Crosslinking-Dependent Drug Kinetics in Hydrogels for Ophthalmic Delivery

Drug-diffusion kinetics in 2-hydroxyethyl methacrylate hydrogels were studied as a function of the crosslinking density and porosity. By varying the concentration of the crosslinker, tetraethylene glycol dimethacrylate, we demonstrated how the release of Timolol maleate could be optimized to allow for efficient drug delivery. FTIR and spectrophotometry supplied optical inferences into the functional groups present. By studying the swelling and degradation of hydrogels, supplemented with drug-release kinetics studies, the relationship between these two tenets could be formulated.

Clinical management of a rare Peters’ anomaly-induced secondary childhood glaucoma: A case report

Childhood glaucoma is a rare disorder that occurs from birth until teenage years caused by an abnormality of aqueous humor pathways. About 50–70% of Peters' anomaly is accompanied by secondary childhood glaucoma. The presence of glaucoma will affect the prognosis. We reported the evaluation and treatment of secondary childhood glaucoma due to Peters’ anomaly. A 5 months-old boy was presented with the complaint of a enlarged left eye since 3 months old. The complaint was accompanied by a watering eye and frequently closed upon light exposure. The left eye looked opaquer than contralateral. Examination under anesthesia showed that the intraocular pressure (IOP) was 35 mmHg in the left eye and the corneal diameter was 14 mm. Other findings were keratopathy, diffuse corneal edema, buphthalmos, shallow anterior chamber, anterior synechiae, and linear slit shaped pupils in the nasal region. Patient was treated with ophthalmic timolol maleate which was later followed by trabeculectomy. After 1 week post-surgery, IOP assessment by palpation suggested the right eye within normal range while the IOP of left eye was higger than normal. Blepharospasm, epiphora, photophobia, bleb on superior, subconjunctiva bleeding, buphthalmos, keratopathy, minimal corneal edema, anterior chamber with shallow image, and posterior synechia were found in left eye anterior segment. In conclusion, trabeculotomy and trabeculectomy are recommended if there is no reduction of IOP observed after receiving timolol maleate therapy. The choice of surgical management is dependent on the feasibility of the protocol.

Comparing the effects and safety of dorzolamide hydrochloride + timolol maleate versus brimonidine after neodymium-doped yttrium aluminium garnet laser capsulotomy posterior capsule opacification

Aim Posterior capsular opacification is treated using neodymium-doped yttrium aluminium garnet laser capsulotomy that leads to increased intraocular pressure. Here, we compare the effects of dorzolamide hydrochloride + timolol maleate versus brimonidine on intraocular pressure. We also investigate their side effects after neodymium-doped yttrium aluminium garnet laser capsulotomy. In these patients, there are no prior studies comparing the results of these two drugs. Materials Ninety patients with posterior capsule opacification contributed to the study. They received yttrium aluminium garnet laser capsulotomy. After yttrium aluminium garnet laser capsulotomy, they were randomized into three groups. Group 1 received dorzolamide hydrochloride + timolol maleate; Group 2 took brimonidine; and Group 3, the control group, took no drug. Group 1 took dorzolamide hydrochloride + timolol maleate eye drops 1 h before the procedure and on the third hour of the first day and two times per day between the second and the seventh days. Group 2 took brimonidine eye drops 1 h before the procedure and on the third hour of the first day, two times per day between the second and the seventh days. Results Brimonidine had a similar side effect profile to the fix combination. Intraocular pressure on the first ( p = 0.87) and third days ( p = 0.124) were similar in Group 1 (dorzolamide hydrochloride + timolol maleate), Group 2 (brimonidine) and the control group. The mean intraocular pressure value of the control group was significantly higher than Groups 1 and 2 because the anti-glaucomatous effects of the drugs become prominent on the seventh day ( p = 0.041). In Group 1 and Group 2, intraocular pressure was significantly lower than the control group on the seventh day ( p = 0.041). Stinging, itching, hyperemia and Tyndall rates were similar in Group 1, Group 2 and the control group. Watery eyes were less common in the brimonidine group than in the dorzolamide hydrochloride–timolol maleate and the control groups on the seventh day ( p = 0.02). Brimonidine also significantly lowered the chemosis rate on the third ( p = 0.04) and seventh ( p = 0.03) days. Conclusion We suggest that brimonidine and a combination of dorzolamide + timolol are similarly effective at reducing eye pressure for routine cases. In cases where intraocular pressure attacks might be at higher risk, using the dorzolamide + timolol combination would be more appropriate.

The Efficacy and Safety of Preservative-containing and Preservative-free Brimonidine-Timolol Fixed Combination in Normal Tension Glaucoma

Purpose: To analyze the efficacy and safety of preservative-containing and preservative-free 0.2% brimonidine tartrate and 0.5% timolol maleate fixed combination drug in normal tension glaucoma.Methods: Fifty-one patients (84 eyes) who were diagnosed with normal tension glaucoma and with preservative-containing or preservative-free brimonidine-timolol fixed combinations alone were analyzed retrospectively from January 2017 to February 2020. Intraocular pressure (IOP) was measured four times a day (9 a.m., 11 a.m., 2 p.m., and 4 p.m.) before and at 6 months after applying eye drops. We analyzed and compared the effect of lowering IOP and the occurrence of intra or extra-ocular adverse effects.Results: A significant mean IOP reduction was shown in both groups: -1.95 ± 2.50 mmHg (-12.26 ± 15.87%) in the preservative-containing group and -1.60 ± 2.06 mmHg (-10.54 ± 13.94%) in the preservative-free group at 6 months after eyedrop instillation. The IOP was lowest in both groups at 11 a.m. There were no significant differences between the two groups in lowering IOP. Serious adverse effects causing discontinuation of the eye drops were not observed.Conclusions: Both preservative-containing and preservative-free brimonidine-timolol fixed combinations are effective in lowering IOP in normal tension glaucoma patients and are considered to be effective as eye drops without serious adverse effects.

Topical Timolol for Infantile Haemangioma of the Orbit

Infantile haemangiomas (IHs) are the most common benign tumours of the eyelid and orbits in infancy. Beta-blockers, in the form of oral propranolol, have become first-line treatment in severe cases with functionally significant or disfiguring IH. However, adverse drug reactions of oral propranolol in infants are reported in 1 in 11 and serious or potentially life-threatening systemic side effects in 1 in 38, including dyspnoea, hypotension, hyperkalaemia, hypoglycaemia, and cyanosis, therefore requiring careful and close monitoring during the course of systemic treatment. More recently, two large meta-analyses have shown topical beta-blockers, such as timolol maleate 0.5%, to be as effective as oral propranolol in superficial IH, but with no or significantly fewer adverse effects, and have advocated that topical beta-blockers replace oral propranolol as the first-line treatment of superficial IH. We have previously reported the therapeutic response of deep periocular IH to primary topical timolol maleate 0.5% monotherapy. Here we also describe the first successful treatments of large orbital IHs with primary topical timolol maleate 0.5% monotherapy in four infants, resulting in immediate cessation of progression and rapid clinical improvement or resolution in all cases. No adverse effects and no recurrence during long-term follow-up of up to 2.5 years after cessation were seen in any of the patients treated with topical timolol maleate 0.5%.