Lens extraction appears a risk factor for late-onset glaucoma after uncomplicated PPV
Researchers used a previously collected data set and retrospective cohort and matched case–control study designs to evaluate the incidence of late-onset open-angle glaucoma (OAG) after uncomplicated pars plana vitrectomy (PPV). Of all patients (285 eyes) followed for at least six months after vitrectomy, 11.6 percent developed OAG. The incidence was highest among patients who had cataract extraction compared to phakic patients (15 percent vs. 1.4 percent). The low incidence among phakic patients suggests a combined mechanism for late-onset OAG involving PPV and lens extraction at any time – before, during or after PPV. Retina, January 2012
IOP readings from 3 tonometry methods compared in Japanese subjects
Investigators compared dynamic contour tonometry (DCT) IOP measurements with those of Goldmann applanation tonometry (GAT) and noncontact tonometry (NCT) in 74 Japanese patients with no history of intraocular surgery. DCT did correlate with GAT and NCT. Mean IOP measured by DCT was 2.8mm Hg higher than GAT measurements and 3.2mm Hg higher than NCT. This difference was greater with thinner central corneal thickness (CCT) in the lower IOP group than in the higher IOP group. GAT and NCT measurements significantly correlated with CCT, while DCT measurements did not. DCT-measured ocular pulse amplitude was positively correlated with patient age, IOP measurement by DCT, and pulse pressure. Journal of Glaucoma, January 2012
Avastin less effective than MMC as adjunct to trabeculectomy
This prospective study compared the outcome of trabeculectomy in 36 eyes randomized to adjunctive subconjunctival bevacizumab or mitomycin C. While bevacizumab was effective, the reduction of IOP was greater with MMC (34% vs. 56%). The bevacizumab group also required more antiglaucoma medications for IOP control, although this difference was statistically insignificant. No difference was observed in terms of bleb morphologic features. While the bevacizumab group had less complete success, the cumulative probability of total success was greater in the bevacizumab group (100% vs. 94.4%). American Journal of Ophthalmology, February 2012
IOP/CCT adjustments don't improve glaucoma prediction model
Researchers assessed whether the accuracy of the baseline prediction model for development of primary open-angle glaucoma is improved by correcting IOP for central corneal thickness. To do this, they reanalyzed the baseline prediction model for POAG development from the Ocular Hypertension Treatment Study, substituting IOP adjusted for CCT using five different correction formulas for unadjusted IOP. Outcomes were no better than the original prediction model that did not adjust IOP for CCT. They recommend using the online Glaucoma 5-year risk calculator, which can be downloaded for free. Ophthalmology, March 2012
Risk of IOP spike after laser peripheral iridotomy appears low in Chinese atients
This prospective, randomized study investigated the immediate impact of laser peripheral iridotomy(LPI)on IOP in 734 Chinese patients with narrow angles, but no evidence of peripheral anterior synechia, elevated IOP or glaucomatous optic neuropathy. Subjects underwent LPI in one randomly selected eye, with the fellow eye serving as a control. Significant IOP rise occurred in 9.8 percent at one hour and 0.82 percent at two weeks. IOP spike was associated with greater laser energy used and shallower central anterior chamber. Ophthalmology, February 2012
Focal optic disc damage may be an indicator of faster glaucoma progression
This prospective study investigated the rate of visual field and optic disc change in glaucoma patients with one of three patterns of optic disc damage – focal, diffuse or sclerotic. Despite similar IOP reductions from untreated levels, patients with focal optic disc damage had the fastest rates of change in both visual field and optic disc; however, only the differences in visual field rates were statistically significant. Patients with diffuse optic disc damage had the slowest rate of visual field change, and patients with sclerotic optic disc damage Ophthalmology, February 2012
Hyaluronic acid with 5-fluorouracil may improve outcomes of bleb needlings
This randomized controlled trial compared the efficacy of a novel sustained release hyaluronic acid with 5-fluorouracil (HA-5FU) formulation as an adjunct in reviving bleb function by needling, compared with 5FU alone. One eye of each of the 50 patients was randomized to receive either needling with HA-5FU or needling with 5FU solution alone. More eyes in the HA-5FU group achieved an IOP below 15 mmHg without medications (48 percent vs. 33.3 percent). At three months, both groups demonstrated a significant decrease in IOP from baseline. However, fewer repeat needlings were required in the HA-5FU group (50 percent vs. 12 percent; P = 0.004). Ophthalmology, February 2012ad the slowest rate of optic disc change. Ophthalmology, February 2012
Serial anti-VEGF injections associated with IOP elevation
This retrospective study evaluated the long-term effect of intravitreal injections of anti-VEGF agents on IOP in 207 patients treated in one eye for wet AMD. Fellow eyes served as controls. They found a significant positive correlation between the number of injections and the probability of experiencing IOP elevation >5 mmHg above baseline IOP on ≥2 consecutive visits. Receiving ≥29 injections increased the odds of IOP elevation almost six-fold compared with receiving ≤12 injections. Ophthalmology, February 2012
Nine of 10 glaucoma patients instill eye drops incorrectly
Investigators observed 70 glaucoma patients aged 35 to 70 administering eye drops. All patients had been self-administering at home for at least six months. When observed instilling one drop of artificial tears, only 8.57 percent could correctly squeeze one drop into the conjunctival sac without bottle tip contact. The rest squeezed more than one drop, spilled the drops, touched the tip of the bottle to the globe or periocular tissue, closed their eyes or occluded the punctum. Journal of Glaucoma, March 2012
Study questions accuracy of CCT adjusted IOP measurements
This retrospective case series assessed the usefulness of central corneal thickness (CCT)-based IOP correction formulae for stratified CCT groups (thin, intermediate and thick), with IOP from the Pascal dynamic contour tonometer (PDCT) as the reference standard. They compared IOP measurements from Goldmann applanation tonometry (GAT), the Ocular Response Analyzer, and adjusted IOP derived using various CCT-based correction formulae. Adjusting IOP using CCT-based correction formulae resulted in poorer agreement with PDCT IOP when compared with unadjusted GAT IOP. The risk of error was greatest in patients with thicker corneas, in which increased IOP may be interpreted as a GAT measurement artifact. With the exception of corneal compensated IOP, all of the IOP measurement and adjustment methods increased the risk of creating clinically significant error, compared with PDCT. Ophthalmology, March 2012
American Journal of Ophthalmology, February 2012OCULUS Pachycam® from OCULUS, Inc. The OCULUS Pachycam® has the automatically correction of the IOP in accordance with various correction tables to obtain the "real" IOP. The Windows® compatible software allows an easy archiving of the patient data as well as the integration into the local network. The advantage, besides the combination of pachymetry, keratometry and IOP-correction, is the high repeatability based on the intuitive alignment and the automatic release.
The OCULUS Pachycam® is the first compact, portable non-contact pachymeter with built-in keratometer.
The pachymetry is based on Scheimpflug images of a horizontal 4mm cut and provides immediately indication of central and thinnest corneal thickness.
The integrated keratometer measures the central K-value as well as the K-values in the central 30°.
The Pachycam® is available as a stand alone unit and alternatively adaptable to the standard focusing rod hole of most slit-lamps.
Optical PachymetryThe pachymetry is based on Scheimpflug images of a horizontal 4mm cut and provides immediately indication of central and thinnest corneal thickness.
Glaucoma risk factors in Latinos
This analysis of data from the Los Angeles Latino Eye Study identified older age, higher IOP, longer axial length, thinner central cornea and greater waist-to-hip ratio as predictors of development of open-angle glaucoma (OAG). Subjects were 3,772 self-identified Latinos free of glaucoma at baseline and followed for four years. Among patients with higher baseline IOP, the risk of developing OAG was highest in those with thin central corneal thickness. The authors note that many could have avoided OAG if IOP were further reduced, especially in those participants without ocular hypertension. Ophthalmology, November 2012
Low-pressure glaucoma may be better treated with topical brimonidine
Researchers investigated baseline and intercurrent risk factors for visual field progression among participants enrolled in the Low-pressure Glaucoma Treatment Study to identify risk factors for progression. Despite similar mean IOP during the study, there was a significant association between topical timolol maleate 0.5% and progression risk compared to brimonidine tartrate 0.2%, which was independent of its effect on perfusion pressure. These findings suggest that the beneficial effect of brimonidine was attributable to factors other than any differences in IOP control or differences in ocular perfusion, and is consistent with a neuroprotective effect. American Journal of Ophthalmology, October 2012
Timolol can treat post-LASIK myopic regression
This prospective, randomized, parallel-controlled, double-masked clinical trial included 90 patients (90 eyes) with myopic regression after LASIK. Half received timolol 0.5% eye drops and half received artificial tears for six months. Spherical equivalent improved significantly in the timolol group at six months of treatment and at six months after timolol discontinuation (both P < .001). Though the refractive effect is mild (mean difference of 0.62 D at month 12), it should be tried soon after signs of regression are observed. American Journal of Ophthalmology, November 2012
Preservative-free tafluprost equivalent to preservative-free timolol
This randomized, double-masked, multicenter trial compared the efficacy and safety of preservative-free tafluprost 0.0015% and preservative-free timolol 0.5% in more than 600 patients with open-angle glaucoma or ocular hypertension. The IOP-lowering effect of tafluprost was noninferior to timolol at all visits and time points over the 12-week treatment period. In addition, the upper boundary of the 95% CI was less than 0 at 4 of 9 time points, suggesting a numerical advantage for tafluprost. Both treatments were well-tolerated. American Journal of Ophthalmology, June 2012
Combining multiple glaucoma stents with cataract surgery further reduces IOP, medication use
This prospective case series evaluated the effect of implanting two or three micro-bypass stents at the time of cataract surgery in 47 patients with open-angle glaucoma. At one year, mean IOP was significantly lower than preop at 14.3 mmHg, with 77 percent of eyes achieving target IOP. The mean number of medications dropped from 2.7 to 0.7 (P < 0.001), with the three-stent group using significantly fewer medications than the two-stent group (0.4 vs. 1.0). Compared with studies of a single stent, multiple stents resulted in a greater propensity to achieve an IOP of 15 mm Hg or less and a greater absolute reduction in medications. Journal of Cataract & Refractive Surgery, November 2012