Soft Contact Lenses for Irregular Astigmatism After Laser in situ Keratomileusis

Correction of moderate to high refractive astigmatism with extended range toric soft contact lenses in patients with different patterns of astigmatism

PURPOSE

This study aimed to evaluate the visual performance of extended range, toric soft contact lenses (TSCLs) in patients with keratoconus and moderate to high astigmatism with different astigmatic patterns.

METHODS

This was a retrospective, cross-sectional clinical study. Extended range TSCL users with astigmatism ≥3.0 D were included. Cases were categorised into three subgroups, namely regular, irregular (non-keratoconus) and keratoconic based on the topographic pattern of astigmatism. In addition, subjects were subdivided based on the degree of astigmatism.

RESULTS

Fifty five patients (82 eyes) were enrolled, of whom 28 (51%) were female. The mean age was 24.2 ± 7.5 (range: 8-41 years) years. Thirty-six eyes with regular astigmatism (43.9%), 34 eyes with irregular astigmatism (41.5%) and 12 eyes with keratoconus (14.6%) were included. The percentage improvement in visual acuity (VA) was significantly higher with contact lenses compared with spectacles in all groups (p < 0.001), with the highest improvement in subjects with keratoconus (p = 0.03). Twenty six (31.7%), 30 (36.6%) and 26 eyes (31.7%) had moderate (-3.0 to -4.24 D), moderate/high (-4.25 to -5.99 D) and high (≤-6.0 D) astigmatism, respectively. The percentage improvement in VA with contact lenses was statistically significantly higher than for spectacle wear in all groups (p < 0.001).

CONCLUSIONS

This study demonstrated that satisfactory visual outcomes can be obtained with extended range TSCLs in patients having moderate to high astigmatism with different astigmatic patterns.

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.

Contact lens fitting post-laser-in situ keratomileusis (LASIK)

Despite recent advances in refractive surgical procedures a small proportion of patients still achieve sub-optimal results for a variety of reasons. In such cases, contact lenses may provide the only option for visual rehabilitation and restoration of binocular vision post-refractive surgery. The indications for contact lenses post-LASIK may be one, or a combination of the following: *Initial bandage lens for corneal protection. *Residual ametropia--over and under correction. *Irregular astigmatism. * Anisometropia. * Decentred ablation zones. In low powered corrections conventional soft lenses can be fitted in the normal way, giving good levels of acuity. Where there is astigmatism (>0.75 DC) then toric soft contact lenses may appropriate. Rigid lenses may prove to be the only viable option in a number of cases where visual correction is required post-refractive surgery, or in the presence of high levels of astigmatism. Fitting can be more complex however, since a conventional rigid lens cannot follow the shape of both the flattened central cornea and the relatively steeper periphery in higher corrections, as the amount of laser ablation increases. Reverse geometry lenses are indicated where there is a significant difference between the flat central ablated zone and the relatively steeper peripheral cornea. On rare occasions scleral lenses may also be indicated.

Survey of complications and recommendations for management in dissatisfied patients seeking a consultation after refractive surgery

PURPOSE

To review complications associated with and management options for dissatisfied patients seeking a consultation after refractive surgery performed elsewhere.

SETTING

Refractive Eye Surgery Center, The Wilmer Institute, Lutherville, Maryland, USA.

METHODS

In this retrospective review, charts of consecutive dissatisfied patients who sought a refractive consultation between June 1999 and January 2003 after refractive surgery performed elsewhere were reviewed and the following parameters were analyzed: visual acuity (uncorrected and best spectacle corrected), prior manifest refraction, complications, and recommendations. The subjective complaints, complications, and visual acuity were reviewed, and the associated historical or visual risk factors as well as treatment options were analyzed.

RESULTS

One hundred sixty-one eyes in 101 patients with ocular complaints were identified. One hundred thirty-four eyes (83.2%) had had laser in situ keratomileusis; 22 eyes, photorefractive keratectomy; 4 eyes, radial keratotomy; and 1 eye, laser thermokeratoplasty. The most common subjective complaints were blurred distance vision (59.0%), glare and night-vision disturbances (43.5%), and dry eyes (21.1%). The most common complications were overcorrection (30.4%), irregular astigmatism (29.8%), dry eyes (29.8%), glare (26.1%), difficulty with night driving (16.7%), and corneal haze (16.7%). The most common cause identified in eyes with best spectacle-corrected visual acuity worse than 20/40 was irregular astigmatism (10 of 18 eyes [55.5%]). The most common recommendation for management was medical treatment or observation (68.3%). Medical therapies recommended included lubrication, punctal plugs, topical and systemic pharmaceutical agents to modulate ocular surface, spectacles, and contact lenses. Keratoplasty (lamellar or penetrating) was recommended in 4 patients (4 eyes [2.5%]). The diagnoses included corneal ectasia in 3 eyes and severe flap complication with irregular astigmatism in 1 eye. Nine patients (5.6% eyes) required nonkeratoplasty surgery. In other patients, waiting for advances in technology, including wavefront-guided customized retreatment, was recommended.

CONCLUSIONS

A spectrum of complications associated with refractive surgery may result in patient dissatisfaction. Proper patient selection, prevention strategies, and prompt diagnosis and medical or surgical intervention may be beneficial in managing complications and improving patient satisfaction.