The additive effect of topical dorzolamide and systemic acetazolamide in pediatric glaucoma

Case Report: Steroid-induced Ocular Hypertension in a 6-year-old Boy

SIGNIFICANCE

Systemic corticosteroid use in children is rare because of known risks of adverse effects. The increased prevalence of multisystem inflammatory syndrome associated with COVID-19 may change this. It is critical for eye care providers to be aware of potential severe and rapid ocular hypertensive response to prevent irreversible vision loss.

PURPOSE

The purpose of this study was to report the importance of early monitoring of intraocular eye pressure in pediatric patients on systemic steroid medication.

CASE REPORT

A 6-year-old White boy presented with a complaint of headache for 2 weeks. He was on his 19th day of treatment for acute lymphoblastic leukemia with oral dexamethasone and chemotherapy. IOP at presentation was 65 mmHg in both eyes measured with iCare tonometry. Treatment with maximum topical glaucoma therapy reduced IOP to normal levels and eliminated the symptom of headache.

CONCLUSIONS

This case reminds eye care providers to be aware of the potential ocular hypertensive response to systemic steroid treatment and the importance of establishing early monitoring. With the emergence of multisystem inflammatory syndrome in children during the current COVID-19 pandemic, eye care providers may encounter more pediatric patients on systemic corticosteroid treatment than previously and should adjust their examinations appropriately.

Acetazolamide-Triggered Acute Flaccid Paralysis and Toxic-Metabolic Encephalopathy in a Toddler with Gastroenteritis: A Case Report

Acetazolamide is an infrequently prescribed medication in the outpatient pediatric setting, as one of its major indications is for the treatment of glaucoma, which is a largely adult disease. Though incredibly rare, serious neurologic side effects such as stroke, flaccid paralysis, and coma can occur after its administration. This case presentation of acute flaccid paralysis with metabolic derangement underscores the unusual, yet possible, toxic-metabolic and neurologic sequelae that can occur in an already acidotic host (in this case, caused by gastroenteritis) with acetazolamide ingestion. Life-threatening conditions must always be ruled out in patients who present with encephalopathy, but a medication history was crucial in clinching this case's unifying diagnosis. While there are case reports highlighting the rare central nervous system toxicities associated with acetazolamide ingestion, to our knowledge, none exist in the pediatric literature.

Osmoprotectants in Hybrid Liposome/HPMC Systems as Potential Glaucoma Treatment

The combination of acetazolamide-loaded nano-liposomes and Hydroxypropyl methylcellulose (HPMC) with similar components to the preocular tear film in an osmoprotectant media (trehalose and erythritol) is proposed as a novel strategy to increase the ocular bioavailability of poorly soluble drugs. Ophthalmic formulations based on acetazolamide-loaded liposomes, dispersed in the osmoprotectant solution (ACZ-LP) or in combination with HPMC (ACZ-LP-P) were characterized and in vivo evaluated. The pH and tonicity of both formulations resulted in physiological ranges. The inclusion of HPMC produced an increment in viscosity (from 0.9 to 4.7 mPa·s. 64.9 ± 2.6% of acetazolamide initially included in the formulation was retained in vesicles. In both formulations, a similar onset time (1 h) and effective time periods were observed (7 h) after a single instillation (25 μL) in normotensive rabbits' eyes. The AUC_0-8h of the ACZ-LP-P was 1.5-fold higher than of ACZ-LP (p < 0.001) and the maximum hypotensive effect resulted in 1.4-fold higher (p < 0.001). In addition, the formulation of ACZ in the hybrid liposome/HPMC system produced a 30.25-folds total increment in ocular bioavailability, compared with the drug solution. Excellent tolerance in rabbits' eyes was confirmed during the study.

Pediatric Glaucoma: Pharmacotherapeutic Options

Childhood glaucoma is a major therapeutic challenge for pediatric ophthalmologists and glaucoma specialists worldwide. Management depends on the etiology and age at presentation. A variety of drugs are available for the control of intraocular pressure in children; however, none of these drugs have been licensed by the regulatory agencies for use in children. Furthermore, evidence gained from randomized controlled trials in the pediatric population is sparse, and little is known regarding the use of newer anti-glaucoma preparations. This evidence-based review aims to discuss the available pharmacotherapeutic options for glaucoma in children. Topical adrenoceptor blockers, topical and systemic carbonic anhydrase inhibitors, prostaglandin (PG) analogs, adrenoceptor agonists, parasympathomimetics, and combined preparations are available for use in children, but usually as an off-label indication. Therefore, it is important to recognize that serious side effects have been reported, even with topical drops, and measures to reduce systemic absorption should be taken. Most drugs have been shown to have comparable ocular hypotensive effects, with the lowest occurrence of systemic side effects with PG analogs. Whereas a newly introduced prostaglandin analog, tafluprost, and some other preservative-free preparations have shown promising results in adult glaucoma patients, no pediatric reports are available as yet. Future studies may describe their role in treating pediatric glaucoma. This review also shares some suggested treatment pathways for primary congenital glaucoma (PCG), juvenile open angle glaucoma (JOAG), developmental glaucoma, aphakic/pseudophakic glaucoma, and uveitic glaucoma.

Raised Intraocular Pressure in Nonjuvenile Idiopathic Arthritis-Uveitis Children: Risk Factors and Effect on Retinal Nerve Fiber Layer

PURPOSE

To determine risk factors for intraocular pressure (IOP) elevation and glaucoma in children with nonjuvenile idiopathic arthritis-related uveitis and any IOP-related changes in the retinal nerve fiber layer (RNFL) thickness.

PATIENTS AND METHODS

Clinical data were collected from children attending a tertiary referral uveitis clinic between May 2010 and October 2012. We assigned 206 eyes of 103 children into 32 normal eyes, 108 normotensive uveitics (NU), 41 hypertensive uveitics (HU: raised IOP without glaucomatous disc), and 25 glaucomatous uveitics (GU: raised IOP with glaucomatous disc). Risk factors for raised IOP, glaucoma and steroid response (SR) were evaluated and RNFL thickness across groups was compared with determine changes related to raised IOP.

RESULTS

IOP elevation occurred in 40 patients (38.8%) or 66/174 eyes with uveitis (37.9%); and SR occurred in 35.1% of all corticosteroid-treated eyes. Chronic uveitis was a significant risk factor for raised IOP [odds ratio (OR)=9.28, P=0.001], glaucoma, and SR (OR=8.4, P<0.001). Higher peak IOP was also a risk factor for glaucoma (OR=1.4, P=0.003). About 70% of SR eyes were high responders (IOP increase >15 mm Hg from baseline), associated with younger age and corticosteroid injections. Although no significant RNFL thinning was detected between HU and NU eyes, significant thinning was detected in the inferior quadrant of GU (121.3±28.9 μm) compared with NU eyes (142.1±32.0 μm, P=0.043).

CONCLUSIONS

Children with chronic uveitis are at higher risk of raised IOP and glaucoma. Thinning of the inferior RNFL quadrant may suggest glaucomatous changes in uveitic children with raised IOP.

Current Approach in the Diagnosis and Management of Uveitic Glaucoma

Uveitic glaucoma (UG) typically is associated with very high intraocular pressure (IOP) and more intense optic nerve damage than other glaucoma types. This secondary glaucoma requires an early diagnosis and adequate management of both uveitis and glaucoma. It is mandatory to identify the mechanisms of IOP elevation that in many eyes have multiple combined mechanisms. Management of these patients commonly requires an interdisciplinary approach that includes a glaucoma specialist and rheumatologist to control the inflammation and IOP. Glaucoma surgery is required early in these patients due to the high IOP usually present and is less successful than in primary open-angle glaucoma. Recurrent uveitic episodes, multiple mechanism, and the complications associated with uveitis make surgical management of UG challenging. In this review, the management and treatment of UG are updated to clarify the pathogenesis and prevent optic nerve damage.

Ahmed glaucoma valve in children: A review

Pediatric glaucoma is potentially a blinding disease. Although goniotomy and trabeculotomy are associated with good early success rates, eventually 20% of these procedures fail and many children will require additional surgery to control the IOP in the long-term. In this review, we reported that adequate IOP control can be achieved with the placement of Ahmed glaucoma valve and can last 5 or more years. However, most patients will need one or more glaucoma medications at some point after surgery. In addition, the implants may be associated with pupillary irregularities, lenticular opacification as well as tube-related complications, particularly in the first year of life, as the globe is enlarging with age.

The safety and efficacy of glaucoma medication in the pediatric population

Topical glaucoma medications are widely used for childhood glaucoma, although little is known concerning the use of the newer glaucoma medications in this population. The majority of the references cited were extracted from PubMed. A literature review of all English language reports related to glaucoma medication in the pediatric population since 1980 was performed. Medical therapy of pediatric glaucoma contains four groups of drugs: beta-blockers (timolol and betaxolol), carbonic anhydrase inhibitors (dorzolamide), alpha2-agonists (brimonidine), and prostaglandin analogs (latanoprost). Timolol is the first choice in pediatric glaucoma. In cases with insufficient reduction of the intraocular pressure (IOP), the combination of timolol once a day and dorzolamide twice a day brings about a good control of the IOP. Both medications are effective and well tolerated. The alpha2-agonists have more and potentially serious adverse effects in children and are contraindicated for children younger than 2 years of age. Latanoprost tends to be less effective in lowering IOP in children than in adults. However, no studies are reported where latanoprost is used in monotherapy. Additional study may further delineate this drug's role in treating pediatric glaucoma. The safety profile of latanoprost in children appears excellent.

Cardiovascular and respiratory considerations with pharmacotherapy of glaucoma and ocular hypertension

Glaucoma and ocular hypertension are highly prevalent conditions in individuals over the age of 40 and are commonly seen together in patients with cardiovascular disease. Many of the antiglaucoma medications, when systemically absorbed, affect the sympathetic and parasympathetic nervous systems of patients and can cause cardiovascular toxicity. Such adverse effects are frequently associated with the long-term use of potentially toxic agents in elderly people, who are most prone to chronic eye disease. Moreover, patients may not associate their symptoms with the topical eye medications, and consequently may not report adverse drug effects. Drug-drug interactions can also occur when patients are taking medications for both cardiovascular disease and glaucoma. In this review, the systemic toxicity of these agents is reviewed, along with possible drug-drug interactions. Mention is made of other antiglaucoma medications used alone and in combination with topical beta-blockers. Identification of genetic loci-a bold new step toward glaucoma treatment-is mentioned briefly at the end of the article.