachment was identified by ultrasound biomicroscopy in all patients, ranging between one and four quadrants. All patients were treated with topical steroids and cycloplegics; three (37.5%) received oral steroids. No surgical intervention for the choroidal or ciliary body detachments was indicated. CONCLUSIONS: In this real-world prospective study, concurrent ciliary body detachment was identified in all patients who presented with choroidal detachment following glaucoma surgery. This observation may deepen our understanding of the mechanism underlying the hypotony that is often seen after glaucoma surgery.

Early postoperative visual acuity changes after trabeculectomy and factors affecting visual acuity.

PURPOSE: To investigate the early visual acuity (VA) changes that occur after trabeculectomy and their reversal with recovery. METHOD: Two hundred ninety-two eyes of 292 patients after initial trabeculectomy as a standalone procedure fulfilling the following conditions were included: 1) patients with a postoperative follow-up of at least 3 months; 2) patients with preoperative corrected VA less than 0.5 logMAR equivalent; 3) patients with reliable results of visual field; and 4) patients who had open angle glaucoma. VA and intraocular pressure (IOP) changes during the first 3 months after surgery and factors affecting VA postoperatively at 3 months were investigated. RESULTS: The mean IOPs (mmHg) after trabeculectomy were significantly lower than preoperatively during the entire period (P < 0.0001). The mean corrected VA for all patients was 0.06 ± 0.17, 0.24 ± 0.38, 0.19 ± 0.26, and 0.14 ± 0.27 preoperatively and at 1 week, 1 month, and 3 months postoperatively, respectively, showing a significant decrease from the preoperative period at all time points (P < 0.0001). VA loss of two or more levels was observed in 13 eyes (4.45%) at 3 months postoperatively. Foveal threshold (FT), shallow anterior chamber (SAC), and choroidal detachment (CD) affected the change in VA before and at 3 months after surgery (P < 0.0001, P = 0.0002, P = 0.0004, respectively). The factors that had significant effects on VA change were FT, SAC, and CD in POAG, FT and hypotonic maculopathy in NTG, and FT in XFG (p < 0.05). CONCLUSION: The frequency of serious vision loss was 4.45% for two or more levels of vision loss, and early postoperative VA changes after trabeculectomy may not be reversed even 3 months later. VA loss is influenced by preoperative FT, postoperative SAC and CD, but the impact of postoperative complications vary with disease type.

Risk factors for ocular hypotony after XEN Gel Stent implantation.

PURPOSE: To investigate the incidence of postoperative hypotony, and risk factors for the development of hypotony in eyes who had undergone XEN Gel Stent implantation. METHODS: In this retrospective, single-centre case series, medical records of 170 consecutive eyes who had undergone XEN Gel Stent implantation with or without simultaneous phacoemulsification for primary or secondary open angle glaucoma were analysed. Primary outcome parameters were the incidence of postoperative hypotony and potential risk factors for its development, and secondary parameters were pre- and postoperative visual acuity, intraocular pressure (IOP), and number of IOP-lowering eye drops. RESULTS: Postoperative hypotony ≤ 6 mmHg occurred in 57% of eyes. Hypotony was without complications in 70.1%, 13.4% had transient complications with spontaneous resolution, and 16.5% had complications requiring treatment. Mean visual acuity logMAR before surgery accounted for 0.47 ± 0.46 in all eyes and 0.47 ± 0.48 at the 4-week visit. There was no significant difference of BCVA in the group of eyes with and without postoperative hypotony before and after surgery. The mean IOP before surgery was 24.6 ± 8.4 mmHg and decreased significantly to 18.4 ± 10.2 after 4 weeks. Eyes with an axial length over 24.3 mm had a threefold increased risk for postoperative hypotony (OR 3.226, 95% confidence interval 1.121-9.279). This risk was decreased in eyes with simultaneous cataract surgery (OR 0.483, 95% confidence interval 0.258-0.903). CONCLUSION: In our sample, postoperative hypotony was a common complication after XEN Gel Stent implantation, but serious, persistent complications were rare. A longer axial length predisposes the eye for the development of hypotony.

Choroidal detachment and hypotony following selective laser trabeculoplasty: a case report.

BACKGROUND: Selective laser trabeculoplasty (SLT) is relatively safe and effective in lowering intraocular pressure (IOP). However, although rare, complications can occur after SLT. This report describes a patient with choroidal detachment due to hypotony following SLT without anterior chamber (AC) inflammation. CASE PRESENTATION: A 67-year-old man was referred for elevated IOP in his left eye with advanced glaucomatous visual field loss. He had previously been diagnosed with idiopathic uveitic glaucoma in the left eye, for which he underwent laser iridotomy, trabeculectomy, and cataract surgery. At the first visit, the IOP of his left eye measured by Goldmann tonometry was 28 mmHg despite maximally tolerated medical treatment. SLT was performed in his left eye, resulting in an IOP of 7 mmHg 7 days later. At 3 weeks post-procedure, the patient experienced ocular pain and decreased visual acuity in his left eye. Slit-lamp examination revealed deep anterior chamber depth and no inflammation reaction, but the IOP in his left eye was 4 mmHg, and both fundus and B-scan ultrasonography showed serous choroidal detachment. All anti-glaucoma agents were stopped, and the patient was started on treatment with oral prednisolone and cyclopentolate eye drops. Three weeks later, choroidal detachment had resolved and the IOP in his left eye had stabilized at 8 mmHg. Follow-up 3 months later showed that the IOP in his left eye remained stable. CONCLUSIONS: Choroidal detachment-related hypotony is a rare complication of SLT. This possible complication following SLT should be informed to the patients and considered when performing the procedure.

A novel predictive model for phthisis bulbi following facial hyaluronic acid cosmetic injection.

PURPOSE: To observe long-term prognosis of anterior segment ischemia (ASI) following hyaluronic acid (HA) injection, propose a severity grading system for ASI and a predictive model for phthisis bulbi (PB) based on long-term secretion dysfunction of ciliary process. METHODS: This is a retrospective case-control study. All enrolled 20 patients were divided into two groups and followed for at least 6 months to observe the formation and transformation characteristics of ASI and long-term prognosis based on the degrees of ciliary function damage. RESULTS: The severity of ASI following HA injection could be subdivided into 4 grades according to the degrees of ciliary function damage, comprising ASI grades 0, 1, 2 and 3. In 20 patients, ophthalmoplegia at 1-month follow-up, ASI within 1 month, ASI at 1-month follow-up, hypotony within 6 months were all significantly more common in study group than in control group (60% vs. 0%, P = 0.011; 100% vs. 20%, P = 0.001; 100% vs. 0%, P < 0.001; 80% vs. 0%, P = 0.001, respectively). Sensitivity, specificity and the area under the receiver operating characteristic curve (AUC) for predicting subsequent PB at 2-year follow-up through the co-occurrence of ophthalmoplegia at 1-month follow-up and hypotony within 6 months was 100%, 100% and 1.00, respectively. CONCLUSIONS: The new grading system for ASI and novel predictive model for PB we proposed could predict the long-term prognosis and probability of subsequent PB due to ASI following HA injection through several dynamic assessments within 6 months. LEVEL OF EVIDENCE: Level IV, observational prognostic study.

Long-term limitations and complications of trans-scleral diode laser cycloablation for refractory glaucoma.

BACKGROUND: Trans-scleral diode laser cycloablation (cyclodiode) is effective in the short-term management of refractory glaucoma where alternative treatments are not feasible. Long-term outcomes of 5-years or more are not well-documented, particularly in relation to intraocular pressure (IOP) control, need for further procedures and complications such as hypotony and phthisis. METHODS: A review was undertaken of patient medical records with refractory glaucoma who underwent cyclodiode at City Eye Centre in Brisbane from 2012 to 2016. Data included sex, age, laterality, type of glaucoma, cyclodiode parameters, number of glaucoma medications, visual acuity and treatment with acetazolamide. Data were analysed using generalised linear modelling and Kaplan-Meier analysis. RESULTS: A total of 54 eyes in 54 patients (29 M:25F) with a mean age of 66 years (range 15-85 years) with a minimum of 5 years follow up were included. The mean number of burns was 23.3 (range 12-40) over 180-270 degrees, mean power per burn was 1967 mW (range 1500-2000 mW), with a mean duration of 1981 ms (1500-2000 ms). The mean pre-treatment IOP was 31.5 mmHg (range 17-56 mmHg) and mean IOP 5 years post-treatment was 16.1 mmHg (2-42 mmHg). The mean number of pre-treatment medications was 3.6 (range 1-6) and 2.7 (range 0-5) 5 years post treatment, including 5 (8.3%) on oral acetazolamide. Complications of cyclodiode were seen in 6 (11.1%) patients, including 3 (5.0%) cases of hypotony, and 2 (3.3%) phthisis. CONCLUSION: Cyclodiode is often utilised for end-stage glaucoma when the IOP is uncontrolled on medical treatment and drainage surgery is not indicated, resulting in long-term reduction of IOP and the number of medications, including acetazolamide. Hypotony and phthisis can be significant complications.

Analysis of risk factors and ocular hypotony characteristics in choroidal detachment after penetrating glaucoma surgery.

PURPOSE: To analyze the risk factors and ocular hypotony characteristics of choroidal detachment (CD) after penetrating glaucoma surgery and to compare between eyes with and without CD. METHODS: This retrospective study enrolled 173 eyes of 168 patients. Patients who underwent trabeculectomy or Ahmed glaucoma valve implantation due to medically uncontrolled glaucoma and who had intraocular pressure (IOP) < 9 mmHg at any time during the first postoperative week were included. RESULTS: The study population consisted of 61 (36.3%) females and 107 (63.7%) males with a mean age of 60.7 ± 14.2 years. The postoperative median follow-up time was 24 months (range, 12-40 months). Postoperatively, CD developed in 47 (27.1%) eyes. Multivariate analyses demonstrated that eyes with high preoperative IOP (> 40 mmHg) were 12.1 times more likely to develop CD (p = 0.000) and that presence of IOP < 9 mmHg on the first day of surgery increased the CD risk 3.8 times (p = 0.002); male gender raised the risk 2.7 times (p = 0.028). The mean preoperative IOP in CD eyes was significantly higher than in non-CD eyes (p = 0.000). The mean IOP change between preoperative and lowest IOP was significantly greater in those with CD than in those without CD (p = 0.000). The mean lowest IOP in the CD eyes was significantly lower than in the non-CD eyes (p = 0.037). For the surgical failure rate, no significant difference was found between the CD and the non-CD groups (p = 0.14). CONCLUSIONS: The present study demonstrated that high preoperative IOP, presence of IOP < 9 mmHg on the first postoperative day, and male gender were significantly associated with CD after penetrating glaucoma surgery. Choroidal detachment accompanied by hypotony did not affect the final outcome negatively.

Chorioretinal Folds in the Trabeculectomized Eye with Normal Intraocular Pressure after Phacoemulsification.

Background and Objectives: This case report discusses possible causes of chorioretinal fold (CRF) formation. Materials and Methods: A case report. Results: A 48-year-old man presented with a history of high myopia and primary open-angle glaucoma in both eyes. He underwent a trabeculectomy followed by phacoemulsification in both eyes. Two months later, he complained of blurred vision in the right eye. The intraocular pressure (IOP) was 17 mmHg in the left eye and 9 mmHg in the right eye. Refraction showed a hyperopic shift in both eyes. Slit-lamp examination showed a deep anterior chamber without cells and a well-functional bleb without leakage. Fundus examination revealed CRFs in the macula of the right eye. No papilledema, choroidal lesions, or other retinal lesions were found. Wrinkling of CRFs at the macula, an increase in central foveal thickness, and a fluid cleft were demonstrated by spectral-domain optical coherence tomography. After using steroid eye drops, the IOP in the right eye and refraction in both eyes recovered to the baseline level. Visual acuity improved in both eyes. Conclusions: CRFs in trabeculectomized eyes with normal IOP after phacoemulsification have not been reported. This case demonstrated that the trabeculectomized eye remains at risk of CRF formation, even if the IOP is normal without hypotony. The importance of a detailed fundus examination in patients with unexplained blurred vision may be necessary after having undergone these procedures. The early recognition of the cause of visual loss may facilitate immediate treatment and may avoid irreversible changes with permanent visual loss.

Pressure restoration and visual recovery time in hypotony after trabeculectomy.

OBJECTIVES: To asses the course of intraocular pressure (IOP) restoration and visual acuity (VA) recovery in eyes with hypotony after trabeculectomy. METHODS: Medical charts of patients undergoing trabeculectomy between January 2017 and June 2019 were reviewed. Cases with hypotony (IOP < 5 mmHg) due to over-filtration in the early postoperative period were assessed retrospectively. Primary outcome measures included change in IOP and VA in the postoperative period and percentage of eyes with hypotony on each follow-up. RESULTS: Thirty-five eyes of 31 patients (23 male, 8 female) were included. The mean follow-up was 18.3 ± 6.9 months. The mean IOP was 3.0 ± 3.2, 9.2 ± 6.2, 9.4 ± 5.6, 9.4 ± 4.0, 10.9 ± 3.6 and 10.2 ± 3.3 mmHg at week 1, months 1, 3, 6, 12 and last follow-up, respectively. Out of 35 hypotonic eyes, 8 (22.8%) had prolonged hypotony at month 1, 4 (11.4%) at month 3, 1 (2.9%) at month 6. The decrease in VA continued to be significant at months 1 and 3 (p = 0.015, p = 0.036, respectively) and returned to baseline after the sixth month (p > 0.524). CONCLUSIONS: In eyes with early hypotony after trabeculectomy while low IOP recovers at first month, it takes longer for the visual restoration. The postoperative month 1 appears to be decisive for recovery of hypotony.

Ultrasound cyclo plasty for the management of refractory glaucoma in chinese patients: a before-after study.

BACKGROUND: Cyclocryotherapy and transscleral cyclophotocoagulation are commonly used procedures for the treatment of refractory glaucoma, but still with many complications. Ultrasound cyclo plasty (UCP) is a novel technique that determines a selective and more precise coagulation necrosis of the ciliary body to reduce intraocular pressure (IOP), but its efficacy and safety have been less investigated in Chinese population. This study aimed to evaluate the clinical efficacy and safety of UCP in Chinese patients with refractory glaucoma. METHODS: We designed a prospective, before-after study involving 36 eyes of 36 patients with refractory glaucoma that underwent uneventful UCP. Mean IOP, mean IOP reduction and subjective pain scale scores before and after UCP were compared to evaluate the efficacy of UCP in these patients. Procedural success defined as no abnormality of the treatment sites, and complications were recorded, along with confirmation of the safety of UCP. RESULTS: The 36 UCP patients had a mean IOP of 53.61 ± 12.4 mmHg and a mean VAS score of 5.69 ± 3.02 preoperatively. Successful operation was achieved in 28 patients, with a success rate of 77.8%. In the follow-up observation at day 1, day 7, and month 1, 2, 3 and 6 postoperatively, both mean IOP and mean VAS score were significantly lower than those before operation (both P < 0.0001). The median baseline IOP reduction ranged from 22 to 36%. The mean reduction was 42.5% in 36 patients when taking IOP at the last follow-up visit as the last. No significant changes in visual acuity were achieved in 4 patients after UCP, and no adverse outcomes were present in other patients after timely treatment of complications such as conjunctival hyperemia, subconjunctival hemorrhage, or hyphema. CONCLUSIONS: UCP is a novel yet reliable option for Chinese patients with refractory glaucoma since its high efficacy and safety.

Assessing risk factors for postoperative hypotony in Ahmed glaucoma valve implantation surgery.

PURPOSE: To assess the risk factors associated with the development of hypotony after Ahmed glaucoma valve (AGV) implantation. METHODS: One hundred and ninety-three eyes of 177 patients with various types of glaucoma that were treated with AGV implantation were retrospectively evaluated. Intraocular pressure lower than 6 mmHg related to the surgery is defined as postoperative hypotony. Patients' demographic characteristics, type of glaucoma, preoperative and postoperative visual acuity, necessity of antiglaucoma treatments, lens status, previous ocular surgeries, intraocular pressure (IOP) measurements before and after surgeries, the need for additional procedures and postoperative complications were recorded from the patients' charts. RESULTS: Hypotony was seen in 68 of 193 eyes (35.2%) postoperatively. In 45 eyes (23.3%), it has occurred in first postoperative day and in 23 eyes (11.9%) after the first day within the first week. There was no difference in intraocular pressures between two groups in the first year follow-up. Pre- and postoperative best-corrected visual acuities, age and gender were not statistically different between hypotony and no hypotony groups (p > 0.05). Also, lens status, history of previous ocular surgery, type of glaucoma and number of preoperative glaucoma medication usage were not found to be different between groups (p > 0.05). CONCLUSIONS: Potential risk factors such as age, sex, lens status, history of previous ocular surgeries, preoperative glaucoma medication usage or glaucoma type are not found to influence upon postoperative hypotony prevalence for AGV surgery. Surgery type and personal ocular factors, which could not be determined beforehand, could be more important than demographic features.

Development of a rabbit model of persistent hypotony without ciliary body injury.

In order to study the pathophysiological alterations of the ciliary body (CB) during persistent hypotony, it is necessary to develop an animal model without CB injury. In this study, we successfully established a modified model of persistent hypotony without CB injury in New Zealand rabbits. A 23-gauge pars plana vitrectomy (PPV) was performed and a trocar-formed fistula was allowed to remain in situ, to produce a continuous outflow of intraocular fluid. Both eyes underwent PPV with normal intraocular pressure (IOP); eyes with no surgical intervention were used as controls. The IOP was monitored and used to evaluate the reliability of the model. Secondary changes of hypotony were evaluated by slit-lamp biomicroscopy and B scans while morphological changes of the CB were observed by haematoxylin and eosin staining. The mean IOP in the hypotony groups were consistently lower than 6 mmHg. Furthermore, there were no significant differences in IOP between the PPV control group and normal eyes. Collectively, our data indicate that this model successfully simulates the secondary changes of hypotony, including a reduction in corneal size, corneal oedema, anterior chamber inflammation, morphological alterations of the CB, cataract, retinal detachment, and choroidal detachment. The morphological structure of the CB tissue changed dramatically after persistent hypotony, indicating that normal IOP may be required in order to maintain normal function in the CB. This model of persistent hypotony potentially represents a valuable tool for future studies aiming to investigate the pathophysiological mechanisms underlying CB dysfunction and other secondary changes that occur during hypotony.

Intraocular endoscopy for the evaluation and treatment of hypotony due to a traumatic cyclodialysis: a case report.

BACKGROUND: A cyclodialysis cleft often leads to direct communication between the anterior chamber and the suprachoroidal space. It is a rare condition that is encountered with blunt trauma, and less commonly, after surgery. Hypotony is the major sequelae that may lead to hypotonous maculopathy, optic disc edema, corneal folds, and astigmatism. These may cumulatively lead to visual loss. We describe how endoscopy in a cyclodialysis repair allowed us to accurately locate the cleft and guided its appropriate management avoiding unnecessary cryopexy. CASE PRESENTATION: A 41-year-old male experienced a traumatic cyclodialysis cleft, which resulted in persistent hypotony. Pars plana vitrectomy was performed to treat vitreous hemorrhage. Scleral indentation was attempted to visualize the cyclodialysis cleft. However, the depression distorted the visualization. Intraocular endoscopy was therefore used to evaluate the cleft. Guided by this assessment, only intraocular gas tamponade was used to reposition the ciliary body. The patient's intraocular pressure was restored to 13 mmHg 3 days after the operation, and OCT confirmed cleft closure 1 month after the operation. CONCLUSION: Endoscopy-assisted repair of cyclodialysis is an approach that enhances visualization and can guard against common causes of persistent cleft and hypotony, as well as reveal the causes of recurrent failure. Hence, it can eliminate unnecessary cryopexy that might worsen the hypotonous state. In our case, intraocular endoscopy was effective for the evaluation of a cyclodialysis cleft and the subsequent selection of an appropriate management technique, gas tamponade, that was more conservative than other approaches initially considered.

Ab interno tube ligation for refractory hypotony following non-valved glaucoma drainage device implantation.

PURPOSE: To report the 2-year outcomes of a novel surgical technique allowing reduction of the intraluminal diameter of the tube without total tube occlusion in order to allow enough increase in outflow resistance to permit resolution of hypotony whilst also achieving adequate IOP control. METHODS: This was a single-surgeon retrospective case note review of all non-valved GDD cases over an 8-year period (2008-2015) that underwent ab interno ligation of the drainage tube in order to manage post-operative hypotony (Baerveldt or Molteno). Twelve eyes of 12 patients (4.4%) developing refractory hypotony that did not respond to multiple intracameral ophthalmic viscoelastic device (OVD) injections were included in this retrospective case series and were treated with our ab interno tube ligation technique. The post-ligation management algorithm consisted of re-instating topical anti-glaucoma agents, laser suture lysis (LSL), or further ab interno ligation. RESULTS: Mean IOP increased from 2.8 mmHg at baseline to 7.8 mmHg, 7.1 mmHg, 9.0 mmHg, 13.6 mmHg, 10.9 mmHg, 13.9 mmHg and 13.6 mmHg at day 1, week 1, month 1, month 3, month 6, year 1 and year 2 respectively, with or without additional topical anti-glaucoma medications. Although hypotony resolution following our technique was achieved in all eyes at 2 years, 8.3% of cases required reinstatement of topical medications to maintain IOP control within the target range. CONCLUSIONS: We propose ab interno partial tube tying as an effective surgical option to achieve an immediate, predictable and sustained IOP elevation either as a primary procedure or when traditional methods have failed to resolve hypotony in eyes with non-valved GDDs.

Use of trypan blue as an aqueous tracer dye to investigate hypotony where cyclodialysis cleft is suspected.

IMPORTANCE: A new method to help diagnose suspected cyclodialysis clefts. BACKGROUND: To study the use of trypan blue stained aqueous flow patterns in diagnosing causes of hypotony where cyclodialysis clefts were suspected. DESIGN: A case series in a tertiary care centre. PARTICIPANTS: Ten subjects presenting with persistent hypotony and retinal changes. METHODS: Trypan blue was injected into the anterior chamber. MAIN OUTCOME MEASURES: The pattern of dye flow in the anterior chamber was categorized. Intraocular pressure prior to surgery was recorded. RESULTS: All seven subjects with cyclodialysis clefts had a preferential flow to the cleft region. Two hypotonous subjects post trabeculectomy had rapid (5 seconds) and extensive lymphatic staining (6 o'clock hours extent) without visible bleb formation. CONCLUSIONS AND RELEVANCE: Preferential flow of dye to the limbus is a reliable sign of cyclodialysis cleft and helps localize cleft extent. A new cause of hypotony, "lymphatic overdrain," is identified.

Argon laser-assisted hypotony model in the rabbit.

To investigate whether ocular hypotony formation with 360 degrees endocyclophotocoagulation is possible. Twelve male New Zealand White rabbits were used. Entire ciliary body epithelium was destructed with green laser photocoagulation after pars plana lensectomy and anterior vitrectomy in six rabbits. Endocyclophotocoagulation was not performed to the remaining six rabbits (control group). Intraocular pressure (IOP) was measured preoperatively and followed up everyday in the first week and weekly until the end of month one. All of the rabbits were sacrificed and ciliary bodies were left for gross and light microscopic examination. Mean baseline IOPs were similar in laser and non-laser group (14.8 ± 1.4 (range 12.2-17.3) vs 14.4 ± 1.4 (range 12.2-15.9), p = 0.650). Mean IOP was 6.6 ± 0.45 mmHg (range 5.9-7.1) in the laser group and 11.5 ± 1.2 mmHg (range 10.2-13.4) in the non-laser group in postoperative day 1. IOP was below 4 mmHg in all eyes on the second day and after in laser group. In the macroscopic evaluation, the entire ciliary body had a white (loss of pigmentation) and atrophic appearance in all of the eyes in the laser-treated group compared to non-laser group. In the laser group, light microscopic examination demonstrated a severe 360 degrees disruption of ciliary processes. Ciliary processes were covered with fibrin exudation consisting of fibroblasts. There was a mild inflammation with disruption or atrophy of ciliary body epithelium with cystic vacuolar degeneration. Three hundred sixty degrees endocyclophotocoagulation yielded severe ciliary epithelium damage. IOP reduction started very early and continued in hypotonic levels during follow up period.

Frequency of post-operative hypotony after 23-gauge transconjunctival vitrectomy with locally made instruments.

The objective of this study was to discern the frequency of post-operative hypotony after 23-gauge vitrectomy with locally made instruments. This study was conducted at the Department of Ophthalmology, Lahore General Hospital, Lahore from July 2012 to June 2016. A total of 300 patients underwent 23-gauge pars-plana vitrectomy. Locally made 23-gauge trocar cannula system was used in all the patients. Post-operative Intraocular Pressure(IOP) was measured using Goldman Applanation Tonometer on the first post-operative day. IOP of less than 06mmHg was termed as hypotonic. In our study, mean post-operative intraocular pressure was recorded as 8.32±3.04mmHg and frequency of post-operative hypotony after 23-guage vitrectomy with locally made instruments reveals 10.67% (n=32) while 89.33% (n=268) had no findings of hypotony. We concluded that the frequency of post-operative hypotony after 23-gauge vitrectomy with locally made instruments is slightly higher when compared with other studies and this instrument can be used for further surgeries.

Efficacy and safety of pop-titrated versus fixed-energy trans-scleral diode laser cyclophotocoagulation for refractory glaucoma.

PURPOSE: To compare the efficacy and safety of pop-titrated versus fixed-energy diode laser trans-scleral cyclophotocoagulation (DLTSC) for refractory glaucoma. METHODS: This is a prospective, interventional, longitudinal, and comparative case-control study. Patients with refractory glaucoma treated with pop-titrated DLTSC were compared to a fixed-energy DLTSC control group. Variables analyzed included: age, gender, diagnosis, pre- and post-treatment intraocular pressure (IOP). Success rate, anti-glaucoma medications reduction, and complications were analyzed at day 90 post-treatment. Primary success criterion consisted of eyes with a postoperative IOP ≤ 22 mmHg or a 30% reduction of pre-treatment IOP and managed with topical anti-glaucoma medications only. RESULTS: A total of 68 eyes from 67 patients were included for analysis: 30 in the pop-titrated group and 38 in the fixed-energy group. Therapeutic success was achieved in 56-72% of the pop-titrated group versus 47-52% in the fixed-energy group considering the 3 different criteria analyzed (p = 0.23-0.4). There was a 22% (from 4.1 to 3.2 drugs) reduction of anti-glaucoma medications in the pop-titrated group, compared to 32% (from 3.5 to 2.4 drugs) in the fixed-energy group (p = 0.42). Five eyes (13.1%) developed hypotony, all of which belonged to the fixed-energy group (p = 0.048). CONCLUSIONS: Pop-titrated DLTSC represents an effective and safe option for the management of refractory glaucoma. We found no statistically significant difference in success rates among both groups. However, there was a significantly higher risk of hypotony in eyes treated with the fixed-energy protocol.