Prediction accuracy of no-history intraocular lens formulas for a diffractive extended depth-of-focus intraocular lens after myopic corneal refractive surgery.

PURPOSE: To compare the accuracy of intraocular lens (IOL) calculation methods for extended depth-of-focus (EDoF) IOLs in eyes with a history of myopic laser-assisted in situ keratomileusis (LASIK)/photorefractive keratectomy (PRK) surgery lacking historical data. SETTING: Changsha Aier Eye Hospital, Changsha, and Wuhan Aier Eye Hospital, Wuhan, China. DESIGN: Retrospective case series. METHODS: Patients with axial lengths (ALs) ≥25.0 mm and a history of myopic LASIK/PRK surgery who underwent cataract surgery with implantation of EDoF IOLs were enrolled. A comparison was performed of the accuracy of 10 IOL methods lacking historical data, including Barrett True-K no history (Barrett TKNH), Haigis-L, Shammas, and Potvin-Hill formulas and average, minimum, and maximum IOL power on the ASCRS online postrefractive IOL calculator; Seitz/Speicher/Savini (Triple-S) formula; and Schuster/Schanzlin-Thomas-Purcell (SToP) formulas based on Holladay 1 and SRK/T formulas. IOL power was calculated with the abovementioned methods in 2 groups according to AL (Group 1: 25.0 mm ≤ AL < 28.0 mm and Group 2: AL ≥ 28.0 mm). RESULTS: 64 eyes were included. Excellent outcomes were achieved with the minimum, Barrett TKNH, SToP (SRK/T), and Triple-S formulas in the whole sample and subgroups, which led to similar median absolute error, mean absolute error, and the percentage of eyes with a prediction error within ±0.5 diopters (D). In the whole sample, the Haigis-L and maximum formulas had a significantly higher absolute error than minimum, SToP (SRK/T), and Barrett TKNH formulas. The maximum formula also had a significantly lower percentage of eyes within ±0.5 D than the Barrett TKNH, and SToP (SRK/T) formulas (15.6% vs 50% and 51.5%, all P < .05 with Bonferroni adjustment). CONCLUSIONS: Predicting the EDoF IOL power in postmyopic refractive eyes by no-history IOL formulas remains challenging. The Barrett TKNH, Triple-S, minimum, and SToP (SRK/T) formulas achieved the best accuracy when AL ≥ 25.0 mm, while the Barrett TKNH and SToP (SRK/T) formulas were recommended when AL ≥ 28.0 mm.

Safety of implantable Collamer lens implantation without ophthalmic viscosurgical device: A retrospective cohort study.

To compare the safety of implantable Collamer lens (ICL) implantation with and without ophthalmic viscosurgical device (OVD).A total of 148 eyes underwent a conventional ICL implantation with OVD (OVD group), and 112 eyes underwent a modified ICL implantation without OVD (OVD-free group). The balanced salt solution was used to load ICL and maintain the anterior chamber in the OVD-free group. The surgical time, postoperative uncorrected distance visual acuity, intraocular pressure, endothelial cell density (ECD), and percentage of hexagonal cells were compared between the OVD and the OVD-free groups.No significant differences were detected in uncorrected distance visual acuity, intraocular pressure, ECD, and percentage of hexagonal cells at any time post-surgery between the 2 groups (P > .05). The mean ECD loss was 1.9% in the OVD-free group and 2.3% in the OVD group at 2 years post-surgery (P = .680). The surgical time was much shorter in the OVD-free group than that in the OVD group (P ≤ .001). None of the following occurred at any time during the 2-year follow-up period in both groups: cataract formation, macular degeneration, or any other vision-threatening complications.OVD-free ICL implantation presented satisfactory results for safety. Compared to OVD, the OVD-free technique had the advantages of decreased surgical time, increased efficiency, and reduced cost.

Comparative Assessment of Distribution Characteristics and Ocular Pharmacokinetics of Norvancomycin Between Continuous Topical Ocular Instillation and Hourly Administration of Eye Drop.

BACKGROUND: The aim of this study was to compare the distribution characteristics and ocular pharmacokinetics of norvancomycin (NVCM) in ocular tissues of the anterior segment between continuous topical ocular instillation and hourly administration of eye drop in rabbits. METHODS: Sixty rabbits were randomly divided into two groups: continuous topical ocular instillation drug delivery (CTOIDD) group and eye drop (control) group. In the CTOIDD group, NVCM solution (50 mg/mL) was perfused to the ocular surface using the CTOIDD system at 2 mL/h up to 10 h and the same solution was administered at one drop (50 µL) per hour for 10 h in the control group. Animals (N=6 per time-point per group) were humanely killed at 2, 4, 6, 10, and 24 h to analyze their ocular tissues and plasma. The concentrations of NVCM in the conjunctiva, cornea, aqueous humour, iris, ciliary body and plasma were measured by HPLC with photodiode array detector. The pharmacokinetic parameters were calculated by Kinetica 5.1. RESULTS: The highest concentrations of NVCM for the CTOIDD group and control group were 2105.45±919.89 µg/g and 97.18±43.14 µg/g in cornea, 3033.92±1061.95 µg/g and 806.99±563.02 µg/g in conjunctiva, 1570.19±402.87 µg/g and 46.93±23.46 µg/g in iris, 181.94±47.11 µg/g and 15.38±4.00 µg/g in ciliary body, 29.78±4.90 µg/mL and 3.20±1.48 µg/mL in aqueous humour, and 26.89±5.57 µg/mL and 1.90±1.87 µg/mL in plasma, respectively. The mean NVCM levels significantly increased at all time-points in cornea, iris, and ciliary body (p<0.05) in the CTOIDD group. The AUC0-24 values in the CTOIDD group were 27,543.70 µg·h/g in cornea, 32,514.48 µg·h/g in conjunctiva, 8631.05 µg·h/g in iris, 2194.36 µg·h/g in ciliary body and 343.9 µg·h/mL in aqueous humour, which were higher than for the eye drop group in all tissues. CONCLUSION: Since continuous instillation of NVCM with CTOIDD could reach significantly higher concentrations and was sustained for a longer period compared with hourly administration of eye drop, CTOIDD administered NVCM could be a possible method to treat bacterial keratitis.