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PurposeTo describe a technique which exploits the transparency and toughness of the pre-Descemets layer (Dua's layer) to safely perform deep anterior lamellar keratoplasty (DALK) and phacoemulsification at the same time.MethodsThree DALK procedures combined with phacoemulsification were performed by the same surgeon using the big-bubble (BB) technique at the Research Institute of Ophthalmology, Cairo, Egypt. In two cases a type-1 BB, baring Dua's layer, was achieved and in one case a type-2 BB, baring the Descemet's membrane (DM), was achieved. The surgeries were video recorded and photo slit-lamp images were taken in the follow-up visits.ResultsDALK with phacoemulsification and lens implant was carried out in both patients where a type-1 BB was achieved. At a follow up of 18 months (first case) and 6 months (second case), the best corrected vision was 6/12 for each. In the case where a type-2 BB was achieved, the DM ruptured during injection of viscoelastic prior to capsulorhexis. The procedure was converted to a penetrating keratoplasty without phacoemulsification.ConclusionWhen a type-1 BB is achieved simultaneous DALK and phacoemulsification can be safely accomplished. Dua's layer allows a clear view for performing phacoemulsification with the added benefit of its toughness, which can maintain a stable anterior chamber for cataract surgery. This should not be attempted when a type-2 BB is achieved. [ABSTRACT FROM AUTHOR]

AimsIn a previous study, we proposed that corneal topography performed 30-40 min after the initial suture removal can identify the next set of sutures requiring removal, for the treatment of post-keratoplasty astigmatism. The aim of this study was to evaluate the effect of removing subsequent sets of sutures at the same sitting.Methods10/0 nylon interrupted sutures were placed, to secure the graft-host junction, at the time of keratoplasty. Topography was performed using Pentacam (Oculus) before suture removal. The sutures to be removed in the steep semi-meridians were identified and removed at the slit-lamp biomicroscope. Topography was repeated 30-40 min post suture removal, the new steep semi-meridians determined, and the next set of sutures to be removed were identified and removed accordingly. Topography was repeated 4-6 weeks later and the magnitude of topographic astigmatism was recorded. A paired-samples t-test was used to evaluate the impact of selective suture removal on reducing the magnitude of topographic and refractive astigmatism.ResultsTwenty eyes of 20 patients underwent sequential selective same-day suture removal (SSSS) after corneal transplantation. This study showed that the topographic astigmatism decreased by about 46.7% (3.68 D) and the refractive astigmatism decreased by about 37.7% (2.61 D) following SSSS. Vector calculations also show a significant reduction of both topographic and refractive astigmatism (P<0.001).ConclusionSSSS may help patients to achieve satisfactory vision more quickly and reduce the number of follow-up visits required post keratoplasty. [ABSTRACT FROM AUTHOR]

AimPost-keratoplasty astigmatism is managed by topography-guided suture removal. This can take several weeks until satisfactory reduction in astigmatism is achieved. This study aimed to assess whether topography performed 30–40 min after the removal of the first pair of sutures would predict the next set of sutures requiring removal.MethodsA prospective study of 20 consecutive penetrating keratoplasty patients was carried out. Topography guided suture removal in the steep meridian was carried out. Topography was repeated after 30–40 min and 4–6 weeks later. The tight sutures requiring removal were identified for each occasion and compared. The difference was considered insignificant if the axes of sutures requiring removal was <22.5°. Paired t-test and χ2 were performed for statistical analysis.ResultsIn 85% of individuals, the 30–40 min topography gave an accurate indication of the next pair of sutures requiring removal. The difference in mean astigmatism at 30–40 min post suture removal (4.37±2.08 D) and at 4–6 weeks (4.24+1.97 D) was not significant (P=0.150). However, the difference between vector-corrected change of topographic astigmatism at 30–40 min after suture removal and at 4–6 weeks (1.72 D) was significant (P<0.001). Improved best-corrected visual acuity was seen in 50% of patients.ConclusionThis study showed that corneal topography performed 30–40 min after suture removal can identify the next set of sutures requiring removal. This can be used as a guide to remove more sutures at the same visit, thereby expediting post-keratoplasty visual rehabilitation and reducing the number of follow-up visits. [ABSTRACT FROM AUTHOR]

Background: Unlike the immune privilege enjoyed by low-risk corneal grafts, high-risk corneal grafts experience rejection rates comparable to liver and kidney transplants. Systemic immunosuppression reduces the risk of rejection in high-risk corneal grafts. Methods: Systemic tacrolimus, a specific I cell inhibitor, was used at a mean daily dose of 2.5 mg to immunosuppress 43 patients undergoing high-risk corneal transplantation. Immunosuppression was continued for a period of 18-24 months after the high-risk corneal graft. Results: During a mean follow-up period of 33.7 months, clarity of the graft was maintained in 65% of patients. Eight patients experienced rejection episodes while on tacrolimus, and this led to graft failure in five patients. Conclusion: Tacrolimus is relatively safe and effective in reducing rejection and prolonging graft survival in patients with high-risk keratoplasty compared with other series where similar immunosuppression was not used. [ABSTRACT FROM AUTHOR]

Aims: To determine the frequency of choroidal detachment (CD) in eyes with non-traumatic corneal ulcer perforation and, also, to assess the efficacy and safety of cyanoacrylate glue in sealing corneal perforations. Methods: 18 eyes of 17 patients were studied. Inclusion criterion was any patient with a non-traumatic perforated corneal ulcer. All patients had a thorough history taken and complete ophthalmic examination including B-scan ultrasonography. Patient demographics, presence of CD, and efficacy of corneal gluing were assessed. Results: Eight of the 18 eyes (44%) were documented to have a CD. Among perforations of >2 mm2, six eyes (75%) were documented to have CD compared with two eyes (20%) with perforations of ⩽2 mm2 (p=0.054). No correlation could be determined between perforation duration and incidence of CD. Of the 15 eyes that underwent gluing, there were 13 successes (87%) and two failures (13%). Within the successes four patients (27%) required re-gluing because of infection (one patient) or progression of melt and glue loosening (three patients). Failure was the result of severe progression of melting (one patient) and a very large perforation (one patient). Conclusion: Choroidal detachment following corneal ulcer perforation is common and is more likely in larger corneal perforations. Preoperative B-scan should be considered in cases of large corned perforations requiring therapeutic keratoplasty to document choroidal detachment, which if large may require drainage. Cyanoacrylate glue is an effective and safe method for sealing small corneal perforations. A vigil must be maintained for infection while the glue and bandage contact lens are in situ. [ABSTRACT FROM AUTHOR]

Aims: To determine the epithelial proliferative capacity of organ cultured limbal tissue and correlate this with various donor and eye banking factors. Methods: 24 corneoscleral limbal (CSL) rims left over from penetrating keratoplasty were split in half and set up as in vitro explant cultures. Corneal epithelial proliferative potential (CEPP) was assessed by the number of "cycles" of growth achieved before explants underwent exhaustion and failure to generate an epithelium to subconfluence. The dependence of CEPP on the age of the donor, time of death to enucleation, time of enucleation to organ culture, and time in organ culture in the eye bank was determined. Results: CSL rims were capable of up to four cycles of culture with a wide variation between tissue samples. Of the various factors examined, death to enucleation time was the only statistically significant factor affecting the CEPP (regression coefficient: -0.062 (cycles/hour), Cl -0.119 to -0.004, p = 0.037). Time in organ culture had little effect on CEPP. Conclusions: Preselected organ cultured CSL rims from eye banks may offer a viable alternative tissue source for use in allo-limbal transplantation. [ABSTRACT FROM AUTHOR]

Background/aim: To compare intraocular pressure (IOP) measurements taken by the Goldmann applanation tonometer, the Tono-Pen and the ocular blood flow pneumotonometer in eyes with varying central corned thickness (CCT) due to penetrating keratoplasty (PK), keratoconus (KC), and Fuchs' endothelial dystrophy (FED). Methods: IOP was measured with the Goldmann applanation tonometer, Tono-Pen XL, and OBF pneumotonometer in 127 eyes with the following corned abnormalities. There were 56 eyes that had undergone PK, 37 eyes with KC, and 34 eyes with FED. CCI was measured using an ultrasound pachymeter after IOP determinations had been made. Results: Mean IOP measurements in all three patient groups were significantly higher when measured by OBF pneumotonometer. Linear regression analysis showed that patients with FED had a significant increase in IOP with increasing CCT of 0.18 mm Hg/10 μm using the Goldmann tonometer, 0.15 mm Hg/10 μm with the Tono-Pen, and 0.26 mm Hg/10 μm with the OBF pneumotonometer. In patients with KC and after PK, linear regression analysis did not show a significant effect of CCT on IOP. A multivariate linear regression model controlling for age, sex, graft size, and patient group, showed that the effect of CCT on IOP for Tono-Pen (0.13 mm Hg/10 μm CCT) and Goldmann (0.14 mm Hg/10 μm CCT) were significantly lower than for the OBF pneumotonometer (0.26 mm Hg/10 μm CCT). Conclusion: This study found that mean IOP measurements using the OBF pneumotonometer were significantly higher than those made using the Goldmann applanation tonometer or Tono-Pen in eyes with a variety of cornel pathologies. The OBF pneumotonometer was found to be mast affected by variation in CCT. For all three instruments, the relation between IOP and CCT depended on the corned pathology and was greatest for FED. [ABSTRACT FROM AUTHOR]

Aim: To determine the immunohistochemical characteristics of putative corneal epithelial stem cells remaining on limbal explants maintained in culture. METHODS: Human limbal explant cultures were generated from 25 residual corneoscleral donor rims following penetrating keratoplasty. Serial sections of these explants were studied using immunohistochemical techniques with a panel of antibodies, on day 0 and 1, 2, and 3 weeks. RESULTS: The number of epithelial cells expressing cytokeratin 19 and vimentin increased with duration in culture, while the number of cells expressing cytokeratin 3 decreased. Connexin 43 expression was lost by 1 week in culture. p63 was expressed by cells that had migrated around the explant and the number of p63 positive cells decreased with longer duration in culture. The explants were initially negative for Ki67, but the epithelial cells were positive at 1 week, and expression of Ki67 was progressively lost with increasing duration in culture. The initial uniform staining of the epithelium for epidermal growth factor receptor and alpha enolase remained unchanged at 3 weeks. CONCLUSIONS: There is an expansion of less differentiated (cytokeratin 3 negative and CK19/vimentin positive) epithelial cells on corneoscleral explants maintained in culture for 3 weeks. The pattern of expression of p63 noted in this study does not support the suggestion that it is a marker of limbal stem cells. The decline in p63 and Ki67 expression among the epithelial cells of the cultured explant button implies that as the epithelial sheet outgrowing from the explant button reaches confluence, the proliferative status of the cells remaining on the explant button declines. These findings are of clinical relevance as explants of limbal tissue are used in limbal stem cell transplantation. There is no information available to date on the fate of epithelial cells on such explants. This study provides some insight into this and suggests that an expansion of the stem cell pool or its progeny may occur in limbal explants. [ABSTRACT FROM AUTHOR]