Corneal cross-linking for treatment of keratoconus relapse in post-keratoplasty eyes

PURPOSE

Keratoconus relapse after penetrating keratoplasty is a rare condition that may result in severe visual deterioration and corneal graft thinning. Therefore, treatment to stabilize the cornea should be considered. The purpose of this study was to evaluate the safety and efficacy of Corneal Cross-Linking (CXL) in eyes with relapse of keratoconus after penetrating keratoplasty for keratoconus.

MATERIALS AND METHODS

A retrospective review of eyes that developed keratoconus relapse following a penetrating keratoplasty and treated with CXL. The main outcome measures were change in maximal keratometry (Kmax), best-corrected distance visual acuity (BCVA), thinnest corneal thickness (TCT) and central corneal thickness (CCT), and complications.

RESULTS

We identified 10 consecutive eyes of 9 patients. Preoperative median BCVA before the CXL and 1 year after the CXL procedure remained stable (p = 0.68). The median (IQR) of Kmax improved from 63.2 (24.9) D before the CXL procedure to 62.2 (27.1) D at 1 year postoperatively (P = 0.028). Median TCT and CCT also remained with no significant change 1 year after CXL. No complications were noted following the procedure.

CONCLUSION

CXL in eyes with keratoconus relapse after keratoplasty is a safe and effective procedure enabling not only visual stabilization but also might bring keratometry improvement. Routine follow-up after keratoplasty should be performed for early detection of keratoconus relapse and CXL is timely advised when such a relapse is documented.

The Change in Corneal and Conjunctival Sensation Following Pterygium Surgery

BACKGROUND

The cornea is one of the most densely innervated in the body. Pterygium surgery includes removal of the pterygium tissue from the cornea and conjunctiva followed by autologous conjunctival grafting.

OBJECTIVES

To examine the change in corneal and conjunctival sensation post-pterygium surgery.

METHODS

This prospective study included patients with primary pterygium. We collected and analyzed demographic data, visual acuity (VA), refraction, quantified sensation, and corneal tomography. Comparison in sensation in the cornea, conjunctiva, and conjunctival autograft was recorded the day of surgery and at least 6 months postoperatively.

RESULTS

Nine patients participated in the study. Mean follow-up time was 9 months (9  3.3, 6-12.4). No complications were documented during or following surgery and no recurrences were found. Statistically significant increases in corneal sensation in the nasal corneal and in the nasal conjunctival areas were noted by the end of follow-up compared to before surgery (P = 0.05, paired samples t-test). There was a significant correlation between the increase in nasal corneal and conjunctival sensation with improved Schirmer testing outcomes and tear break-up time after surgery (P = 0.05, P = 0.01, Pearson correlation). There was a positive correlation between the changes in nasal corneal sensation after surgery and improved changes in VA (P = 0.02, Pearson correlation).

CONCLUSIONS

We found improvement in sensation 9 months after pterygium surgery, which may be due to reinnervation of the cornea and conjunctival autograft from the neighboring non-injured nerve fibers. Larger studies with confocal microscopy should be conducted for further analysis.

Accelerated Versus Standard Corneal Collagen Crosslinking in the Treatment of Keratoconus: One-Year Results

BACKGROUND

Keratoconus is a non-inflammatory disease characterized by progressive corneal steepening, which leads to decreased visual acuity secondary to high irregular astigmatism.

OBJECTIVES

To compare the one-year outcomes of accelerated vs. standard collagen crosslinking (CXL) in the treatment of keratoconus.

METHODS

A database search of patients who underwent CXL from 2009 to 2017 was conducted at the cornea clinic at Sheba Medical Center. Charts of 99 adult patients (124 eyes) were reviewed. All patients were diagnosed with keratoconus. Main outcome measures were change in keratometry, uncorrected visual acuity (UCVA), and best-corrected visual acuity (BCVA.

RESULTS

We evaluated outcomes in two groups: CXL with standard (3 mW/cm2 for 30 minutes) vs. the accelerated (9 mW/cm2 for 10 minutes) protocol. There were no significant differences between the groups with regard to BCVA, UCVA, and mean spherical equivalent (P =0.83, 0.0519, 0.181, respectively). The corneal thickness in the center and thinnest location were higher in the accelerated group than the in the standard group (P = 0.126). Complication rates did not differ between the two groups.

CONCLUSIONS

Accelerated and standard CXL are both safe and effective techniques. Accelerated CXL confers the added benefit of being a faster procedure to both patients and surgeons.