Advances in the management of paediatric glaucoma

Medication Adherence and Common Barriers for Caregivers of Preschool Children with Pediatric Glaucoma

Purpose. To investigate the medication adherence among caregivers of preschool children with pediatric glaucoma and to elucidate common barriers leading to poor adherence. Methods. A cross-sectional study. Caregivers of preschool children with pediatric glaucoma completed a questionnaire on demographic information of caregivers, demographic and disease characteristics of children, caregivers-reported medication adherence (by an adapted Morisky Adherence Scale), and possible 13 barriers. Results. Overall 132 questionnaires were considered valid. Thirty-six percent of all reported poor medication adherence. Caregivers’ age and self-evaluated knowledge about pediatric glaucoma showed a significant difference between the adherent and nonadherent groups ( $P<0.05$ ). Nineteen percent of all reported only one barrier as important, 65% cited multiple barriers, and 16% cited no barriers. Anxiety and depression were cited as important by most caregivers in both groups. Univariate logistic regression analysis demonstrated that difficulty with the acquisition of medications (OR, 2.5; 95% CI, 1.1–5.7; $P=0.025$ ), difficulty with medication schedule (OR, 2.3; 95% CI, 1.0–5.0; $P=0.043$ ), and high expenses for medications (OR, 4.8; 95% CI, 1.4–15.9; $P=0.011$ ) were significantly associated with higher odds of poor adherence. Conclusions. Over one-third of caregivers of preschool children with pediatric glaucoma were in poor medication adherence. Nearly two-thirds of caregivers cited multiple barriers simultaneously as important hindrances to medication usage. Anxiety and depression, difficulty with the acquisition of medications, difficulty with the medication schedule, and high expenses for medications were prominent barriers. Individualized solutions should be provided according to reported barriers by each caregiver and the other most common barriers.

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.

Referral patterns of children with glaucoma and their caretakers in Northern Tanzania

AIM

To describe the referral patterns of children with primary childhood glaucoma (PCG) or secondary childhood glaucoma (SCG) and their presenting symptoms in Northern Tanzania.

METHODS

A retrospective observational study of children <17y with PCG or SCG who were referred to Kilimanjaro Christian Medical Centre (KCMC) Eye Department between 2000 and 2013 was conducted. Presenting symptoms, age at presentation, place of origin, distance to hospital, type of glaucoma, visual acuity, optic disc appearance (vertical cup-to-disc ratio) and type of referral were described.

RESULTS

Seventy patients with PCG and 27 patients with SCG were included in the study. Median age at first presentation was 1y in the PCG group (range 0-16y) and 9y in the SCG group (range 1-15y). In both groups around 87% of the children presented already with low vision (logMAR>0.48, better eye). Most of the children (60%) and their caretakers presented on their own initiative, while 24% were sent by different general health cadres and 16% by eye care professionals. Buphthalmos was the main symptom mentioned as a trigger for presentation.

CONCLUSION

The study shows that most of the children presented late resulting in advanced stages of glaucoma at the time of initiation of treatment. The majority attended the referral eye department on their own initiative with buphthalmos being the most commonly described symptom. Awareness creation among caretakers of children, general health and eye care providers, ideally embedded in general child health promotion activities, is needed to increase and accelerate referrals.

The Hub-and-Spoke Management of Glaucoma

Glaucoma is an extremely significant public health issue, since it is the most common cause of irreversible blindness worldwide, nevertheless it is still widely undiagnosed because of its devious nature. Glaucoma diagnosis criteria are well-defined and have to be strictly observed and recognized: the earlier the disease is diagnosed, the earlier the patient can undergo the most suitable treatment, the better can be the prognosis. The three levels of prevention are essential in the approach to the disease and its pathophysiological features make it eligible for screening. This review provides an overview of the current state of the art in glaucoma management, starting from its prevention and coming to the hub-and-spoke organization. This model applied to glaucoma aims to direct patients toward professional and not professional figures who may guide them in integrated care pathway. This path should be designed in accordance with best practice to coordinate glaucoma prevention, diagnosis, treatment and follow up with the best cost-benefit ratio, protecting both the interests of the patient and of the society.

Micropulsed diode laser cyclophotocoagulation in recurrent pediatric glaucoma

PURPOSE

To evaluate the intermediate-term efficacy and safety of micropulsed diode laser cyclophotocoagulation in recurrent pediatric glaucoma.

PATIENTS AND METHODS

A prospective interventional study included children <16 years old diagnosed with recurrent glaucoma, attending Mansoura University, during the period from July 2017 to November 2017. Micropulsed diode laser sessions were performed in all the cases. The main outcome was the intraocular pressure reduction with monitoring of complications as secondary outcome. The mean follow-up period was 15.08 ± 1.1 (mean: 12-16) months.

RESULTS

A total of 36 eyes of 29 patients were included (62% males) with median age of 24 months. Primary congenital glaucoma represented 47.2% of the initial diagnoses. At the 15th month, the mean intraocular pressure dropped significantly from 37.5 ± 11.3 mmHg at baseline to 20.03 ± 2.7 mmHg (p < 0.001) with 37.15% reduction. The mean number of glaucoma medications decreased significantly from 2.6 ± 0.5 pretreatment to 1.7 ± 0.6 at the 15th month (p < 0.001). A total of 24 eyes (66.7%) required second session of treatment with mean number of 1.7 ± 0.5 sessions per eye. The cumulative probability of qualified success was 69.4%, 58.3%, 52.8%, 47.2%, and 41.7% at 1, 3, 6, 12, and 15 months after treatment. Qualified success was achieved in 61% at 15 months without statistically significant difference between the initial diagnoses (p = 0.61). None of the eyes developed any major ocular complications throughout the follow-up period.

CONCLUSION

Micropulsed diode laser was proved to be a safe approach with relative effectiveness in controlling intraocular pressure in children with recurrent glaucoma.

Surgical Outcomes of Trabeculotomy in Newborns with Primary Congenital Glaucoma

Background:

Early surgical intervention is required for the primary congenital glaucoma (PCG). There are currently few reports on the surgical outcomes in infants with PCG. This study aimed to evaluate the efficacy and safety of trabeculotomy and the postoperative visual outcomes in Chinese newborns with PCG within 4 weeks of birth.

Methods:

A total of 21 eyes of 12 patients with PCG who underwent primary trabeculotomy within 4 weeks of birth were retrospectively studied. Preoperative and postoperative intraocular pressure (IOP), corneal clarity and diameter, axial length and optic disc cupping, visual acuity and postoperative refractive error, success rates, and complications were evaluated. Kaplan-Meier survival analysis was applied to evaluate the success rates.

Results:

The mean follow-up time was 46.9 ± 34.4 months (range: 12–122 months). The postoperative IOP was significantly lower than the preoperative IOP at all of the follow-up visits (P < 0.001). The complete success rates for all eyes at 1, 2, 3, and 5 years postoperatively were 90.5%, 85.7%, 85.7%, and 85.7%, respectively. The IOPs of the three patients who needed antiglaucomatous medications postoperatively were also well controlled. At the last visit, the cornea became clear, and the cup-to-disc ratio decreased significantly (P = 0.01) although the horizontal corneal diameter did not change significantly (P = 0.11). Visual acuities were able to be recorded in eight eyes at the last visit, among which six eyes had a best-corrected visual acuity of 20/40 or better. There were no severe intraoperative or postoperative complications.

Conclusions:

Trabeculotomy proves to be a safe and effective treatment in reducing IOP in this group of Chinese newborns with PCG. The outcomes of vision function were satisfactory in most of the patients.

ExPRESS Mini-Shunt as a Treatment Alternative for Medically Uncontrolled Steroid-Induced Glaucoma in a Pediatric Patient

This case report illustrates the use of ExPRESS mini-shunt in a pediatric glaucoma patient. We describe the management of steroid-induced glaucoma with ExPRESS mini-shunt in a 9-year-old boy with allergic keratoconjunctivitis. The intraocular pressure of both of his eyes was uncontrolled with medical and laser treatment. Both eyes were treated with ExPRESS mini-shunt and mitomycin-C. Transient overfiltration with postoperative hypotony occurred in both eyes and resolved after 2 weeks. One year postoperatively, intraocular pressure was maintained below 21 mm Hg without medication in 1 eye. Bleb needling with mitomycin-C was done to maintain filtration. The fellow eye received cataract extraction but developed bleb failure a few months afterwards. The intraocular pressure was controlled medically. To conclude, ExPRESS mini-shunt is a new surgical option in selected patients. Bleb failure developed after cataract extraction. Postoperative inflammation should be minimized. Patient selection, such as those with stable ocular condition, is important to increase surgical success.

Primary trabeculotomy compared to combined trabeculectomy-trabeculotomy in congenital glaucoma: 3-year study

PURPOSE

To compare the outcome of primary trabeculotomy with that of combined trabeculectomy-trabeculotomy (CTT) with mitomycin C (MMC) in children with congenital glaucoma.

METHODS

This is a prospective comparative study, carried out on a cohort of 28 eyes (28 infants) with congenital glaucoma. Infants with proved congenital glaucoma [based on intra-ocular pressure (IOP), cup/disc (C/D ratio), corneal diameter and axial length measurements] were randomly allocated to either group A (trabeculotomy) or group B (CTT with MMC). Postoperatively, all patients were followed regularly for 3 years; for IOP and C/D evaluation. Criteria for successful outcome included resolution of corneal oedema, reversal of disc cupping, and IOP 18 mmHg or less.

RESULTS

Success rate in each group was 85.7% (p = 1.00). All preoperative parameters, including horizontal corneal diameter, axial length, IOP and C/D ratio, were not statistically significantly different between the two groups. Also, postoperative C/D ratio, IOP, IOP difference and percentage difference (compared to preoperative values), at different follow-up visits, were not statistically significantly different between both surgical techniques. Comparing preoperative to postoperative IOP and C/D ratio in each group was statistically significant.

CONCLUSION

Both primary trabeculotomy and CTT with MMC had similar outcomes, which could mean that trabeculotomy could be resorted to first.

Outcomes of surgical interventions for primary childhood glaucoma in Northern Tanzania

AIM

To evaluate goniotomy, trabeculotomy, transscleral cyclophotocoagulation (TSCPC) and trabeculectomy as initial procedures in children with primary childhood glaucoma from Northern Tanzania.

METHODS

A retrospective analysis of consecutive interventions for primary childhood glaucoma from 2000 to 2013 was conducted at the Kilimanjaro Christian Medical Centre. Success was defined as postoperative intraocular pressure (IOP) below 22 mmHg. Success rates, IOP, visual acuity (VA), subsequent interventions and potential risk factors for failure were reported for the respective interventions.

RESULTS

The study included 116 eyes of 70 children (age 4.6±5.9 years) with primary childhood glaucoma; 46 (65.7%) children were male. The preoperative IOP was 33.1±10.2 mmHg, the preoperative cup/disc (CD) ratio 0.71±0.3 and the corneal diameter 13.3±1.4 mm. As a primary intervention, 61 (52.6%) eyes underwent goniotomy, 10 (8.6%) eyes trabeculotomy, 12 (10.3%) TSCPC and 33 (28.4%) trabeculectomy. Follow-up data after 12 months were available for 63 (54.3%) eyes. Success rates at 12 months were 38% (goniotomy), 30% (trabeculotomy), 17% (TSCPC) and 64% (trabeculectomy). All interventions achieved a statistically significant IOP reduction at 3, 6 and 12 months, except for trabeculotomy after 6 months and TSCPC at all time points. Postoperative endophthalmitis occurred in one child treated with trabeculectomy. VA in 82% of all eyes was maintained or had improved after 12 months.

CONCLUSIONS

Based on the success rates of this retrospective analysis, goniotomy or trabeculotomy for younger and trabeculectomy for older children can be recommended in our setting to reduce IOP. Late presentation in combination with advanced glaucomatous damage as well as erratic postoperative follow-up and treatment were likely factors that compromised overall success rates. More efforts are necessary to detect the blinding disease earlier and improve adherence to follow-up.

In vitro characteristics of Tenon's fibroblast lines derived from pediatric and adult eyes do not fully explain pediatric glaucoma surgery failure: a preliminary report

PURPOSE

To compare the in vitro characteristics of Tenon's capsule fibroblasts from children and adults that may be relevant to filtration surgery success.

METHODS

Fibroblast cell lines derived from 5 young (median patient age, 2.4 years) and 7 old (median patient age, 71 years) discarded Tenon's capsule surgical specimens were used at early passage (P2-P3). Fibroblasts were plated at "high" (10(4)cells/cm(2)) or "low" density (10(3)cells/cm(2)) and harvested at days 0-14, for growth curve and doubling time comparisons. Migration was measured using a wound model (confluent monolayers ± 5-fluorouracil [5-FU] over 1-96 hours). Collagen synthesis was measured as secreted hydroxyproline/24 hours from confluent monolayers.

RESULTS

At low density, "young" fibroblasts achieved higher cell numbers at confluence (day 14) compared with "old": 158 ± 35 versus 105 ± 12 × 10(3)cells/cm(2) (P = 0.0034). Mean doubling time for young versus old was similar at low density plating: 20.95 ± 1.55 versus 22.37 ± 2.09 hours (P = 0.26). It was shorter, however, for young versus old at high-density plating: 42.11 ± 6.01 versus 54.26 ± 4.24 hours (P = 0.0051). Wound closure rates were similar for young versus old cells (4 lines for each group) with and without 5-FU. Collagen synthesis was similar for young and old (4 lines for each group).

CONCLUSIONS

Although young fibroblasts reached higher density than old at confluence and had shorter doubling times at high-density plating, wound closure/migration and collagen synthesis rates were similar. Despite the preliminary nature of this study (few specimens, limited cell features explored), factors besides those intrinsic to the fibroblasts themselves likely mediate the more rapid healing/scarring after glaucoma filtration surgery in children.

[Trabeculotomy as first-line surgical treatment in pediatric glaucoma: surgical and visual outcomes from a 7-year retrospective study]

INTRODUCTION

Intraocular pressure and visual outcomes in primary pediatric glaucoma treated with trabeculotomy.

MATERIALS ET METHODS

All children undergoing trabeculotomy as first-line surgical treatment between January 2002 and January 2012 were included in a retrospective monocentric study. We report initial clinical features, surgical complications, ophthalmological outcome and clinical progression.

RESULTS

Twenty-nine eyes of 16 children met the inclusion criteria and were treated with trabeculotomy as first-line treatment (mean age: 6 months). Median follow-up was 7 years. No major perioperative complications occurred, but minor complications were observed in 11 eyes. Mean pre-operative and initial post-operative intraocular pressures were 25.4 and 9.1mmHg respectively, thus a decrease of 16.3 points (63%). Overall surgical success rate was 89% at first follow-up, 72% at one year and 64% on last follow-up. A mean intraocular pressure of 15mmHg on no medications was achieved for two-thirds of eyes. After 7 years of follow-up, over 50% of eyes did not require a 2nd surgery. Visual acuity was at least 20/30 for 62% of eyes (83% for eyes requiring only trabeculotomy).

DISCUSSION AND CONCLUSION

Trabeculotomy as first-line treatment of primary juvenile glaucoma is a safe and effective surgery in about two-thirds of cases. It allows pressure control and satisfactory visual outcome in the majority of children.

Ectopia lentis associated with primary congenital glaucoma

PURPOSE

To describe 3 cases of ectopia lentis (EL) associated with primary congenital glaucoma (PCG) and differentiate between primary and secondary EL regarding pathogenesis.

METHODS

We reviewed the clinical charts of 3 children previously diagnosed with congenital glaucoma who developed secondary EL. The following points were noted: medical and surgical history, refraction, keratometry, corneal diameter, axial length (AL), intraocular pressure, and cup/disc ratio.

RESULTS

The 3 patients were respectively aged 12, 3, and 4 months. A trabeculectomy was performed in both eyes at 1-week interval in all cases. The EL was noted during follow-up controls. Lensectomy/vitrectomy was performed in 2 patients, in case of high astigmatism (>5.00 D) and/or the lens border visible in the pupillary area. Postoperative refraction was hyperopic.

CONCLUSIONS

Ectopia lentis secondary to PCG should be differentiated from primary EL regarding pathogenesis. Anterior segment distension appears to be the principal mechanism in these cases. Postoperative hyperopia is observed despite the increased AL secondary to PCG. These biometric results are due to global distension of the globe, which also flattens the cornea with consequently lower refractive effect.

Glaucoma

Most medical practitioners have regular contact with adults who have one of the two forms of glaucoma: open-angle glaucoma or angle-closure glaucoma. Data from population-based surveys indicate that one in 40 adults older than 40 years has glaucoma with loss of visual function, which equates to 60 million people worldwide being affected and 8·4 million being bilaterally blind. Even in developed countries, half of glaucoma cases are undiagnosed. Glaucoma is mostly asymptomatic until late in the disease when visual problems arise. Vision loss from glaucoma cannot be recovered, and improved case-detection methods for glaucoma are needed. Glaucoma is commonly treated with daily eye-drop drugs, but adherence to treatment is often unsatisfactory. As a usually asymptomatic and chronic disease, glaucoma has similar treatment challenges to chronic systemic diseases. Similarities to the pathogenesis of common CNS diseases mean that common neuroprotective strategies might exist. Successful gene therapy, which has been used for other eye diseases might be possible for the treatment of glaucoma in the future.

Combined trabeculotomy and trabeculectomy: outcome for primary congenital glaucoma in a West African population

PURPOSE

To evaluate the surgical outcome of combined trabeculotomy-trabeculectomy in Ghanaian children with primary congenital glaucoma.

MATERIALS AND METHODS

A retrospective case series involving 19 eyes of 12 consecutive children with primary congenital glaucoma who had primary trabeculotomy-trabeculectomy from 12 August 2004 to 30 June 2008, at the Korle-Bu Teaching Hospital, Ghana. Main outcome measures were preoperative and postoperative intraocular pressures, corneal diameter, corneal clarity, bleb characteristics, duration of follow-up, surgical success, and complications.

RESULTS

A total of 19 eyes of 12 patients met the inclusion criteria. Six of the patients were males. Mean age at diagnosis was 4.4 (range 2-8) months. Mean age at surgery was 5.9 months (range 3-16). Eight (67%) infants had bilateral disease. Mean duration of follow-up was 13.1 (range 5-38) months. The preoperative mean horizontal corneal diameter was 13.4 ± 1.1(range 12-16) mm. Complete success (intraocular pressure <21 mm Hg) was obtained in 15 (79%) eyes. The probability of success was 94.4, 83.3, 66.7, 44.4, 38.9, 33.3, and 13.3% at 3, 6, 9, 12, 15, 18, and 21 months, respectively (Kaplan-Meier analysis). All eyes had corneal oedema preoperatively. Seventeen eyes (90%) had clear cornea at their last follow-up. Mean preoperative and postoperative intraocular pressures were 30.3 ± 8.8 and 18.1 ± 6.8 mm Hg respectively (P<0.001, t-test). Twelve (63%) eyes had well-functioning blebs at the last follow-up. One eye (5%) developed seclusio pupillae and cataract postoperatively.

CONCLUSION

The overall success for combined trabeculotomy-trabeculectomy in Ghanaian children with primary congenital glaucoma was 79%. The probability of success reduced from more than 66% in the first 9 months postoperatively to below 45% after that.

[Glaucoma in children and adolescents: diagnosis and therapeutic difficulties]

The management of glaucoma in young patients has made considerable progress over the recent years. Its treatment is essentially surgical, mainly filtration procedure. Use of antimetabolites combined with filtration is highly recommended. Medical treatment has a limited place, but should not be neglected. The number of topical pressure-lowering treatments permits a large therapeutic choice, but their clinical efficacy and tolerability should be assessed on an individual patient's basis. These topically applied treatments have not been tested in sufficient, adequate, clinical studies to guarantee their efficacy and safety in children and adolescents. Consequently, their approved labelling indicates "not recommended for use in these patients", which means that they are prescribed outside of their granted marketing authorization. Therefore, such clinical studies appear particularly needed. Indications of cyclodestruction or drainage implants has to be confined to refractory glaucoma and complicated cases.

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.

Pharmacogenetics of ophthalmic topical beta-blockers

Glaucoma is the second leading cause of blindness worldwide. The primary glaucoma risk factor is elevated intraocular pressure. Topical beta-blockers are affordable and widely used to lower intraocular pressure. Genetic variability has been postulated to contribute to interpersonal differences in efficacy and safety of topical beta-blockers. This review summarizes clinically significant polymorphisms that have been identified in the beta-adrenergic receptors (ADRB1, ADRB2 and ADRB3). The implications of polymorphisms in CYP2D6 are also discussed. Although the candidate-gene approach has facilitated significant progress in our understanding of the genetic basis of glaucoma treatment response, most drug responses involve a large number of genes, each containing multiple polymorphisms. Genome-wide association studies may yield a more comprehensive set of polymorphisms associated with glaucoma outcomes. An understanding of the genetic mechanisms associated with variability in individual responses to topical beta-blockers may advance individualized treatment at a lower cost.