Predictability of Sirius dual-scanning corneal tomography in the measurement of corneal power after photorefractive surgery.

Determining an accurate central corneal power (K) measurement is crucial for calculating the intraocular lens power in patients who are undergoing cataract extraction. The ideal method for measuring K is to use a device that works independently of the refractive surgery information. The Scheimpflug camera system offers a promising means of measuring the true corneal power after keratorefractive surgery. In this study, we investigated the accuracy of this system in measuring central corneal power after photorefractive corneal surgery by comparing it to the theoretically derived central corneal power by history method. A total of 120 eyes of 65 (35 females and 30 males) patients were included in this study. The mean change of refraction at the spectacle plane was 3.75 D, whereas the mean change of refraction at the corneal plane was 3.37 D. Using the Sirius dual-scanning corneal tomography, the mean change in corneal power was 3.96 D. No significant differences were detected between the mean post-operative corneal power measured by the Sirius tomographer and the mean change in refraction at the corneal plane calculated clinically (P = 0.076) and the correlation was found to be high (0.913). This study suggests that Sirius dual-scanning corneal tomography offers high predictability when measuring the central 5 mm corneal power in patients who have had myopic corneal photorefractive surgery.

Secondary Intraocular Lens Implantation After Simultaneous Penetrating Keratoplasty and Cataract Extraction for Coexisting Corneal and Lens Opacities.

PURPOSE: To report the results of a new approach to the 2-stage surgical management of coexisting visually significant corneal opacities and cataract. METHODS: A retrospective analysis of eyes with corneal opacities and cataract that were surgically treated with simultaneous penetrating keratoplasty and cataract surgery, followed by secondary intraocular lens (IOL) implantation after removal of corneal sutures, was conducted. The parameters used for assessment were the following: mean percentage of graft endothelial cell loss after IOL implantation, deviation of the postoperative mean spherical equivalent from the target refraction, and mean uncorrected distance visual acuity (UDVA). RESULTS: Twenty-nine eyes were included in the study. The mean baseline UDVA was 1.94 ± 0.46, and the mean baseline best-corrected distance visual acuity was 1.56 ± 0.42. The mean interval between the 2 surgical interventions was 13.3 ± 2.2 months. Just before secondary IOL implantation, the mean endothelial cell density was 2198 ± 311 cells. The mean percentage of corneal endothelial cell loss was 7.3% at 6 months after IOL implantation (P = 0.16). Before IOL implantation, the mean spherical equivalent was +11.75 ± 3.38 D. After IOL implantation, the mean spherical equivalent improved to -0.19 ± 0.93 D (P = 0.003) at 6 months. The mean UDVA improved to 0.34 ± 0.18 (P = 0.017), whereas the mean corrected distance visual acuity improved to 0.18 ± 0.29 at 6 months (P = 0.016). All grafted corneas maintained their clarity until the final follow-up visit. CONCLUSIONS: Postponing IOL implantation some months after simultaneous penetrating keratoplasty and cataract extraction has a negligible effect on the corneal graft endothelium and achieves near postoperative target refraction with significant improvement in UDVA.

Validity of Specific Immunoglobulin E Assay in Tear Film for Detection of Allergens Inducing Different Types of Allergic Conjunctivitis.

This is a prospective interventional comparative study which aimed to investigate correlation between tear film allergen specific IgE levels and the skin prick test in diagnosing different types of allergic conjunctivitis. One hundred twenty patients with allergic conjunctivitis were included in this study and were classified into 4 groups based on the type of allergic conjunctivitis. Patients were subjected to skin prick test (SPT). Micro capillary method was used to collect tear samples for the quantitative assessment of specific IgE by Immune blot assay. The most common allergens were mixed mould, mixed pollen, and mixed mite. The results of tear film specific IgE in detection of allergens were evaluated against the SPT. The Receiving Operating Characteristic Curve (ROCs) revealed that tear film allergen-specific IgE specificity was 100% and sensitivity was 75%-100% to the three common allergens in the 4 studied groups. The correlation between tear's specific IgE and skin prick test was statistically significant for pollen, mite, and mould allergens in patient with SAK (r = 0.821, P ˂ 0.001 for pollen, r = 0.964, P ˂ 0.001 for mite, and r= 0.811, P ˂ 0.02 for mould ), PAC (r = 0.851, P ˂ 0.001 for pollen, r = 0.826, P ˂ 0.001 for mite, and r= 0.861, P ˂ 0.001 for mould) and VKC (r = 0.802, P ˂ 0.001 for pollen, r = 0.894, P ˂ 0.001 for mite, and r= 0.861, P ˂ 0.061 for mould). In patient with AKC, the correlation was statistically significant for only mite allergen (r = 1, P ˂ 0.001). We concluded that Tear film specific IgE test can be considered as a good alternative to skin prick test in diagnosis of the causative allergens in allergic conjunctivitis.

Retropupillary iris-claw intraocular lens for the surgical correction of aphakia in cases with microspherophakia.

PURPOSE: This study aimed to evaluate the safety and efficacy of retropupillary fixation of an iris-claw intraocular lens (IOL; Verisyse polymethyl methacrylate IOL, Abbott Medical Optics [AMO], Netherlands) for the surgical correction of aphakia in microspherophakic eyes without sufficient capsular support. DESIGN: This was a prospective, interventional, noncomparative case series. METHODS: This interventional case series comprised 17 eyes of 9 microspherophakic patients. Retropupillary fixation of the Verisyse iris-claw IOL (AMO) was performed in all cases. The surgical time was measured. Corrected distance visual acuity, astigmatism, intraocular pressure (IOP), tissue reaction, pigment dispersion, and stability of the IOL were studied 1 day, 3 days, 1 week, 2 weeks, 1 month, and 6 months postoperatively. RESULTS: Eight patients had familial microspherophakia and one patient had Marfan's syndrome. Eighty-two percent of the cases achieved a visual acuity of 0.3 or better. There was no significant postoperative inflammatory reaction. Transient elevation of IOP was recorded in two cases in the 1st week only. One IOL developed disengagement of one of the haptics from the iris and was successfully re-engaged. All the other IOLs were well centered and stable. The mean surgical time was 18.0 ± 4.5 min. CONCLUSIONS: Retropupillary fixation of an iris-claw IOL is a safe and effective procedure that provides early visual recovery. It is also a time-saving method for correcting aphakia in microspherophakic eyes without sufficient capsular support.