Use of latanoprost in the treatment of glaucoma associated with Sturge-Weber syndrome

Incidence of Sturge-Weber Syndrome and Risk of Secondary Glaucoma: A Nationwide Population-based Study Using a Rare Disease Registry

PURPOSE

To determine Sturge-Weber syndrome (SWS) incidence and secondary glaucoma risk.

DESIGN

Nationwide retrospective cohort study.

METHODS

The Korean National Health Insurance (NHI) claims database from 2002 to 2019 along with the registration-program database for rare intractable diseases (ie, the rare disease registry) were accessed to identify ophthalmologist/neurologist-confirmed SWS patients. SWS incidence was estimated in a same-birth-year population (ie, a birth cohort) from 2002 to 2009. Among the SWS patients born between 2002 and 2019, the incidence of SWS-associated glaucoma was estimated.

RESULTS

During the 18-year observational period, a total of 1049 patients were registered as SWS. The mean birth-cohort SWS incidence was 3.08 (95% CI 2.52-3.64) per 100 000 people per year, with an approximate female-to-male ratio of 0.97:1. Among the 217 SWS patients born between 2002 and 2019, secondary glaucoma arose in 18 (8.3%) cases, including 12 males (66.7%). Among these 18 SWS-associated glaucoma cases, 15 (83.3%) were diagnosed before 1 year of age, and the other 3 (16.7%) between age 1 and 2 years. Among the 660 SWS patients under age 40 years during the study period, SWS-associated glaucoma was identified in 79 (12.0%) cases. Neurologic manifestations such as epilepsy, hemiparesis, and mental retardation did not significantly differ between SWS patients with and those without secondary glaucoma.

CONCLUSIONS

This study identified birth-cohort SWS incidence and determined secondary-glaucoma risk in a population of East Asian ethnicity. These data could help to promote better understanding of the epidemiologic features of SWS patients.

Ocular Manifestations of the Sturge-Weber Syndrome

Sturge-Weber syndrome (SWS) or encephalotrigeminal angiomatosis is a non-inherited congenital disorder characterized by neurologic, skin, and ocular abnormalities. A somatic activating mutation (R183Q) in the GNAQ gene during early embryogenesis has been recently recognized as the etiology of vascular abnormalities in SWS. Approximately, half of the patients with SWS manifest ocular involvement including glaucoma as the most common ocular abnormality followed by choroidal hemangioma (CH). The underlying pathophysiology of glaucoma in SWS has not been completely understood yet. Early onset glaucoma comprising 60% of SWS glaucoma have lower success rates after medical and surgical treatments compared with primary congenital glaucoma. Primary angle surgery is associated with modest success in the early onset SWS glaucoma while the success rate significantly decreases in late onset glaucoma. Filtration surgery is associated with a higher risk of intraoperative and postoperative choroidal effusion and suprachoroidal hemorrhage. CH is reported in 40-50% of SWS patients. The goal of treatment in patients with CH is to induce involution of the hemangioma, with reduction of subretinal and intraretinal fluid and minimal damage to the neurosensory retina. The decision for treating diffuse CHs highly depends on the patient's visual acuity, the need for glaucoma surgery, the presence of subretinal fluid (SRF), its chronicity, and the potential for visual recovery.

Medical management of pediatric glaucoma: lessons learned from randomized clinical trials

PURPOSE

To critically discuss the randomized clinical trials (RCTs) on glaucoma medical therapy for the management of pediatric glaucoma.

METHODS

RCTs on glaucoma drugs carried out on pediatric subjects with ocular hypertension and glaucoma were identified through systematic searches. The methods of the RCTs and the safety and the efficacy of the glaucoma drugs were reviewed and discussed.

RESULTS

We included five RCTs. One study compared dorzolamide with 0.5% timolol gel; one brinzolamide with 0.5% levobetaxolol; one 0.25% betaxolol, 0.25% timolol gel, and 0.5% timolol gel; one latanoprost with 0.5% timolol; and one travoprost with 0.5% timolol. The primary outcome was safety for two studies and efficacy for three studies. None of the RCTs was powered to detect statistically significant differences in intraocular pressure (IOP) between treatments. In total, 658 subjects received at least one dose of study medication. Beta-blockers were administered to 359 patients, carbonic anhydrase inhibitor (CAI) to 154, and prostaglandins to 145 patients. IOP-lowering efficacy ranged from 20 to 23% for CAI, from 9 to 36% for beta-blockers, and from 26 to 27% for prostaglandins. The percentage of responders was 50% for CAI, ranged from 38 to 74% for beta-blockers and from 60 to 83% for prostaglandins. Two patients receiving timolol experienced a systemic, drug-related serious adverse event (one patient bradycardia and one pneumonia). Systemic, nonserious drug-related events occurred in 15 patients randomized to beta-blockers and in 8 patients randomized to CAI. No adverse events occurred in children treated with prostaglandins.

CONCLUSION

RCTs that are available on medical therapy for glaucoma are few and underpowered. The proportion of responders is lower in children; however, in subjects who are responders, the efficacy of glaucoma drugs seemed to be comparable to that in adults. As systemic adverse events have been reported, including serious events with timolol, a particular attempt to minimize the absorption of the drug (using the lowest dose and the gel formulation of beta-blockers or considering the lacrimal punctum occlusion) and a follow-up that is more frequent and more focused on safety should be considered in pediatric subjects who are on topical glaucoma medications.

Glaucoma in children with facial port wine stain

PURPOSE

To report on the clinical presentation and surgical treatment (procedure and outcome(s)) of glaucoma in children with facial port wine stain.

MATERIALS AND METHODS

This is a retrospective chart review of children with facial port wine stain referred to Alexandria University paediatric ophthalmology practice from 2005 to 2016. The charts of 22 children (44 eyes) with facial port wine stain were reviewed. The data extracted included demographics, results of ophthalmic examination findings and treatment(s). The main outcome measures were the number of eyes stratified as glaucoma, glaucoma suspects and no glaucoma at the initial and final presentations.

RESULTS

The average age of presentation was 18.2 (±33.9) months. After a follow-up of over 16.1 (±24.8) months, there were 34%, 30% and 36% of the study eyes diagnosed as glaucoma, glaucoma suspects and no glaucoma, respectively with mean ± standard deviation of intraocular pressure of 20.6 ± 5.1, 13.6 ± 5.4 and 7.5 ± 1.7 mmHg. The majority (91%) of eyes presenting with glaucoma had clear corneas. In total, 11 eyes were operated upon for glaucoma. The recorded success rate was 91%. Two eyes developed a postoperative exudative choroidal detachment, of which one resolved spontaneously and the other was successfully managed by intravitreal gas injection.

CONCLUSION

Glaucoma is a significant ocular hazard in children with facial port wine stain that may not be evident on the initial presentation. The presentation is usually with a clear cornea and surgical intervention is associated with a high success rate and a low rate of complications.

Results of external beam radiotherapy for diffuse choroidal hemangiomas in Sturge-Weber syndrome

PURPOSE

The Sturge-Weber Syndrome (SWS) is a phacomatosis which include facial nevus flammeus, glaucoma, diffuse choroidal hemangioma, and leptomeningeal hemangiomatosis. External beam radiotherapy (EBRT) using photons was used to treat retinal detachment. We investigate the anatomical and functional results in a long-term basis.

METHODS

Retrospective review of SWS patients treated by EBRT (20 Gy in 10 fractions) for an exudative diffuse choroidal hemangioma. Visual acuity, B-scan tumor thickness, size of retinal detachment, intra-ocular pressure, and hypotonic treatment were collected before EBRT, 1 year after, and at the latest news.

RESULTS

Twenty-five patients (26 eyes) were treated between 2001 and 2014. Retinal detachment including the macula was found among twenty-six eyes before treatment. The average follow-up time was 47 months. The mean tumor thickness was initially 4.5 mm, 2.8 mm at first year, and 2.7 mm at the last visit. The retina was reattached at the last visit for all eyes except two. The visual acuity was stable or better for 20 eyes (p = 0.02). Four patients developed mild cataract during the follow-up.

CONCLUSION

EBRT using 20 Gy in 10 fractions is efficient, decreases tumor thickness, reattaches the retina, and stabilizes visual acuity. In the long term, retinal reattachment allows ocular conservation by preventing phthisis bulbi.

Ocular manifestations of Sturge-Weber syndrome: pathogenesis, diagnosis, and management

Sturge–Weber syndrome has been included in the group of phakomatoses that is characterized by hamartomas involving the brain, skin, and eyes. The characteristic facial port-wine stain, involving the first branch of the trigeminal nerve and the embryonic vasculature distribution in this area, leads to several ocular complications of the anterior segment and can involve the eyelids and conjunctiva. The posterior segment of the eyes is also affected with diffuse choroidal hemangiomas. However, the most frequent ocular comorbidity is glaucoma with a prevalence rate ranging from 30%–70%. Glaucoma is related to anterior chamber malformations, high episcleral venous pressure (EVP), and changes in ocular hemodynamics. Glaucoma can be diagnosed at birth, but the disease can also develop during childhood and in adults. The management of glaucoma in Sturge–Weber syndrome patients is particularly challenging because of early onset, frequently associated severe visual field impairment at the time of diagnosis, and unresponsiveness to standard treatment. Several surgical approaches have been proposed, but long-term prognosis for both intraocular pressure control and visual function remains unsatisfactory in these patients. Choroidal hemangiomas may also lead to visual impairment thorough exudative retinal detachment and macular edema. Treatment of exudative hemangioma complications is aimed at destructing the tumor or decreasing tumor leakage.

Ophthalmic Alterations in the Sturge-Weber Syndrome, Klippel-Trenaunay Syndrome, and the Phakomatosis Pigmentovascularis: An Independent Group of Conditions?

The phakomatoses have been traditionally defined as a group of hereditary diseases with variable expressivity characterized by multisystem tumors with possible malignant transformation. The Sturge-Weber syndrome, Klippel-Trenaunay syndrome, and the phakomatosis pigmentovascularis have the facial port-wine stain in common. Numerous pathophysiogenetic mechanisms have been suggested such as venous dysplasia of the emissary veins in the intracranial circulation, neural crest alterations leading to alterations of autonomic perivascular nerves, mutation of the GNAO gene in the Sturge-Weber syndrome, PIK3CA mutation in malformative/overgrowth syndromes such as the Klippel-Trenaunay syndrome, and the twin-spotting phenomenon in phakomatosis pigmentovascularis. Other features linked to the port-wine stain and typical to all of the three conditions are glaucoma and choroidal alterations. Glaucoma can be due to malformations of the anterior chamber or high episcleral venous pressure and in phakomatosis pigmentovascularis it can also be associated with angle hyperpigmentation. The choroid can be thickened in all diseases. Furthermore, choroidal melanocytosis in the phakomatosis pigmentovascularis can lead to malignant transformation. Although the multiple pathophysiological mechanisms still require clarification, similarities in ophthalmic manifestations make it reasonable to classify these diseases in an independent group.

Long-term efficacy of latanoprost in primary congenital glaucoma

PURPOSE

To investigate the success (glaucoma control) of latanoprost therapy of primary congenital glaucoma (PCG) and factors affecting the long-term outcome.

METHODS

Patients with PCG treated with latanoprost were re-examined. At study visit and from clinical charts, we evaluated: intraocular pressure, length of glaucoma control with latanoprost, need of further medication or glaucoma surgery, systemic and topical side effects. Multivariate analysis was used to test factors related to the final outcome of the treatment.

RESULTS

Eighty-one eyes of 44 patients with PCG, and 42 eyes of 29 patients with previous glaucoma surgery, had received latanoprost therapy. In the first group, a success (glaucoma control by latanoprost therapy) was found in 24 eyes (29.6%), whereas 57 eyes (70.4%) had received surgery (45 eyes (55.6%) in the first year); among the eyes with previous surgery, a success was found in 12 eyes (28.6%), 13 eyes (31%) required an additional therapy, and 17 eyes (40.5%) had received further glaucoma surgery. No patient discontinued the treatment because of side effects. Factors related to the failure of the latanoprost treatment were: the high score of severity of glaucoma (P=0.014) and low age at PCG presentation (P=0.042).

CONCLUSIONS

Long-term treatment with latanoprost is effective in about 30% of the eyes; factors related to failure were severe glaucomatous alterations, and young age at PCG presentation.

Sturge-weber syndrome

OPINION STATEMENT

We try to see the babies prior to the onset of symptoms so that their parents can receive anticipatory guidance regarding seizures and how to recognize and respond to them and so that proper referrals to ophthalmology can be made. If there is any concern on history, exam, or EEG then we obtain a magnetic resonance imaging (MRI) with contrast. If presymptomatic diagnosis of brain involvement is made then treatment with low-dose aspirin is offered and if the brain involvement is extensively bilateral then an anticonvulsant such as levetiracetam is offered as well. Seizures are treated aggressively with a goal of obtaining and maintaining complete seizure suppression as much as possible often with a combination of low-dose aspirin and two anticonvulsants such as levetiracetam and oxcarbazepine. For many patients, this will provide adequate control of their seizures and stroke-like episodes. If the patient fails medical management and seizures are regular and accompanied by plateaued development, significant hemiparesis and visual field deficit and the patient is unilaterally involved and a surgical candidate then surgical management is urged. When the seizures are less regular, little or no hemiparesis or visual field deficit exist, and development is reasonable then this decision is more difficult. For bilaterally involved patients surgery is usually not a good option unless seizures are very severe and mostly coming from one side. Other therapeutic options include the ketogenic/Atkins diet and vagal nerve stimulator although in our experience these usually do not result in cessation of seizures. Endocrine problems occur with increased frequency and must be treated when they are present. The recent discovery of the somatic mutation causing Sturge-Weber syndrome holds promise for new treatment options in the future.

Encephalotrigeminal Angiomatosis (Sturge-Weber Syndrome, Klippel-Trenaunay-Weber Syndrome): A Review

Sturge-Weber syndrome (SWS) (encephalotrigeminal angiomatosis) is a phakomatosis associated with port-wine stains of the face, seizures, mental retardation, and usually ipsilateral meningeal vascular malformations. The classic form affects leptomeninges, eyes, and face. Although the precise etiology and pathogenesis are unclear, the postulated defect is primary venous dysplasia with failure of the primordial embryonic venous plexus to regress. A spontaneous somatic mutation in fibroblast fibronectin gene expression in the vascular malformation may occur during embryonic development. Ocular involvement is characterized by conjunctival, episcleral, retinal, and choroidal vascular abnormalities. The vascular lesions have been inconsistently described as angiomas, hemangiomas, and vascular malformations. Based on the endothelial cellular activity, they can be considered vascular malformations (or port-wine stains), which never regress spontaneously. Congenital, developmental, and adult-onset glaucoma are often seen when the malformations involve the distribution of the first branch of the trigeminal nerve.Both mechanical and vascular causes have been proposed to account for the development of glaucoma. The mechanical theory is based on obstruction of aqueous outflow secondary to developmental anterior chamber angle abnormalities, and the vascular theory is based primarily on elevated episcleral venous pressure. Management of glaucoma in patients with SWS is often challenging and is aimed at controlling intraocular pressure and preventing progressive visual loss and blindness. It also carries an increased risk for surgical complications. This review summarizes the literature regarding the genetics, clinical features, and management of ocular complications of SWS with special focus on glaucoma.

A review of the use of latanoprost for glaucoma since its launch

INTRODUCTION

Prostaglandins are increasingly used as first choice treatment for glaucoma because they are highly effective, lack relevant systemic side effects and require just once-daily administration. Latanoprost is an ester prodrug analog of prostaglandin F2α, which reduces intraocular pressure (IOP) by increasing uveoscleral outflow. Latanoprost 0.005% has received European and US approval as the first-line drug for reducing IOP in patients with open-angle glaucoma or ocular hypertension. Following the recent patent expiry for Xalatan®, a number of latanoprost generics have entered the glaucoma market.

AREAS COVERED

This review, achieved through PubMed and Medline research methods, describes the composition, pharmacokinetics, mode of action, efficacy, side effects and safety profile of latanoprost.

EXPERT OPINION

Latanoprost was the first prostaglandin analog introduced in glaucoma management and it dramatically changed the market of the disease thanks to its efficacy and safety. Conjunctival hyperemia, which is commonly found after latanoprost use, is associated with a minor efficacy and duration of trabeculectomy; yet, from the ophthalmologist's perspective, this side effect seems largely counterbalanced by the high efficacy and safety of this compound. It is always advisable to consider the pro-inflammatory mode of action of latanoprost because this may have negative effects in particular patients (i.e., those with uveitis and cystoid macular edema) for whom caution and close follow-up is necessary.

Latanoprost systemic exposure in pediatric and adult patients with glaucoma: a phase 1, open-label study

OBJECTIVE

To evaluate short-term safety and steady-state systemic pharmacokinetics (PK) of latanoprost acid in pediatric subjects with glaucoma or ocular hypertension who received the adult latanoprost dose.

DESIGN

Phase 1, open-label, multicenter study.

PARTICIPANTS

Pediatric patients of 3 age groups (<3, 3-<12, and 12-<18 years) and adults (≥18 years) receiving latanoprost ophthalmic solution 0.005% once daily in 1 or both eyes for ≥2 weeks.

INTERVENTION

Latanoprost was administered in both eyes each morning post-screening. Subjects returned 3 to 28 days later for evaluation of plasma concentrations, withholding morning latanoprost. At the clinic, a single drop of latanoprost ophthalmic solution was instilled into both eyes. Plasma latanoprost acid concentrations were collected predose and 5, 15, 30, and 60 minutes after administration.

MAIN OUTCOME MEASURES

Latanoprost acid plasma exposure.

RESULTS

The evaluable PK analysis set included data from 39 of 47 enrolled subjects. The median peak plasma concentration value was higher in the <3-year age group (166 pg/ml) versus other groups (49, 16, and 26 pg/ml for the 3-<12-year, 12-<18-year, and ≥18-year age groups, respectively). The median area under the concentration-time curve from zero to last measurable concentration value was also higher in the <3-year age group (2716 pg/min/ml) versus other groups (588, 106, and 380 pg/min/ml for the 3-<12-year, 12-<18-year, and ≥18-year age groups, respectively). Latanoprost acid was rapidly eliminated from the blood, with plasma concentrations undetectable within 10 to 30 minutes postdose in all but the <3-year age group. There were no discontinuations or dose reductions due to adverse events or treatment-emergent adverse events.

CONCLUSIONS

Latanoprost acid systemic exposure was higher in younger children versus adolescents and adults, attributed primarily to lower body weight and smaller blood volume. Latanoprost acid was eliminated rapidly in all age groups and resulted in only a brief period of systemic exposure after once-daily dosing. Higher systemic exposure was not accompanied by adverse events, and on the basis of extrapolation of safety data from adults, this pilot study suggests an adequate safety margin for systemic adverse effects with use of the adult topical dose of latanoprost in pediatric patients.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosures may be found after the references.

The management of complicated glaucoma

Complicated glaucomas present considerable diagnostic and management challenges. Response to treatment can be unpredictable or reduced compared with other glaucomas. However, target intraocular pressure and preservation of vision may be achieved with selected medical, laser and surgical treatment. The evidence for such treatment is expanding and consequently affords clinicians a better understanding of established and novel techniques. Herein we review the mechanisms involved in the development of complicated glaucoma and the current evidence supporting its management.

Latanoprost in pediatric glaucoma--pediatric exposure over a decade

BACKGROUND

Although numerous studies of latanoprost in adult glaucoma have shown it to be an effective hypotensive agent with a low incidence of side effects, these issues have not been well studied in pediatric glaucomas. The purpose of the current study is to evaluate the safety and intraocular pressure (IOP) lowering effect of latanoprost in various pediatric glaucomas over a long period.

SUBJECTS AND METHODS

This retrospective study included all children treated with latanoprost at our institution from 1996 to 2007. Demographic, glaucoma-related, and side-effect information was recorded for each subject. Duration of latanoprost exposure was calculated in child-months (1 child exposed for 1 month). If interpretable IOP data were available, the presence or absence of a treatment response (IOP reduction > or =15% from baseline) was determined for each subject.

RESULTS

A total of 115 subjects with latanoprost exposure were identified, with a collective exposure of 2,325 child-months. Exposure for > or =1 year occurred in 52 subjects. Side effects were mild and infrequently reported. Of the 115 subjects, 63 had interpretable IOP data, and 22 (35%) were treatment responders. Predictors of a response included a diagnosis of juvenile open-angle glaucoma, monotherapy, and older age.

CONCLUSIONS

This large study of latanoprost-treated children confirms the excellent safety profile of the drug in the treatment of pediatric glaucoma. The study also confirms latanoprost's IOP-lowering ability in older children with juvenile open-angle glaucoma and in some children with aphakic glaucoma. Prospective studies are needed to better define the optimal role of latanoprost in the treatment of pediatric glaucoma, especially congenital glaucoma.

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.

Advances in the management of paediatric glaucoma

The paediatric glaucomas present some of the greatest clinical challenges. We review the advances in the management of the paediatric glaucomas, which have improved the outlook for these patients and their families. These advances include improvements in diagnosis, investigations, anaesthetic techniques, medical, surgical, and laser therapies.

Glaucoma in children: are we making progress?

BACKGROUND

Glaucoma in children presents difficult clinical challenges. Even when appropriately treated, blindness can occur.

DESIGN

Retrospective interventional case series and literature review.

METHODS

All clinical records of children seen by the author with a diagnosis of glaucoma established before 16 years of age were reviewed from 1977 to 2003. Glaucoma was classified as primary infantile, aphakic, syndrome-related, and secondary. The best-corrected visual acuity, refractive error, configuration of the optic nerve cup, and perimetry were recorded. The intraocular pressure (IOP) for each visit was recorded. IOP measurements of 19 mm Hg or less were considered "good." The percentage of "good" readings was calculated for each eye. Representative visual acuities, refractive errors, IOP, disk configuration, and perimetry were recorded at 6, 12, 18, and 24 years of age for each patient. The admitting ophthalmologic diagnosis for each child at the Western Pennsylvania School for Blind Children was recorded from 1887 to 2003.

RESULTS

One hundred twenty-six children (204 eyes) were studied: infantile glaucoma, 52 eyes; aphakic glaucoma, 40 eyes; syndrome associated, 69 eyes; and secondary glaucoma, 43 eyes. The mean follow-up was 11.6 years (1 to 30 years). Overall, 60 (29.4%) of 204 eyes had a 6/12 (20/40) or better corrected visual acuity at the most recent visit. The percentage with this acuity remained stable throughout the follow-up period. Eyes with infantile glaucoma had the best acuity, and 40% had 6/12 (20/40) or better. Amblyopia was common and responded to treatment. Eyes with aphakic glaucoma had the worst acuity with only 10% achieving 6/12 or better. These eyes had a bimodal onset of glaucoma; eyes with an early onset had an angle closure configuration and eyes with a delayed onset had an open angle. Early cataract removal and microcornea were risk factors for glaucoma. If the IOP was maintained at 19 mm Hg or less (good) on 80% of the determinations over time, the optic nerve cup compared with the diameter of the optic nerve (C/D ratios) were stable. Eight patients had multiple, good quality, visual fields performed over 3 to 15 years. If the patients had "good" IOP on 70% of the measurements, the visual fields remained stable. A historical perspective of glaucoma control was gained by looking at the admitting diagnosis at the Western Pennsylvania School for Blind Children. From 1910 to 1970, an average of 9.2 children blind due to glaucoma were admitted each decade. From 1971 to 2003, there were only three children with glaucoma admitted over 30 years.

CONCLUSION

Removal of congenital cataracts should be delayed until 3 to 4 weeks of age. Consideration should be given for using 19 mm Hg or less to measure the success of glaucoma treatment in children. Treatment of amblyopia is as important as IOP control in children. Imaging technology such as optical coherence tomography and measurement of central corneal thickness may play an important future role in the assessment of children with suspected or known glaucoma.

Latanoprost : an update of its use in glaucoma and ocular hypertension

Latanoprost (Xalatan) is an ester analogue of prostaglandin F2alpha that reduces intraocular pressure (IOP) by increasing uveoscleral outflow. The IOP-lowering efficacy of latanoprost 0.005% lasts for up to 24 hours after a single topical dose, which allows for a once-daily dosage regimen. In patients with ocular hypertension or open-angle glaucoma, a single drop of latanoprost 0.005% solution (about 1.5 microg) administered topically once daily reduced diurnal IOP by 22 to 39% over 1 to 12 months' treatment in well-controlled trials; efficacy was maintained during treatment periods of up to 2 years. At this dosage, latanoprost was significantly more effective than timolol 0.5% twice daily in 3 of 4 large, double-blind, randomised studies, was generally as effective as bimatoprost or travoprost, and was significantly more effective than dorzolamide, brimonidine or unoprostone. Furthermore, in patients whose IOP was poorly controlled with timolol, switching to latanoprost monotherapy was at least as effective at lowering IOP as adding dorzolamide or pilocarpine to the regimen. Latanoprost has also shown significant additive effects when used in combination with one or more other glaucoma medications. The fixed combination of latanoprost plus timolol was significantly more effective than either of its individual components in two double-blind randomised studies and more effective than the fixed combination of dorzolamide and timolol in a 3-month, evaluator-masked study. Data in patients with angle-closure glaucoma are limited, but in patients with elevated IOP after undergoing iridotomy, latanoprost 0.005% once daily was significantly more effective than timolol 0.5% twice daily at reducing IOP over 12 weeks of treatment in a large double-blind, randomised study. Latanoprost is generally well tolerated and, unlike timolol, induces minimal systemic adverse events. In well-controlled, 6-month trials, the most commonly occurring drug-related ocular events in latanoprost recipients were mild to moderate conjunctival hyperaemia (3 to 15%) and iris colour change (2 to 9%); these seldom required patient withdrawal although the latter may be permanent. Latanoprost 0.005% as a single daily drop has shown good IOP-lowering efficacy in patients with open-angle glaucoma or ocular hypertension and does not produce the cardiopulmonary adverse effects associated with beta-blockers. Thus, latanoprost is a valuable addition to the first-line treatment options for patients with open-angle glaucoma or ocular hypertension. In addition, adjunctive treatment with latanoprost in patients who are refractory to beta-blocker therapy is a viable, second-line treatment option. Although preliminary findings are promising, wider clinical experience is required to define the place of latanoprost in the treatment of angle-closure glaucoma.

Sturge-Weber syndrome

Sturge-Weber syndrome is a sporadic neurocutaneous disease characterized by facial port-wine stain, ocular abnormalities (glaucoma and choroidal hemangioma) and leptomeningeal angioma. Although the precise pathogenesis is unknown, available data regarding genetics, embryogenesis, and pathologic features are briefly reviewed. Clinical features vary from mild incomplete forms to full-blown disease with facial stain, seizures, and glaucoma. Frequencies of associated complications are reviewed. To plan treatment and further follow-up, diagnosis of glaucoma and intracranial involvement, even if asymptomatic, is fundamental in children at risk. Early neuroimaging features are important to recognize. Management of patients with Sturge-Weber syndrome is focused on treating associated neurologic and ocular abnormalities.

Latanoprost in port wine stain related paediatric glaucoma

AIM

To evaluate the efficacy of latanoprost (Xalatan) as adjunctive therapy in port wine stain related paediatric glaucoma.

METHODS

A retrospective non-randomised study. Patients with previous surgical intervention and medical treatment were included. Measurements were recorded from clinic and/or examination under anaesthetic (EUA) visits. A successful outcome was considered to be patients who required no further intervention following initiation of latanoprost, with stable glaucoma factors as well as drop in intraocular pressure.

RESULTS

14 patients and 17 eyes were reviewed in total. The mean age of glaucoma diagnosis was 2.59 years (0.1-5.25 years) and of commencing latanoprost was 6.8 years (1.40-12.90 years). Percentage success at 1 month, 3 months, 6 months, and 1 year was 70.6%, 64.7%, 58.9%, and 47.1%, respectively, of eyes treated which translated to 71.4%, 64.2%, 57.1%, and 50% respectively of patients treated.

CONCLUSIONS

A trial of latanoprost as adjunctive therapy in patients with port wine stain related glaucoma may temporise the need for surgery; with 50% of patients being controlled at 1 year follow up. Lack of efficacy was detected as early as 1 month following commencement of treatment.

Current status of prostaglandin therapy: latanoprost and unoprostone

Latanoprost, a prostaglandin F(2alpha) analog prodrug, and unoprostone, an analog of a prostaglandin metabolite, have been shown to be effective in decreasing intraocular pressure when used alone or in combination with other ocular hypotensive agents. The increase in the uveoscleral outflow and some of the side effects are probably FP-receptor mediated, which may account for some differences between the cited drugs. This article reviews the recent literature available on the clinical efficacy of these prostanoids, as well as the studies directly comparing these drugs.

Latanoprost for the treatment of pediatric glaucoma

Latanoprost is a prostaglandin F(2alpha) analog that reduces intraocular pressure (IOP) by 20-40% in adults with open-angle glaucoma or ocular hypertension. The efficacy and safety of latanoprost in children has not been widely reported, but there are at least three peer-reviewed publications involving the use of this drug in the treatment of pediatric patients with glaucoma. Most of the patients in these studies showed disappointingly little IOP effect from this drug, but some children, particularly older children and those with juvenile-onset open-angle glaucoma, do have a significant ocular hypotensive effect with latanoprost. Systemic and ocular side effects in children on latanoprost are infrequent and mild.

The pros and cons of different prostanoids in the medical management of glaucoma

The prostaglandin analogs are new exciting drugs added to the therapeutic armamentarium for patients with glaucoma. Several studies have evaluated the ocular hypotensive properties and side effects of latanoprost in different forms of glaucoma. This drug, seems to be the most effective intraocular pressure (IOP)-reducing agent currently available, and has a low incidence of ocular and systemic side effects. Fewer data are available regarding unoprostone, but the IOP-reducing effect of this drug seems to be comparable or slightly inferior to that of timolol and it produces fewer side effects. When compared with unoprostone, latanoprost has been shown to effect a greater reduction in IOP. A major drawback to the use of prostaglandin analogues is the lack of long-term experience such as that currently available for other classes of agents.

Pharmaceutical management of the childhood glaucomas

Glaucoma in childhood is a diverse, blinding group of conditions, which presents a major therapeutic challenge. Treatment is primarily surgical with medical treatments used as an adjunct. None of these drugs has been granted approval by the regulatory agencies for use in children, but they are used on a compassionate basis. Issues of efficacy and safety of these medications in children are discussed. beta-adrenoceptor blockers have been employed as first line pharmaceutical therapy for many years. Recently three new classes of drugs have been developed for use in glaucoma in adults. beta-blockers remain first line therapy if there are no contraindications such as asthma. Topical carbonic anhydrase inhibitors (CAI) appear to be less effective than beta-blockers, but seem safe systemically, although associated with local irritation. They are useful as an adjunct to beta-blockers or as first line therapy when beta-blockers are contraindicated. Prostaglandins have not proved as effective in childhood glaucoma as in adult glaucoma, although it works well in some patients with juvenile open angle glaucoma (JOAG) and others with aphakic glaucoma. alpha-adrenergic agonists, although effective at least in the short-term, have serious, potential systemic side effects, which demand close observation when used in neonates and young infants.