Eccentric lamellar keratolimbal grafts harvested with a manually guided microkeratome

Background: To perform lamellar keratolimbal allograft transplantation in a one- step procedure with a single graft, we investigated the feasibility of harvesting eccentric lamellar keratolimbal grafts from conventionally processed corneoscleral buttons using a manually guided microkeratome in conjunction with an artificial anterior chamber system. Methods: We used the Moria LSK- One microkeratome and the automated lamellar therapeutic keratoplasty ( ALTK) system ( Antony, France). Ten human donor eyes were used to obtain single- piece lamellar keratolimbal grafts. Specimens were processed for light and electron microscopy. Results: Eccentric keratolimbal grafts could be obtained from all human donor buttons. Grafts include a crescent- shaped limbal and a large corneal portion. No visible damage to the limbal region was discernible. Conclusion: Our data show that the LSK- One microkeratome in conjunction with the ALTK system allows harvesting eccentric keratolimbal grafts from donor corneoscleral buttons. Copyright (c) 2007 S. Karger AG, Basel

Lens stem cells may reside outside the lens capsule: an hypothesis

In this paper, we consider the ocular lens in the context of contemporary developments in biological ideas. We attempt to reconcile lens biology with stem cell concepts and a dearth of lens tumors

Comparison of Conjunctival Autografts, Amniotic Membrane Grafts, and Primary Closure for Pterygium Excision

Objectives: The purpose of the study is to determine whether amniotic membrane can be used as an alternative to conjunctival autograft after pterygium excision.Design: A prospective study of amniotic membrane grafts (group A) and primary closure (group B) was compared retrospectively with conjunctival autografts (group C) in patients with pterygia.Participants: Group A included 46 eyes with primary pterygia and 8 eyes with recurrent pterygia, group B had 20 eyes with primary pterygia, and group C consisted of 78 eyes with primary and 44 eyes with recurrent pterygia.Intervention: For the above three different surgeries, the amount of tissue removed was estimated from histopathologic analysis, and the result was evaluated by clinical examination.Main Outcome Measures: Recurrence, survival analysis, and final appearance were compared.Results: In group A, the recurrence rate was 10.9%, 37.5%, and 14.8% for primary, recurrent, and all pterygia, respectively (mean follow-up, II months), These three rates were significantly higher than 2.6%, 9.1%, and 4.9% noted in group C (mean follow-up, 23 months) (P < 0.001, 0.018, and 0.01, respectively). However, the latter recurrence rate was significantly lower than 45% (mean follow-up, 5.2 months) in group B for primary pterygia (P < 0.001), The onset of recurrence was delayed significantly in group C as compared with that of groups A and B.Conclusions: The relatively low recurrence rate for primary pterygia allows one to use amniotic membrane transplantation as an alternative first choice, especially for advanced cases with bilateral heads or those who might need glaucoma surgery later

Does amniotic membrane transplantation improve the outcome of autologous limbal transplantation?

Purpose. To evaluate the additional benefits of amniotic membrane transplantation (AMT) when combined with conjunctival limbal autograft (CLAU) in the treatment of chronic chemical burns. Methods. Thirty eyes of 30 rabbits underwent a chemical burn to create limbal deficiency. Forty-five days later, the animals were randomized into three groups of 10 rabbits each. Eyes from group I were treated with CLAU, group 2 underwent CLAU and AMT, and group 3 served as control without surgery. Corneal vascularization and opacity were documented with external photographs at postoperative days 30, 60, and 90. the rabbits were killed 3 months after surgery, and their corneas divided into two halves. One half was prepared for hematoxylin-eosin and periodic acid-Schiff staining and the other for frozen sections and immunostaining with AM3 (to MUC 5AC mucin) and AE5 (to K3 keratin). Final clinical outcome was also scored using external photographs at the last follow-up examination. Results. After chemical burn, all groups showed similar degrees of conjunctivalization. After transplantation, corneal vascularization was worse in controls at 60 and 90 days (p < 0.001). At 30 days, eyes from group 1 had less corneal opacity (p < 0.05). At 90 days, corneal opacity was worse in controls but the same in groups I and 2 (p < 0.05). At the same time, limbal deficiency was significantly worse in controls (p < 0.05) but similar between groups 1 and 2. Corneal phenotype was present in 70% of the eyes in group 1, 50% in group 2, but in 10% of the controls. Clinical success with clear corneas was significantly more common in groups I and 2 when compared with controls (p < 0.001). Conclusions. CLAU is effective in treating limbal deficiency. the concurrent AMT does not add benefits in this rabbit model of chemical burns.Univ Fed Rio Grande Sul, Hosp Clin Porto Alegre, Ophthalmol Serv, BR-90046900 Porto Alegre, RS, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, São Paulo, BrazilOcular Surface Ctr, Miami, FL USAOcular Surface Res & Educ Fdn, Miami, FL USAUniversidade Federal de São Paulo, Dept Ophthalmol, São Paulo, BrazilWeb of Scienc