The N?rlund matrix Nt in the theory of sequence space was firstly used by Wang. In this paper, by using the N?rlund mean Nt and the notion of ideal convergence, we introduce some new sequence spaces cI 0(Nt), cI (Nt), and `I 1(Nt) as a domain of N?rlund mean. We study some topological and algebraic properties on these spaces. Further, some inclusion concerning these spaces are discussed.

Purpose: To assess the outcomes of triangular tarsectomy and limited orbicularis myectomy with lower eyelid retractor plication versus an everting sutures technique for the correction of lower eyelid involutional entropion.Methods: A prospective quasi-study was conducted at two tertiary eye hospitals in Bangladesh between January 2016 and December 2019. Non-probability purposive sampling was used to select patients with lower eyelid involutional entropion. Patients in group A underwent triangular tarsectomy and limited orbicularis myectomy with lower eyelid retractor plication, whereas those in group B received everting sutures. All participants underwent regular follow-up and all surgeries were performed by a single surgeon. Results: A total of 58 patients in whom 60 eyelids were affected by lower eyelid involutional entropion were included in the study. The success rate was higher in group A compared to group B (100% versus 86.7%; p <0.50). Recurrence at a one-year follow-up was noted in only four (13.3%) cases, all of whom were in group B. However, patients in group A experienced a higher frequency of minimal postoperative complications, including short-term pain (83.3%) and ecchymosis (40%). Both approaches to entropion correction were successful in terms of cosmetic outcome. Conclusions: Triangular tarsectomy and limited orbicularis myectomy with eyelid retractor plication should be considered the definitive procedure for the correction of lower eyelid involutional entropion with minimal or no recurrence. However, everting sutures represent a minimally invasive and cost-effective alternative which can be considered for patients with comorbidities or contraindications, those afraid of surgery, and those of low socioeconomic means.