Ocular Hypertension Research Articles

The effect of continuous positive airway pressure therapy on intraocular pressure in patients with OSA: a systematic review and meta-analysis.

To assess the effect of continuous positive airway pressure (CPAP) therapy on intraocular pressure in Obstructive sleep apnea (OSA) patients. The search was performed in Ovid Medline and Embase database then followed by a manual bibliography search. Abstract search and screening were independently performed followed by eligible full-text versions reviewed. Then disagreements were discussed in a group. This systematic review and meta-analysis considered 15 studies with 495 participants. The pooled mean intraocular pressure after CPAP therapy shows no significant difference compared to the baseline (MD, 0.58 mmHg; 95% CI, -0.33 to 1.19). Subgroup analysis shows significantly higher intraocular pressure after in-lab PAP titration and after long-term CPAP used (MD, 4.28 mmHg; 95% CI, 0.91 to 7.66; MD, 0.45 mmHg; 95% CI, 0.07 to 0.83; respectively). Ocular perfusion pressure was also significantly decreased after CPAP therapy. (MD, -2.15 mmHg; 95% CI, -3.50 to -0.80). The pooled data showed no significant difference in RNFL thickness and macular layer thickness. After long-term treatments CPAP therapy, there is a significant increase in intraocular pressure in patients with OSA and a decrease in ocular perfusion pressure but did not show a significant difference in other ophthalmologic parameters. For this reason, CPAP usage in glaucoma patients necessitates to be done cautiously. This systematic review protocol was registered with PROSPERO (registration number CRD42022370734).

A Systematic Review of Micropulse Laser Trabeculoplasty (MLT) in Primary Open-Angle Glaucoma (POAG) Management: Efficacy, Safety, and Future Perspectives

Background/Objectives: Micropulse laser trabeculoplasty (MLT) is gaining attention as a non-invasive treatment option for primary open-angle glaucoma (POAG), offering an alternative to traditional surgeries and medications. This systematic review evaluates the effectiveness, safety, and potential of MLT in glaucoma management. Methods: This review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The strength of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, following the 2011 Oxford Centre for Evidence-Based Medicine (OCEBM) recommendations. Results: We identified 79 articles, and after removing duplicates and screening abstracts, 56 articles were eligible for further review. A detailed full-text analysis was conducted on 26 articles, of which 15 met the predefined inclusion criteria. Conclusions: MLT shows promise as a primary or adjunctive treatment for reducing intraocular pressure (IOP) in glaucoma and ocular hypertension patients. Current evidence supports its efficacy and safety; however, additional long-term studies are needed to confirm its durability and compare its effectiveness with traditional surgical and pharmacological approaches. Standardizing treatment protocols and refining patient selection criteria could enhance MLT’s clinical value and support its broader adoption in glaucoma care.

Advancements in nanotechnology for glaucoma detection and treatment: A focus on biosensors, IOP monitoring, and nano-drug delivery systems

Biosensors are essential tools designed to monitor physiologically significant data for diverse applications, including environmental pollution detection, food safety, medication research, and disease diagnosis. The integration of microfluidics, nanotechnology, and advanced electronics has significantly advanced the development of wearable and implantable biosensors for managing chronic diseases such as cancer, diabetes, and glaucoma. Among these, glaucoma remains a leading cause of visual impairment, predominantly driven by elevated intraocular pressure (IOP), with limited treatment effectiveness due to challenges like suboptimal drug bioavailability and therapeutic inefficiency. Despite advances, unmet needs in early diagnosis and sustained management persist, demanding innovative solutions.Recent advancements in nanotechnology offer transformative potential, addressing these challenges by enhancing both the detection and treatment of ocular diseases. This review explores cutting-edge developments in nano-drug delivery systems and continuous IOP monitoring technologies. Particular emphasis is placed on nanoparticle and nanofiber-based biosensors and contact lenses, which represent a promising leap forward in improving therapeutic precision and patient outcomes in glaucoma care. The manuscript uniquely contributes by synthesizing these advancements and highlighting their potential to bridge existing gaps in glaucoma management.

Development and Evaluation of Polymethacrylate-Based Ophthalmic Nanofiber Inserts Containing Dual Drug-Loaded Dorzolamide and Timolol: In Vivo Study in Rabbit’s Eye

Background/objectives: The aim of the study was to create a nanofiber insert incorporating Timolol (TIM) and Dorzolamide (DOR), targeting the management of glaucoma. This condition encompasses a variety of chronic, advancing ocular disorders typically associated with elevated intraocular pressure (IOP). Methods: The insert was made of Eudragite RL100 (EUD) polymer, a biocompatible material with high bioavailability, using the electrospinning method. The inserts were studied for morphology, drug–polymer interaction, physicochemical properties, and in vitro drug-release study. The pharmacokinetic properties of fibers were examined alongside consideration for irritation using a rabbit model and cell compatibility. Results: The results of the in vitro drug-release test showed retention and controlled release of both DOR/TIM over 80 h. Morphological examination demonstrated uniform nanofibers with mean diameters < 465 nm. The cell compatibility test showed a high percentage of cell survival, and none of the formulations irritated the rabbit’s eye. The Area Under the Curve (AUC0-72) for DOR and TIM in EDT formulations was approximately 3216.63 ± 63.25 µg·h/mL and 2598.89 ± 46.65 µg·h/mL, respectively, with Mean Residence Times (MRTs) of approximately 21.6 ± 0.19 h and 16.29 ± 6.44 h. Conclusions: Based on the results, the dual drug-loaded nanofiber preservative-free system can potentially be a suitable alternative to eye drops and can be used to reduce fluctuation and dose frequency.

Impact of diabetes mellitus on tear secretion, intraocular pressure, and contrast sensitivity: A comparative study of controlled and uncontrolled diabetics

Diabetes mellitus (DM) is a prevalent metabolic disorder associated with systemic and ocular complications that impair visual function. This study evaluates the impact of DM on tear secretion, intraocular pressure (IOP), and contrast sensitivity (CS), and explores the relationship between DM duration and these parameters.To compare tear secretion, IOP, and CS in non-diabetic individuals and diabetic patients with controlled and uncontrolled DM, and to assess the influence of DM duration on these ocular measures.This prospective observational study was conducted from August 2023 to July 2024 at a tertiary eye care center in Surat, India, with 150 participants (300 eyes). Participants were divided into three groups: 50 non-diabetic controls, 50 with controlled DM (HbA1c ≤7), and 50 with uncontrolled DM (HbA1c >7). Tear secretion was measured using the Schirmer test, CS with the Pelli-Robson chart, and IOP using non-contact tonometry. Statistical analysis included ANOVA for group comparisons and Pearson correlation to assess relationships with DM duration.Diabetic patients had significantly lower tear secretion (controlled DM: 12mm; uncontrolled DM: 8mm) than non-diabetic controls (18 mm; p <0.05). CS was also reduced in diabetic groups, with controlled DM patients averaging 1.4 log units and uncontrolled DM patients 1.1 log units, compared to 1.9 log units in controls (p <0.05). IOP was higher in diabetic groups but not statistically significant. DM duration positively correlated with reduced CS (r = 0.45, p <0.05) but not with tear secretion or IOP.DM significantly impairs ocular health, evidenced by elevated IOP, reduced tear secretion, and diminished CS, particularly in uncontrolled cases. While DM duration is strongly associated with progressive CS decline, it does not significantly affect tear secretion or IOP. These findings underscore the need for routine ocular assessments and effective glycemic control to prevent visual complications in diabetic patients.

Aging-enhanced autophagy activity promotes fibrotic progression via the TGF-β2/Smad signaling pathway in trabecular meshwork cells—a new insight from POAG

IntroductionGlaucoma, a leading cause of irreversible blindness, is characterized by optic neuropathy and retinopathy, with primary open-angle glaucoma (POAG) being the most prevalent form. The primary pathogenic mechanism of POAG involves elevated intraocular pressure caused by chronic fibrosis of the trabecular meshwork (TM). Autophagy, a critical process for maintaining cellular homeostasis, has been implicated in fibrosis across various organs. However, its precise role in the fibrosis associated with POAG pathogenesis remains unclear. This study investigates the involvement of autophagy in TM fibrosis and explores its potential impact on POAG development, aiming to provide insights into new therapeutic targets.MethodsTo assess autophagy activity and its relationship with fibrosis, we analyzed TM tissues from POAG patients and healthy donors. Autophagic activity in human TM tissues was measured through immunohistochemical analyses. An in vitro aging model using chronic H2O2 treatment was established to investigate the change of fibrosis in TM cells. Additionally, we used dexamethasone-treated TM cells as a POAG model to explore the role of autophagy in fibrotic progression. The involvement of the TGF-β2/Smad signaling pathway was investigated through western blot analysis and quantitative real-time PCR.ResultsThis study reveals increased autophagic activity in tissues from POAG patients and an age-related upregulation of autophagy in healthy human TM tissues. In the H2O2-induced aging model, TM cells displayed both elevated autophagic activity and fibrosis. Further investigation showed that enhanced autophagy activity promoted fibrotic progression via activation of the TGF-β2/Smad signaling pathway. Similarly, in the dexamethasone-treated TM cell model, autophagy was found to exacerbate fibrosis, aligning with observations in the aging model.DiscussionIn this study, we uncover the interplay between autophagy and the TGF-β2/Smad pathway in the pathogenesis of POAG. We observed increased autophagic activity in TM tissues from POAG patients and in TM tissues of aging healthy individuals. In human primary TM cells, we confirmed that autophagy becomes activated in the context of cellular senescence and the development of POAG, which further facilitates fibrotic progression via the TGF-β2/Smad signaling pathway. These findings underscore the important role of autophagy in POAG pathogenesis and confirm senescence as a pivotal risk factor.

Short-Term Safety and Efficacy of PreserFlo™ Microshunt in Patients with Refractory Intraocular Pressure Elevation After Dexamethasone Implant Intravitreal Injection

Background: The PreserFlo™ MicroShunt (PFMS) is a bleb-forming device considered to be less invasive than traditional glaucoma surgery such as trabeculectomy. This study evaluates the 1-year success rates as well as safety profile of PFMS in patients having high intraocular pressure (IOP) and/or glaucoma refractory to drop therapy with a history of prior intravitreal dexamethasone therapy. Methods: A total of 16 eyes after PFMS implantation due to elevated IOP after intravitreal dexamethasone implant (DEX-I) administration were included in this retrospective cohort study. Success rates and secondary outcomes were evaluated. Results: Qualified and complete success rates at 12 months, respectively, were 14/16 and 12/16 eyes for criterion A, 13/16 and 11/16 eyes for B, 13/16 and 11/16 eyes for C, and 6/16 and 6/16 eyes for D. The overall mean (range) preoperative IOP decreased from 27 (16–38) mmHg to 13 (10–17) mmHg at 12 months. BCVA was not significantly different up to 12 months (p = 0.63). The preoperative mean (range) number of medications decreased from 3.56 (2–4) to 0.31 (0–3) at 12 months. One eye underwent needling twice, and two eyes were revised surgically. One patient needed replacement of the PFMS. There were no hypotony-related complications. Conclusions: The PFMS is an effective surgical option for patients with steroid-induced IOP elevation. It demonstrates satisfactory short-term success rates, a reduced need for pressure-lowering eye drops, an excellent safety profile with minimal postoperative care, and a low complication rate. Additional interventions such as needling or revisions were infrequently necessary. However, PFMS may not be the ideal choice for cases requiring a low target pressure (≤12 mmHg).

Conversion to Glaucoma After Ocular Trauma in Pediatric Patients

Background: The outcomes of pediatric glaucoma suspects with a history of ocular trauma remains unknown; we describe the rate of conversion to glaucoma of this population of patients at a research-intensive academic center. Methods: We conducted a retrospective case series of pediatric patients with a history of open- or closed-globe trauma who were being monitored as pediatric glaucoma suspects at the Wilmer Eye Institute between 2005 and 2016. Results: A total of 62 eyes from 62 patients with a history of ocular trauma were identified with a median age at presentation of 9.7 years (7.8 years) and a median follow-up of 2.7 (5.8 years). There were 29 eyes (46.8%) with open-globe injuries and 33 eyes (53.2%) with closed-globe injuries. A higher proportion of eyes that sustained closed-globe injuries were started on topical therapy for persistent ocular hypertension than eyes that sustained open-globe injuries (36.4% versus 10.3%, X2 = 5.6976, p = 0.017). Five eyes (8.1%) developed glaucoma during the follow-up period, all of which had a history of closed-globe injury (15.2%, X2 = 4.7794, p = 0.029). Four eyes of these eyes underwent glaucoma-related surgical intervention. Most eyes (3/5, 60%) that went on to develop post-traumatic glaucoma had undergone additional and/or concurrent intraocular surgical interventions to address sequelae of ocular trauma, such as traumatic cataract and retinal detachment. Conclusions: All eyes that developed glaucomatous damage or underwent glaucoma-related surgical intervention in this cohort of patients with a history of ocular trauma were those that had sustained close-globe injuries. No eyes that sustained open-globe injury progressed to glaucoma.

Optimizing outcomes in phacoemulsification: Addressing intraoperative and postoperative complications in a case series from Iraq

Background Phacoemulsification is still considered the most performed surgery in the field of cataract extraction, boasting one of the highest successes of all surgical procedures. However, complications of posterior capsular rupture (PCR) and increased intra-ocular pressure (IOP) bear the potential for great risk, especially in patients with comorbidities such as diabetes or advanced age. Methods A retrospective analysis of 31 cases regarding patients undergoing phacoemulsification in a private ophthalmology clinic in Baghdad was done by noting intraoperative and postoperative complications. A systematic review is also carried out so that findings could be contextualized; studies have been sourced from both PubMed and Scopus databases. Our review covered studies that researched complications such as PCR, increased IOP, and corneal edema, chronicling developments in surgical techniques and patient management. Results The case series resulted in a postoperative best-corrected visual acuity of 6/6 in 35.5% of the patients in the right eye and 29% in the left eye. This series was associated with PCR and raised IOP; however, appropriate management ensured good improvement in vision for the majority of cases. The systematic review supports these findings, pointing out that contemporary surgical procedures and personalized attention can reduce complications substantially, even among high-risk patients. Conclusion Case series and systematic review bring forth the importance of meticulous surgical techniques combined with early recognition of risk factors and personalized postoperative management in attempting to minimize complications. These findings point to the implication of an ideal strategy in handling complications from phacoemulsification, but also have shown that continuing improvement in the surgical and postoperative protocols could further improve patient outcomes, especially those very highly at-risk.

Bilateral conspicuous iris configuration and elevation of intraocular pressure of unclear origin

Bilateral conspicuous iris configuration and elevation of intraocular pressure of unclear origin

Evaluation of a modified sutureless technique for scleral fixation of one-piece posterior chamber intraocular lens: a retrospective study

BackgroundThis study presents the one-year outcomes of a modified technique for transscleral suture fixation of a posterior chamber intraocular lens (PCIOL) in aphakic eyes.MethodsA retrospective chart review was conducted on 45 patients who underwent transscleral suture fixation of a foldable one-piece PCIOL through scleral pockets. Preoperative data and follow-up data for a minimum of 12 months were collected for all patients.ResultsThe mean preoperative and postoperative uncorrected distance visual acuity (UDVA) in LogMAR was 2.49 ± 0.54 and 0.54 ± 0.25, respectively (p < 0.01). The mean preoperative and postoperative best-corrected visual acuity (BCVA) in LogMAR was 0.52 ± 0.22 and 0.45 ± 0.24, respectively (p < 0.01). The mean endothelial cell loss was 110.46 ± 11.5 cells/mm2. Postoperative complications included transient corneal edema (17.7%), transient elevated intraocular pressure (22.2%), and non-significant vitreous hemorrhage (11.1%). No severe complications were observed.ConclusionThe modified technique provides stable PCIOL placement in aphakic eyes with long-term follow-up.

Rapamycin protects glucocorticoid-induced glaucoma model mice against trabecular meshwork fibrosis by suppressing mTORC1/2 signaling.

Systemic or local use of glucocorticoids (GCs) can induce pathological elevation of intraocular pressure (IOP), potentially leading to permanent visual loss. Previous studies have demonstrated that rapamycin (Rapa) inhibits the activation of retinal glial cells and the production of neuroinflammation, achieving neuroprotective goals. However, there has been little research on the effect of Rapa on the trabecular meshwork (TM). This study aimed to investigate the protective effect and potential mechanism of Rapa in a glucocorticoid-induced glaucoma (GIG) model. Our findings indicate that Rapa significantly inhibited the IOP increase induced by dexamethasone acetate (Dex-Ac) and improved TM fibrosis and retinal ganglion cell (RGC) damage. In cultured human trabecular meshwork cells (HTMCs) treated with dexamethasone (Dex) and Rapa under different conditions revealed that Rapa inhibits Dex-induced HTMC fibrosis and cytoskeletal changes. This effect may result from the specific suppression of the mechanistic target of rapamycin complex 1 (mTORC1) pathway by Rapa, which reduces abnormal extracellular matrix (ECM) deposition. Alternatively, the improvement in cytoskeleton entanglement might be due to the inhibition of the mechanistic target of rapamycin complex2 (mTORC2) pathway. These two potential mechanisms may collectively contribute to the protective effects of Rapa in GIG. This study provides a new theoretical basis for using of Rapa in the treatment of GIG.

Risk for Ocular Hypertension With Intravitreal Dexamethasone Implants in Black and White Patients With Diabetic Macular Edema.

Purpose: To compare the effects of intravitreal (IVT) 0.7 mg dexamethasone implants on the intraocular pressure (IOP) in Black patients and White patients with diabetic macular edema (DME). Methods: A retrospective cohort study was performed of Black patients and White patients with DME who received dexamethasone implants with 12 or more months of follow-up. Results: The study included 145 eyes (69 Black; 76 White) with a mean (±SD) of 3.6 ± 3.9 dexamethasone implants and 58 ± 31 months of follow-up. Black patients had higher baseline rates of glaucoma (23% vs 8%; P = .010) but similar rates of ocular hypertension after receiving IVT dexamethasone (20% vs 16%; P = .52). By the last follow-up visit, the mean central subfield thickness had decreased from 387 ± 129 µm to 314 ± 104 µm (P < .001). Conclusions: IVT dexamethasone implants decreased macular thicknesses in patients with DME; however, there was no difference in the rate of ocular hypertension after IVT dexamethasone between Black patients and White patients.

Intravitreal Sustained Release Steroid Implants Are Safe and Effective in Patients With Glaucoma Drainage Devices.

To describe effects of sustained-release steroid delivery devices on intraocular pressure (IOP) in eyes with glaucoma drainage devices (GDD). Retrospective case series of eyes with steroid implants (dexamethasone or fluocinolone acetonide) and prior GDD (Ahmed, Baerveldt) without uveitis. Outcomes included IOP, IOP rise, central foveal thickness (CFT), and IOP medications. We included 14 eyes (14 patients, 38% male, 94% pseudophakic). Mean age at steroid implantation was 64 ± 12 years. Baerveldt (64%) was more common than Ahmed (36%). Tubes were in the anterior chamber (57.1%), sulcus (28.6%), and pars plana (14.3%). Ozurdex (93%) was more common than Yutiq (7%). Mean IOP was 13.5 ± 3.4 mmHg pre-implant, 11.8 ± 3.7 mmHg at month 1, 13.3 ± 3.6 mmHg at month 3 (p=0.35), and 11.3 ± 3.8 mmHg at 1 year (p=0.032). Mean antihypertensive medications was unchanged at month 3 (p = 1.0), and -0.36 medications at last follow-up (p = 0.35). Mean CFT change was -204 ± 158 μm (p = 0.001). There were no cases of endophthalmitis. Intravitreal steroid implants were safe and effective for the treatment of post-surgical CME in patients with pre-existing GDD. There was no increase in IOP and no increase in antihypertensive drops.

Bioequivalence of Preservative-free and Preserved Omidenepag Isopropyl (OMDI) 0.002% Ophthalmic Solutions in Patients with Primary Open-Angle Glaucoma or Ocular Hypertension: Results from the Phase 3 DAISY Study

Précis: Preservative-free omidenepag isopropyl (OMDI) 0.002% ophthalmic solution and OMDI 0.002% ophthalmic solution preserved with benzalkonium chloride were bioequivalent in lowering intraocular pressure after 4 weeks’ treatment in patients with primary open-angle glaucoma or ocular hypertension. Purpose: Preservatives in ophthalmic solutions for lowering intraocular pressure (IOP) are associated with ocular surface disease. The DAISY study evaluated the bioequivalence of preservative-free omidenepag isopropyl (OMDI) 0.002% ophthalmic solution (DE-117B), with OMDI 0.002% preserved with benzalkonium chloride (BAK). Methods: DAISY was a phase 3, randomized, evaluator-masked, crossover study conducted in Japan. Patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT) were randomized 1:1 to DE-117B or OMDI 0.002% for 4 weeks (period 1) then crossed over for 4 weeks (period 2). A 4-week washout preceded both periods. The primary efficacy endpoint was mean diurnal (MD) IOP at Week 4 (combined periods 1 and 2). Bioequivalence between DE-117B and OMDI was defined as 95% confidence interval (CI) between −1.5 and 1.5 for least-squares (LS) mean between-group difference in MD IOP. Adverse events were monitored. Results: Of 74 patients enrolled, 38 were randomized to DE-117B then OMDI, and 36 were randomized to OMDI then DE-117B. DE-117B and OMDI demonstrated bioequivalence at Week 4 (MD IOP±standard deviation in summary statistics: 17.76±2.05 mm Hg [DE-117B] vs. 17.71±2.01 mm Hg [OMDI]; LS mean±standard error between-group difference in linear mixed effects model: −0.02±0.18 mm Hg [95% CI −0.38 to 0.35]). DE-117B versus OMDI was associated with numerically lower overall ocular discomfort. Conclusions: Preservative-free DE-117B and BAK-containing OMDI were bioequivalent in lowering IOP after 4 weeks’ treatment in Japanese patients with POAG or OHT. DE-117B was well tolerated with a similar safety profile to OMDI.

TREATMENT OF EARLY POSTOPERATIVE COMPLICATIONS IN CHILDREN WITH PRIMARY CONGENITAL GLAUCOMA

Purpose – to study the nature of early postoperative complications in children with primary congenital glaucoma and methods of their correction after antiglaucoma surgery using a combined method with a simultaneous effect on three outflow tracts. Material and methods The total number of children who underwent antiglaucoma surgery using the combined method (simultaneous impact on the outflow tracts in three directions: sinus trabeculectomy according to Burian in the scleral sinus, cyclodialysis-cycloretraction with autoscleral pedicle into the suprachoroidal space, basal iridectomy with sclerectomy beneath the scleral flap into the episcleral venous system) was 151 (270 eyes). Results On the first postoperative day following antiglaucoma surgery, the incidence of early postoperative complications was 62.6%, which increased to 67.4% by the third day. Among these, the highest proportion of patients presented with severe hypotony – 33.3%, hyphema – 10.0%, and ocular hypertension – 6.7%. After conservative treatment, the incidence of complications in children decreased to 10% by the seventh postoperative day. Conclusion Thus, following conservative treatment, the incidence of complications in the early postoperative period decreased by 52.6%. There was no need for repeated surgical intervention in these patients. Patients were discharged home under the supervision of an ophthalmologist at their place of residence. Key words: primary congenital glaucoma, glaucoma surgery, early postoperative complications

SOME FEATURES OF LINEAR AND ANGULAR PARAMETERS OF THE EYE’S ANTERIOR SEGMENT IN PATIENTS WITH OCULAR HYPERTENSION AND GLAUCOMA

Purpose – detection of some features of the relationship between anterior segment structures in eyes with ocular hypertension and primary glaucoma using ultrasound biomicroscopy (UBM). Material and methods A total of 60 patients (60 eyes) aged 27-60 years (46.6±11.4) with ophthalmic hypertension (n=7) and primary glaucoma (n=53) (0-2 stages in accordance with Mills glaucoma classification) were examined. They were divided into 3 groups in accordance with the axial length (AL): 16 short (&lt;23.0mm), 23 medium (23.0-24.5mm) and 11 long eyes (&gt;24.5mm). Main linear (mm) and angular (°) parameters of the eye’s anterior segment were measured using UBM (Ellex Eye Cubed, 40 MHz, Ellex Inc., Australia). Results The anterior chamber depth in short eyes was measured as 2.11±0.05, in medium – 2.47±0.04, in long – 3.02±0.06, posterior chamber depth: 0.58 ± 0.04, 0.65 ± 0.03, 0.69 ± 0.05. Iris thickness in root zone was 0.34±0.02, 0.34±0.01, 0.33±0.03. Ciliary body thickness at 1 mm from scleral spur: 0.47±0.03, 0.55±0.04, 0.62±0.05, at 2 mm: 0.28±0.03, 0.33±0.02, 0.38±0.03 respectively. “Trabecula-iris” distances at 250 µm from the scleral spur was: 0.09±0.03, 0.12±0.03, 0.21±0.04, at 500 µm: 0.14±0.02, 0.18±0.03, 0.27±0.03. “Trabecula-ciliary processes” was 0.65±0.05, 0.87±0.04, 1.07±0.06, length of Zinn zonules – 0.33±0.05, 0.52±0.04, 0.71±0.06 respectively. Anterior chamber angle (at 12´) was 16.34±5.65, 22.49±3.85, 27.04±3.23, “sclera-iris” angle: 15.80±2.34, 19.56±1.12, 24.97±1.59, “sclera-ciliary processes” angle – 38.21±2.44, 48.69±2.97, 51.22±3.66. Almost all patients had a predominantly flat iris profile, in short eyes it was more convex and anterior positioned, in long eyes – a straight iris profile combined with predominant posterior position, but in several cases – a concave profile. Conclusion Anterior chamber depth in combination with different AL is the most important factor in spatial arrangement of the eye's anterior segment structure. In eyes with a short AL a shallow posterior chamber depth, adjoining the iris to trabecula and partial coverage of posterior chamber by ciliary processes were observed. There were some difficulties in visualizing Zinn zonules due to coverage by ciliary processes and their adjoining to the root zone of iris in medium and long eyes. A flat iris profile was found in all 3 groups of glaucoma patients, but in eyes with medium and high AL it was more convex. Key words: ultrasound biomicroscopy, glaucoma, ocular hypertension, biometry

COMBINED USE OF TRANSSCLERAL DIODE LASER CYCLOPHOTOCOAGULATION AND INTRAVITREAL ANTI-VEGF INJECTION IN THE TREATMENT OF REFRACTORY NEOVASCULAR GLAUCOMA

Purpose – is to assess the effectiveness of combined intravitreal anti-VEGF injection with transscleral diode laser cyclophotocoagulation (TDLC) in the treatment of refractory neovascular glaucoma. Materials and methods The study included 20 patients (20 eye) diagnosed with refractory neovascular glaucoma in one eye. Among them, 14 (70%) developed the condition due to proliferative diabetic retinopathy, and 6 (30%) due to ischemic central retinal vein occlusion. All patients were divided into two groups. In the first group (I), TDLC was performed (10 patients, 10 eye), whereas in the second group (II), an intravitreal injection of Bevacizumab was administered 14 days prior to the procedure as part of a combined therapy (10 patients, 10 eye). Results In the I group, despite improvements in indicators, hyphema was detected in the anterior chamber of 8 out of 10 patients (80%), while two had hemophthalm (20%). In II group, stable improvements in all indicators were observed after 21 days; however, in the I group, one patient required a repeat procedure due to an increase in intraocular pressure to 32 mm Hg. Conclusion The preoperative use of anti-VEGF agents, including Bevacizumab, before TDLC is a rationally justified method and is recommended in the treatment of neovascular glaucoma. Key words: refractory neovascular glaucoma, anti-VEGF injection, transscleral diode laser cyclophotocoagulation

Using a Theoretical Model to Assess the Impact of Vascular Risk Factors on Autoregulation in the Retina.

Vascular impairments, including reduced capillary density (CD), impaired autoregulation capacity (Reg), and elevated intraocular pressure (IOP), have been identified as significant contributors to glaucomatous disease. This study implemented a theoretical model to quantify the impact of these impairments on retinal blood flow and oxygenation as intraluminal pressure (Pa) is varied. A theoretical model of the retinal vasculature was used to simulate reductions in CD by 10% (early glaucoma) and 30% to 50% (advanced glaucoma), a range in autoregulation capacity from 0% (totally impaired) to 100% (totally functional), and normal (15mm Hg) and elevated (25mm Hg) levels of IOP. Under baseline conditions of CD = 500mm-2, Reg = 100%, and IOP = 15mm Hg, an autoregulation plateau was predicted for Pa = 28 to 44mm Hg. Decreased CD, impaired flow regulation mechanisms, and increased IOP all cause a loss of the autoregulation plateau and a corresponding decrease in tissue oxygenation in this pressure range. Although the detrimental effects of small decreases in CD or elevations in IOP are mostly offset by functional flow regulation, larger changes and/or combinations of vascular impairments lead to a significant drop in retinal oxygenation. Model predictions indicate that isolated or combined vascular impairments in CD, flow regulation, and IOP contribute to poor retinal tissue oxygenation, which could lead to vision loss in advanced glaucoma patients. This study motivates early identification of vascular changes to prevent a substantially worse effect of these factors on retinal oxygenation during the progression of glaucoma.

Fluocinolone acetonide implant (FAci) one month after dexamethasone implant (DEXi) for chronic diabetic macular edema: 1-year results

Purpose: To evaluate the safety and efficacy of FACi injected 1 month after the last DEXi injection in pseudophakic patients without ocular hypertension who required frequent DEXi injections (< 6 months).Patients and Methods: This was a prospective study including pseudophakic patients with chronic diabetic macular edema (DME) previously treated with DEXi without secondary ocular hypertension. All patients received DEXi followed by FAci one month later. Visits were scheduled at baseline, M1, then every 3 months up to 12 months.Results: 14 eyes of 11 patients were included and were followed until the 12-month time point. Visual gain was significant at M6 (+5.6 letters) and at M9 (+7.1 letters). A reduction in central macular thickness was obtained at 1 month (-86 µm), remaining stable over subsequent visits. The rate of ocular hypertension requiring pressure lowering treatment was 14%. Three eyes needed additional treatment (21%); one eye was treated with aflibercept, and 2 eyes with DEXi at M5 and M11. No patient underwant additional FAc implantation during the 11 months of follow-up.Conclusion: Injection of FAci one month after DEXi in pseudophakic patients with chronic DME who responded previously to DEXi results in anatomical improvement and deferred visual gain. This prospective study demonstrates the efficacy and safety of both implants in DME patients who have been previously treated with other therapies.