João Baptista Nigro Santiago Malta

Recurrent ectasia in corneal grafts and outcomes of repeat keratoplasty for keratoconus

Aim: To analyse cases of recurrent ectasia in donor corneas after penetrating keratoplasty (PK) for keratoconus. Methods: Data on 25 patients (36 eyes) with recurrent ectasia were retrospectively analysed in this study. The main outcome measures were time to development of recurrent ectasia after first PK for keratoconus, change in keratometric sphere and astigmatism between final suture removal and development of recurrent ectasia, status of regrafts for recurrent ectasia, and histopathology of grafts excised for recurrent ectasia. Results: The age at first PK was 32.6 (SD 8.5) years, and ectasia developed 21.9 (7.0) years after PK. The mean keratometric sphere and cylinder increased by 4.2 D and 3.0 D, respectively, between final suture removal and diagnosis of recurrent ectasia. Ectasia was often preceded by thinning without bulging of the recipient stroma at the graft–host junction. Fifteen eyes (13 patients) were regrafted for recurrent ectasia, and histopathology of the excised grafts showed changes characteristic of keratoconus in the donor tissue in all cases. Two regrafts (two eyes of one patient) developed ectasia again, with one eye requiring a third PK to improve vision. Conclusions: Recurrent ectasia was diagnosed on average two decades after PK. Ectatic changes were often bilateral and occasionally recurred after regrafting, suggesting that host cellular and/or biochemical factors may be responsible. Repeat PK for recurrent ectasia is successful in the intermediate term.

Treatment of ocular graft-versus-host disease with topical cyclosporine 0.05%.

Purpose: To evaluate the efficacy of topical cyclosporine-A 0.05% (CsA) in the treatment of dry eye syndrome in ocular graft-versus-host disease after bone marrow transplantation (BMT) of hematopoietic stem cells. Methods: One-hundred five patients were enrolled in a retrospective, comparative, interventional case series. Eighty-one patients received topical CsA starting 1 month before BMT (treatment group), and 24 patients did not receive CsA until at least 6 months after the transplantation (control group). Mean follow-up time was 17.5 ± 11.0 months (range: 6.0-49.0 months). Clinical history, ocular surface disease index questionnaire, slit-lamp examination, lissamine green and fluorescein staining of the ocular surface, tear breakup time, and Schirmer test with topical anesthesia were obtained to create a composite dry eye-grading score. Results: Dry eye symptoms were significantly more severe in the control group at 3 months, 1 year, and 2 years (P < 0.05). There was no correlation with type of stem cell transplant (related vs. unrelated donor), presenting indication for BMT, or concurrent systemic immunosuppressive medications. Conclusions: Pre-BMT initiation of topical CsA may reduce the inflammatory response in the lacrimal glands that may be responsible for the development of post-BMT keratitis sicca.

Femtosecond Laser-Assisted Keratoplasty: Laboratory Studies in Eye Bank Eyes

Purpose: To optimize the surgical technique for performing femtosecond laser-assisted keratoplasty (FLAK) using the IntraLase FS® to cut both recipient and donor cornea buttons in eye bank globes. Methods: FLAK was performed in six globes and six corneoscleral buttons for each of the following trephination patterns: top hat, mushroom, tongue-groove, and vertical. Manual trephination was performed as control. The wound integrity was tested in incisions closed with 8 sutures, 8 sutures with fibrin adhesive, and 16 sutures by measuring the intraocular pressure required to produce graft-host wound leakage (IOPL). Light microscopy (LM) and scanning electron microscopy (SEM) were performed to assess cut surface quality and graft-host interface regularity. Results: Mushroom and top hat FLAK had significantly higher IOPL than vertical or manual trephination (p < 0.0001) for wounds closed with 16 sutures. There was no difference in IOPL between top hat, mushroom, and tongue-groove FLAK in wounds closed with 8 sutures with fibrin adhesive (p > 0.75). LM and SEM demonstrated cut surfaces with good quality and smooth edges. Conclusions: These preliminary studies show that FLAK produces precise trephination cuts of superior wound strength and stability to that of manual trephination. Adjuvant fibrin glue may further improve wound integrity.

Antibacterial properties of cyanoacrylate tissue adhesive: Does the polymerization reaction play a role?

Purpose: To ascertain if the polymerization reaction also contributes additionally to the antibacterial effects of two commonly used cyanoacrylate tissue adhesives. Materials and Methods: Fresh liquid ethyl-cyanoacrylate (EC) and N-butyl-cyanoacrylate (BC) adhesives were applied onto 6-mm sterile filter paper discs. In the first group, the adhesive-soaked discs were immediately placed onto confluent monolayer cultures of bacteria, allowing the polymerization reaction to proceed while in culture. In the second group, the adhesive-soaked disc was allowed to first polymerize prior to being placed onto the bacterial cultures. Four types of bacteria were studied: Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, and Pseudomonas aeruginosa. Immediately after the discs were applied, the cultures were incubated at 35° C for 24 h. Bacterial inhibitory halos were measured in the cultures at the end of the incubation period. Results: For EC, exposure of the bacteria to the cyanoacrylate polymerization reaction increased the bacterial inhibitory halos in Streptococcus pneumonia, Staphylococcus aureus and Escherichia coli. For BC, it increased the bacterial inhibitory halos in Staphylococcus aureus and Streptococcus pneumoniae. No inhibitory halos were observed in Pseudomonas aeruginosa. The bactericidal effect was higher in actively polymerizing EC, compared to previously polymerized EC in Staphylococcus aureus, Streptococcus pneumoniae, and Escherichia coli; however, no such differences were observed for BC. Conclusions: The polymerization reaction may also be an important factor in the antibacterial properties of EC and BC.

Wound integrity of clear corneal incisions closed with fibrin and N-butyl-2-cyanoacrylate adhesives

Purpose: To compare the integrity of clear corneal incisions closed with fibrin (Tisseel®) and n-butyl-2-cyanoacrylate (Histoacryl®) tissue adhesives to those closed with conventional sutures. Methods: Four replicate experiments were performed on porcine eyes with each of the following conditions: three limbal clear corneal incision sizes (3.0 mm, 4.5 mm, and 6.0 mm), three incision closure techniques (fibrin adhesive, n-butyl-2-cyanoacrylate adhesive, and 10-0 interrupted nylon sutures)—1, 2, and 3 sutures at the 3.0-mm, 4.5-mm, and 6.0-mm incision sizes, respectively. Wound integrity was then measured by elevating the intraocular pressure of the eye to the point where wound leakage (IOPL) occurred. Two-way repeated measures analysis of variance (ANOVA) was used to analyze the IOPL data. Results: Incision closure technique and incision size showed significant interaction in the ANOVA model (p = 0.0008). Fibrin adhesive demonstrated higher IOPL compared to suture closure at the 3.0-mm incision size (p < 0.0001). There was no significant difference in IOPL when comparing wound closure with fibrin adhesive and sutures at the 4.5-mm and 6.0-mm incision sizes (p = 0.52 and p = 0.56, respectively). There was no significant difference between the three closure techniques for the 6.0-mm incisions (p > 0.15). When comparing the wound closure techniques for all incision sizes, the mean IOPL significantly increased in the following order: suture(s), fibrin adhesive, n-butyl-2-cyanoacrylate glue. Conclusions: Fibrin or n-butyl-2-cyanoacrylate tissue adhesive may be used as a more stable alternative to conventional sutures in the closure of clear corneal incisions.

Long-term outcome of combined penetrating keratoplasty with scleral-sutured posterior chamber intraocular lens implantation.

Purpose: To evaluate the long-term outcomes of combined penetrating keratoplasty (PKP) with scleral-sutured posterior chamber intraocular lens (PC-IOL) implantation. Methods: Medical records from patients with aphakic and pseudophakic bullous keratopathy were retrospectively reviewed for preoperative indications and postoperative results of 105 consecutive patients (105 eyes) who underwent combined PKP and scleral-sutured PC-IOL implantation over a 13-year period. Main outcomes measures were graft survival rate, visual acuity, and intraoperative and postoperative complications. Results: The principal indications for PKP were pseudophakic and aphakic corneal edema. Graft survival rates were 97% at 1 year, 91% at 2 years, 75% at 5 years, and 68% at 7 years. Mean postoperative follow-up was 44.8 ± 37.0 months (range 1-156). The best-corrected visual acuity improved at least 1 line on the Snellen chart in 59.0% of the patients, with 42.9% of the eyes achieving acuities of 20/100 or better. Postoperative complications included new glaucoma in 21.4%, worsening of pre-existing glaucoma in 28.6%, cystoid macular edema in 17%, infectious endophthalmitis in 3.8%, and intraocular lens dislocation in 1.9%. No intraoperative complications were encountered. Conclusions: PKP combined with scleral-sutured PC-IOL implantation can achieve acceptable outcomes with a low rate of intraocular lens dislocation, but may be associated with significant short and long-term complications.

Rupture of anterior lens capsule from blunt ocular injury

We report 3 cases of blunt trauma causing rupture of the anterior lens capsule with cataract formation. The injuries were caused by a paintball gun, a ball-bearing air pistol, and an aluminum rivet. In all 3 cases, the anterior capsule tears were central and the posterior capsules and zonules intact; uneventful cataract extraction with implantation of an intraocular lens was performed. The postoperative visual acuities was 20/40 in 1 case and 20/20 in the other 2 cases. We propose that the anterior lens capsule may have been torn by direct contusion from rapid focal indentation of the cornea onto the lens (coup injury) or by a fluid-mechanical, anteriorly directed rebound of the vitreous, bursting open the anterior capsule (contrecoup injury).

Delayed-onset isolated central Descemet membrane blister detachment following phacoemulsification.

We report 2 patients who developed delayed-onset isolated central Descemet membrane (DM) blister-like detachment following phacoemulsification. The detachments were not associated with a DM tear or inadvertent injection of fluid under DM, and no fluid tracks from the periphery were present. When the detachments failed to resolve spontaneously over several months, intracameral air or C(3)F(8) gas was injected. In 1 patient, a therapeutic paracentral puncture in DM was also performed to facilitate escape of the entrapped fluid. Although a small residual detachment (confirmed by optical coherence tomography) remained in both cases, the visual acuity improved to 20/25 in 1 patient and 20/30 in the other. We think these unique focal detachments in DM may be associated with an underlying preexisting weakness in the DM attachment to the stroma.

Femtosecond laser-assisted lamellar keratoplasty

Lamellar keratoplasty consists of transplanting partial-thickness donor cornea onto a complementary recipient bed. Manual lamellar dissection is technically very difficult, time-consuming, and imprecise. Also, the manually-dissected lamellar interface often has topographical irregularities that may optically degrade the best-corrected visual acuity. The femtosecond clinical laser (IntraLase FS Laser, Irvine, CA) is a recent innovation that can be programmed to produce bladeless, precise lamellar cuts at any depth with accompanying trephination cuts for both anterior and posterior lamellar transplantation. Posterior laser cuts may be used to assist in deep lamellar endothelial keratoplasty or Descemets stripping automated endothelial keratoplasty.

Confiabilidade das medidas de espessura central da córnea com Orbscan II e paquímetro ultra-sônico

OBJETIVO: Avaliar a confiabilidade das medidas de espessura central de cornea comparando o Orbscan II com o paquimetro ultra-sonico. METODOS: Foi realizado estudo retrospectivo de 134 olhos, por meio do levantamento de prontuarios de 67 pacientes avaliados entre o periodo de janeiro a junho de 2001. Foram avaliados o sexo, idade, acuidade visual com a melhor correcao, refracao e medidas de espessura central corneal pelo paquimetro ultra-sonico e Orbscan II. Os dados paquimetricos foram submetidos a analise do teste t pareado e as diferencas consideradas significativas se p<0,05. RESULTADOS: Dos 67 pacientes avaliados 34 (50,7%) eram do sexo feminino e 33 (49,3%) eram do sexo masculino. A idade variou entre 20 e 59 anos com media de 32,44 anos (±9,98). A media do equivalente esferico foi de -2,68±2,62, da espessura central corneal avaliada com o Orbscan II foi de 534,81±34,45 e pelo paquimetro US foi de 535,00±29,53 nao havendo diferenca significativa entre os resultados das medidas de ECC (p = 0,8922). O coeficiente de correlacao entre as duas medidas paquimetricas foi de 0,8774, sendo esta uma correlacao forte. CONCLUSAO: A analise de regressao demonstrou que houve alto grau de concordância entre as medidas do paquimetro ultra-sonico e do Orbscan II. O coeficiente de correlacao (0,8774) demonstra que os dois metodos possuem significativa correlacao linear na medida da espessura central da cornea. Desta maneira, na amostra estudada, o Orbscan II apresentou boa confiabilidade, demonstrando ser exame extremamente util em pacientes que necessitam serem avaliados para posterior intervencao refrativa.