Fitting of aspheric high gas-permeable rigid contact lenses to scarred corneas

Reverse geometry contact lens fitting in corneal scar caused by perforating corneal injuries

PURPOSE

To describe a reverse geometry rigid gas permeable (RGP) contact lens fitting in corneal scar caused by perforating corneal injuries with intraocular strange body.

METHODS

A reverse geometry RGP lens, with large diameter, was empirically fitted in a 38-year-old male patient who had previous open globe injuries due to work accident in right eye. Corneal suture, vitrectomy and lens extraction were performed. Irregular corneal surface with corneal scar in line with the visual axis were found with low uncorrected visual acuity.

RESULTS

Snellen visual acuity improved from counterfinger to 0.8 with high contact lens acceptance, 6-9h per day of wear. Only three diagnostic contact lenses, in two visits, were necessary. Orbscan simulated fluorescein pattern was different to definitive fluorescein pattern.

CONCLUSIONS

Reverse geometry RGP contact lens, with large diameters, could be a good alternative in irregular corneal surface with corneal scar. Fluorescein pattern analysis could be the proper fitting technique. This fitting could involve less time and fewer visits. Computer-aided fitting was of limited value in these cases.

Visual outcome of cataract surgery with pupillary sphincterotomy in eyes with coexisting corneal opacity

BACKGROUND

To evaluate the visual outcome following cataract surgery with pupillary sphincterotomy in eyes with coexisting corneal opacity.

METHODS

Patients with leucomatous corneal opacity with significant cataract were enrolled for the study. The uncorrected visual acuity and best-corrected visual acuity (BCVA) were recorded and the anterior segment was thoroughly evaluated by a slit lamp biomicroscope before the surgery. Only those patients who had some amount of clear peripheral cornea were selected. Posterior segment pathology was ruled out by indirect ophthalmoscopy after pupillary dilatation, if possible, or by B-scan ultrasonography. Conventional extracapsular cataract extraction with pupillary sphincterotomy was performed and an intraocular lens was implanted. Postoperatively, the eyes were evaluated on day 1, and 1 week and 6 weeks following surgery for similar parameters.

RESULTS

Fourteen eyes of 14 patients were included in the study, of which 13 (92.85%) patients were male. The mean age of the patients was 47.85 +/- 7.37 years. All the eyes had a dense central leucomatous corneal opacity. Twelve (85.71%) eyes had two or more quadrants of deep vascularisation. Sphincterotomy was performed mostly (71.42%) in the nasal or inferonasal quadrant. The intraocular lens was implanted in 13 (92.85%) eyes, and one (7.1%) eye was left aphakic due to the occurrence of a large posterior capsular tear. Preoperatively, all eyes had BCVA < 6/60. At 6 weeks after surgery, all eyes had BCVA >or= 6/60 and four (28.57%) eyes had BCVA >or= 6/18. The mean BCVA preoperatively in these eyes was 0.015 +/- 0.009, which changed to 0.249 +/- 0.102 at 6 weeks following surgery.

CONCLUSIONS

Extracapsular cataract extraction and intraocular lens implantation with pupillary sphincterotomy provides ambulatory and useful vision to patients of cataract with coexisting central leucomatous corneal opacity.

Twenty-five years of contact lenses: the impact on the cornea and ophthalmic practice

PURPOSE

The history of contact lenses has occurred in the latter half of the 20th century. In particular, events in the 1970s through the 1980s related to the invention of soft, hydrogel contact lenses have revolutionized the contact lens industry and the eye care attached to it. This article recounts that history from the perspective of market forces, inventions, and discoveries about the physiologic functioning of the cornea.

METHODS

The relevant literature is critically reviewed.

RESULTS

Discoveries about the oxygen needs of the cornea and consumer pressure for clear, comfortable, around-the-clock vision have resulted in a history of rigid gas permeable and soft lenses that leads to today's contact lens picture. The short-term and long-term effects of chronic hypoxia and the levels of lens oxygen transmissibility necessary to avoid them have been well-described. The advent of the soft lens, followed by the "human experiment" with initial extended-wear modalities, led to the advent of the disposable soft contact lens.

CONCLUSIONS

In the past 25 years, the development and wide acceptance of soft contact lenses have revolutionized the management of refractive error and corneal diseases.