• Certain characteristics including increased vascularity may be a risk factor for recurrence of pterygium following surgery, reports research published online in the journal Cornea.¹ Researchers in Korea collected data on clinical and demographic variables of 149 subjects including length, width, area and vascularity of pterygium and age and sex of patients. Anterior segment photos were taken prior to the procedure, and patients were followed up with at one year postoperatively. Recurrence rate was measured at 18.8% of the patients, with univariate analysis demonstrating that relative length and width of the pterygium and degree of vascularity were all correlated with the trend. Multivariate analysis, however, demonstrated only higher vascularity was correlated with recurrence. As such, automated image analysis of anterior segment photos could assist with determining which patients might develop pterygium again, the researchers concluded.  

1. Han SB, Jeon HS, Kim M, et al. Risk factors for recurrence after pterygium surgery: an image analysis study. Cornea. 2016. [Epub ahead of print.] 

• Soft contact lens wearers with dry eye symptoms may also exhibit reduced tear menisci, reports a study in the May 2016 issue of Eye and Contact Lens.¹ A reduction in tear volume is one of the common factors associated with ocular surface disease; indeed, previous research has indicated there are more abnormal corneal nerve morphologic changes in patients with the aqueous tear deficiency form of dry eye. However, to date no research has examined whether symptomatic contact lens wearers have had a similar reduction in corneal nerve density due to reduced tear volume. In this study, scientists in China found that upper and lower tear menisci height and area were significantly lower in patients who wore soft contact lenses, compared with those who did not. Interestingly, this effect occurred specifically in the midperipheral area of the cornea. 

1. Hu L, Chen J, Zhang L, et al. Effects of long-term soft contact lenses on tear menisci and corneal nerve density. Eye Contact Lens. 2016 May;42(3):196-201.

• A study investigating corneal densitometry and higher-order aberrations (HOAs) one year post-transplantation of Bowman’s layer found that corneal HOAs decreased for both anterior and posterior corneal surfaces following surgery, while corneal backscattering increased. Neither trend correlated with alterations in corrected distance visual acuity, however. These results, published online in the journal Cornea, suggest further research involving larger populations with patient-subjective visual outcomes and contrast sensitivity analysis is needed to help further explain the effect of corneal backscattering on optical quality.¹

1. Luceri S, Parker J, Dapena I, et al. Corneal densitometry and higher order aberrations after bowman layer transplantation: 1-year results. Cornea. 2016. [Epub ahead of print.] 

Surgical Trends
A national study from Switzerland suggests the number of keratoconus-related corneal transplants has decreased in the last 10 years, while lamellar techniques are being increasingly performed. Furthermore, among anterior lamellar keratoplasty techniques, maximal depth DALK is the most prevalent keratoplasty. Frequency of penetrating keratoplasty (PKP) is expected to remain stable.¹

1. Godefrooij DA, Gans R, Imhof SM, Wisse RPL. Trends in penetrating and anterior lamellar corneal grafting techniques for keratoconus: a national registry study. Acta Ophthalmologica. 2016 Apr 7. [Epub ahead of print.]