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.

Corneal Higher-Order Aberrations in Infectious Keratitis

PURPOSE

To characterize the corneal higher-order aberrations (HOAs) in eyes with Acanthamoeba keratitis (AK), bacterial keratitis (BK), and fungal keratitis (FK).

DESIGN

Retrospective consecutive case series.

METHODS

This retrospective study includes 18 normal subjects and 63 eyes of 62 consecutive patients with corneal scarring due to AK (20 eyes), BK (35 eyes), and FK (8 eyes) from 2010 to 2016. HOAs of the anterior and posterior surfaces and the total cornea were analyzed by anterior segment optical coherence tomography. Corneal HOA patterns were assigned on the basis of corneal topography maps. Corneal opacity grading was assigned on the basis of slit-lamp examinations. We evaluated corneal HOAs, corneal opacity grading, and their correlation with visual acuity.

RESULTS

HOAs of the total cornea within a 4-mm diameter were significantly larger in eyes with infectious keratitis (AK, 1.15 ± 2.06 μm; BK, 0.91 ± 0.88 μm; FK, 1.39 ± 1.46 μm) compared with normal controls (0.09 ± 0.01 μm, all, P < .001). Asymmetric pattern was the most common topographic pattern (30% in AK, 51.4% in BK, and 37.5% in FK), followed by the protrusion patterns (10% in AK, 20% in BK, and 12.5% in FK). The visual acuity significantly correlated with HOAs (anterior surface: R = 0.764, P < .0001; posterior surface: R = 0.745, P < .0001; total cornea: R = 0.669, P < .0001).

CONCLUSIONS

Larger corneal HOAs in patients with infectious keratitis were associated with poorer visual acuity values. Asymmetric pattern was the most common topographic pattern in infectious keratitis.

Clinical evaluation of rigid gas permeable contact lenses and visual outcome after repaired corneal laceration

OBJECTIVE

To evaluate the clinical value of rigid gas permeable contact lenses (RGPCLs) in patients with traumatic corneal scarring and address implications of primary corneal repair.

METHODS

Eighteen subjects with a history of corneal laceration were fit with RGPCLs. Scar locations were divided into two zones; each patient was examined using Pentacam. Entering data included uncorrected visual acuity (UCVA), spectacle-corrected visual acuity (SVA), time between injury and RGPCL fitting, location and size of scar, and amount of corneal astigmatism. Follow-up data included RGPCL visual acuity (RGPCLVA), RGPCL-related complications, and dropout characteristics. Visual acuity values were converted to logMAR for analysis.

RESULTS

No serious complications occurred. The average time between suture removal and RGPCL fitting was 5.7±5.5 months. Average corneal astigmatism was -3.44±2.09 diopters. One subject had developed corneal ectasia. RGPCLVA was more than 0.1 in three subjects: one experienced primary corneal repair complications, and two subjects (<10 years) developed amblyopia. In both zones, the difference in RGPCLVA outcome between zone I and zone II was not statistically significant (F=0.060, P=0.809). The difference between SVA in zones I and II was found to be statistically significant (F=6.131, P=0.026), as were the differences between SVA and RGPCLVA (F=8.598, P=0.010). The scar size had no significant influence on RGPCLVA, SVA, or UCVA. Four participants (22.2%) were successfully fit. Dropout characteristics included ocular discomfort, inconvenience, parental apprehension, and low motivation.

CONCLUSIONS

Rigid gas permeable contact lens is an ideal method for evaluating visual potential in patients with traumatic corneal astigmatism. Pentacam examinations of those patients with poor RGPCLVA can help an ophthalmologist find and understand existing problems in suture techniques.

Rigid gas-permeable contact lenses for visual rehabilitation of traumatized eyes in children

PURPOSE

The aim of this study was to investigate the usefulness and tolerance of rigid gas-permeable (RGP) contact lenses in the visual rehabilitation of children postocular trauma.

METHODS

In this retrospective case series, children below 15 years of age with ocular trauma were included. The best-corrected visual acuity with RGP contact lenses was compared with that of spectacle correction. The factors affecting visual improvement were analyzed, and problems caused by contact lens use were identified.

RESULTS

Twelve eyes of 12 boys were included. The mean best-corrected visual acuity was 0.81 ± 0.29 (LogMar equivalent) with spectacles and 0.47 ± 0.27 (LogMar equivalent) with contact lenses (P < 0.001). Seven of the 12 eyes achieved a >2 line increase in visual acuity with contact lens correction as compared with that using spectacle correction. The mean astigmatism in eyes that achieved this improvement in vision was 5.45 ± 1.6 diopters, whereas the mean astigmatism in the eyes that did not improve was 2.6 ± 1.2 diopters, which was statistically significant (P = 0.009). No other factors (age, corneal scar location/density, grade/zone of injury, lens status, and occlusion) seemed to affect visual improvement with contact lenses. The mean follow-up duration was about 15 months during which 91% of the patients continued their contact lens usage.

CONCLUSIONS

RGP contact lenses offer a useful refractive treatment alternative in traumatized eyes of children. Eyes with high degrees of astigmatism were found to benefit the most. RGP contact lenses were found to be well tolerated in this population.