Recent research from the University of Utah shows that dry-eye disease is a substantial economic burden for those affected. To estimate both the direct and indirect annual cost of managing dry eye in the United States from a societal and a payer’s perspective, researchers developed an analytic model to estimate the annual cost for managing a cohort of patients with dry eye of differing severities and treatments. The direct costs included ocular lubricants, cyclosporine, punctal plugs, physician visits and nutritional supplements. The indirect costs were measured as the productivity loss because of absenteeism and presenteeism. The model was populated with data that were obtained from surveys completed by dry-eye sufferers who were recruited from online databases. Sensitivity analyses were employed to evaluate the impact of changes in parameters on the estimation of costs. All costs were converted to 2008 U.S. dollars.
Survey data were collected from 2,171 respondents with dry eye. Analysis indicated that the average annual cost of managing a patient with dry eye was $783 (variation, $757 to $809) from the payers’ perspective. When adjusted to the prevalence of dry eye nationwide, the overall burden of the disease for the U.S. health-care system would be $3.84 billion. From a societal perspective, the average cost of managing dry eye was estimated to be $11,302 per patient and $55.4 billion to the U.S. society overall.
Yu J, Asche CV, Fairchild CJ.
Toric IOLs Reduce Astigmatism After Cataract Surgery
Injectable, one-piece hydrophilic acrylic toric intraocular lenses have been shown to effectively reduce visually significant keratometric astigmatism as well as increase spectacle independence after cataract surgery. A cohort study—conducted at Hillingdon Hospital in Uxbridge, Middlesex, U.K.—enrolled consecutive patients who had 2 D or more of preexisting corneal astigmatism as a means of testing the IOLs’ efficacy and rotational stability. Patients had phacoemulsification with implantation of a T-flex 623T toric IOL through a 2.8-mm astigmatically neutral incision. Uncorrected and corrected distance visual acuities, refraction, keratometry and the cylinder axis for the toric IOL were measured.
Thirty-three eyes of 25 patients were evaluated. The mean preoperative refractive astigmatism was 3.35 D ±1.20 and the mean keratometric astigmatism, 3.98 D ±1.89, respectively. Four months postoperatively, the mean UDVA was 0.28 ±0.23 D logMAR, improving to 0.19 ±0.23 D logMAR CDVA. The mean refractive astigmatism was 0.95 ±0.66 D; vector analysis using the Holladay-Cravy-Koch method showed that the mean reduction in refractive astigmatism was 2.94 ±0.89 D. The mean difference between the intended and the actual final IOL cylinder axis was 3.44 degrees (range: 0 to 12).
J Cataract Refract Surg 2011;
Entabi M, Harman F, Lee N, Bloom PA.
Brimonidine Leads to Fewer Progression Cases Than Timolol
A new study shows that low-pressure glaucoma patients treated with brimonidine tartrate 0.2% who do not develop ocular allergy are less likely to have field progression than patients treated with beta-adrenergic antagonist timolol maleate 0.5%. Authors of the study launched a randomized, double-masked, multicenter clinical trial to compare the efficacy of both treatments. Exclusion criteria included untreated intraocular pressure >21 mmHg, visual field mean deviation worse than -16 decibels and contraindications to study medications. Both eyes of the test subjects received twice-daily monotherapy randomized in blocks of seven (four brimonidine to three timolol). Standard automated perimetry and tonometry were performed at four-month intervals. The main outcome measure was field progression in either eye, defined as the same three or more points with a negative slope ≥-1 dB/year at p<5 percent, on three consecutive tests, assessed by pointwise linear regression. Secondary outcome measures were progression based on glaucoma change probability maps (GCPM) of pattern deviation and the three-omitting method for pointwise linear regression.
Ninety-nine patients were randomized to brimonidine and 79 to timolol. Mean follow-up time for all patients was 30 ±two months. Statistically fewer brimonidine-treated patients (9, 9.1 percent) had visual field progression by pointwise linear regression than timolol-treated patients (31, 39.2 percent, log-rank 12.4, p=0.001). Mean treated IOP was similar for brimonidine- and timolol-treated patients at all time points. More brimonidine-treated (28, 28.3 percent) than timolol-treated (9, 11.4 percent) patients discontinued study participation because of drug-related adverse events (p=0.008). Similar differences in progression were observed when analyzed by GCPM and the three-omitting method.
Am J Ophthalmol 2011;151:671-81
Krupin T, Liebmann JM, Greenfield DS, et al.
Boston Ocular Prosthesis
Effective in Astigmatic Eyes
The Boston Ocular Surface Prosthesis appears to be very effective in reducing higher-order wavefront aberrations in patients with irregular astigmatism resulting from a number of corneal and ocular surface conditions that had not responded satisfactorily to conventional methods of optical correction, according to a study at Cullen Eye Institute at Baylor College of Medicine in Houston. The prospective study evaluated 56 eyes of 39 patients with irregular astigmatism who were treated with the Boston Ocular Surface Prosthesis when conventional treatments failed. Patients were stratified into four clinical groups based on the underlying cause of irregular astigmatism, including keratoconus (Group 1), post-penetrating keratoplasty (Group 2), post-refractive surgery (Group 3) and ocular surface diseases (Group 4). Another six eyes of five patients who were treated with rigid gas-permeable lenses were also evaluated. Best-corrected visual acuity; topographic refractive indices, including spherical, cylindrical and spherical equivalent values; and higher-order and total wavefront aberration errors were noted at baseline and after fitting the lens.
In all groups, higher-order wavefront aberration error was noted to decrease significantly in eyes wearing the Boston Ocular Surface Prosthesis (p<0.001, p=0.001, p=0.002, and p=0.001, respectively). By post hoc analysis, significant differences in the level of higher-order aberrations were observed only between Groups 1 and 4 (p=0.012) and Groups 1 and 2 (p=0.033). In the overall group, mean correction rate of higher-order aberration error with the Boston Ocular Surface Prosthesis was 72.3 percent. However, in eyes with rigid gas permeable lenses, two eyes demonstrated increased higher-order aberration error, whereas the mean correction rate in the other four eyes was only 42.5 percent.
Am J Ophthalmol 2011;151:682-690.e2
Gumus K, Gire A, Pflugfelder SC.
Post-Surgery Astigmatisms Predictable from Eye to Eye
Refractive and keratometric oblique astigmatisms that occur in the first eye after cataract surgery can serve to predict post-surgery astigmatism in the second eye, says new research. To predict postoperative refractive astigmatism in the second eye undergoing cataract surgery, using standard biometry and information obtained from the first eye, researchers conducted a retrospective study of 160 patients undergoing bilateral sequential phacoemulsification with capsular bag implantation of a hydrophobic acrylic lens at a Veterans Affairs medical center in Richmond, Va. Keratometric and refractive astigmatism were described by Jackson cross cylinder with-the-rule (J0) and oblique (JX) components. Preoperative predictors of postoperative refractive astigmatism in the second eye were determined by multivariable regression.
The postoperative refractive astigmatism in the first eye predicted 40 percent of the variation in the second eye (r2=0.40; p<0.001). The multivariable model to predict postoperative with-the-rule astigmatism was J(0PostopEye2) = (0.376 × J(0PostopEye1) + (0.327 × J(0KeratomEye2) + (0.097 × J(0PreopEye2) - 0.099 (p<0.001 for first two terms; r2=0.56). The multivariable model for oblique astigmatism was J(XPostopEye2) = (0.350 × J(XKeratomEye2) + (0.231×J(XKeratomEye1) + (0.064 × J(XPreopEye2) - 0.07 (p≤0.01 for first two terms; r2=0.20). Refractive with-the-rule astigmatism observed postoperatively in the first eye is a strong independent predictor of postoperative with-the-rule astigmatism in the second eye. Keratometric oblique astigmatism in the first eye is a weak but statistically significant independent predictor of postoperative oblique astigmatism in the second eye. Both findings are consistent with mirror symmetry of the corneas about the midsagittal plane and may improve the prediction (and hence control) of postoperative astigmatism in the second eye.
Arch Ophthalmol 2011;129:295-300
Leffler CT, Wilkes M, Reeves J, Mahmood MA.