Identification of high intraocular pressure responders to topical ophthalmic corticosteroids

Glaucoma and refractive surgery: A comprehensive review

The global surge in refractive surgeries, particularly among myopic individuals, has elicited concerns regarding potential inaccuracies in the measurement of intraocular pressure (IOP) post surgery, primarily associated with central corneal thinning. The incidence of elevated IOP after intraocular refractive surgeries is higher than expected and is multifactorial. Myopic eyes have a higher susceptibility to both primary and secondary glaucoma. Consequently, meticulous preoperative screening for glaucoma is imperative, coupled with systematic postoperative follow-up and evaluation. This comprehensive review analyses the etiology, mechanisms, and therapeutic strategies for managing elevated IOP following refractive surgery. We propose an algorithm to summarize the causative factors of elevated IOP and formulate effective interventions in these instances.

Glucocorticoid-Induced Ocular Hypertension and Glaucoma

Glucocorticoid (GC) therapy is indicated in many diseases, including ocular diseases. An important side-effect of GC therapy is GC-induced ocular hypertension (GIOHT), which may cause irreversible blindness known as GC-induced glaucoma (GIG). Here, we reviewed the pathological changes that contribute to GIOHT including in the trabecular meshwork and Schlemm's canal at cellular and molecular levels. We also discussed the clinical aspects of GIOHT/GIG including disease prevalence, risk factors, the type of GCs, the route of GC administration, and management strategies.

Diagnosing and Managing Uveitis Associated with Immune Checkpoint Inhibitors: A Review

This review aims to provide an understanding of the diagnostic and therapeutic challenges of uveitis associated with immune checkpoint inhibitors (ICI). In the wake of these molecules being increasingly employed as a treatment against different cancers, cases of uveitis post-ICI therapy have also been increasingly reported in the literature, warranting an extensive exploration of the clinical presentations, risk factors, and pathophysiological mechanisms of ICI-induced uveitis. This review further provides an understanding of the association between ICIs and uveitis, and assesses the efficacy of current diagnostic tools, underscoring the need for advanced techniques to enable early detection and accurate assessment. Further, it investigates the therapeutic strategies for ICI-related uveitis, weighing the benefits and limitations of existing treatment regimens, and discussing current challenges and emerging therapies in the context of their potential efficacy and side effects. Through an overview of the short-term and long-term outcomes, this article suggests recommendations and emphasizes the importance of multidisciplinary collaboration between ophthalmologists and oncologists. Finally, the review highlights promising avenues for future research and development in the field, potentially informing transformative approaches in the ocular assessment of patients under immunotherapy and the management of uveitis following ICI therapy.

Small RNA Sequencing Reveals a Distinct MicroRNA Signature between Glucocorticoid Responder and Glucocorticoid Non-Responder Primary Human Trabecular Meshwork Cells after Dexamethasone Treatment

Glucocorticoids (GCs) are known to regulate several physiological processes and are the mainstay in the management of inflammatory eye diseases. The long-term use of GC causes raised intraocular pressure (IOP) or ocular hypertension (OHT) in about 30-50% of the susceptible individuals depending on the route of administration, and can lead to steroid-induced secondary glaucoma. The present study aims to understand the role of microRNAs (miRNAs) in differential glucocorticoid (GC) responsiveness in human trabecular meshwork (HTM) cells using small RNA sequencing. The human organ-cultured anterior segment (HOCAS) model was used to identify whether donor eyes were from GC-responders (GC-R; n = 4) or GC-non-responders (GC-NR; n = 4) following treatment with either 100 nM dexamethasone (DEX) or ethanol (ETH) for 7 days. The total RNA was extracted from cultured HTM cells with known GC responsiveness, and the differentially expressed miRNAs (DEMIRs) were compared among the following five groups: Group #1: ETH vs. DEX-treated GC-R; #2: ETH vs. DEX-treated GC-NR; #3: overlapping DEGs between Group #1 and #2; #4: Unique DEMIRs of GC-R; #5: Unique DEMIRs of GC-NR; and validated by RT-qPCR. There were 13 and 21 DEMIRs identified in Group #1 and Group #2, respectively. Seven miRNAs were common miRNAs dysregulated in both GC-R and GC-NR (Group #3). This analysis allowed the identification of DEMIRs that were unique to GC-R (6 miRNAs) and GC-NR (14 miRNAs) HTM cells, respectively. Ingenuity Pathway Analysis identified enriched pathways and biological processes associated with differential GC responsiveness in HTM cells. This is the first study to reveal a unique miRNA signature between GC-R and GC-NR HTM cells, which raises the possibility of developing new molecular targets for the management of steroid-OHT/glaucoma.

Role of Glucocorticoids and Glucocorticoid Receptors in Glaucoma Pathogenesis

The glucocorticoid receptor (GR), including both alternative spliced isoforms (GRα and GRβ), has been implicated in the development of primary open-angle glaucoma (POAG) and iatrogenic glucocorticoid-induced glaucoma (GIG). POAG is the most common form of glaucoma, which is the leading cause of irreversible vision loss and blindness in the world. Glucocorticoids (GCs) are commonly used therapeutically for ocular and numerous other diseases/conditions. One serious side effect of prolonged GC therapy is the development of iatrogenic secondary ocular hypertension (OHT) and OAG (i.e., GC-induced glaucoma (GIG)) that clinically and pathologically mimics POAG. GC-induced OHT is caused by pathogenic damage to the trabecular meshwork (TM), a tissue involved in regulating aqueous humor outflow and intraocular pressure. TM cells derived from POAG eyes (GTM cells) have a lower expression of GRβ, a dominant negative regulator of GC activity, compared to TM cells from age-matched control eyes. Therefore, GTM cells have a greater pathogenic response to GCs. Almost all POAG patients develop GC-OHT when treated with GCs, in contrast to a GC responder rate of 40% in the normal population. An increased expression of GRβ can block GC-induced pathogenic changes in TM cells and reverse GC-OHT in mice. The endogenous expression of GRβ in the TM may relate to differences in the development of GC-OHT in the normal population. A number of studies have suggested increased levels of endogenous cortisol in POAG patients as well as differences in cortisol metabolism, suggesting that GCs may be involved in the development of POAG. Additional studies are warranted to better understand the molecular mechanisms involved in POAG and GIG in order to develop new disease-modifying therapies to better treat these two sight threatening forms of glaucoma. The purpose of this timely review is to highlight the pathological and clinical features of GC-OHT and GIG, mechanisms responsible for GC responsiveness, potential therapeutic options, as well as to compare the similar features of GIG with POAG.

Early Inflammation Control After Trabeculectomy by Steroid and Non-steroidal Eye Drops: A Randomized Controlled Trial

INTRODUCTION

To compare the effect of three different anti-inflammatory regimens consisting of preservative-free dexamethasone (DEX), diclofenac (DICLO) eye drops, and their combination (DEX + DICLO) following trabeculectomy on early postoperative inflammation.

METHODS

A prospective randomized controlled trial. Sixty-nine patients undergoing trabeculectomy were randomized to receive either postoperative treatment with topical DEX (n = 23), topical DICLO (n = 23), or a combination of topical DEX and topical DICLO (n = 23) after trabeculectomy. The primary outcome was the anterior chamber flare measurement in the first 3 months postoperatively. Secondary outcomes included intraocular pressure, central corneal thickness, conjunctival injection, and number of cells in the anterior chamber from baseline to 3 months postoperatively.

RESULTS

Anterior chamber flare reached a maximum 1 day after trabeculectomy with an increase of 55% (95% CI 37-73%) for DEX, 64% (95% CI 47-82%) for DICLO, and 57% (95% CI 39-75%) for DEX + DICLO and returned to near pre-operative values 6 weeks after surgery. There were no significant differences in anterior chamber flare [effect size for DICLO: 0.16 (95% CI - 4.3 to 4.6), effect size for DEX + DICLO: 0.09 (95% CI - 4.1 to 4.3)], intraocular pressure, central corneal thickness, conjunctival injection, or number of cells in the anterior chamber between DEX, DICLO, or DEX + DICLO groups.

CONCLUSION

We found that topical diclofenac was not statistically different from topical dexamethasone in controlling early postoperative inflammation after trabeculectomy, while combining diclofenac and dexamethasone offered no added anti-inflammatory control compared to dexamethasone alone.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov (NCT04054830).

A Comparative Genome-Wide Transcriptome Analysis of Glucocorticoid Responder and Non-Responder Primary Human Trabecular Meshwork Cells

Aim: To investigate genes and pathways involved in differential glucocorticoid (GC) responsiveness in human trabecular meshwork (HTM) cells using RNA sequencing. Methods: Using paired human donor eyes, human organ-cultured anterior segment (HOCAS) was established in one eye to characterize GC responsiveness based on intra ocular pressure (IOP) change and, in the other eye, primary HTM cell culture was established. For RNA sequencing, total RNA extracted from GC-responder (GC-R) and non-responder (GC-NR) cells after dexamethasone (DEX) or ethanol (ETH) treatment for 7d was used. Differentially expressed genes (DEGs) were compared among five groups and validated. Results: In total, 616 and 216 genes were identified as significantly dysregulated in Group #1 and #2 (#1: ETH vs. DEX-treated GC-R; #2: ETH vs. DEX-treated GC-NR), respectively. Around 80 genes were commonly dysregulated in Group #3 (overlapping DEGs between #1 and #2), whereas 536 and 136 genes were uniquely expressed in GC-R (#4) and GC-NR HTM (#5) cells, respectively. Pathway analysis revealed that WNT signaling, drug metabolism cytochrome p450, cell adhesion, TGF-β signaling, and MAPK signaling were associated with GC responsiveness. Conclusion: This is the first study reporting distinct gene signatures and their associated pathways for GC-R and GC-NR HTM cells. WNT and MAPK signaling are potential therapeutic targets for the management of GC-induced glaucoma.

Effect of anti-inflammatory regimen on early postoperative inflammation after cataract surgery

PURPOSE

To investigate whether a combination of topical nonsteroidal anti-inflammatory drugs (NSAIDs) and steroids were superior in controlling early postoperative inflammation after cataract surgery compared with topical NSAIDs alone and with dropless surgery where a sub-Tenon depot of steroid was placed during surgery.

SETTING

Department of Ophthalmology, Rigshospitalet-Glostrup, Denmark.

DESIGN

Prospective randomized controlled trial with masked statistical analyses.

METHODS

Patients undergoing phacoemulsification for age-related cataract were randomized to 1 of 5 regimens: ketorolac and prednisolone eyedrops combined (Pred+NSAID-Pre [control group] and Pred+NSAID-Post group) vs ketorolac monotherapy (NSAID-Pre and NSAID-Post groups) vs sub-Tenon depot of dexamethasone (dropless group). Drops were used until 3 weeks postoperatively, starting 3 days preoperatively in the Pre groups and on the day of surgery in the Post groups. Aqueous flare was measured at baseline and 3 days postoperatively.

RESULTS

Four hundred fifty-six participants, with a mean age of 72.1 (SD 7.0) years and 283 (62%) women, were included. Flare increased significantly more in the dropless group compared with the control group (Pred+NSAID-Pre), but none of the other groups differed significantly from the control group. Intraocular pressure decreased in all groups but significantly less in groups receiving prednisolone eyedrops (Pred+NSAID-Pre and Pred+NSAID-Post groups) compared with NSAID monotherapy and dropless groups. No differences in postoperative visual acuity were found compared with the control group.

CONCLUSIONS

No differences were found between groups randomized to NSAID monotherapy or combination of NSAID and steroid in controlling early inflammation after cataract surgery, but sub-Tenon depot of dexamethasone was less efficient. Initiating prophylactic eyedrops prior to surgery did not influence early postoperative anterior chamber inflammation.

Inducible rodent models of glaucoma

Glaucoma is one of the leading causes of vision impairment worldwide. In order to further understand the molecular pathobiology of this disease and to develop better therapies, clinically relevant animal models are necessary. In recent years, both the rat and mouse have become popular models in glaucoma research. Key reasons are: many important biological similarities shared among rodent eyes and the human eye; development of improved methods to induce glaucoma and to evaluate glaucomatous damage; availability of genetic tools in the mouse; as well as the relatively low cost of rodent studies. Commonly studied rat and mouse glaucoma models include intraocular pressure (IOP)-dependent and pressure-independent models. The pressure-dependent models address the most important risk factor of elevated IOP, whereas the pressure-independent models assess "normal tension" glaucoma and other "non-IOP" related factors associated with glaucomatous damage. The current article provides descriptions of these models, their characterizations, specific techniques to induce glaucoma, mechanisms of injury, advantages, and limitations.

Steroid-induced glaucoma: Epidemiology, pathophysiology, and clinical management

Glucocorticoids are a class of anti-inflammatory drugs commonly used to treat various ocular and systemic conditions. Although the role of glucocorticoids in the treatment of numerous serious inflammatory diseases is pivotal, their prolonged use may increase intraocular pressure resulting in steroid-induced glaucoma. We provide a detailed update on steroid-induced glaucoma as a preventable cause of blindness in the adult and pediatric population and describe its epidemiology, social impact, and risk factors. Furthermore, we explore the propensity of different steroids to increase the intraocular pressure, the role of different routes of steroid administration, dosage and duration of treatment, as well as the clinical features, genetics, and management of steroid-induced glaucoma.

A review of systemic medications that may modulate the risk of glaucoma

With increasing longevity, patients are developing more and more chronic diseases that require treatment with medications. Yet, it is not fully understood the extent by which these systemic medications affect ocular structures and whether they may increase or decrease the risk of sight-threatening ocular diseases. This review provides a summary of reported associations between different systemic medications and the risk of developing glaucoma or experiencing disease progression. Medication classes covered in this review that are known to or may modulate the risk of open-angle glaucoma include corticosteroids, beta blockers, calcium channel blockers, metformin, statins, selective serotonin reuptake inhibitors, bupropion, postmenopausal hormones, and cannabinoids. Medication classes addressed in this review that may increase the risk of angle closure glaucoma include anticholinergics, adrenergic agonists, certain classes of antidepressants, sulfonamides, and topiramate.

The Genetic Influence on Corticosteroid-Induced Ocular Hypertension: A Field Positioned for Discovery

PURPOSE

To provide evidence that corticosteroid-induced ocular hypertension has a genetic component.

DESIGN

Evidence-based perspective.

METHODS

We conducted a comprehensive literature search for studies exploring genetic influences on intraocular pressure responses to corticosteroid treatment.

RESULTS

Studies demonstrating increased risk of corticosteroid-induced ocular hypertension among first-degree relatives of affected individuals support a genetic contribution to the disease. Family and personal history of primary open-angle glaucoma also increases the risk of corticosteroid-induced intraocular pressure elevation, suggesting common genetic etiologies. A number of studies have attempted to identify predisposing genetic factors; however, reproducible findings have not yet been reported. The recent availability of large data sets with clinical and genetic data for patients affected by corticosteroid-induced ocular hypertension and glaucoma provides new opportunities to study the genetic underpinnings of this important condition.

CONCLUSIONS

There is substantial evidence suggesting a genetic component to corticosteroid-related ocular hypertension and glaucoma, but specific genetic risk factors have yet to be identified. The current confluence of large genetic data sets and affordable genetic sequencing technologies has great potential for discovering the genes that increase risk for this blinding complication of corticosteroid therapy.

Clinical Applications of Dexamethasone for Aged Eyes

The risk of severe eye problems has been found to increase significantly with age, particularly between the fifth and sixth decades of life. Cataracts, dry eye, neovascular age-related macular degeneration, diabetic retinopathy and retinal vein occlusion (RVO) are very common and very different age-related ocular diseases that reduce the patient's quality of life. The rationale for using corticosteroids to treat anterior and posterior ocular segment diseases is driven by inflammation. Dexamethasone, one of the most powerful corticosteroids available, is widely used for topical or intravitreal administration. Topical dexamethasone has proven efficacy for the management of postoperative inflammation in the anterior segment after cataract surgery and symptom relief in dry-eye disease. A new sustained-release 700 µg dexamethasone intravitreal implant (DEX) was recently approved for the treatment of macular edema following RVO, diabetic macular edema, or non-infectious uveitis, and its use is increasing, especially when other therapeutic agents have failed. The most common side effects are increased intraocular pressure and cataract formation. The potency of DEX, alone or in combination with other agents, makes DEX a promising option for treating several retinal diseases.

[Treatment of macular edema: Comparison of efficacy and tolerability of subconjunctival triamcinolone injections, sub-tenon's triamcinolone injections and intravitreal dexamethasone implant]

The area of uveitis is related to numerous pathological entities. One of the main causes of decreased visual acuity in these patients is macular edema. One aspect of the treatment includes cortosteroids used peri- and intra-ocularly.

MATERIALS AND METHODS

The goal of our work was to estimate the criteria of efficacy (on improvement in visual acuity and macular edema, as well as time to recurrence) and safety (on intraocular pressure and cataract) of these various routes of administration of corticosteroid after a single injection. We compared patients treated with Ozurdex^® versus subconjonctival triamcinolone versus sub-tenon's triamcinolone. This is a retrospective study conducted in 2 tertiary centers, the university medical center of Nantes and La Pitié-Salpêtrière hospital from November, 2011 to November, 2013.

RESULTS

At presentation, 25 % of the patients displayed VA better than 5/10. During follow-up, this proportion increased to 45 % at M1, 50 % at M3, 49 % at M6 and 48 % at the end of follow-up. There was no significant difference between the groups with respect to VA gain. The reductions in mean CMT compared with D0 were all statistically significant (improvement of one line in log-OCT). We observed an improvement in macular thickness of 88 % at M1, 86 % at M3, 61 % at M6 and 60 % at the end of follow-up, significant at each time, with no significant difference between the three groups. A comparison of time to anatomic vs. functional recurrence was performed, showing no difference. The largest increase in IOP was observed at M1, statistically different from the other time points.

DISCUSSION

Intra- and periocular injections should be considered as an adjuvant therapy, since the majority of the conditions in question require systemic treatment. They allow for increased intravitreal concentrations with fewer systemic effects.

CONCLUSION

We demonstrated neither any true superiority of any of the 3 treatments nor any difference in tolerability between the 3 groups.

Vehicle-Controlled, Phase 2 Clinical Trial of a Sustained-Release Dexamethasone Intracanalicular Insert in a Chronic Allergen Challenge Model

PURPOSE

To evaluate the efficacy and safety of a sustained-release dexamethasone intracanalicular insert (Dextenza™) in a model of allergic conjunctivitis.

METHODS

This was a randomized, double-masked, vehicle-controlled, Phase 2 study. Subjects had to have a positive conjunctival allergen challenge (CAC) reaction to allergen (bilateral +2 itching and redness on 5-point, 0-4 scales) at Visit 1, and for 2 of 3 time points on subsequent visits. Subjects who met entry criteria were randomized to receive Dextenza or PV (vehicle insert). Challenges occurred over 42 days, with efficacy assessed at 14 (primary endpoint visit), 28, and 40 days postinsertion. Outcome measures included the evaluation of ocular itching, redness, tearing, chemosis, eyelid swelling, rhinorrhea, and congestion.

RESULTS

Twenty-eight subjects completed the study in the Dextenza group and 31 in the vehicle group. At 14 days postinsertion, Dextenza was statistically superior to PV, with least square mean differences for ocular itching of -0.76, -0.97, and -0.87 at 3, 5, and 7 min post-CAC, and for conjunctival redness of -0.46, -0.66, and -0.68 at 7, 15, and 20 min post-CAC. Clinical significance, defined as a 1-U decrease from PV, was not met for primary efficacy. Secondary endpoints, including number of subjects reporting itching and conjunctival redness, indicated superior performance of Dextenza compared with vehicle. Eleven Dextenza-treated (35.5%) and 10 vehicle-treated (30.3%) subjects each experienced a single adverse event.

CONCLUSION

This Phase 2 study demonstrated preliminary efficacy and safety data of Dextenza for treatment of allergic conjunctivitis.

Steroid-induced ocular hypertension/glaucoma: Focus on pharmacogenomics and implications for precision medicine

Elevation of intraocular pressure (IOP) due to therapeutic use of glucocorticoids is called steroid-induced ocular hypertension (SIOH); this can lead to steroid-induced glaucoma (SIG). Glucocorticoids initiate signaling cascades ultimately affecting expression of hundreds of genes; this provides the potential for a highly personalized pharmacological response. Studies attempting to define genetic risk factors were undertaken early in the history of glucocorticoid use, however scientific tools available at that time were limited and progress stalled. In contrast, significant advances were made over the ensuing years in defining disease pathophysiology. As the genomics age emerged, it appeared the time was right to renew investigation into genetics. Pharmacogenomics is an unbiased discovery approach, not requiring an underlying hypothesis, and provides a way to pinpoint clinically significant genes and pathways that could not have been discovered any other way. Results of the first genome-wide association study to identify polymorphisms associated with SIOH, and follow-up on two novel genes linked to the disorder, GPR158 and HCG22, is discussed in the second half of the article. However, knowledge of genetic variants determining response to steroids in the eye also has value in its own right as a predictive and diagnostic tool. This article concludes with a discussion of how the Precision Medicine Initiative®, announced by U.S. President Obama in his 2015 State of the Union address, is beginning to touch the practice of ophthalmology. It is argued that SIOH/SIG may provide one of the next opportunities for effective application of precision medicine.

Evaluation of Triamcinolone Acetonide Following Intravitreal Injection in New Zealand White Rabbits

The safety of intravitreally injected triamcinolone acetonide suspension (TA) was evaluated in rabbits. Each animal received 0.1 ml (1) balanced salt solution (BSS) vehicle, (2) formulation vehicle, (3) 4% TA (4-mg dose), (4) 16% TrAc (16-mg dose) or (5) 25% TA (25-mg dose) as a single intravitreal injection into the right eye. The left eyes served as untreated controls. All animals were observed for 1 month following treatment. In-life evaluations included clinical signs, body weights, slit-lamp biomicroscopic and indirect ophthalmoscopic examinations, intraocular pressure and corneal thickness measurements, and electroretinograms (ERGs). Ocular tissues were harvested following a 1-month post-treatment observation period, fixed, processed, and evaluated by light microscopy. No significant or treatment-related clinical signs were observed for any animals during the study. The opaque white test article was clearly visible in the eye for all TrAc-treated groups, and remained so throughout the study. No statistically significant differences in mean body weights were present between the control and treatment groups, though changes in body weight varied. Corneal thickness was slightly reduced for some treated groups. Intraocular pressures were not statistically significantly different from controls for any treatment group. No significant changes in ERG were evident between treatment groups or from baseline readings. Microscopically, basophilic material (presumed to be drug) was seen in the vitreous of all or most treated eyes, with accumulations in the vitreous or in clumps adjacent to the retinal surface. No pathological changes were observed in the retina or other ocular structures. Triamcinolone acetonide suspension was safe and well tolerated following intravitreal injection in New Zealand white rabbits.

Glucocorticoid therapy and ocular hypertension

The projected number of people who will develop age-related macular degeneration in estimated at 2020 is 196 million and is expected to reach 288 million in 2040. Also, the number of people with Diabetic retinopathy will grow from 126.6 million in 2010 to 191.0 million by 2030. In addition, it is estimated that there are 2.3 million people suffering from uveitis worldwide. Because of the anti-inflammatory properties of glucocorticoids (GCs), they are often used topically and/or intravitreally to treat ocular inflammation conditions or edema associated with macular degeneration and diabetic retinopathy. Unfortunately, ocular GC therapy can lead to severe side effects. Serious and sometimes irreversible eye damage can occur as a result of the development of GC-induced ocular hypertension causing secondary open-angle glaucoma. According to the world health organization, glaucoma is the second leading cause of blindness in the world and it is estimated that 80 million will suffer from glaucoma by 2020. In the current review, mechanisms of GC-induced damage in ocular tissue, GC-resistance, and enhancing GC therapy will be discussed.

Analyses of Sequence Variants in the MYOC Gene and of Single Nucleotide Polymorphisms in the NR3C1 and FKBP5 Genes in Corticosteroid-Induced Ocular Hypertension

BACKGROUND

To perform an independent replication study to determine whether genetic variants in MYOC, NR3C1 and FKBP5 are involved in steroid-induced ocular hypertension.

MATERIALS AND METHODS

A retrospective case-control study was peformed on native Dutch patients who were treated with 4.0 mg intravitreal triamcinolone acetonide (IVTA). The patients were divided into an intraocular hypertension group (intraocular pressure >21 mmHg within a year after IVTA) and a non-intraocular hypertension group. The cohort was genotyped for 31 single-nucleotide polymorphisms (SNPs): 21 in NR3C1 and 10 in FKBP5. In addition, the open reading frame of MYOC was sequenced.

RESULTS

A total of 102 patients were included in this study: 58 steroid responders and 44 non-responders. No significant associations were found for the studied SNPs in NR3C1 and FKBP5. Heterozygous amino acid variants were detected in the MYOC gene in two patients of the non-intraocular hypertension group.

CONCLUSIONS

This study does not confirm a role for genetic variants in the MYOC, NR3C1 and FKBP5 genes in the pathogenesis of corticosteroid-induced ocular hypertension.

Animal models of glucocorticoid-induced glaucoma

Glucocorticoid (GC) therapy is widely used to treat a variety of inflammatory diseases and conditions. While unmatched in their anti-inflammatory and immunosuppressive activities, GC therapy is often associated with the significant ocular side effect of GC-induced ocular hypertension (OHT) and iatrogenic open-angle glaucoma. Investigators have generated GC-induced OHT and glaucoma in at least 8 different species besides man. These models mimic many features of this condition in man and provide morphologic and molecular insights into the pathogenesis of GC-OHT. In addition, there are many clinical, morphological, and molecular similarities between GC-induced glaucoma and primary open-angle glaucoma (POAG), making animals models of GC-induced OHT and glaucoma attractive models in which to study specific aspects of POAG.

Clinical relevance of the glucocorticoid receptor gene polymorphisms in glucocorticoid-induced ocular hypertension and primary open angle glaucoma

AIM

To avoid the side effects of ocular hypertension of glucocorticoid (GC) usage in eye, we must identify susceptible individuals, which exists in about one-third of all population. Further, the majority of all primary open angle glaucoma (POAG) patients show this phenotype. Glucocorticoid receptor (GR) regulates C responsiveness in trabecular meshwork (TM) cells. In this study, single nucleotide polymorphism (SNP) genotyping was used to determine whether there are differences in the BclI (rs41423247) and N363S (rs6195) polymorphisms of the GR gene in healthy and POAG patients, and glucocorticoid-induced ocular hypertension (GIOH) populations.

METHODS

Three hundred and twenty-seven unrelated Chinese adults, including 111 normal controls, 117 GIOH subjects and 99 POAG patients, were recruited. DNA samples were prepared and the BclI and N363S polymorphisms were screened using real-time polymerase chain reaction (RT-PCR)-restriction fragment length polymorphism (RFLP) analysis. Frequencies of the BclI and N363S polymorphisms were determined and compared using Fisher's exact test and the Chi-squared test.

RESULTS

Only the BclI polymorphism was identified in the Chinese Han population. The frequency of the G allele was 21.6 % in normal controls, 18.3% in GIOH patients, and 13.64% in the POAG patients. There was no significant difference in polymorphism or allele frequency in the 3 groups. Furthermore, no N363S polymorphism was found in the study subjects.

CONCLUSION

The BclI polymorphisms in GR gene had no association with GIOH and POAG patients, and N363S polymorphism might not exist in the Chinese Han population. Therefore, the BclI polymorphism might not be responsible for the development of GC-induced ocular hypertension or POAG.

Comparison of peroperative subconjunctival injection of methylprednisolone and standard postoperative steroid drops after uneventful cataract surgery

PURPOSE

To compare the safety and efficacy of a single subconjunctival injection of methylprednisolone and a standard postoperative steroid regimen in terms of intraocular inflammation and intraocular pressure (IOP) after uncomplicated phacoemulsification surgery.

METHODS

Two groups of 25 patients each were included in this prospective randomized controlled trial. Patients in the injection group were given a subconjunctival injection of 20 mg methylprednisolone and the topical group received the conventional postoperative care with steroid eye drops (dexamethasone 1 mg/ml). The patients were examined 1 week and 1 month after surgery. Slit-lamp evaluation of anterior chamber inflammation and IOP were performed. Changes in IOP of ≥2.4 mmHg were considered clinically relevant.

RESULTS

In the injection group, mean IOP decreased from 15.4 ± 2.2 mmHg (baseline) to 14.1 ± 3.2 mmHg at 1 week (p = 0.03). The topical group had a stable IOP at 1 week (16.3 ± 2.6 mmHg) compared to baseline (16.1 ± 2.7 mmHg; p = 0.74). At 1 month, mean IOP was 14.3 ± 2.6 mmHg (p = 0.03) in the injection group and 15.6 ± 2.3 mmHg (p = 0.2) in the topical group. The intragroup changes were neither statistically significant nor clinically relevant at any postoperative visit. Both groups had the highest values of intraocular inflammation at the 1-week postoperative visit, followed by a decline to barely traceable levels at 1 month. The difference was not clinically relevant at any postoperative visit.

CONCLUSIONS

The subconjunctival injection of methylprednisolone appears to be as safe and effective as the conventional treatment, and it might therefore be considered for treatment of individuals with compliance issues.

Loteprednol etabonate ophthalmic gel 0.5% following cataract surgery: integrated analysis of two clinical studies

INTRODUCTION

We aimed to evaluate the safety and efficacy of loteprednol etabonate (LE) gel 0.5% compared with vehicle in the treatment of postoperative inflammation and pain following cataract surgery, using the integrated analysis of data from two identical, prospective, multicenter, randomized, double-masked, parallel-group, vehicle-controlled trials.

METHODS

Patients with anterior chamber cell (ACC) inflammation ≥ grade 2 (6-15 cells) 1 day post-surgery were randomized to receive 1 or 2 drops of LE gel 0.5% or vehicle 4 times per day instilled in the study eye for 14 days. Primary outcome measures included the proportion of patients with complete resolution of ACC and grade 0 (no) pain on postoperative Day 8. Safety endpoints included adverse events (AEs), changes from baseline in intraocular pressure (IOP) and visual acuity (VA), biomicroscopy, and funduscopy findings. Gel comfort was graded by patients according to drop sensation.

RESULTS

The intent-to-treat population included 813 patients (409 LE gel 0.5% and 404 vehicle). At postoperative Day 8, 30.8% and 15.1% of patients randomized to LE gel 0.5% or vehicle, respectively, had complete resolution of ACC, while 74.3% and 43.8% of patients, respectively, had grade 0 pain (P < 0.001 for both). Tolerability assessments for ocular itching, photophobia, and tearing favored LE gel 0.5% compared with vehicle at different time points beginning at Day 3. Two patients in the LE gel 0.5% group and 1 patient in the vehicle group exhibited a transient treatment-emergent increase in IOP ≥ 10 mmHg. Treatment-related AEs were generally mild to moderate and occurred less frequently with LE gel 0.5% than with vehicle. Reports of treatment-related blurred vision were rare (n = 2, vehicle).

CONCLUSION

LE gel 0.5% was efficacious and well tolerated in the treatment of postoperative pain and inflammation following ocular surgery, with minimal risk of IOP elevation.

Intraocular pressure effects of common topical steroids for post-cataract inflammation: are they all the same?

The efficacy of topical corticosteroids as ocular anti-inflammatory agents following cataract surgery is well-documented. They also help to prevent a number of complications associated with post-operative ocular inflammation, including corneal edema and cystoid macular edema. However, topical corticosteroids are associated with side effects, such as increased intraocular pressure (IOP). Indeed, corticosteroid-induced ocular hypertension and the potential for steroid-induced glaucoma remain the leading drawbacks of topical corticosteroid therapy. Some individuals are known to experience a high degree of IOP elevation with low doses or short durations of treatment with topical corticosteroids. Careful monitoring of IOP in such individuals is essential. Few randomized, controlled studies are available on the comparative safety and efficacy of common topical corticosteroids in the treatment of post-operative ocular inflammation. Furthermore, the lack of consistent reporting criteria for clinically significant IOP increases across clinical studies makes meaningful comparisons among corticosteroids difficult. This review aims to examine data from available published studies, including studies in steroid responders, to determine whether topical corticosteroids are the same in terms of their effect on IOP. Early generation corticosteroids, such as dexamethasone and prednisolone, are more likely to result in clinically significant increases in IOP. Newer corticosteroids, such as rimexolone and the retro-metabolically designed corticosteroid, loteprednol etabonate, offer similar anti-inflammatory efficacy to older corticosteroids with less effect on IOP. However, randomized controlled trials of newer corticosteroids are needed. The proportion of patients exhibiting an increase of ≥10 mmHg IOP in clinical studies has emerged as the most clinically relevant parameter for ophthalmologists to consider when deciding on which topical corticosteroid to use.

Analysis of single nucleotide polymorphisms in the SFRS3 and FKBP4 genes in corticosteroid-induced ocular hypertension

BACKGROUND

The use of intravitreal triamcinolone acetonide (IVTA) can cause ocular hypertension. This steroid response appears to be heritable and alleles in the SFRS3 and FKBP4 genes have recently been suggested to play a role. The purpose of the present study was to perform an independent replication study to determine whether single nucleotide polymorphisms (SNPs) in SFRS3 and FKBP4 are involved in the steroid response.

MATERIALS AND METHODS

A retrospective case-control study of native Dutch patients was performed who were treated with 4.0mg IVTA. The patients were divided into an intraocular hypertension group (intraocular pressure > 21 mmHg within a year after IVTA) and a non-intraocular hypertension group. The cohort was genotyped for three SNPs: rs7759778 and rs1406945 in SFRS3, and rs2968909 in FKBP4.

RESULTS

A total of 102 patients was included: 58 steroid responders and 44 non-responders. No significant differences in demographic parameters or medical history were observed between the study groups. None of the SNPs were found to be significantly associated with the disease as no difference was revealed either in the genotype or allele frequencies between responders and non-responders.

CONCLUSIONS

This study does not confirm a role for genetic variants in the SFRS3 and FKBP4 genes in the pathogenesis of corticosteroid-induced ocular hypertension. However, our limited sample size may have restricted the power of our study, and we therefore cannot exclude the involvement of these genetic variants in steroid response.

Steroid-induced ocular hypertension in Asian children with severe vernal keratoconjunctivitis

Background

We describe clinical characteristics and risk factors for corticosteroid response in children with severe vernal keratoconjunctivitis (VKC).

Design

Retrospective, noncontrolled, comparative case series.

Participants

Patients from three tertiary centers in Singapore.

Methods

We reviewed patients with severe VKC (clinical grade > 2) who were on topical steroid therapy, with a minimum follow-up period of 1 year post-presentation. Logistic regression was used to determine risk factors for corticosteroid response.

Main outcome measure

Corticosteroid response was defined as intraocular pressure (IOP) >21 mmHg (three consecutive readings), or a rise of more than 16 mmHg from baseline, after commencement of steroid therapy in the absence of other possible causes of raised IOP.

Results

Forty-one of 145 (28.3%) patients developed a corticosteroid response, of which eight (5.5%) progressed to glaucoma. The overall mean age of onset of VKC was 9.9 ± 4.4 years. Longer duration of corticosteroid use (OR, 5.06; 95% CI: 1.04–25.56; P = 0.45) and topical dexamethasone 0.01% (OR, 2.25; 95% CI: 1.99–5.08; P = 0.40) were associated with corticosteroid response. Mixed type of VKC (OR, 9.76; 95% CI: 3.55–26.77; P < 0.001), the presence of limbal neovascularization of ≥ three quadrants (OR, 6.33; 95% CI: 2.36–16.97; P < 0.001), and corneal involvement (OR, 3.51; 95% CI: 1.31–9.41; P = 0.012) were significant clinical risk factors after adjusting for potential confounders such as age, sex, ethnicity, duration, and type of corticosteroid used.

Conclusion

Children on long-term oral corticosteroids with severe, mixed-type VKC and corneal involvement are more likely to develop corticosteroid response, and may require early treatment to prevent progression to glaucoma.

Fluorescent protein-labeled glucocorticoid receptor alpha isoform trafficking in cultured human trabecular meshwork cells

PURPOSE

To characterize the roles of the cytoskeleton and heat shock protein 90 (HSP90) in steroid-induced glucocorticoid receptor alpha (GRα) translocation in cultured human trabecular meshwork cells.

METHODS

Stably transfected red fluorescent protein (RFP)-GRα NTM5 cell lines were developed. Nuclear localization of RFP-GRα in NTM5 cells treated with vehicle (ethanol), dexamethasone (DEX), or RU486 was measured in cytosolic and nuclear fractions by western blotting and laser confocal microscopy. Cytochalasin D, colchicine, and 17-demethoxygeldanamycin (17AAG, an HSP90 inhibitor), were tested for their abilities to affect GRα trafficking. Nuclear export of RFP-GRα was studied using confocal microscopy following DEX or RU486 removal.

RESULTS

NTM5 cells transfected with RFP-GRα showed a clear cytosolic localization of receptor that underwent nuclear localization after DEX treatment. RFP-GRα translocation was temperature sensitive, occurring at 37°C but not at room temperature. Neither cytochalasin D nor colchicine blocked DEX-induced or RU486-induced RFP-GRα nuclear translocation; however, 17AAG prevented DEX-induced RFP-GRα nuclear translocation. Both nuclear import and export of DEX-induced RFP-GRα were faster than RU-486-induced nuclear shuttling.

CONCLUSIONS

RFP-GRα receptor behaves similarly to the wild-type GRα with its cytosolic localization and shuttling to nucleus after DEX or RU486 treatment. HSP90 is required for nuclear translocation, but the disruption of cytoskeleton had no effect on nuclear translocation of RFP-GRα.

Loteprednol and tobramycin in combination: a review of their impact on current treatment regimens

IMPORTANCE OF THE FIELD

The treatment of ocular inflammation continues to be a challenge. Topical corticosteroids are effective in reducing ocular inflammation but are limited by adverse events including elevation of intraocular pressure, development of cataracts, glaucoma and inhibition of wound healing with associated risk of infection. Loteprednol etabonate (LE) is a unique C-20 ester corticosteroid designed to produce a predictable therapeutic effect with a low incidence of side effects. Zylet (LE/T) a combination of LE and tobramycin (T) is indicated for the treatment of steroid-responsive ocular inflammatory conditions in which there exists either superficial bacterial ocular infection or a potential risk of bacterial infection.

AREAS COVERED IN THIS REVIEW

The current review of the literature (Medline and the Cochrane Library, 1996 - 2009) examines the safety and efficacy of LE/T in the treatment of ocular inflammation.

WHAT THE READER WILL GAIN

Studies with either LE or LE/T indicate that LE has a lower risk of IOP elevation compared with C-20 ketone corticosteroids owing to its rapid de-esterification to inactive metabolites. LE also lacks the ability to form Schiff base intermediates with lens proteins, a common first step in cataractogenesis. LE/T was noninferior to dexamethasone 0.1%/tobramycin 0.3% in the treatment of blepharokeratoconjunctivitis.

TAKE HOME MESSAGE

LE/T may be a safer treatment option for ocular inflammation in which there is risk of superficial bacterial infections.

Systemic disease associations of familial and sporadic glaucoma: the Glaucoma Inheritance Study in Tasmania

BACKGROUND

This aim of this study was to compare the prevalence of various disease-associated and potentially modifiable risk factors between people with familial and sporadic forms of primary open angle glaucoma (OAG).

METHODS

A cross-sectional, retrospective study design was utilized. A detailed questionnaire enquiring about knowledge of family history, demographic data, current medications, and medical history of systemic disorders was administered. Where possible, living relatives were examined for signs of OAG.

RESULTS

A total of 3,800 potential patients with OAG were identified, of whom 2062 were examined. One thousand twelve (59.5%) subjects were found to have familial OAG, and 688 (40.5%) subjects had no known or identified relative with OAG (sporadic glaucoma). One thousand forty-two unaffected family members examined. A past history of migraine was found more often with familial OAG (OR: 1.67 95% CI: 1.15-2.42). This effect was primarily driven by patients who had a first-degree relative also affected by OAG. Following adjustment for male gender and the age at review, the presence of atherosclerosis was also found to be more common in patients with familial glaucoma than in people with sporadic disease (OR: 1.42 95% CI: 1.05-1.92). No significant difference in the prevalence of hypertension, Raynaud's phenomenon, diabetes mellitus or thyroid disease was identified.

CONCLUSIONS

Patients with a known relative affected by OAG were statistically significantly more likely to have a past history for migraine or presence of atherosclerosis compared to people with no known affected relative. An understanding of such differences and systemic comorbidities will be useful for further work investigating the underlying molecular mechanisms of this disease.

Intraocular pressure elevation after intravitreal triamcinolone acetonide injection in a Chinese population

PURPOSE

To study the prevalence and risk factors of intraocular pressure (IOP) elevation and refractory IOP elevation after a single 4 mg intravitreal triamcinolone acetonide (IVTA) injection in a Chinese population.

DESIGN

Retrospective, observational case series.

METHODS

Retrospective chart review of all the patients who received an IVTA injection at one medical center from January 2003 through June 2005. A postoperative IOP increase of more than 6 mm Hg was defined as an IOP elevation. Postoperative IOP elevation that could not be controlled by glaucoma medications was defined as refractory IOP elevation.

RESULTS

Sixty-four (43.5%) of the 147 enrolled patients experienced IOP elevation. Males had a higher risk of IOP elevation, with an odds ratio (OR) of 3.17 (95% confidence interval [CI], 1.38 to 7.27; P = .006), after adjusting for age, glaucoma history, and diagnosis of retinal disease. Patients 55 years of age and younger had a larger magnitude of IOP elevation than those older than 55 years (11.2 +/- 10.1 mm Hg vs 7.3 +/- 7.7 mm Hg; P = .020). Ten patients (6.8%) had refractory IOP elevation, and those 55 years of age or younger had a higher risk of refractory IOP elevation compared with those older than 55 years, with an OR of 8.16 (95% CI, 1.67 to 39.81; P = .009), after adjusting for preoperative IOP and diagnosis of retinal disease.

CONCLUSIONS

Elevated IOP after IVTA injection is common in this Chinese population. Male patients have a higher risk of IOP elevation. Younger patients should be monitored carefully after IVTA injection because they exhibit a greater magnitude of IOP elevation and have an increased chance of developing refractory IOP elevation.

FK506-binding protein 51 regulates nuclear transport of the glucocorticoid receptor beta and glucocorticoid responsiveness

PURPOSE

A spliced variant of the human glucocorticoid receptor GRbeta has been implicated in glucocorticoid responsiveness in glaucoma. Over-expression of the FK506-binding immunophilin FKBP51 also causes a generalized state of glucocorticoid resistance. In the present study, the roles of FKBP51 in the nuclear transport of GRbeta and glucocorticoid responsiveness were investigated.

METHODS

Human trabecular meshwork cells (GTM3 and TM5) and HeLa cells were treated with dexamethasone (DEX) and FK506 and transfected with GRbeta and FKBP51 expression vectors. Coimmunoprecipitation and Western blot analyses were performed to study interactions of FKBP51 and FKBP52 with GRalpha, GRbeta, Hsp90, or dynein. The cells were transfected with a GRE-luciferase reporter to evaluate the effects of DEX and FK506 and the overexpression of GRbeta and FKBP51 on glucocorticoid-mediated gene expression.

RESULTS

FKBP51 was involved in constitutive nuclear transport of both GRalpha and -beta in the absence of ligands. FKBP52 appeared to be solely responsible for the nuclear transport of ligand-activated GRalpha. DEX stimulated the translocation of GRalpha but not GRbeta. Overexpression of either GRbeta or FKBP51 stimulated GRbeta translocation and reduced DEX-induced luciferase in HeLa cells. FK506 did not alter DEX-induced translocation of GRalpha. However, FK506 increased the association of FKBP51 with GRbeta and stimulated DEX-induced translocation of GRbeta in normal TM cells, but not in glaucoma TM cells. Increased nuclear GRbeta significantly inhibited glucocorticoid responsiveness in TM cells.

CONCLUSIONS

Nuclear transport of GRbeta represents a novel mechanism through which FKBP51 alters GC sensitivity. GRbeta and FKBP51 may be responsible for increased responsiveness in steroid-induced ocular hypertensive individuals as well as in patients with glaucoma.

Effect of FK506 eye drops on late and delayed-type responses in ocular allergy models

BACKGROUND

It is well-known that FK506 strongly inhibits cytokine production by T cells in vitro. However, less evidence is available from in vivo studies of ocular allergy.

OBJECTIVE

To study the anti-inflammatory effect of FK506 eye drops on late and delayed-type responses in several animal models of ocular allergy.

METHODS

Rats and guinea-pigs were sensitized with egg albumin (EA) in adjuvant and later challenged by topical EA application to their eyes to examine the late response. Biopsy specimens of conjunctiva were stained with haematoxylin-eosin or stained for T cells and eosinophils. In addition, rats, rabbits and guinea-pigs were sensitized with complete Freund's adjuvant and later challenged by injecting purified protein derivatives for the delayed-type response. Bulbar conjunctival oedema and hyperaemia were graded by score in rabbits, and Evans blue (EB) extravasation was measured in rats and guinea-pigs. FK506 (0.01-1%) and steroid (0.1%) eye drops were instilled in the eyes of animals several times, before and after challenge.

RESULTS

FK506 eye drops inhibited T cell and eosinophil infiltration in the late response and EB extravasation in the delayed-type response in rats. Also, they inhibited conjunctival oedema, hyperaemia and ocular mucus in the delayed-type response in rabbits. These effects were similar to those of steroid eye drops (betamethasone sodium phosphate, fluorometholone). FK506 eye drops also inhibited inflammatory cell infiltration, the loss of conjunctival epithelium and decrease of goblet cells in the late response as well as EB extravasation in the delayed-type response in guineapigs, a steroid-resistant species.

CONCLUSION

FK506 eye drops inhibit late and delayed-type responses in animal models of ocular allergy.

Locally administered ocular corticosteroids: benefits and risks

Corticosteroids, used prudently, are one of the most potent and effective modalities available in the treatment of ocular inflammation. However, they can produce a plethora of adverse ocular and systemic events. In order to optimise and target drug delivery, whilst minimising systemic adverse effects, a diverse range of local ophthalmic preparations and delivery techniques have been developed. Topical drops and ointments remain the primary methods for administration of ocular corticosteroids. However, ocular penetration of topical corticosteroid drops depends upon drug concentration, chemical formulation of corticosteroid, and composition of the vehicle, therefore, apparently small modifications in preparations can produce a more than 20-fold difference in intraocular drug concentration. Periocular injections of corticosteroids continue to have a useful, but limited, therapeutic role and longer acting, intraocular delayed-release devices are in early clinical studies. Although newer corticosteroids with lesser pressure elevating characteristics have been developed, corticosteroid-induced ocular hypertension and glaucoma continue to be significant risks of local and systemic administration. Posterior subcapsular cataract, observed following as little as 4 months topical corticosteroids use, is thought to be due to covalent binding of corticosteroid to lens protein with subsequent oxidation. Inappropriate use of topical corticosteroid in the presence of corneal infections also continues to be a cause of ocular morbidity. Other risks of locally administered ophthalmic corticosteroids include: tear-film instability, epithelial toxicity, crystalline keratopathy, decreased wound strength, orbital fat atrophy, ptosis, limitation of ocular movement, inadvertent intraocular injection, and reduction in endogenous cortisol. This extensive review assesses the therapeutic benefits of locally administered ocular corticosteroids in the context of the risks of adverse effects.

Association between intraocular pressure and budesonide inhalation therapy in asthmatic patients

BACKGROUND

The extent to which inhaled glucocorticoids increase the risk of intraocular pressure elevation has been controversial.

OBJECTIVE

The authors attempt to assess such risk attributable to budesonide, an inhaled glucocorticoid for asthma therapy.

METHODS

Data were pooled from four prospective, randomized, double-blind, parallel-group, placebo-controlled, multicenter clinical trials of 12 to 20 weeks in duration. One thousand two hundred and fifty-five patients, 6 to 70 years of age whose intraocular pressures (IOPs) were less than 23 mmHg at screening were randomized to receive placebo or inhaled budesonide at doses ranging from 100 to 800 microg, administered twice daily. Intraocular pressure was measured at screening and at the end of double-blind treatment. Intraocular change was compared between budesonide and placebo, accounting for the confounding effects of gender, race, age, history of diabetes, history of hypertension, clinical trial, systemic glucocorticoid use during the trials, ophthalmic glucocorticoid use during the trials, and prior oral glucocorticoid use.

RESULTS

No budesonide treatment effect on the IOP was evident either in the crude analysis or after adjustment for possible confounding factors. For patients exposed to budesonide at a total daily dose of 1600 microg for 20 weeks, there was no difference in IOP change compared with the placebo controls.

CONCLUSIONS

No association with an increased IOP was observed in asthmatic patients treated with budesonide at daily doses ranging from 200 to 1600 microg for durations of 12 to 20 weeks. The subgroup analysis, which focused on the highest dose and longer term therapy was reassuring, as was the overall result.

Intravitreal triamcinolone and elevated intraocular pressure

PURPOSE

To ascertain whether intravitreal triamcinolone given for subretinal neovascularization is associated with an ocular pressure rise.

METHODS

A total of 113 patients with angiographically proven subretinal neovascularization were enrolled into a prospective study of the effects of intravitrea triamcinolone. Intraocular pressure was one of the parameters studied.

RESULTS

Approximately 30% of the study group developed a significant rise (> or =5 mm Hg) in intraocular pressure above baseline during the first 3 months.

CONCLUSIONS

Patients considering this form of treatment should be fully informed of the known risks of intraocular injections of steroids.

PCR-SSCP analysis of the glucocorticoid-responsive element of the atrial natriuretic peptide gene in familial primary open-angle glaucoma

1. Familial primary open-angle glaucoma (POAG) is a heterogeneous disease of unknown aetiology and the elucidation of the underlying genetic mechanisms contributing to phenotypic expression will be essential if earlier diagnosis of at-risk individuals and more specific medical treatment can be achieved. In a significant percentage of patients with POAG, intraocular pressure increases in response to topical ocular glucocorticoids. 2. Atrial natriuretic peptide (ANP) assists in the regulation of intraocular pressure levels and binding of the glucocorticoid receptor dimer to the glucocorticoid-responsive element in intron 2 of the ANP gene has been shown to increase ANP mRNA levels in vitro. We amplified and examined this sequence in the ANP gene by PCR-SSCP analysis in 100 patients with familial POAG and in 60 normal control subjects. No base alterations in the amplified product were found. 3. Thus, the present study found no evidence for an alteration in the sequence of the glucocorticoid-responsive element of the ANP gene that could alter ANP gene transcription in patients with familial POAG. The mechanism responsible for the increase in intraocular pressure levels in response to glucocorticoids is most likely independent of the glucocorticoid-responsive element in the ANP gene.