TFOS DEWS II iatrogenic report.

Dry eye can be caused by a variety of iatrogenic interventions. The increasing number of patients looking for eye care or cosmetic procedures involving the eyes, together with a better understanding of the pathophysiological mechanisms of dry eye disease (DED), have led to the need for a specific report about iatrogenic dry eye within the TFOS DEWS II. Topical medications can cause DED due to their allergic, toxic and immuno-inflammatory effects on the ocular surface. Preservatives, such as benzalkonium chloride, may further aggravate DED. A variety of systemic drugs can also induce DED secondary to multiple mechanisms. Moreover, the use of contact lens induces or is associated with DED. However, one of the most emblematic situations is DED caused by surgical procedures such as corneal refractive surgery as in laser-assisted in situ keratomileusis (LASIK) and keratoplasty due to mechanisms intrinsic to the procedure (i.e. corneal nerve cutting) or even by the use of postoperative topical drugs. Cataract surgery, lid surgeries, botulinum toxin application and cosmetic procedures are also considered risk factors to iatrogenic DED, which can cause patient dissatisfaction, visual disturbance and poor surgical outcomes. This report also presents future directions to address iatrogenic DED, including the need for more in-depth epidemiological studies about the risk factors, development of less toxic medications and preservatives, as well as new techniques for less invasive eye surgeries. Novel research into detection of early dry eye prior to surgeries, efforts to establish appropriate therapeutics and a greater attempt to regulate and oversee medications, preservatives and procedures should be considered.

Advancements in ocular drug delivery.

This review covers both noninvasive and invasive ophthalmic drug delivery systems that can have application to therapy of veterinary ophthalmic diseases. Noninvasive approaches include gel technologies, permeation enhancement via pro-drug development, solubilization agents and nanoparticle technologies, iontophoresis, microneedles, drug-eluting contact lenses and eye misters, and microdroplets. More invasive systems include both eroding implants and noneroding technologies that encompass diffusion based systems, active pumps, intraocular lenses, suprachoroidal drug delivery, and episcleral reservoirs. In addition to addressing the physiologic challenges of achieving the necessary duration of delivery, tissue targeting and patient compliance, the commercial development factors of biocompatibility, sterilization, manufacturability and long-term stability will be discussed.

Controlled flow-through dissolution methodology: a high-performance system.

Measuring release rates using compendial systems, especially for sparingly soluble compounds, often produces complex results with less than desired precision and lacks relevance to key formulation or biological parameters. A flow-through approach was used by focusing on convective diffusion and controlling certain key physical-chemical factors. Results are presented for an automated multisample flow-through system that displays significant advantages over compendial (1) stirred and (2) flow-through systems. Advantages include precision, physicochemical, and in vivo relevance, along with analytical and formulation sensitivity. The convective diffusion/dissolution process was also simulated by using finite element modeling with predictions agreeing with measurements to within a few percent.

Response to travoprost in black and nonblack patients with open-angle glaucoma or ocular hypertension.

Two prospective, controlled, multicenter, double-masked studies--one lasting 6 months (n=594) and the other, 12 months (n=787)--examined the intraocular pressure (IOP)-lowering efficacy of travoprost in 1381 black and nonblack patients with open-angle glaucoma or ocular hypertension. Investigated regimens were travoprost 0.004% once daily, latanoprost 0.005% once daily, and timolol 0:5% twice daily. In both studies, mean IOP was significantly lower in blacks treated with travoprost. The IOP reduction was also significantly greater in blacks after adjustments for age, sex, iris color, diagnosis, and corneal thickness. Timolol lowered mean IOP to a greater extent in nonblack patients. The significantly larger IOP reduction with travoprost compared with timolol in both racial groups was more pronounced in blacks. Travoprost also was superior to latanoprost in blacks. Mean changes from baseline generally were greater for black than for nonblack patients, although the differences did not achieve statistical significance. The response rate to travoprost was higher in blacks. The most common adverse effect was hyperemia.

Identification and characterization of the ocular hypotensive efficacy of travoprost, a potent and selective FP prostaglandin receptor agonist, and AL-6598, a DP prostaglandin receptor agonist.

The structure-activity studies that led to the identification of travoprost, a highly selective and potent FP prostaglandin analog, and AL-6598, a DP prostaglandin analog, are detailed. In both series, the 1-alcohol analogs are very effective and are thought to be acting as prodrugs for the biologically active carboxylic acids. The efficacy of amide prodrugs depends on the degree of substitution and the size of the substituents. Selected compounds are profiled in vitro and in vivo preclinically. Clinical studies show that travoprost 0.004% (isopropyl ester) provided intraocular pressure control superior to timolol 0.5% when used as monotherapy in patients with open-angle glaucoma or ocular hypertension. In clinical studies, AL-6598 0.01% provided a sustained intraocular pressure reduction with q.d. application; b.i.d. provided greater intraocular pressure control. The acute and, apparently, conjunctival hyperemia associated with topical ocular AL-6598 can be attenuated while maintaining intraocular pressure-lowering efficacy by formulating with brimonidine.

Comparison of travoprost 0.0015% and 0.004% with timolol 0.5% in patients with elevated intraocular pressure: a 6-month, masked, multicenter trial.

OBJECTIVE: To compare the safety and intraocular pressure (IOP)-lowering efficacy of once-daily travoprost (0.0015% and 0.004%) to twice-daily timolol 0.5%. DESIGN: Prospective, 6-month, randomized, controlled, multicenter, double-masked, phase III study. PARTICIPANTS: Six hundred five patients with open-angle glaucoma or ocular hypertension. METHODS: Patients with an 8 AM IOP between 24 to 36 mmHg in at least one eye (the same eye) at two eligibility visits received either travoprost 0.0015%, travoprost 0.004% (dosed every day), or timolol 0.5% (dosed twice daily). MAIN OUTCOME MEASURES: Mean IOP at 8 AM, 10 AM, and 4 PM in the patient's eye with the higher baseline IOP. RESULTS: The mean IOP was significantly lower for both concentrations of travoprost compared with timolol. Travoprost was statistically superior to timolol at 9 of 13 visits, with differences in IOP reductions ranging from 0.9 to 1.8 mmHg (0.0015%) and 10 of 13 visits with differences in IOP reductions from 0.9 to 2.4 mmHg (0.004%). Mean IOP changes from baseline ranged from -6.0 to -7.5 mmHg (0.0015%), -6.5 to -8.0 mmHg (0.004%), and -5.2 to -7.0 mmHg for timolol. Hyperemia was experienced at rates of 29.2% (59 of 202) for travoprost 0.0015%, 42.8% (86 of 201) for travoprost 0.004%, and 8.9% (18 of 202) for timolol. Iris pigmentation changes were observed in 1.0% (2 of 200) of patients receiving travoprost 0.004% with no changes noted in the travoprost 0.0015% group or the timolol group. A decrease in pulse and systolic blood pressure was observed in the timolol group. There were no other clinically relevant or statistically significant changes from baseline in ocular signs or laboratory values, and no serious, related, unexpected adverse events were reported for any group. CONCLUSIONS: Travoprost (0.0015% and 0.004%), dosed once daily in the evening, is statistically superior or equal to timolol 0.5% dosed twice daily at all treatment visits during this 6-month study. IOP reductions of up to 2.0 mmHg greater than timolol were found in the travoprost 0.004% pooled data group. Travoprost is safe and well tolerated in patients with open-angle glaucoma or ocular hypertension.