Brinzolamide induced reversible corneal decompensation

Corneal thickness and endothelial change after use of ocular hypotensive agents

Corneal transplantation can restore visual function when visual impairment is caused by a corneal disease. However, this treatment is associated with the scarcity of cornea donors. The suitability of corneal donation from patients with glaucoma using ocular hypotensive agents (OHAs) is controversial. This study aimed to elucidate changes in corneal thickness, corneal endothelial cell density, and corneal endothelial cell hexagonality after OHA use in patients with primary open-angle glaucoma. We retrospectively reviewed the data of 53 glaucoma suspect eyes without OHA use and 106 primary open-angle glaucoma eyes under OHA use. All participants underwent corneal parameter assessment using SP-3000P (Topcon Corp., Tokyo, Japan) at the time of diagnosis and the final visit. The OHA dose and timing of use were recorded. The ocular hypotensive agents score (OHAS) was determined based on the number, formula, frequency, and duration of OHA use. Baseline data showed no significant differences between the two groups with and without OHA use. At the final visit, the OHA-treated group showed significantly lower corneal thickness and corneal endothelial cell density than those of the control group. A weak positive correlation between the OHAS and changes in corneal endothelial cell hexagonality was noted. However, no correlation was observed between the OHAS and changes in corneal thickness or endothelial cell density. In conclusion, patients with glaucoma and using OHAs should undergo the corneal structural properties examinations before donation to ensure the quality of donor cornea.

Stable Gastric Pentadecapeptide BPC 157-Possible Novel Therapy of Glaucoma and Other Ocular Conditions

Recently, stable gastric pentadecapeptide BPC 157 therapy by activation of collateral pathways counteracted various occlusion/occlusion-like syndromes, vascular, and multiorgan failure, and blood pressure disturbances in rats with permanent major vessel occlusion and similar procedures disabling endothelium function. Thereby, we revealed BPC 157 cytoprotective therapy with strong vascular rescuing capabilities in glaucoma therapy. With these capabilities, BPC 157 therapy can recover glaucomatous rats, normalize intraocular pressure, maintain retinal integrity, recover pupil function, recover retinal ischemia, and corneal injuries (i.e., maintained transparency after complete corneal abrasion, corneal ulceration, and counteracted dry eye after lacrimal gland removal or corneal insensitivity). The most important point is that in glaucomatous rats (three of four episcleral veins cauterized) with high intraocular pressure, all BPC 157 regimens immediately normalized intraocular pressure. BPC 157-treated rats exhibited normal pupil diameter, microscopically well-preserved ganglion cells and optic nerve presentation, normal fundus presentation, nor- mal retinal and choroidal blood vessel presentation, and normal optic nerve presentation. The one episcleral vein rapidly upgraded to accomplish all functions in glaucomatous rats may correspond with occlusion/occlusion-like syndromes of the activated rescuing collateral pathway (azygos vein direct blood flow delivery). Normalized intraocular pressure in glaucomatous rats corresponded to the counteracted intra-cranial (superior sagittal sinus), portal, and caval hypertension, and aortal hypotension in occlusion/occlusion-like syndromes, were all attenuated/eliminated by BPC 157 therapy. Furthermore, given in other eye disturbances (i.e., retinal ischemia), BPC 157 instantly breaks a noxious chain of events, both at an early stage and an already advanced stage. Thus, we further advocate BPC 157 as a therapeutic agent in ocular disease.

The Multifarious Effects of Various Glaucoma Pharmacotherapy on Corneal Endothelium: A Narrative Review

Corneal endothelium is a single cell layer that is mainly responsible for maintaining corneal clarity. Endothelial damage secondary to toxicity, stress, or genetic predisposition are common and in conjunction with the low regenerative ability of the cells, making their preservation critical for maintaining visual acuity. Patients with glaucoma, who are estimated to be close to 80 million worldwide, have a plethora of reasons for developing endothelial damage, being exposed to a spectrum that extends from various medical and surgical interventions to the disease itself. The wide spectrum of glaucoma pharmacotherapy that has been recently extended by addition of newer classes of medications has been the focus of extensive research on its effects on corneal endothelium. Both basic and clinical research have attempted to shine a light on the complex mechanisms associated with the effects of glaucoma medication on corneal endothelium and to answer the important question as to whether these findings are clinically significant. The aim of this review is to summarize and present current literature of the various findings, both from in vivo and in vitro studies that have focused on the complex relationship between different classes of glaucoma medication and their effect on corneal endothelium.

Two pediatric cases of reticular corneal epithelial edema associated with netarsudil

Purpose

To report two pediatric cases of reticular corneal epithelial edema associated with the use of netarsudil ophthalmic solution 0.02%.

Observations

In Case 1, a six-year-old male with glaucoma following cataract surgery was treated with netarsudil for thirteen months and developed diffuse reticular corneal epithelial edema on post-operative day one after undergoing transscleral diode cyclophotocoagulation for persistently elevated intraocular pressures. In Case 2, a three-month-old male with bilateral ocular hypertension developed unilateral inferior reticular corneal epithelial edema five weeks after initiation of netarsudil, which had been discontinued in the fellow eye two weeks prior. In both cases, the reticular epithelial edema resolved following cessation of netarsudil.

Conclusions and Importance

Netarsudil-associated reticular corneal epithelial edema can occur in infants and young children.

A Narrative Review of Ocular Surface Disease Related to Anti-Glaucomatous Medications

Topical anti-glaucomatous medications are still the most important measure to lower intraocular pressure. Large number of studies have confirmed that long-term use of anti-glaucomatous eye drops, especially containing benzalkonium chloride, a preservative, can cause or aggravate ocular surface injury. Ocular surface diseases damage the ocular microenvironmental health status, reduce the patients’ compliance with the treatment, and finally affect the treatment result. Therefore, the ocular surface management of patients with glaucoma is very important. This includes the selection of drugs that are better tolerated according to individual conditions, preservative-free formulations, drugs that protect against ocular surface disease, or selecting surgery and laser treatment, to prevent the damage to the ocular surface by topical anti-glaucomatous drugs.

Corneal Endothelial Transplantation in Uveitis: Incidence and Risk Factors

PURPOSE

To estimate the incidence of corneal endothelial transplantation (CET) and identify risk factors among patients with noninfectious ocular inflammation.

DESIGN

Retrospective cohort study.

METHODS

Adult patients attending United States tertiary uveitis care facilities diagnosed with noninfectious ocular inflammation were identified from the Systemic Immunosuppressive Therapy for Eye Diseases Cohort Study. Time-to-event analysis was used to estimate the incidence of CET, including penetrating keratoplasty, Descemet stripping endothelial keratoplasty, or Descemet membrane endothelial keratoplasty procedures. The incidence of CET was calculated. Potential risk factors for CET were also evaluated using Cox regression, accounting for correlation between eyes of the same patient.

RESULTS

Overall, 14,264 eyes met eligibility criteria for this analysis, with a median follow-up of 1.8 eye-years. The Kaplan-Meier estimated incidence of CET within 10 years was 1.10% (95% CI, 0.68%-1.53%). Risk factors for CET included age >60 years vs <40 years (adjusted hazard ratio [aHR], 16.5; 95% CI, 4.70-57.9), anterior uveitis and scleritis vs other types (aHR, 2.97; 95% CI, 1.46-6.05; and aHR, 4.14; 95% CI,1.28-13.4, respectively), topical corticosteroid treatment (aHR, 2.84; 95% CI, 1.32-6.13), cataract surgery (aHR, 4.44; 95% CI, 1.73-11.4), tube shunt surgery (aHR, 11.9; 95% CI, 5.30-26.8), band keratopathy (aHR, 5.12; 95% CI, 2.34-11.2), and hypotony (aHR, 7.38; 95% CI, 3.14-17.4). Duration of uveitis, trabeculectomy, peripheral anterior synechia, and ocular hypertension had no significant association after multivariate adjustment.

CONCLUSIONS

In patients with ocular inflammation, CET occurred infrequently. Tube shunt surgery, hypotony, band keratopathy, cataract surgery, and anterior segment inflammation were associated with increased risk of undergoing CET; these factors likely are associated with endothelial cell damage.

Short-term effect of topical brinzolamide 1%-timolol 0.5% fixed combination on human central corneal thickness

PURPOSE

To evaluate the short-term effect of fixed combination of brinzolamide 1% and timolol 0.5% (FCBT) application on human central corneal thickness (CCT).

METHODS

This prospective clinical study included 97 patients having Nd:YAG laser posterior capsulotomy for posterior capsule opacification. Patients were randomized to receive apraclonidine hydrochloride 0.5% (APRA) (n=48) or FCBT (n=49) at 1 h before laser surgery. The baseline CCT was evaluated by ultrasonographic pachymetry from the central region ∼1 h before the laser procedure. CCT measurements were applied just before the laser application and then the first, second, and third hour, and the first, third, and seventh day after the Nd:YAG laser capsulotomy.

RESULTS

There was no statistically significant difference between the baseline intraocular pressures, CCTs, and demographic and clinical data (age, sex, surgery laser interval, total laser energy) of the APRA and the FCBT groups. The mean CCT values of the APRA group at the first, second, and third hour, and the first, third, and seventh day were 553.8±28.0, 551.4±35.3, 556.8±28.7, 552.6±27.5, 548.2±26.2, and 546.2±25.5 μm, respectively. The mean CCT values of the FCBT group at the first, second, and third hour, and the first, third, and seventh day were 544.21±34.4, 549.4±27.6, 555.94±33.1, 550.8±33.4, 547.2±33.6, and 544.9±33.4 μm, respectively. No statistically significant difference was detected between the 2 groups.

CONCLUSION

The difference in CCT increase between both groups was not statistically significant at any follow-up visits. FCBT application does not have a short-term effect on CCT.

CD147 required for corneal endothelial lactate transport

PURPOSE

CD147/basigin is a chaperone for lactate:H(+) cotransporters (monocarboxylate transporters) MCT1 and MCT4. We tested the hypothesis that MCT1 and -4 in corneal endothelium contribute to lactate efflux from stroma to anterior chamber and that silencing CD147 expression would cause corneal edema.

METHODS

CD147 was silenced via small interfering ribonucleic acid (siRNA) transfection of rabbit corneas ex vivo and anterior chamber lenti-small hairpin RNA (shRNA) pseudovirus in vivo. CD147 and MCT expression was examined by Western blot, RT-PCR, and immunofluorescence. Functional effects were examined by measuring lactate-induced cell acidification, corneal lactate efflux, [lactate], central cornea thickness (CCT), and Azopt (a carbonic anhydrase inhibitor) sensitivity.

RESULTS

In ex vivo corneas, 100 nM CD147 siRNA reduced CD147, MCT1, and MCT4 expression by 85%, 79%, and 73%, respectively, while MCT2 expression was unaffected. CD147 siRNA decreased lactate efflux from 3.9 ± 0.81 to 1.5 ± 0.37 nmol/min, increased corneal [lactate] from 19.28 ± 7.15 to 56.73 ± 8.97 nmol/mg, acidified endothelial cells (pHi = 6.83 ± 0.07 vs. 7.19 ± 0.09 in control), and slowed basolateral lactate-induced acidification from 0.0034 ± 0.0005 to 0.0012 ± 0.0005 pH/s, whereas apical acidification was unchanged. In vivo, CD147 shRNA increased CCT by 28.1 ± 0.9 μm at 28 days; Azopt increased CCT to 24.4 ± 3.12 vs. 12.0 ± 0.48 μm in control, and corneal [lactate] was 47.63 ± 6.29 nmol/mg in shCD147 corneas and 17.82 ± 4.93 nmol/mg in paired controls.

CONCLUSIONS

CD147 is required for the expression of MCT1 and MCT4 in the corneal endothelium. Silencing CD147 slows lactate efflux, resulting in stromal lactate accumulation and corneal edema, consistent with lactate efflux as a significant component of the corneal endothelial pump.

Effects of common topical antiglaucoma medications on the ocular surface, eyelids and periorbital tissue

Glaucoma affects millions of people around the world. With the baby boom generation aging, the number of people affected by primary open-angle glaucoma in the US is expected to reach 3.3 million by 2020, and about half may not know they have the disease. The treatment of most forms of glaucoma includes the use of topical agents that enhance aqueous humour outflow, reduce aqueous production, or both. Topical intraocular pressure-lowering drugs must penetrate across the tissues of the eye to reach their therapeutic targets. Often, these tissues show the first signs and symptoms of drug toxicity and adverse effects. These include eyelid dermatitis, malpositions, lacrimal system scarring, ocular discomfort upon instillation, tear film instability, conjunctival inflammation, subconjunctival fibrosis, conjunctival epithelium changes, and corneal surface and endothelial impairment. For these reasons, ophthalmologists should evaluate the risks and benefits of ophthalmic medications before initiating therapy, identify the minimum dosages necessary to achieve a therapeutic benefit, and monitor patients for local and systemic adverse effects. Adverse events may be reduced by changing to a different class of topical medication, using corticosteroids, lubricating the eyes frequently, and reducing exposure to preservatives. This in turn can lead to higher levels of adherence to antiglaucoma therapy, improved outcomes and a reduction in the costs associated with long-term glaucoma complications. This article reviews the ocular adverse effects associated with the various classes of topical antiglaucoma drugs, with a particular focus on the ocular surface, eyelids and periorbital tissue.

Brinzolamide ophthalmic suspension: a review of its pharmacology and use in the treatment of open angle glaucoma and ocular hypertension

Brinzolamide is a white powder commercially formulated as a 1% ophthalmic suspension to reduce intraocular pressure (IOP). Pharmacologically, brinzolamide is a highly specific, non-competitive, reversible, and effective inhibitor of carbonic anhydrase II (CA-II), able to suppress formation of aqueous humor in the eye and thus to decrease IOP. Several clinical trials have evaluated its safety and the most commonly ocular adverse events are blurred vision (3%-8%), ocular discomfort (1.8%-5.9%), and eye pain (0.7%-4.0%). Brinzolamide has been introduced to treat ocular hypertension and primary open-angle glaucoma. In some clinical studies it has been estimated that brinzolamide reduced IOP by was about 18%. Brinzolamide can be added to beta-blockers and prostaglandins. In the latter combination, because prostaglandin derivatives improve the uveoscleral outflow but also increase the activity of CA in ciliary epithelium with a secondary increase in aqueous humor secretion, and slightly reduce the efficacy of prostaglandin analogues, theoretically topical CA inhibitors (CAI) decrease IOP by inhibiting CA-II, thus improving prostaglandin efficacy as well as lowering IOP. Brinzolamide could have a secondary possible effect on ocular flow too. Some clinical studies showed a mild improvement of ocular blood flow. Theoretically, CAI could give rise to metabolic acidosis, with secondary vasodilatation and improvement of blood flow. Systemic acidosis can occur in the setting of oral CAI therapy, and local acidosis within ocular tissues is theoretically possible with topical CAI therapy, with the potential for a local increase in ocular blood flow. In conclusion, topical CAI treatment has efficacy in IOP-lowering ranging from 15% to 20%. From published data, brinzolamide can be used as first-line medication, even if other medications have a higher efficacy, with few side effects and it is a good adjunctive treatment. In some type of glaucoma patients with a vascular dysregulation, topical CAI could have a double effect: reducing IOP and improving ocular blood flow.