CLEAR - Medical use of contact lenses

The medical use of contact lenses is a solution for many complex ocular conditions, including high refractive error, irregular astigmatism, primary and secondary corneal ectasia, disfiguring disease, and ocular surface disease. The development of highly oxygen permeable soft and rigid materials has extended the suitability of contact lenses for such applications. There is consistent evidence that bandage soft contact lenses, particularly silicone hydrogel lenses, improve epithelial healing and reduce pain in persistent epithelial defects, after trauma or surgery, and in corneal dystrophies. Drug delivery applications of contact lens hold promise for improving topical therapy. Modern scleral lens practice has achieved great success for both visual rehabilitation and therapeutic applications, including those requiring retention of a tear reservoir or protection from an adverse environment. This report offers a practical and relevant summary of the current evidence for the medical use of contact lenses for all eye care professionals including optometrists, ophthalmologists, opticians, and orthoptists. Topics covered include indications for use in both acute and chronic conditions, lens selection, patient selection, wear and care regimens, and recommended aftercare schedules. Prevention, presentation, and management of complications of medical use are reviewed.

The impact of the Boston ocular surface prosthesis on wavefront higher-order aberrations

PURPOSE

To evaluate the effect of the Boston Ocular Surface Prosthesis (Boston Foundation for Sight) on higher-order wavefront aberrations in eyes with keratoconus, eyes that have undergone penetrating keratoplasty, eyes that have undergone refractive surgery, and eyes with ocular surface diseases.

DESIGN

Prospective, clinical study.

METHODS

The 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 sorted into 4 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 6 eyes of 5 patients who were treated with rigid gas permeable lenses also were evaluated. Best-corrected visual acuity; topographic refractive indices, including spherical, cylindrical, spherical equivalent values; and higher-order and total wavefront aberration errors were noted at baseline and after fitting the lens.

RESULTS

In all groups, higher-order wavefront aberration error was noted to decrease significantly in eyes wearing the Boston Ocular Surface Prosthesis (P<.001, P=.001, P=.002, and P=.001, respectively). By post hoc analysis, significant differences in the level of higher-order aberrations were observed only between groups 1 and 4 (P=.012) and groups 1 and 2 (P=.033). In the overall group, mean correction rate of higher-order aberration error with the Boston Ocular Surface Prosthesis was 72.3%. However, in eyes with rigid gas permeable lenses, 2 eyes demonstrated increased higher-order aberration error, whereas the mean correction rate in other 4 eyes was only 42.5%.

CONCLUSIONS

With its unique structure, the Boston Ocular Surface Prosthesis was found 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 who had not responded satisfactorily to conventional methods of optical correction.