Mini-scleral lenses in the visual rehabilitation of patients after penetrating keratoplasty and deep lamellar anterior keratoplasty.

OBJECTIVE: To evaluate fitting feasibility, efficacy, and safety of mini scleral contact lenses in correcting post corneal graft vision. METHODS: Prospective interventional case series, 56 visually unsatisfied post corneal graft eyes of 45 patients were fitted with miniscleral lenses (15.8 mm). Keratometric values, UCVA and BSCVA, fit, best corrected vision with the lens, decision to order lens, comfortable daily wearing time (CDWT), contact lens handling issues, and contact lens related complications were documented. RESULTS: The mean age was 34.6 years (SD: 10.9), ranging from 8 to 63 years. Forty-three eyes had history of full thickness corneal graft, 12 eyes had deep anterior lamellar graft (DALK) and 1 eye had the rotational graft. The mean UCVA was 1.05 logMar (SD: 0.54), ranging from 0.30 to 2.52 logMar. The mean BSCVA was 0.73 logMar (SD: 0.50) ranging from 0.09 to 2.00 which improved to 0.17 logMar (SD: 0.19) with the miniscleral lens. All eyes had ideal (40 eyes) or acceptable (16 eyes) fits. Nineteen patients (23 eyes) ordered their lenses of whom 11 (14 eyes) continued using the lens with a mean follow up time of 21.92 months (SD: 6.8). These patients reported a mean CDWT of 9.62 h/day (SD: 4.5). Five eyes of 4 patients discontinued the lens. Four eyes were lost to follow-up. The main reported barriers for ordering the lenses were economic and handling concerns. CONCLUSION: Miniscleral contact lenses can be considered helpful in the visual management of post corneal graft patients. Other factors may influence the acceptance of the lenses.

Dry eye and its correlation to diabetes microvascular complications in people with type 2 diabetes mellitus.

AIMS: This study was performed to investigate the correlation between dry eye disease and diabetes microvascular complications. METHODS: In this study 243 people with type 2 diabetes were enrolled. Tear osmolarity was measured using tear lab osmolarity system. All of the participants were evaluated for diabetes microvascular complications. The Michigan neuropathy screening instrument was used for detection of peripheral neuropathy, and the albumin/creatinine ratio in a spot urine sample was considered to diagnose diabetic nephropathy. RESULTS: The prevalence of dry eye disease was 27.7%. The mean value for tear osmolarity was 301.97±13.52 mOsm/L. We found a significant correlation between dry eye disease and diabetic retinopathy (P=0.01). However no significant correlation was found between dry eye disease, diabetic neuropathy, and diabetic nephropathy. Dry eye disease was more prevalent in people with proliferative diabetic retinopathy and/or clinically significant macular edema (0.006). In a binary logistic regression analysis model, there was a significant correlation between dry eye disease and retinopathy (OR=2.29, CI=1.16-4.52, P=0.016). In addition, both dry eye and retinopathy had significant correlation with HbA1C. CONCLUSIONS: Dry eye disease is common in people with type 2 diabetes, especially in those with diabetic retinopathy. In addition, it is more prevalent in people who suffer from advanced stages of diabetic retinopathy.

Cell engineering: nanometric grafting of poly-N-isopropylacrylamide onto polystyrene film by different doses of gamma radiation.

Poly-N-isopropylacrylamide was successfully grafted onto a polystyrene cell culture dish and γ-preirradiated in air. In this study, the effect of a γ-pre-irradiation dose of radiation (radiation absorbed dosages of 10, 20, 30, 40 KGy) under appropriate temperature and grafting conditions was investigated. The Fourier transform infrared spectroscopy analysis showed the existence of the graft poly-N-isopropylacrylamide (PNIPAAm) on the substrate. The optimal value of the dose for grafting was 40 KGy at 50°C. The scanning electron microscopy and atomic force microscopy (AFM) images clearly showed that increasing the absorbed dose of radiation would increase the amount of grafting. Surface topography and graft thickness in AFM images of the radiated samples showed that the PNIPAAm at the absorbed dose of radiation was properly grafted. The thickness of these grafts was about 50-100 nm. The drop water contact angles of the best grafted sample at 37°C and 10°C were 55.3 ± 1.2° and 61.2 ± 0.9° respectively, which showed the hydrophilicity and hydrophobicity of the grafted surfaces. Differential scanning calorimetry analysis also revealed the low critical solution temperature of the grafted sample to be 32°C. Thermoresponsive polymers were grafted to dishes covalently which allowed fibroblast cells to attach and proliferate at 37°C; the cells also detached spontaneously without using enzymes when the temperature dropped below 32°C. This characteristic proves that this type of grafted material has potential as a biomaterial for cell sheet engineering.