Hypotony maculopathy

Multiple serous retinal detachments after Anti-VEGF Intravitreal Injection for pachychoroid related choroidal neovascularization

Purpose

To describe a case of serous retinal detachment (SRD) resembling Vogt Koyanagi-Harada (VKH) disease following anti-vascular endothelial growth factor (anti-VEGF) intravitreal injection (IVI) for pachychoroid related choroidal neovascularization (CNV).

Observation

A 23-year-old female complained of vision loss in her right eye (OD) one day after receiving an anti-VEGF IVI for CNV. Her best-corrected visual acuity (BCVA) in OD dropped from 20/40 to 20/200, and intraocular pressure (IOP) measured 9 mmHg. The IVI resulted in development of hypotony maculopathy, manifesting as evident chorioretinal folds. Notably, there was significant increase in choroidal thickness and dilation of choroidal vessels. Multiple SRD were observed, and fundus fluorescein angiography (FFA) findings resembled those seen in VKH. Topical and systemic steroids were prescribed to prevent inflammation, resulting in an increase in IOP and improvement in choroidal thickness and SRD.

Conclusion

Pachychoroid spectrum diseases (PSD) is associated with alterations in pachyvessel permeability and RPE damage. Hypotony maculopathy following IVI for PSD can manifest as SRD, with FFA findings resemble VKH. Careful monitoring of IOP and vigilance regarding scleral wound integrity at the injection site are imperative after IVI procedures in patients with PSD.

Usefulness of Intraocular Pressure With the Ocular Response Analyzer to Predict Postoperative Hypotony Complications in Glaucoma

Purpose

To investigate the usefulness of intraocular pressure (IOP) using the ocular response analyzer to predict the occurrence of hypotony complications following trabeculectomy or bleb needling revision with mitomycin C.

Methods

This study included 66 eyes of 66 patients who underwent trabeculectomy (58 eyes of 58 patients) or bleb needling (8 eyes of 8 patients) with mitomycin C. A significant predictor of hypotony complications was identified from (1) operation (trabeculectomy or bleb needling), (2) age, (3) sex, (4) disease type (primary open-angle glaucoma, primary angle closure glaucoma, or exfoliation glaucoma), (5) lens status (phakia or pseudophakia), (6) preoperative Goldmann applanation tonometry IOP, (7) preoperative central corneal thickness, (8) preoperative axial length, (9) preoperative anterior chamber depth, (10) preoperative corneal hysteresis, (11) preoperative corneal resistance factor, (12) preoperative corneal compensated IOP (IOPcc), and (13) minimum IOP (IOP value when hypotony complications occurred, otherwise the minimum IOP during 3 months from trabeculectomy or bleb needling) using multivariate logistic regression.

Results

The probability of the occurrence of hypotony complications tended to increase by applying higher cutoff values to preoperative Goldmann applanation tonometry IOP and IOPcc, but not lower cutoff values to the minimum IOP. Multivariate logistic regression suggested that higher preoperative IOPcc and pseudophakia were significant predictors of the occurrence of hypotony complications (P = 0.0062 and 0.0069, respectively).

Conclusions

Higher preoperative IOPcc and pseudophakia were significant predictors of the occurrence of hypotony complications.

Translational Relevance

It is useful to measure IOP using the ocular response analyzer before trabeculectomy.

Prolonged hypotony maculopathy following uneventful strabismus surgery

Hypotony is a rare postoperative complication of strabismus surgery. Resolution has been reported to occur within 1 month of surgery. Here, we describe the case of a 14-year-old boy with prolonged hypotony maculopathy following uneventful bilateral medial rectus recession. The hypotony resolved without long-term sequela after 7 months of treatment with topical steroids and atropine. Ultrasound biomicroscopy revealed a ciliary body effusion, which we hypothesize was the cause of decreased aqueous humor production and hypotony.

Usefulness of Eye Deformation in the Corvis ST Measurement to Predict Postoperative Hypotony Complications in Glaucoma

PURPOSE

This study aimed to investigate the usefulness of measuring biomechanical parameters using the Corvis ST to predict the occurrence of hypotony maculopathy and choroidal detachment (CD) following trabeculectomy or bleb needling revision with mitomycin C.

DESIGN

Clinical cohort study.

METHODS

This study included 100 eyes of 100 patients who underwent trabeculectomy (88 eyes of 88 patients) or bleb needling (12 eyes of 12 patients) with mitomycin C. A significant predictor of hypotony complications was identified from (1) operation (trabeculectomy or bleb needling), (2) age, (3) sex, (4) disease type (primary open-angle glaucoma, exfoliation glaucoma or other), (5) lens status (phakia or pseudophakia), (6) preoperative Goldmann applanation tonometry (GAT) intraocular pressure (IOP), (7) preoperative central corneal thickness (CCT), (8) preoperative axial length (AL), (9) preoperative anterior chamber depth, (10) "Min IOP" (IOP value when hypotony complications occurred, otherwise the minimum IOP during 3 months from trabeculectomy or bleb needling), (11) preoperative corneal curvature, and (12-24) 12 Corvis ST parameters using multivariate logistic regression.

RESULTS

There were 13 and 21 eyes developed hypotony maculopathy and CD, respectively. Male gender, greater preoperative GAT IOP, and greater highest concavity deflection Amplitude were significant predictors of the occurrence of hypotony maculopathy (P < .05). On the other hand, shorter AL, thinner CCT, greater preoperative GAT IOP and pseudophakia were significant predictors of the occurrence of CD (P < .05).

CONCLUSIONS

A careful attention should be paid to the occurrence of hypotony maculopathy with male gender and greater highest concavity deflection Amplitude despite higher preoperative GAT IOP. Different risk factors were identified; shorter AL, thinner CCT, greater preoperative GAT IOP, and pseudophakia.

Hypotony Failure Criteria in Glaucoma Surgical Studies and Their Influence on Surgery Success

PURPOSE

Review hypotony failure criteria used in glaucoma surgical outcome studies and evaluate their impact on success rates.

DESIGN

Systematic literature review and application of hypotony failure criteria to 2 retrospective cohorts.

PARTICIPANTS

A total of 934 eyes and 1765 eyes undergoing trabeculectomy and deep sclerectomy (DS) with a median follow-up of 41.4 and 45.4 months, respectively.

METHODS

Literature-based hypotony failure criteria were applied to patient cohorts. Intraocular pressure (IOP)-related success was defined as follows: (A) IOP ≤ 21 mmHg with ≥ 20% IOP reduction; (B) IOP ≤ 18 mmHg with ≥ 20% reduction; (C) IOP ≤ 15 mmHg with ≥ 25% reduction; and (D) IOP ≤ 12 mmHg with ≥ 30% reduction. Failure was defined as IOP exceeding these criteria in 2 consecutive visits > 3 months after surgery, loss of light perception, additional IOP-lowering surgery, or hypotony. Cox regression estimated failure risk for different hypotony criteria, using no hypotony as a reference. Analyses were conducted for each criterion and hypotony type (i.e., numerical [IOP threshold], clinical [clinical manifestations], and mixed [combination of numerical or clinical criteria]).

MAIN OUTCOME MEASURES

Hazard ratio (HR) for failure risk.

RESULTS

Of 2503 studies found, 278 were eligible, with 99 studies (35.6%) lacking hypotony failure criteria. Numerical hypotony was predominant (157 studies [56.5%]). Few studies used clinical hypotony (3 isolated [1.1%]; 19 combined with low IOP [6.8%]). Forty-nine different criteria were found, with IOP < 6 mmHg, IOP < 6 mmHg on ≥ 2 consecutive visits after 3 months, and IOP < 5 mmHg being the most common (41 [14.7%], 38 [13.7%], and 13 [4.7%] studies, respectively). In both cohorts, numerical hypotony posed the highest risk of failure (HR, 1.51-1.21 for criteria A to D; P < 0.001), followed by mixed hypotony (HR, 1.41-1.20 for criteria A to D; P < 0.001), and clinical hypotony (HR, 1.12-1.04; P < 0.001). Failure risk varied greatly with various hypotony definitions, with the HR ranging from 1.02 to 10.79 for trabeculectomy and 1.00 to 8.36 for DS.

CONCLUSIONS

Hypotony failure criteria are highly heterogenous in the glaucoma literature, with few studies focusing on clinical manifestations. Numerical hypotony yields higher failure rates than clinical hypotony and can underestimate glaucoma surgery success rates. Standardizing failure criteria with an emphasis on clinically relevant hypotony manifestations is needed.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Permanent ocular remodeling in the setting of chronic hypotony after trabeculectomy: A case report

Purpose

Trabeculectomy surgery is a commonly performed procedure for treatment of glaucoma. While the goal is to lower intraocular pressure, over-filtration may cause hypotony with ocular structural changes and vision loss.

Observations

A 53-year-old woman with primary open-angle glaucoma was referred to our service for further evaluation. The patient previously underwent trabeculectomy 9 years prior and was found to have a cataract and hypotony maculopathy in the right eye. Treatment options included cataract surgery alone, bleb revision alone, or combined cataract extraction and bleb revision. Biometry revealed corneal astigmatism in the right eye, and significant disparity in axial length between the two eyes. Since the axial length and corneal astigmatic changes were presumed to be at least partially reversible, measurements from the non-operative left eye influenced the lens selection for the hypotonous right eye. The patient underwent combined phacoemulsification and bleb revision. While IOP increased and hypotony was partly reversed, there was hyperopic and astigmatic refractive surprise after surgery.The patient subsequently underwent intraocular lens exchange using biometric values of the previously hypotonous eye and met the target post-operative refractive goal.

Conclusions and importance

This case demonstrates changes to the axial length and ocular structure following longstanding hypotony maculopathy may be permanent, even after restoration of normotensive intraocular pressure.

Gas Tamponade Improved Cilio-Choroidal Effusion Induced by an Ab Interno Trabeculotomy with a Microhook: Two Cases

Purpose

We treated two patients with ciliary detachment due to an ab interno trabeculotomy. The ciliary detachment was improved by the use of sulfur hexafluoride (SF6) gas or octafluoro propane (C3F8) tamponade.

Patients and Methods

Patient 1 was a 52-year-old Brazilian man with primary open angle glaucoma (POAG). His preoperative intraocular pressure (IOP) was 29 mmHg. Patient 2 was a 57-year-old Japanese woman with POAG. Her preoperative IOP was 35 mmHg. Both patients underwent an ab interno trabeculotomy with a microhook. They caused ciliary detachment as a postoperative complication. We could observe their ciliary detachment with anterior segment optical coherence tomography (AS-OCT). Hypotony persisted for 2 months and the patients' ciliary detachment had not improved. They each underwent a pars plana vitrectomy (PPV) with simultaneous 20% SF6 filling.

Results

In Patient 1, the use of the SF6 gas tamponade successfully attached the ciliary body. His IOP was increased to 30 mmHg after this resolution of the ciliary detachment. He underwent additional tube shunt surgery. For Patient 2, the SF6 gas tamponade improved the ciliary detachment but the ciliary body could not be attached. We injected 0.6 cc of 100% C3F8 gas into the vitreous cavity, and this gas tamponade was able to attach the ciliary body.

Conclusion

AS-OCT is very useful to evaluate ciliary detachment. PPV+Gas tamponade can be a treatment option for ciliary detachment.

Navigating hypotony challenges with XEN gel implantation

INTRODUCTION

The XEN Gel, a hydrophilic tube meticulously crafted to adhere to the principles of the Hagen - Poiseuille law, is designed to facilitate efficient aqueous shunting without inducing hypotony. Implantable ab interno or ab externo, with or without conjunctival opening, the device shows no significant outcome differences. Despite numerical hypotony signaling failure, patients may fare well below 6 mmHg.

AREAS COVERED

This review provides insights into device variability, challenges related to hypotony, associated risk factors, and hypotony management.

EXPERT OPINION

The progressive evolution of the XEN Gel constitutes a significant advancement in the field of glaucoma management. Comparative studies investigating diverse implantation methodologies, particularly the ab interno and closed conjunctival approaches, highlight the device versatility in addressing individual patient needs. Exploring hypotony from both statistical and clinical perspectives challenges the traditional view of intraocular pressure as a straightforward success or failure indicator. The incidence of hypotony-related issues varies between device models, emphasizes the need for an individualized approach during device selection. Overall, understanding the dynamics of hypotony is crucial for optimizing the outcomes of XEN Gel implantation.

Intraoperative optical coherence tomography-guided transconjunctival bleb suturing - A minimally invasive technique for managing overfiltering bleb

With the recent advancement in technologies, real-time integrated intraoperative optical coherence tomography (iOCT) microscopes are available, which facilitates surgical precision and also reduces the risk of complications. Two glaucoma patients with advanced glaucomatous optic neuropathy, who underwent uneventful trabeculectomy with 0.02% mitomycin C, developed persistent hypotony postoperatively till 4-6 weeks. On clinical examination, visual acuity was 1/60 with low intraocular pressure (IOP) of 4 mmHg. Elevated, overfiltering bleb was seen on slit-lamp examination, along with hypotonous maculopathy. Anterior segment optical coherence tomography (AS-OCT) showed multiple large hyporeflective fluid spaces suggestive of overfiltering bleb. Considering the risk of choroidal detachment and further deterioration of vision, iOCT-guided transconjunctival bleb suturing was planned. iOCT helped to identify the exact location of scleral flap, and transconjunctival suturing was done with successful outcomes in terms of improved IOP and visual acuity.

Trabeculectomy in Eyes With High Myopia

PRCIS

Primary trabeculectomy was safe and effective at lowering intraocular pressure (IOP) in patients with primary open angle glaucoma and high myopia.

PURPOSE

To investigate the efficacy and safety of trabeculectomy in patients with glaucoma and high myopia.

PATIENT AND METHODS

Retrospective case-control study. Glaucomatous patients with high myopia undergoing primary trabeculectomy surgery with at least 1 year of follow-up were compared with an age-matched control group without high myopia undergoing the same procedure. Surgical success was defined as: IOP ≤ 15 mm Hg with (qualified) or without (complete) antiglaucoma medications and at least 20% reduction from baseline IOP at the end of 48 months of follow-up.

RESULTS

We included a total of 90 eyes from 90 patients (45 eyes with high myopia and 45 controls). Within the 90 eyes, 70 eyes underwent trabeculectomy and 20 eyes underwent combined phacoemulsification and trabeculectomy. Although patients with high myopia had higher chances for failure (37% vs. 22%) compared with controls, the difference was not statistically significant ( P =0.067). In the multivariable analysis, patients of African descent ( P =0.043) and those with juvenile glaucoma ( P =0.001) had more chances of failure, even after adjusting for myopia. There was no statistically significant difference between complication rates in both groups.

CONCLUSION

Trabeculectomy was effective in reducing IOP in patients with high myopia and glaucoma, without the additional risk of complications compared with a control group.

Microfluidics in the eye: a review of glaucoma implants from an engineering perspective

Glaucoma is a progressive optic neuropathy in the eye, which is a leading cause of irreversible blindness worldwide and currently affects over 70 million individuals. Clinically, intraocular pressure (IOP) reduction is the only proven treatment to halt the progression of glaucoma. Microfluidic devices such as glaucoma drainage devices (GDDs) and minimally invasive glaucoma surgery (MIGS) devices are routinely used by ophthalmologists to manage elevated IOP, by creating an artificial pathway for the over-accumulated aqueous humor (AH) in a glaucomatous eye, when the natural pathways are severely blocked. Herein, a detailed modelling and analysis of both the natural microfluidic pathways of the AH in the eye and artificial microfluidic pathways formed additionally by the various glaucoma implants are conducted to provide an insight into the causes of the IOP abnormality and the improvement schemes of current implant designs. The mechanisms of representative glaucoma implants have been critically reviewed from the perspective of microfluidics, and we have categorized the current implants into four groups according to the targeted drainage sites of the AH, namely Schlemm's canal, suprachoroidal space, subconjunctival space, and ocular surface. In addition, we propose to divide the development and evolution of glaucoma implant designs into three technological waves, which include microtube (1st), microvalve (2nd) and microsystem (3rd). With the emerging trends of minimal invasiveness and artificial intelligence in the development of medical implants, we envision that a comprehensive glaucoma treatment microsystem is on the horizon, which is featured with active and wireless control of IOP, real-time continuous monitoring of IOP and aqueous rate, etc. The current review could potentially cast light on the unmatched needs, challenges, and future directions of the microfluidic structural and functional designs of glaucoma implants, which would enable an enhanced safety profile, reduced complications, increased efficacy of lowering IOP and reduced IOP fluctuations, closed-loop and on-demand control of IOP, etc.

Addressing Glaucoma in Myopic Eyes: Diagnostic and Surgical Challenges

Epidemiological and genetic studies provide strong evidence supporting an association between myopia and glaucoma. The accurate detection of glaucoma in myopic eyes, especially those with high myopia, remains clinically challenging due to characteristic morphologic features of the myopic optic nerve in addition to limitations of current optic nerve imaging modalities. Distinguishing glaucoma from myopia is further complicated by overlapping perimetric findings. Therefore, longitudinal follow-up is essential to differentiate progressive structural and functional abnormalities indicative of glaucoma from defects that may result from myopia alone. Highly myopic eyes are at increased risk of complications from traditional incisional glaucoma surgery and may benefit from newer microinvasive glaucoma surgeries in select cases.

Ab-externo canaloplasty with and without suture in highly myopic eyes

PURPOSE

To evaluate the effectiveness of ab-externo canaloplasty using the iTrack canaloplasty microcatheter (Nova Eye Inc, Fremont, California), with or without suture, in glaucoma patients with high myopia.

METHODS

This was a prospective, single-center, single-surgeon, observational study comparing the outcomes of ab-externo canaloplasty performed with a tensioning suture (suture group) and without a tensioning suture (no-suture group) in mild to severe glaucoma patients with high myopia. Twenty-three eyes received canaloplasty as a standalone procedure, 5 in combination with phacoemulsification. Primary efficacy endpoints included intraocular pressure (IOP) and the number of glaucoma medications. Safety was assessed based on reported complications and adverse events.

RESULTS

Twenty-nine eyes of 29 patients with a mean age of 61.2 ± 12.3 years; 19 eyes in the no-suture group and 10 eyes in the suture group. All eyes demonstrated a significant reduction in IOP 24 months postoperatively, from 21.9 ± 7.22 to 15.4 ± 4.86 mmHg in the suture group and from 23.8 ± 7.58 to 19.7 ± 3.68 mmHg in the no-suture group. The mean number of anti-glaucoma medications reduced from 3.1 ± 0.6 to 0.4 ± 0.7 in the suture group and 3.3 ± 0.9 to and 0.2 ± 0.6 in the no-suture group at 24 months. IOP was not significantly different at baseline between the 2 groups, but it was statistically different at 12 and 24 months. There was no statistically significant difference in the number of medications between the groups at baseline, 12 and 24 months. No serious complications were reported.

CONCLUSION

Ab-externo canaloplasty performed either with or without a tensioning suture demonstrated good effectiveness in highly myopic eyes with a significant reduction in IOP and number of anti-glaucoma medications. The suture group achieved a lower postoperative IOP. However, the no-suture modification provides a similar reduction in medications with reduced tissue handling.

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.

Quantification of Hypotony Maculopathy Using Spectral-Domain Optical Coherence Tomography

PRCIS

We provide a free-to-use, open-source algorithm to quantify macular hypotony based on optical coherence tomography (OCT) images. This numerical approach calculates a metric that measures the deviations of Bruch's membrane from a smooth ideal retinal layer.

PURPOSE

Hypotony maculopathy is a recurrent complication of glaucoma surgical interventions in which extremely low intraocular pressure triggers changes in the shape of retinal layers. Abnormal folds can often be observed in the retina using standard fundoscopy, but OCT is particularly important to appreciate the severity of symptoms at different depths. Despite the need for metrics that could be used for the informed clinical decision to evaluate the progression and resolution of macular hypotony, algorithms that quantify the retinal folds are not available in the literature or included in clinical imaging equipment. The purpose of this work is to introduce a simple algorithm that can be used to assess hypotony maculopathy from OCT B-Scans and volumes and a free, open-source implementation.

METHODS

The pipeline we present is based on a straightforward segmentation of Bruch's membrane complex. The principal idea of quantification is to compute a smoothed version of this complex and analyze the deviations from an ideal interface. Such deviations are then measured and added to create a metric that characterizes each OCT B-Scan. A full OCT volume reconstruction is thus characterized by the average metric obtained from all planes.

RESULTS

We tested the metric we proposed against the assessment of 3 experts and obtained a very good correspondence, with Pearson correlation coefficients higher than 0.8. Furthermore, agreement with automatic analysis seemed better than between experts. We describe the pipeline in detail and illustrate the results with a group of patients, comparing baseline images, severe hypotony maculopathy, and a variety of outcomes.

CONCLUSION

The tool we introduce and openly provide fills a clinical gap to quantitatively grade hypotony maculopathy. It offers a metric of relatively simple interpretation that can be used to help clinicians in cases where the regression of symptoms is not obvious to the naked eye. Our pilot study demonstrates reliable results, and an open-source implementation facilitates easy improvements to our algorithm.

Safety and Efficacy of Ab Interno XEN 45 Gel Stent in Patients with Glaucoma and High Myopia

This study reports on the safety and efficacy of Xen 45 in patients with glaucoma and high myopia. It was a retrospective study including patients with high myopia (>6D) who underwent Xen implant with 2 years of follow-up. The primary outcome was to report the incidence of hypotony (IOP ≤ 5 mmHg) and hypotony-related complications. Patients with high myopia treated with mitomycin-C-augmented trabeculectomy were included as a control group. We included 14 consecutive patients who underwent Xen implant (seven eyes) and trabeculectomy (seven eyes). The mean myopia was −14.71 ± 5.36 and −15.07 ± 6.11 in the trabeculectomy and Xen groups, respectively (p > 0.05). The success rate and the mean IOP at 1 and 2 years from the intervention were statistically comparable between the two groups. The group undergoing trabeculectomy showed a higher incidence of hypotony (six eyes (85.71%) vs. two eyes (28.57%)) and hypotony maculopathy (three eyes (42.86%) vs. zero eyes (0%)) and required more postoperative procedures. Patients with high myopia were at higher risk of hypotony-related complications after trabeculectomy. The Xen implant can achieve an IOP control comparable to trabeculectomy with a significantly better safety profile and can be considered as an option for the management of patients with high myopia and glaucoma.

Glaucoma and Myopia: Diagnostic Challenges

The rising global prevalence of myopia is a growing concern for clinicians, as it predisposes patients to severe ocular pathologies including glaucoma. High myopia can be associated with clinical features that resemble glaucomatous damage, which make an accurate glaucoma diagnosis challenging, particularly among patients with normal intraocular pressures. These patients may also present with established visual field defects which can mimic glaucoma, and standard imaging technology is less useful in disease detection and monitoring due to the lack of normative data for these anatomically unique eyes. Progression over time remains the most critical factor in facilitating the detection of early glaucomatous changes, and thus careful longitudinal follow-up of high-risk myopic patients is the most important aspect of management. Here, we review our current understanding of the complex relationship between myopia and glaucoma, and the diagnostic challenges and limitations of current testing protocols including visual field, intraocular pressure, and imaging. Furthermore, we discuss the clinical findings of two highly myopic patients with suspected glaucoma.

Effectiveness and Safety of XEN45 in Eyes With High Myopia and Open Angle Glaucoma

PRCIS

XEN45 implant was an effective and safe procedure in primary open angle glaucoma (OAG) eyes with high myopia. Although the hypotony incidence rate was relatively high, it resolved with medical therapy and was of short duration.

PURPOSE

The purpose of this study is to evaluate the effectiveness and safety of the XEN45 stent in eyes with OAG and high myopia.

DESIGN

Retrospective and multicenter study.

METHODS

Consecutive OAG patients who underwent a XEN45, either alone or in combination with cataract surgery, and had a refractive error higher than -6 D and an axial length ≥26 mm. The primary endpoint was the mean intraocular pressure (IOP) lowering at the last follow-up visit.

RESULTS

Thirty-one eyes were included (96.8% with a primary OAG diagnosis). The mean refraction was -13.2±5.6 (range: -6.75 to-23.0) D. In the overall study sample, preoperative mean IOP (95% CI) was significantly lowered from 23.5 (20.5-26.4) mm Hg to 13.0 (12.2-13.8) mm Hg at the last follow-up visit, P <0.0001. At the last follow-up visit, 16 (57.1%) eyes achieved an IOP ≤14 mm Hg, 11 (68.9%) of them without treatment. The number of ocular hypotensive medications was significantly reduced from 3.0±1.1 drugs at preoperatively to 0.6±1.0 drugs at the last follow-up visit, P <0.0001. Median (95% CI) follow-up was 24.0 (12.0-24.0) months. Linear regression analysis showed a significant correlation between the preoperative refraction and the IOP lowering ( r =0.43, P =0.0155). Needling procedure was performed in 11 eyes (39.3%) and hypotony (defined as an IOP <6 mm Hg) was observed in 8 eyes (28.6%) during the first postoperative day and remained for a week.

CONCLUSION

Although the Xen implant effectively lowered IOP in highly myopic eyes with glaucoma, the incidence of hypotony was high, and in most cases, resolved within the first month with medical management and monitoring.

Anaesthetic considerations for the surgical management of ocular hypotony in adults

Ocular hypotony can occur from many causes, including eye trauma, ophthalmic surgery and ophthalmic regional anaesthesia-related complications. Some of these patients require surgical intervention(s) necessitating repeat anaesthesia. While surgical management of these patients is well described in the literature, the anaesthetic management is seldom discussed. The hypotonous eye may also have altered globe anatomy, meaning that the usual ocular proprioceptive feedbacks during regional ophthalmic block may be altered or lost, leading to higher risk of inadvertent globe injury. In an 'open globe' there is a risk of sight-threatening expulsive choroidal haemorrhage as a consequence of ophthalmic block or general anaesthesia. This narrative review describes the physiology of aqueous humour, the risk factors associated with ophthalmic regional anaesthesia-related ocular hypotony, the surgical management, and a special emphasis on anaesthetic management. Traumatic hypotony usually requires urgent surgical repair, whereas iatrogenic hypotony may be less urgent, with many cases scheduled as elective procedures. There is no universal best anaesthetic technique. Topical anaesthesia and regional ophthalmic block, with some technique modifications, are suitable in many mild-to-moderate cases, whilst general anaesthesia may be required for complex and longer procedures, and severely distorted globes.

Long-Term Efficacy and Safety of Modified Canaloplasty Versus Trabeculectomy in Open-Angle Glaucoma

BACKGROUND

To evaluate the long-term efficacy and safety of modified canaloplasty versus trabeculectomy in open-angle glaucoma.

METHODS

In total, 210 subjects with open-angle glaucoma were included. 70 were treated with Mitomycin C-augmented modified canaloplasty with enhanced subconjunctival filtration and 140 with Mitomycin C-augmented trabeculectomy. Cases were matched 1:2 by sex and age.

RESULTS

In canaloplasty and trabeculectomy groups, 61.4% and 57.9% of participants were female. Mean age was 60.0 ± 13.9 and 63.0 ± 12.2 years, median follow-up time was 4.6 [IQR 4.3, 5.05] years and 5.8 [IQR 5.4, 6.3]. Strict success was achieved in 20.0% and 56.4%, complete success in 24.3% and 66.4%, and qualified success in 34.3% and 73.6% (each p < 0.001). Kaplan-Meier survival analysis showed a better survival probability for trabeculectomy than for canaloplasty (p < 0.001) and Cox regression analysis revealed an HR of 6.03 (95%-CI 3.66, 9.93, p < 0.001) after canaloplasty. Trabeculectomy showed superiority in terms of IOP decrease (9.2 ± 7.9 mmHg vs. 13.7 ± 10.4 mmHg, p = 0.002), use of AGM (50.0% vs. 10.7%, p < 0.001), and the number of revision surgeries (41.4% vs. 21.4%, p = 0.004). Occurrence of complications was similar in both groups (14.5% vs. 7.5%, p = 0.19).

CONCLUSIONS

Trabeculectomy showed superiority in efficacy and equality in safety compared to modified canaloplasty.

Maculopathies in Glaucoma

In the presence of glaucoma, various changes in the macula can occur during the course of the disease itself or its treatment. Maculopathies that can be observed in glaucoma include cystoid macular edema, hypotony maculopathy, and microcystic macular edema. The following article discusses the pathophysiology, causes, course, clinical presentation, and treatment of these maculopathies.

Recurrent macular neurosensory detachment in hypotony maculopathy managed with topical corticosteroids

A female patient in her late 70s underwent uncomplicated non-penetrating deep sclerectomy surgery. Three years after surgery, she presented with a sudden decrease in visual acuity, intraocular pressure (IOP) of 2 mmHg, macular folding and significant macular subretinal fluid. Assuming hypotony as the cause, topical dexamethasone was started, with complete functional and imagological improvement. Two months after withdrawal, she returned with the same symptoms and imagological findings. The same topical treatment was re-established, with progressive and complete improvement. After 14 months of follow-up and a maintenance dose of topical dexamethasone (1id), the patient remained stable with an IOP of 16 mm Hg. Hypotony maculopathy can, in rare cases, lead to subretinal fluid and neurosensory detachment. Topical corticosteroids can reverse and prevent hypotony in patients who are corticosteroid responsive. In advanced glaucoma, extremely low IOP may be as dangerous as high IOP. Timely normalisation of IOP may restore normal retinal architecture with associated functional improvement.

Keratoprosthesis, silicone oil placement, and fluocinolone acetonide implant for treatment of uveitis-associated hypotony and keratopathy

Purpose

To describe a case series of combined Boston Type 1 Keratoprosthesis with pars plana vitrectomy, silicone oil placement, and fluocinolone acetonide intravitreal 0.59 mg implant (RETISERT®), and report its safety and efficacy in preventing phthisis bulbi in patients with uveitis-associated hypotony and concurrent corneal edema.

Findings

A retrospective review of patients with chronic uveitis, corneal decompensation and concurrent hypotony who underwent the combined approach described here between 2015 and 2020 was conducted. Three patients were treated using the combined approach. Post-operative recovery was unremarkable in all cases and the patients’ corneal condition remained stable on follow up. No patient developed phthisis, retroprosthetic membrane, or infectious endophthalmitis. Average intraocular pressure one year after intervention was 2.7 to 6.4 mmHg higher compared to a year prior.

Conclusions

The approach described is potentially safe and effective in preventing phthisis and membrane formation in uveitis-associated hypotony and keratopathy.

Effect of Different Preoperative Intraocular Pressures on the Prognosis of Traumatic Cyclodialysis Cleft Associated with Lens Subluxation

Purpose

To evaluate the prognosis of patients with blunt trauma-mediated cyclodialysis cleft and lens subluxation treated by dual capsular tension rings (CTRs) with different preoperative intraocular pressures (IOPs).

Methods

Twenty-five patients with cyclodialysis cleft and lens subluxation after blunt trauma were recruited in this study. They were categorized into the low IOP group (IOP < 10 mmHg) and normal IOP group (between 10 mm and 21 mmHg). A modified CTR (MCTR) or CTR was sutured into the ciliary sulcus, and another MCTR or CTR was implanted in the capsular bag. The prognosis outcome measurements, including BCVA (LogMAR), IOP, UBM, and macular character on OCT, were collected during the regular outpatient follow-up after surgery until the recovery of cyclodialysis cleft was found. Measures of cyclodialysis cleft recovery included successful IOP control (defined as an IOP within 10–21 mmHg), confirmation of cleft closure on UBM, and confirmation of IOL centration under slit-lamp examination. Follow-up period or recovery time was regarded as the duration between discharge from the hospital after the operation and the recovery of cyclodialysis cleft. The longest follow-up period was 1 year.

Results

Cyclodialysis cleft was successfully treated in 21/25 eyes, whereas lens subluxation was treated effectively in all 25 eyes. CTRs and IOLs were stable in all eyes. BCVA (P < 0.001) and IOP (P < 0.001) were significantly improved after surgery. The primary surgical complication included reversible IOP spike in seven eyes. Postoperative BCVA was found to have correlation with the preoperative IOP (P = 0.016), maculopathy (P = 0.002,), and trauma duration (P = 0.046). Worse BCVA (P = 0.037) and more severe grade of maculopathy (P = 0.030) were observed in the low IOP group (14 eyes). In contrast, a better prognosis and greater probability of IOP spike (P = 0.021) were observed in the normal IOP group (11 eyes).

Conclusion

Timely and proper intervention for traumatic cyclodialysis cleft associated with lens subluxation is essential. Lower preoperative IOP is associated with worse prognosis and prolonged recovery time, while caution should be taken in IOP spike monitoring in patients with normal preoperative IOP.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-022-00468-0.

Is canaloplasty with mitomycin c a safe procedure in myopic glaucoma?

PURPOSE

Myopic glaucoma patients display a considerable risk of complications following antiglaucomatous filtering surgery, e.g., trabeculectomy. Canaloplasty with mitomycin C may reduce this risk by avoiding massive overfiltration.

METHODS

We performed retrospective analysis of 31 eyes with myopia that underwent canaloplasty modified with mitomycin C in a consecutive single-surgeon case series. Annual data and success rates were analysed. Twenty-three myopic eyes that had received conventional trabeculectomy with mitomycin C were recorded as a comparison.

RESULTS

The 31 eyes with a follow-up of 40 ± 26 months after canaloplasty had a mean spherical equivalent of - 8.4 ± 4.5 dioptres. Intraocular pressure decreased from 32.3 ± 9.6 mmHg (range: 17 to 58) to 16.8 ± 8.1 mmHg (range: 5 to 44) 1 year after surgery (- 46%; p < 0.001) with a medication score reduction from 5 to 1.2 (p < 0.001). Qualified success rates (Criterion B: no revision surgery, IOP < 21 mmHg, IOP reduction > 20%) were 83% after 1 year and 61% at the 2nd and 3rd years. In 5 eyes (16%), early ocular hypotony (≤ 5 mmHg) was observed. Two eyes (7%) showed transient choroidal detachment and swelling. The 23 eyes that had received trabeculectomy had success rates (Criterion B) of 91% at the 1st and 86% at the 2nd and 3rd years. Hypotony occurred in 10 eyes (44%), and 4 eyes (17%) showed choroidal detachment or macular folds.

CONCLUSIONS

Postoperative complications related to overfiltration were less frequent after canaloplasty with mitomycin C. Midterm data proved good efficacy. Pressure reduction, success rates and rates of medication free patients were significantly higher in trabeculectomy compared to modified canaloplasty with mitomycin C.

MÜLLER CELL CONE-ASSOCIATED FOVEAL DETACHMENT AS A RISK FACTOR FOR VISUAL ACUITY LOSS AFTER GLAUCOMA FILTERING SURGERY

PURPOSE

To examine hypotony-associated foveal lesions (FovLs) using optical coherence tomography, and to assess the risk factors of visual deterioration after glaucoma filtering surgery.

METHODS

Parameters that may be associated with postsurgical deterioration of visual acuity were retrospectively studied in 44 eyes of 44 patients who experienced postsurgical intraocular hypotension ≤6 mmHg between 2015 and 2019.

RESULTS

Six eyes (14%) had FovLs, such as detachment of photoreceptors (5 eyes, 11%) and acquired vitelliform lesions (1 eye, 2%) at 3 months after trabeculectomy. Logistic regression analysis revealed that hypotony maculopathy (P = 0.0141 at 3 months) and FovLs (P = 0.0486 and 0.0296 at 3 and 12 months, respectively) were significant risk factors for Visual acuity loss after trabeculectomy. The FovLs were located just behind the Müller cell cone. Visual acuity at 3 and 12 months after surgery in patients with FovLs was significantly lower than in those without FovLs (P = 0.0013 and P = 0.006, respectively). Epiretinal membrane was more common in eyes with FovLs (5 of 6 eyes, 83%) than in eyes without FovLs (7 of 38 eyes, 18%; P = 0.0037).

CONCLUSION

Müller cell cone-associated FovLs lead to long-lasting visual acuity loss after filtering surgery.

Hypotony Following Intravitreal Silicone Oil Removal in a Patient With a Complex Retinal Detachment With Giant Retinal Tear

Postoperative ocular hypotony after silicone oil removal in complex cases of retinal detachment is a complication that can occur in about 20% of cases and can prevent the successful management of retinal detachments. Thus, it is critical to understand the mechanisms of hypotony and the potential interventions that can be done in order to avoid irreversible tissue damage. We present a case of a 35-year-old man who underwent intraocular surgery for removal of silicone oil tamponade following a combined scleral buckling and pars plana vitrectomy (PPV) surgery for a rhegmatogenous retinal detachment associated with a giant retinal tear. On Day 1 after the operation, the patient was found to have hypotony with optic disc edema, chorioretinal folds, and visual acuity of ‘hand movement’ perception. Two weeks postop, the patient’s condition stabilized, with a visual acuity of 0.38 logMAR, an intraocular pressure (IOP) of 12 mmHg, and the absence of macular edema.

Optic disc edema and chorioretinal folds develop during strict 6° head-down tilt bed rest with or without artificial gravity

Spaceflight associated neuro-ocular syndrome (SANS) is hypothesized to develop as a consequence of the chronic headward fluid shift that occurs in sustained weightlessness. We exposed healthy subjects (n = 24) to strict 6° head-down tilt bed rest (HDTBR), an analog of weightlessness that generates a sustained headward fluid shift, and we monitored for ocular changes similar to findings that develop in SANS. Two-thirds of the subjects received a daily 30-min exposure to artificial gravity (AG, 1 g at center of mass, ~0.3 g at eye level) during HDTBR by either continuous (cAG, n = 8) or intermittent (iAG, n = 8) short-arm centrifugation to investigate whether this intervention would attenuate headward fluid shift-induced ocular changes. Optical coherence tomography images were acquired to quantify changes in peripapillary total retinal thickness (TRT), retinal nerve fiber layer thickness, and choroidal thickness, and to detect chorioretinal folds. Intraocular pressure (IOP), optical biometry, and standard automated perimetry data were collected. TRT increased by 35.9 µm (95% CI, 19.9-51.9 µm, p < 0.0001), 36.5 µm (95% CI, 4.7-68.2 µm, p = 0.01), and 27.6 µm (95% CI, 8.8-46.3 µm, p = 0.0005) at HDTBR day 58 in the control, cAG, and iAG groups, respectively. Chorioretinal folds developed in six subjects across the groups, despite small increases in IOP. Visual function outcomes did not change. These findings validate strict HDTBR without elevated ambient CO2 as a model for investigating SANS and suggest that a fluid shift reversal of longer duration and/or greater magnitude at the eye may be required to prevent or mitigate SANS.

The use of Ologen Collagen Matrix implants to treat ocular hypotony developing after trabeculectomy: A case series

PURPOSE

Late hypotony is an undesirable and challenging complication of glaucoma surgery. We describe our use of the Ologen Collagen Matrix to treat late hypotony developing after trabeculectomy.

STUDY DESIGN

A retrospective study performed at three eye surgery centers in Brazil.

PARTICIPANTS

Eighteen patients who underwent 19 eye surgeries.

INTERVENTION

Subconjunctival Ologen was implanted at the trabeculectomy sites to treat over-filtering or leaking blebs in patients experiencing late hypotony after trabeculectomy (obtained 6 months after glaucoma surgery). The primary outcome was the intraocular pressure (IOP); we gathered preoperative data records from 19 Ologen treated eyes and days 1, 7, 30, 60, and 180 postoperatively. The secondary outcomes included visual acuity and macular thickness measured via optical coherence tomography; we compared preoperative data to subsequent ones up to sixth-month-evolution.

RESULTS

Over the 6-month period, the IOP rose from 2.89 ± 1.59 mmHg preoperatively to 8.21 ± 3.46 mmHg (p = 0.0001). Visual acuity improved from 0.33 ± 0.29 to 0.21 ± 0.31 LogMar (p = 0.0013). Macular thickness fell from 325.62 ± 58.7 to 283.08 ± 47.35 µm (p = 0.0097). We encountered two complications: one related to suture dehiscence following an ocular trauma and one instance of transitory choroidal detachment.

CONCLUSION

Subconjunctival Ologen implants preserved bleb function and successfully treated post-trabeculectomy hypotony as revealed by data collected at the 6-month follow-up. Longer follow-up is necessary to confirm long-term efficacy and safety. There are no financial conflicts of interest to disclose.

Bleb Compressive Sutures in the Management of Hypotony Maculopathy after Glaucoma Surgery

PURPOSE

The aim of the study was to assess the efficacy and safety of compressive sutures in patients with hypotony maculopathy after glaucoma surgery.

METHODS

This retrospective case series analyzes the clinical outcomes of conjunctival compressive sutures in 17 patients with hypotony maculopathy developed after glaucoma surgery. Compressive Nylon 10-0 single sutures were used in all patients; in two patients, the procedure was repeated. All patients underwent ophthalmic evaluation and macular OCT scanning before the surgery, one month, six months, and one year after the procedure.

RESULTS

Mean intraocular pressure (IOP) before suturing was 2.3 ± 1.57 mmHg and increased to 14.2 ± 7.03 mmHg (p = 0.00065) one month after the procedure. After six months, mean IOP was 10.2 ± 4.3 mmHg (p = 0.005), and after one year ± 4.7 mmHg (p = 0.0117). To obtain the target pressure, the sutures had to be removed in one patient, and medical therapy was undertaken in three patients. Mean decimal best-corrected visual acuity (BCVA) before the sutures was 0.18 ± 0.13 and increased to 0.53 ± 0.25 (p = 0.0004) after one month, to 0.46 ± 0.31 (p = 0.005) after six months, and to 0.31 ± 0.22 (p = 0.025) after one year. In one case, leakage from the bleb was observed after the procedure and bleb revision was required.

CONCLUSIONS

transconjuctival compressive sutures seem to be an efficient and safe technique for managing hypotony maculopathy after glaucoma surgery.

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.

Hypotony maculopathy and photoreceptor folds with disruptions after vitrectomy for epiretinal membrane removal: two case reports

Background

Hypotony maculopathy has been classically reported as a complication of glaucoma surgery or ocular trauma. There have been only a few reports of hypotony maculopathy following pars plana vitrectomy (PPV). Here, we report two cases of hypotony maculopathy occurring after PPV for epiretinal membrane (ERM) removal and characteristic photoreceptor folds observed on optical coherence tomography (OCT).

Case presentation

A 53-year-old Korean woman (case 1) underwent phacoemulsification and posterior chamber lens implantation combined with 25-gauge PPV for ERM removal in the right eye. On the following day, she had severe ocular hypotony, with an intraocular pressure (IOP) that was unmeasurable using a pneumatic tonometer. Despite normalization of IOP, macular retinal and photoreceptor folds with photoreceptor disruptions developed, and Henle’s fiber layer hyperreflectivity was identified. Thereafter, retinal and photoreceptor folds gradually disappeared but photoreceptor disruption and Henle’s fiber layer hyperreflectivity did not improve until 1 year postoperatively, with persistent central visual field distortion and visual acuity worse than that at the preoperative state. A 20-year-old Korean man (case 2) underwent an additional 25-gauge PPV for ERM removal in the left eye. Examination on the following day showed ocular hypotony and retinal folds with peripheral choroidal detachment. Although IOP was normalized, further OCT revealed photoreceptor folds and photoreceptor disruptions. Since then, the photoreceptor folds resolved; however, the photoreceptor disruption remained in the macula at the 1-year follow up, with persistent distorted vision and visual acuity worse than that at the preoperative state.

Conclusions

Early hypotony after vitrectomy for ERM could result in maculopathy leading to irreversible visual decline and metamorphopsia. Photoreceptor folds on OCT are characteristic features and the predominant mechanism of central visual loss in cases of hypotony maculopathy.

Ocular Hypotension and Epiretinal Membrane as Risk Factors for Visual Deterioration Following Glaucoma Filtering Surgery

PRECIS

Postsurgical hypotension at 1 week and the presence of an epiretinal membrane (ERM) were significant risk factors for the deterioration of postsurgical visual acuity (VA) at 3 and 12 months, respectively.

PURPOSE

The purpose of this study was to assess the effects of an ERM and postsurgical hypotension <6 mm Hg at 1 week on postsurgical VA loss.

PATIENTS AND METHODS

A total of 69 patients (69 eyes) who underwent trabeculectomy with adjunctive mitomycin C between 2017 and 2019 (mean follow-up period: 22.8 mo) were enrolled, and 14 parameters that could be associated with the deterioration of VA at 3 and 12 months were studied.

RESULTS

There was a significant association between VA loss at 3 months and postsurgical intraocular pressure at 1 week (P=0.006 by multiple regression) and hypotony maculopathy (P=0.024 by Fisher exact test). However, this association was lost at 12 months. Instead of postsurgical hypotension, the presence of an ERM was significantly associated with VA loss at 12 months (P=0.035 by Fisher exact test, and P=0.023 by logistic regression).

CONCLUSIONS

Postsurgical hypotension at 1 week was significantly associated with mid-term, but not long-term, postsurgical VA loss. The presence of an ERM, which was not a risk factor for mid-term acuity loss, was a significant risk factor for VA loss at 12 months.

[Management of posttraumatic ocular hypotony]

The posttraumatic ocular hypotony (3% after ocular contusion, 50-74% after open globe injury) can lead to severe secondary damage of the eyeball. In addition to corneal folds, ciliary body and choroidal detachment, papilledema e vacuo and macular folds, the shrinking of the eye can lead to substantial visual impairment. Subsequently, the contralateral eye may react with ocular hypertension. The cause of the hypotony must be identified and causally treated. A preservation of the globe is possible if more than 210 ° of the ciliary body are intact. One of the major causes of posttraumatic hypotony is cyclodialysis. Smaller cyclodialysis clefts respond to a cycloplegic treatment, larger clefts require a surgical approach. The direct cyclopexy can be combined with primary wound repair or pole to pole surgery. An alternative consists of silicone oil endotamponade or occlusion of Schlemm's canal. The posttraumatic ocular hypotony is complex and requires exact diagnostics to be able to differentially and specifically treat the causes of hypotony.

Frequency of hypotonic maculopathy observed by spectral domain optical coherence tomography in post glaucoma filtration surgery eyes

Purpose

To report the frequency of post glaucoma filtration surgery hypotonic maculopathy determined by spectral domain optical coherence tomography (SD-OCT).

Methods

A cross-sectional retrospective observational study. Post glaucoma filtration surgery patients whose intraocular pressures (IOP) achieved 30% reduction from baseline or was controlled to IOP <14 mm Hg and had SD-OCT images and fundus photographs were enrolled. Hypotonic maculopathy was diagnosed independently on SD-OCT images and on fundus photographs.

Results

112 eyes of 88 patients were included in this study. 17 eyes of 14 patients were diagnosed with hypotonic maculopathy on SD-OCT images (17/112, 15.2%). Among these eyes, only 3 eyes were also diagnosed with hypotony maculopathy on fundus photography. Hypotonic maculopathy on SD-OCT was found only in eyes with IOP ≤10 mm Hg. (17.4% in eyes with IOPs between 7 and 10 mm Hg, and 22.7% in eyes with IOP ≤ 6 mm Hg). Associations with age, sex, central corneal thickness, refractive error, IOP reduction rate and interval between surgery and OCT acquisition were not significant (P > 0.05).

Conclusion

In most cases, hypotonic maculopathy detected by SD-OCT were not recognizable on fundus photographs. Hypotonic maculopathy was detected not only in eyes with conventional ocular hypotony (IOP < 6 mm Hg) but also in eyes with IOP between 7 and 10 mm Hg.

Serous retinal detachment accompanied by pachychoroid in hypotony maculopathy after trabeculectomy for diabetic neovascular glaucoma

Purpose

Two diabetic case reports of serous retinal detachment (SRD) accompanied by pachychoroid in hypotony maculopathy after trabeculectomy for neovascular glaucoma (NVG).

Observations

Case 1: A 66-year-old female with stage 3 NVG and decreased vision acuity in the left eye. After trabeculectomy, postoperative laser suture lysis (LSL) resulted in development of hypotony maculopathy, followed by pachychoroid and SRD. Injection of C3F8 gas in the anterior chamber was unsuccessful and transconjunctival scleral re-suturing was performed. Intraocular pressure (IOP) consequently increased and SRD improved. Case 2: A 60-year-old man with stage 2 NVG and decreased vision acuity in the right eye. Trabeculectomy was uneventful, but postoperative LSL also resulted in development of hypotony maculopathy followed by pachychroid and SRD. Intravitreal bevacizumab injection had no effect and transconjunctival flap re-suturing was performed. IOP consequently increased and SRD improved.

Conclusions

SRD accompanied by pachychoroid was observed in hypotony maculopathy in diabetic cases. VEGF-independent exudative change in hypotony maculopathy may be due to hydrostatic pressure elevation in choroidal blood vessels based on Starling's hypothesis with the consequent breakdown of retinal pigment epithelium barrier in diabetic patients.

Concurrent Phacoemulsification and Encircling for Hypotony Maculopathy after Blunt Trauma

A 37-year-old Japanese man had his right eye hit by a fist. His right eye developed hypotony maculopathy and secondary cataract, and his visual acuity decreased to 20/200 with an intraocular pressure of 4 mmHg. He underwent phacoemulsification and aspiration, implantation of the intraocular lens, and encircling with a silicone tire. His visual acuity improved to 20/20 and stable for more than one year postoperatively. The intraocular pressure in his right eye increased to 12 mmHg, and maculopathy was resolved entirely. It was suggested that an encircling buckle obstructed the uveoscleral outflow through the cyclodialysis and increased intraocular pressure. Concurrent cataract surgery and encircling was sufficient to improve the vision.

Bleb reconstruction using donor scleral patch graft for late bleb leak and hypotony

PURPOSE

Bleb dysfunction may occur as a late complication following glaucoma filtration surgery. Over-filtering, thinning and cystic blebs can lead to hypotony, leak and corneal dellen. We report our surgical management and outcomes of this specific entity using donor scleral patch grafts.

METHODS

This is a 10-year non-comparative, retrospective interventional case series. Bleb reconstruction involved excision of encysted conjunctiva and sclera to identify the original fistula. A functioning donor scleral patch graft was sited over this with fixed and releasable sutures and the conjunctiva advanced. Intraocular pressure, visual acuity and post-operative issues were assessed.

RESULTS

A total of 18 eyes of 17 patients with mean age 65 years (standard deviation 13.5) were included. Trabeculectomy was the primary procedure in 72% (n = 13) and deep sclerectomy in 28% (n = 5). Bleb leak accounted for 61% (n = 11), hypotony 33% (n = 6) and corneal dellen 6% (n = 1). Mean pre-operative intraocular pressure was 7 mm Hg (standard deviation 4.6) which increased to 18.5 mm Hg (standard deviation 12) at day 1 (p < 0.001), 11.8 mm Hg (standard deviation 4.6) at 3 months (p < 0.05), 12.1 mm Hg (standard deviation 4.2) at 1 year (p < 0.01) which was maintained at 12.1 mm Hg (standard deviation 5.3) at last follow-up (p < 0.001). Post-operative interventions included bleb needling, re-suturing, suture removal, further glaucoma management, bleb leak and cataract surgery. Visual acuity also improved post-operatively and was maintained.

CONCLUSION

Reconstruction of the filtering bleb architecture with donor sclera results in improved intraocular pressure while maintaining visual acuity. Post-operative care is required to support the restored bleb function. Our findings support the use of scleral patch graft as an effective and safe method for the long-term management of hypotony and bleb leak as a late complication of glaucoma filtration surgery.

Learning from the past: Mitomycin C use in trabeculectomy and its application in bleb-forming minimally invasive glaucoma surgery

Trabeculectomy has been performed since the mid-1960s and remains the gold standard for glaucoma surgery. Newer surgical options have evolved, collectively referred to as minimally invasive glaucoma surgeries. Despite producing large intraocular pressure decreases, full-thickness procedures into the subconjunctival space may be limited by fibrosis. Mitomycin C (MMC) and 5-fluorouracil have been in use with trabeculectomy with good evidence of significantly increased success at the cost, however, of an increased risk of complications. Off-label MMC application can be found in almost all clinical trials, including in combination with minimally invasive glaucoma surgeries. We explore current evidence for MMC use in trabeculectomy and how this may differ for minimally invasive glaucoma surgery devices and analyze the range of agents and doses that are used. Although we found that most studies could not show any correlation between MMC dosage and the surgical outcome, the success rates with the Xen® microshunt seemed to be higher when using 20 mcg of MMC than when using 10 mcg. Certain important methodological considerations make this hard to confirm definitively, and other factors such as placement of the device may play a more substantial role. For the PreserFlo® microshunt, preliminary data suggest higher success rates with higher MMC dosage at the cost of higher device-related adverse events and reoperations. Although the ideal dose still needs to be established, it seems very likely that MMC provides significant improvement in outcomes in bleb-forming minimally invasive glaucoma procedures.

From international ophthalmology to space ophthalmology: the threats to vision on the way to Moon and Mars colonization

PURPOSE

To report the ophthalmological risks of space travel.

METHODS

The literature about the effect of microgravity and cosmic radiation on the human eye has been reviewed, focusing on the so-called "spaceflight related neuro-ocular syndrome (SANS)", and possible remedies.

RESULTS

The eye is the major candidate to suffer from the adverse space conditions, so much so that SANS is the main concern of the National Aeronautics and Space Administration (NASA). SANS, that affects astronauts engaged in long-duration spaceflights, is characterized by optic nerve head swelling, flattening of the posterior region of the scleral shell, choroidal folds, retinal cotton wool spots, and hyperopic shift. Even if it seems related to an increased volume of the cerebrospinal fluid in the brain and the optic nerve sheaths, its pathogenesis is still unclear. In addition, cataract is related to the effect of galactic cosmic rays on the lens. Centrifuges, pressurizing chambers, and mechanical counter-pressure suits have been advanced to counteract the upward fluid shift responsible for the SANS syndrome. Shields with a high content of hydrogen, magnetic shielding systems, and wearable radiation shielding devices are under study to mitigate the exposure to galactic cosmic rays.

CONCLUSIONS

Since 1961, the year of the first manned mission outside the Earth, history has shown that the human being may venture in space. Yet, visual impairment is the top health risk for long-duration spaceflight. Effective remediation is mandatory in anticipation of long space missions and Moon and Mars colonization.

Hypotony maculopathy: a surgeon's nightmare

A 14-year-old myopic male patient diagnosed as steroid-induced glaucoma and cataract elsewhere presented to the eye opd with painless and progressive diminution of vision in the right eye (oculus dexter (OD)) for last 6 months. Phacotrabeculectomy was already done in the left eye (oculus sinister (OS)) 1 year ago and he was on topical latanoprost e/d-H.S in OD and brimonidine e/d-BD and dorzolamide e/d-TDS in both eyes (oculus uterque (OU)) postsurgery. Uneventful phacotrabeculectomy was performed in the right eye under 300 mL intravenous injection mannitol. He developed hypotony maculopathy postsurgery which was managed conservatively.

Transduction Pattern of AAVs in the Trabecular Meshwork and Anterior-Segment Structures in a Rat Model of Ocular Hypertension

Adeno-associated viruses (AAVs) are the vector of choice for gene therapy in the eye, and self-complementary AAVs (scAAVs), which do not require second-strand DNA synthesis, can be transduced into cells of the trabecular meshwork (TM). The scAAV transduction patterns in the anterior segment of normotensive eyes have been investigated previously, but those in ocular hypertensive (OHT) eyes have not. We assessed the transduction efficiencies of AAV serotypes 2, 5, and 8 in the anterior-segment structures of the eyes of Sprague-Dawley rats with OHT by circumlimbal suturing, followed 3 days later by intracameral injection of scAAV serotype 2 (scAAV2), scAAV5, or scAAV8 packaged with EGFP. The transduction of scAAV2 and scAAV5 in the TM of OHT rats was markedly enhanced after 1 month, and transduction of scAAV5 was more efficient than that of scAAV2; transduction of scAAV8 into the TM did not occur. The transduction of scAAV2, scAAV5, and scAAV8 was enhanced in the ciliary body, iris, and corneal endothelium of the OHT eyes for 3 months. The expression levels of receptors for scAAV2 and scAAV5 were significantly increased in the OHT compared with control eyes. The results demonstrated that scAAV2 and scAAV5 target the ciliary body and TM in OHT eyes, and that the OHT-related changes in anterior-segment structures enhance scAAV transduction.

Short-term Optic Disc Cupping Reversal in a Patient With Mild Juvenile Open-angle Glaucoma Due to Early Idiopathic Intracranial Hypertension

PURPOSE

The purpose of this study was to report a case of optic disc cupping reversal in an adult without significant intraocular pressure-lowering treatment.

PATIENT

A 20-year-old female with a history of mild juvenile open-angle glaucoma who developed subjective blurred vision and a decrease in cupping of her optic discs.

RESULTS

Dilated examination demonstrated decreased cup-to-disc ratios in both eyes with a slight blurring of the disc margin in the right eye. The appearance of both optic discs returned to baseline after weight loss therapy.

CONCLUSIONS

An unexplained reduction of optic nerve cup-to-disc ratio should prompt a workup for other etiologies, such as increased intracranial pressure. Baseline photographs not subjected to computerized scan obsolescence are extremely useful in monitoring the long-term appearance of asymmetric optic discs as an adjunct to the clinical examination.

The treatment of ocular hypotony after trabeculectomy with a scleral lens: A case series

PURPOSE

Ocular hypotony after trabeculectomy may be treated medically, surgically and with a tamponade. Three cases are reported in which a scleral lens was applied to treat ocular hypotony after mitomycin C (MMC) augmented trabeculectomy.

METHODS

In this retrospective case series the records of three eyes of three patients who developed ocular hypotony after they had undergone trabeculectomy augmented with MMC were evaluated. The patients were between 11 and 69 years of age and the intraocular pressure (IOP) after surgery ranged between 3 and 6 mmHg. All three patients showed a negative Seidel test; one had suspected hypotonic maculopathy and one had a collapsed anterior chamber. After unsuccessful treatment with large bandage lenses all three patients were subsequently fitted with a scleral lens. The scleral lens was fitted to fully cover and compress the bleb. Scleral lenses were worn continuously with a check-up after one night of wear and subsequent check-ups when needed. One patient continued to wear the scleral lens for a further 6.5 months on a daily wear basis.

RESULTS

In all three eyes the IOP was higher after wearing the scleral lens. Two patients stopped wearing the scleral lens after the IOP was stable. One patient developed a cataract; the cataract surgery was combined with a bleb revision and scleral lens wear was therefore discontinued.

DISCUSSION

The scleral lens might be a useful tool in the treatment of ocular hypotony after trabeculectomy augmented MMC surgery. The effect of the scleral lens on the ocular pressure is unpredictable. Caution is advised in vulnerable corneas due to risk factors such as hypoxia and infection. Further research is warranted to establish the safety of the procedure, the patient selection and the overall success in a larger patient group.

Inner, outer, and full-thickness retinal folds after rhegmatogenous retinal detachment repair: A review

Partial-thickness folds of the inner retina and outer retina, as well as full-thickness retinal folds, may occur after the repair of rhegmatogenous retinal detachment. Although these can look similar on clinical examination, imaging with optical coherence tomography facilitates differentiation. With optical coherence tomography analysis, inner retinal folds exhibit corrugations of the inner retina while outer retinal folds display hyperreflective lesions located just above the retinal pigment epithelium that may extend into the outer nuclear layer. In the case of a classic full-thickness retinal fold, all layers of the neurosensory retina may separate together from the retinal pigment epithelium with retinal reduplication and base-to-base photoreceptor orientation. We review the pathogenesis, risk factors, prevention, and management options of retinal folds. As the terminology for retinal folds is diverse, we highlight optical coherence tomography-based descriptions for retinal folds that have been used in the literature. Factors predicting visual recovery, mechanisms of spontaneous fold regression, and the effect of internal limiting membrane peeling on the incidence of folds are potential areas of future study.