No abstract

Purpose To review the published literature regarding cataract surgery in keratoconus (KCN) patients with emphasis on challenges encountered during intraocular lens (IOL) power calculation and their solutions. Methods A literature review was performed to investigate all the relevant articles on the advancements of IOL calculations in KCN patients. Results Cataract surgery in keratoconic eyes can improve patients' refraction, and proper patient selection and IOL calculation methods are necessary to get the best results. The main problem in KCN patients is unreliable biometric measurements. It is more difficult to make conclusions in more advanced keratoconic corneas, as the steep keratometric values in these eyes will result in the selection of a low-power IOL. Presence of a low-power IOL will yield in extreme postoperative hyperopia, and IOL exchange might be mandatory. In cases in which keratoplasty may be needed in the future, contact lens fitting can help surgeons make a better decision preoperatively. Axial length (AL) measurements may have better repeatability and reproducibility than keratometry (K) readings in keratoconic eyes. SRK II formula may provide the most accurate IOL power in mild KCN. There is still not a comprehensive consensus of which formula is the best one in moderate and severe KCN, as the literature is limited in this subject. Conclusions Various methods of IOL power calculation optimization and recommendations may hold the key to improve surgical outcomes in keratoconic eyes. There are multiple sources of biometric error in KCN patients, hence IOL calculation methods may not be as efficient as expected in these eyes.

No abstract

Susceptibility to ciprofloxacin and imipenem was found in all isolates tested. Despite appropriate treatment, visual and anatomic outcomes were generally poor.

Purpose To evaluate the role of methotrexate (MTX) injected into the silicone oil at the end of pars plana vitrectomy for advanced proliferative diabetic retinopathy (PDR). Methods In this prospective comparative interventional study, eyes with severe diabetic tractional macular detachment or combined tractional/rhegmatogenous retinal detachment were included. Standard 20 gauge pars plana vitrectomy, and retinal reattachment was performed. In the case group, 250 μg MTX was injected into the silicone oil at the end of surgery. The rate of retinal re-detachment associated with fibrovascular proliferation or proliferative vitreoretinopathy (PVR) was assessed. Results Overall, 38 eyes of 35 patients (19 cases and 19 controls) were studied. The two groups were matched for age, sex, preoperative visual acuity, and the type of surgery (vitrectomy alone vs combined phacoemulsification/vitrectomy). Retinal re-detachment with fibrovascular proliferation or PVR occurred in seven eyes (36.8%) in the MTX group and eight eyes (42.1%) in the control group (P = 0.74). Mean change in visual acuity was 0.04 ± 0.71 and 0.39 ± 0.70 logMAR in the MTX and the control group, respectively (P = 0.14). The rate of improvement or worsening of visual acuity was similar between the two groups (P = 0.51 and P = 0.12). Conclusion Intra-silicone injection of MTX at the end of vitrectomy for retinal detachment associated with severe PDR did not reduce the risk of postoperative retinal detachment due to the fibrous or fibrovascular proliferations.

In this 6-month follow-up study, intravitreal injection of 400 μg methotrexate had no significant effect on corneal endothelial cell measurements performed by specular microscopy.

No abstract

Purpose: To determine the effect of a single-segment intrastromal corneal ring segment (ICRS;Intacs-SK) on early keratoconus (KCN) or pellucid marginal degeneration (PMD).Methods: It is a prospective interventional study. One-hundred-twenty-four eyes (99 patients) with KCN and 36 eyes (26 patients) with PMD at early stage (the maximum keratometric reading less than 55 diopters) were included to ICRS implantation using femtosecond laser at a tertiary university-based hospital and a private outpatient center. The uncorrected distance and spectacle-corrected visual acuity (UDVA and SCDVA), manifest spherical and cylindrical refractions, and keratometry indices were measured preoperatively and postoperatively, 1 week, 2 and 6 months.Results: One week after surgery, signi cant improvements were observed in UDVA, SCDVA, cylinder and keratometry readings of both KCN and PMD groups (all P<0.05) with no signi cant changes afterwards. No signi cant change occurred in the sphere refraction of PMD group (P=0.10) in contrast to KCN group (P<0.001). Corneal irregularity of KCN group in central 3 and 5 mm zones increased at 1 week (both P<0.001) and then continued to decrease up to 6 months. However, the corneal irregularity of PMD group had signi cant reduction only at 1 week in 5-mm zone (P=0.02) and 2 months in 3-mm zone (P=0.01) postoperatively. The nal e cacy indexes were 1.44±0.71 and 0.87±0.40 in KCN and PMD groups, respectively. Conclusion: Visual acuity and keratometry values reached stability at 1 week, after one-segment Intacs-SK implantation in KCN and PMD groups. The short-term e cacy of the procedure was more in early KCN compared to early PMD.