á2-adrenergic agonists (AAs), â-adrenergic antagonists (BBs) and topical carbonic anhydrase inhibitors (TCAIs) have all been shown to be similarly effective in lowering mean diurnal intraocular pressure when used in combination with a prostaglandin analog, based on a comprehensive journal search at the Northwestern University Feinberg School of Medicine in Chicago. Ten observer-masked, randomized clinical trials that reported baseline IOP while receiving PGA monotherapy, and follow-up IOP while receiving combination therapy, were identified.

The pooled IOP-lowering efficacy achieved with each class of adjunctive agent was calculated using random-effects models. Mean diurnal IOP reduction achieved in all three groups was statistically similar (p=0.22). At trough, IOP reduction was greater in the TCAI (p<0.001) and BB (p<0.001) groups than in the AA group. Peak reduction was similar in each group (p=0.66). Eye or eyelid pain or burning and xerostomia were significantly more common in the AA group. Fatigue, weakness or dizziness was more common in the AA and BB groups than the TCAI group. Taste disturbance was significantly more common in the TCAI group.

Arch Ophthalmol 2010;128:825-33.

Tanna AP, Rademaker AW, Stewart WC, Feldman RM.


Vitrectomy May Mar CCC Wound Integrity

A San Francisco-based retrospective case series reports on intraoperative complications related to clear corneal incisions that can occur during pars plana vitrectomy. Five patients with a median age of 75 years, were followed for a median of 7.5 months (range, six months to five years). In each eye, the patient had previously undergone cataract surgery and intraocular lens implantation through a clear corneal wound. Each patient developed a surgical complication during the subsequent vitrectomy (20-ga.: three cases; 23-ga.: one case; combined 20- and 25-ga.: one case) related to leakage through the clear corneal wound. Vitrectomy was performed for retained lens fragments (three), macular hole (one) and repair of combined rhegmatogenous/tractional diabetic retinal detachment (one). Median time between cataract surgery and vitrectomy was eight days (range, 0 to 14 days).

In each eye, the clear corneal wound leaked extensively with minimal manipulation of the sclera at the pars plana. Four eyes developed choroidal detachment associated with hypotony caused by leakage through the clear corneal wound. Three of these eyes developed hemorrhagic choroidal detachment with subretinal and/or vitreous hemorrhage. One eye developed iris incarceration and anterior subluxation of a sulcus-placed intraocular lens associated with leakage through the clear corneal wound. In all five cases, extra sutures were placed to secure the clear corneal incision, and the cases were completed. Two eyes underwent repeat vitrectomy to address complications associated with hemorrhagic choroidal detachments. Median final visual acuity was 20/400 (range, 20/40 to hand motion). The retina remained attached in all cases at the latest follow-up visit.

Cataract surgeons encountering complications during surgery should secure clear corneal wounds in anticipation of eventual vitrectomy surgery. It is incumbent on the retinal surgeon to carefully inspect the corneal wound at the start of the vitrectomy procedure and to close it with sutures if it appears to leak with minimal manipulation. This should help to minimize additional intraoperative and/or long-term complications,
the authors say.

Retina 2010;30:850-5

Wong RW, Kokame GT, Mahmoud TH, et al.


Three Prostaglandin Analogs Prove Equally Tolerable

A recent study conducted at UT Southwestern Medical Center, Dallas, has found no significant differences among bimatoprost (preserved with 0.005% benzalkonium chloride), latanoprost (preserved with 0.02% BAK) and travoprost (preserved with proprietary preservative system, sofZia) in objective clinical measures of ocular tolerability, including physician-graded hyperemia, corneal staining and tear breakup time after three months of treatment. Authors of the Allergan-supported, randomized, multicenter, investigator-masked, parallel-group study enrolled patients with open-angle glaucoma or ocular hypertension who had been on latanoprost monotherapy for at least four weeks. At baseline, patients were randomized to receive once-daily bimatoprost (n=35), latanoprost (n=38) or travoprost (n=33) monotherapy for three months. Follow-up visits were at one week, one month and three months. The primary outcome measure was physician-graded conjunctival hyperemia at three months. Secondary outcome measures included corneal staining with fluorescein and TBUT.

There were no significant differences among the treatment groups in conjunctival hyperemia scores, corneal staining or TBUT at the latanoprost-treated baseline or at any follow-up. Baseline mean values were as follows: Conjunctival hyperemia: bimatoprost 0.74 (Standard error of mean: 0.10), latanoprost 0.74 (0.11), travoprost 0.86 (0.12), p=0.692; corneal staining: bimatoprost 0.59 (0.12), latanoprost 0.70 (0.13), travoprost 0.48 (0.11), p=0.423; TBUT (in seconds): bimatoprost 9.1 (1.0), latanoprost 8.6 (0.8), travoprost 7.9 (0.8), p=0.578. Three-month values were as follows: Conjunctival hyperemia: bimatoprost 0.80 (0.12), latanoprost 0.74 (0.10), travoprost 0.98 (0.13), p=0.340; corneal staining: bimatoprost 0.71 (0.78), latanoprost 0.47 (0.64), travoprost 0.36 (0.62), p=0.110; TBUT (in seconds): bimatoprost 9.7 (5.3), latanoprost 9.2 (5.3), travoprost 9.7 (6.3), p=0.909. The authors suggest that longer-term studies are needed to further evaluate the ocular surface tolerability of these prostaglandin analogs.

J Ocul Pharmacol Ther 2010;26:287-92

Whitson JT, Trattler WB, Matossian C, et al.


Azithromycin Helps Restore Lipid Order in Meibomian Gland Disorder

Results from a new study at the University of Louisville strongly suggest that meibomian gland dysfunction alters the ordering of lipid molecules in the meibomian gland and that topical azithromycin (Inspire) solution can improve that abnormal condition in a way that correlates with clinical response to therapy. During a prospective, observational, open-label clinical trial supported in part by the manufacturer, researchers evaluated patients affected by MGD with slit-lamp examination. Symptoms  were measured by the response of subjects to a questionnaire. Meibum lipid, lipid-lipid interaction strength and conformation and phase transition parameters were measured using Fourier transform infrared spectroscopy.

In subjects with clinical evidence of MGD, changes in ordering of the lipids and resultant alteration of phase transition temperature were identified. Topical therapy with azithromycin relieved signs and symptoms and restored the lipid properties of the meibomian gland secretion to normal. Improvement in phase transition temperature of the meibomian gland lipid with the determined percent trans rotamer composition of the lipid demonstrates the importance of lipid order in regards to MGD.

Cornea. 2010;29:781-8

Foulks GN, Borchman D, Yappert M, et al.


How Glaucoma Treatments Impact Patients' Annual Finances

Researchers at the Washing-ton University School of Medicine in St. Louis have calculated the annual costs to patients with primary open-angle glaucoma (considering both visual and nonvisual medical costs over a lifetime with the disease). The group constructed a Markov model to replicate health events over the remaining lifetime of someone newly diagnosed with glaucoma. Costs of this group were compared with those estimated for a control group without glaucoma. The cost of managing glaucoma (including medications) before the onset of visual impairment was not considered. The model was populated with probability data estimated from Medicare claims data (1999 through 2005). Cost of nonocular medications and nursing home use was estimated from California Medicare claims, and all other costs were estimated from Medicare claims data.

Over their expected lifetime, the cost of care for people with primary open-angle glaucoma was higher than that of people without the disease by $1,688 or approximately $137 per year. Among Medicare beneficiaries, diagnosis was not found to be associated with significant risk of comorbidities before onset of visual impairment. Further study was deemed necessary to consider the impact of glaucoma on quality of life, as well as aspects of physical and visual function not captured in this claims-based analysis.

Am J Ophthalmol 2010;150:74-81

Kymes SM, Plotzke MR, Li JZ, et al.