Propranolol eye drops in patients with corneal neovascularization

RATIONALE

Studies performed in animal models of corneal neovascularization suggested the possible efficacy of a treatment with propranolol. Corneal neovascularization is one of the most feared complications of Stevens-Johnson syndrome that frequently involves ocular surface. We report the first 2 patients with severe ocular neo-vascularization treated with different degrees of success, with propranolol eye drops.

PATIENT CONCERNS

Two patients with corneal neovascularization complicating the Stevens-Johnson syndrome, not responsive to steroids and cyclosporine, were treated with propranolol eye drops.

DIAGNOSES

Corneal neovascularization was detected by ophthalmoscopic evaluation.

INTERVENTIONS

Topical treatment with propranolol eye drops at different concentrations.

OUTCOMES

Both patients reported dramatic subjective benefits (reduction of photophobia and discomfort) without adverse effects, and in the patient with a less advanced disease, an objective reduction of neovascularization and an improved visual acuity was observed.

LESSONS

This experience suggests that propranolol might be an inexpensive, safe and effective treatment in counteracting the progression of corneal neovascularization.

Analysis of stray-light effects related to intraocular lens edge design

PURPOSE

To study the behavior of light rays that impact the frosted, double-square edge of an intraocular lens (IOL).

SETTING

Optical Phisiophatological Department, University of Florence, Florence, Italy.

METHODS

The interaction of light rays as a function of the edge design of a frosted, sharp-edged IOL was evaluated using an experimental eye model and an advanced ray-tracing program. The model simulates the irregularities of the frosted edge by the random overlap of sinusoidal phase gratings that have a random phase, an orientation, and a fixed period.

RESULTS

The reduction in the maximum intensity of the ghost image by frosting the square edge was linked to the period of the microroughness. At a maximum microroughness, when the period is less than 5 microm, the reduction in the value of an unfrosted, square-edged IOL was 17.5%.

CONCLUSIONS

The frosted edge had a small impact on reducing the intensity of the ghost image caused by the reflection of light from the double square edge of the IOL. Furthermore, in optics, the stray light from microroughness is generally considered to be a drawback because it can decrease contrast sensitivity.

Computerized analysis of the effects of intraocular lens edge design on the quality of vision in pseudophakic patients

PURPOSE

To study the distribution and intensity of reflected glare images from 3 intraocular lens (IOL) edge designs.

SETTING

Eye Institute, University of Florence, Florence, Italy.

METHODS

The interaction of light rays as a function of edge design was evaluated using an experimental eye model and an advanced ray-tracing program. Three hydrophobic acrylic IOLs were studied: an acrylic square-edged (sharp) design, an acrylic round-edged design, and a new acrylic IOL with a rounded anterior edge and a sharp posterior edge.

RESULTS

The rays hitting the sharp edge of an IOL caused peripheral arcs or circles of light on the side of the retina opposite the focused image. Edge reflections also occurred with the round-edged IOL, but the intensity of the reflected image was one tenth that of the intensity with the sharp-edged design. The new round-/sharp-edged design reduced the maximum intensity of the reflected image to one third the intensity of the sharp-edged reflected image.

CONCLUSIONS

The experimental findings with an acrylic IOL that combines a sharp posterior edge with a low incidence of reflected edge glare are promising.