Improvement of Vision and Ocular Surface Symptoms With a Scleral Lens After Microbial Keratitis

Visual rehabilitation with mini scleral contact lenses in scarred corneas

PURPOSE

To present a case series of patients with corneal scars who were successfully fitted with mini scleral contact lenses (mSCL).

METHODS

Case series study.

RESULTS

Six eyes of six patients with corneal scars were fitted with mSCLs. All scars were situated in the visual axis within the scotopic pupillary zone. The sizes of the scars varied, with the smallest being confined to a central corneal area (case 5) and the largest covering the entire visual axis (case 2). In addition to compromising corneal transparency, these scars also induced significant corneal irregularities, especially in cases 1, 3, and 4. The average corrected distance visual acuity (CDVA) with spectacles was 20/80, with a range of 20/200 to 20/40. With the use of mSCLs, CDVA improved to an average of 20/25, ranging from 20/40 to 20/16. The mean visual acuity improvement observed was five optotype lines, with a range of 3 to 7 lines.

CONCLUSION

Corneas with scars often exhibit increased higher-order aberrations (HOA), and affected patients not only experience reduced vision but also suffer from seriously reduced optical quality and optical phenomena such as photophobia. Utilizing mSCLs in such individuals can significantly enhance visual acuity and improve optical side effects resulting from corneal opacity and irregularity.

Prospective assessment of corneal biomechanical properties and intraocular pressure after scleral lens wear: A 12-month follow-up study

PURPOSE

To investigate the long-term influence of scleral lens (SL) wear on corneal biomechanical properties and intraocular pressure (IOP) in irregular and regular corneas. Secondary goal comprised evaluate the fluid reservoir (FR) thickness overtime and correlate it with the changes in corneal biomechanical parameters and IOP.

METHODS

Seventy (70) eyes with irregular corneas (IC Group) and 21 eyes with regular corneas (RC Group) were fitted with 16.4 mm SL and wore the lenses for 12 months. Corrected IOP (IOPcc), Goldmann equivalent IOP (IOPg) and corneal biomechanical parameters (Corneal Hysteresis (CH) and Corneal Resistance Factor (CRF)) were measured with Ocular Response Analyzer. Slit lamp images were analyzed with ImageJ software to assess FR thickness overtime. Measurements were taken at lens dispensing visit prior lens wear (LDV1) and after 60 min of lens wear (LDV2) and at 1, 6 and 12-month follow-up visits. Measurements were done immediately after lens removal.

RESULTS

There were no statistically significant differences on IOPcc, IOPg, CRF and CH over the follow-up visits in both groups. Mean IOPcc and IOPg fluctuations overtime were clinically insignificant and below 1 mmHg in both groups. IOPg, CH and CRF were significantly lower on IC Group (p < 0.001), although no statistically significant differences were found between groups for IOPcc. Regarding FR thickness, statistically significant differences were found over the follow-up on both groups, with a mean decrease of 186.29 µm on IC Group and 175.32 µm on RC Group (p < 0.001). Statistically significant moderate to high negative correlations between FR and IOPg, CRF and CH were found only in the RC Group.

CONCLUSIONS

Long-term SL wear was not associated to changes in corneal biomechanical parameters neither on IOP as measured after lens removal. Besides IOP measurement without SL removal, more studies are needed to investigate the potential relationship with SL fitting characteristics (namely FR thickness).

Evidence of Contact Lenses for Vision Rehabilitation in Corneal Diseases: A Review

OBJECTIVES

To evaluate the efficacy and safety of contact lenses (CL) as a therapeutic option for patients affected by a corneal disease and to determinate which is the best lens modality for each disease.

METHODS

A literature review using PubMed was performed. All relevant articles published during the last 15 years have been included.

RESULTS

Various studies point to CL as the best therapeutic option for some corneal diseases and even as an alternative to surgery in some cases. After fitting, patients show an improvement in their functional vision and quality of life, in some cases being able to drive or work again.

CONCLUSIONS

There is a lack of scientific evidence to determine which lens modality is suitable for each corneal pathology. Currently, according to this review, the reason for choosing between the different options depends on the severity of symptoms, and it is worth mentioning that scleral lenses seem to be the best option in advanced stages of disease. However, the expertise of professionals is also an important factor at the time of choosing a particular CL modality. Standardized criteria are still necessary for correct selection of lens modality for a correct management of the disease.

How Can We Best Measure the Performance of Scleral Lenses? Current Insights

Scleral lenses (SLs) present several unique advantageous characteristics for patients. As these lenses are mainly fitted in severely diseased eyes, a thorough evaluation of the ocular surface before and after SL fitting and the on-eye SL fitting evaluation are essential and help minimize potential physiological complications. This review will explore the current and emerging techniques and instrumentation to best measure SL performance ensuring optimal lens fitting, visual quality, comfort and physiological responses, highlighting some potential complications and follow-up recommendations. A single physician could perform the great majority of evaluations. Still, the authors consider that the assessment of SL fitting should be a collaborative and multidisciplinary job, involving contact lens practitioners, ophthalmologists and the industry. This publication has reviewed the most up-to-date work and listed the most used techniques; however, the authors encourage the development of more evidence-based recommendations for SL clinical practice.