Prediction of excessively low vault after implantable collamer lens implantation using iris morphology.

Purpose: To identify the iris morphology-related factors for prediction of outcomes of excessively low vault (< 100 µm) after Implantable Collamer Lens V4c (ICL V4c; STAAR Surgical) implantation. Methods: This retrospective case-control study included 81 eyes from 2,080 patients who underwent ICL implantation. Twenty-seven eyes of 27 patients with excessively low vault (< 100 µm) constituted the case group (excessively low vault group). Patients with vault (250 to 750 µm) were selected as the optimal vault group by matching anterior chamber depth, white-to-white distance and ICL size with cases with excessive low vault (< 100 µm) at a proportion of 1:2. The preoperative biometric parameters and postoperative vault were recorded. Multiple linear regression analysis was performed to assess the relationship between the postoperative vault and various variables. Conditional logistic regression analysis was used to estimate the risk factors for excessively low vault. Results: The postoperative vault was associated with preoperative pupil diameter (PD), crystalline lens rise, iris concavity and the ratio of the iris concavity to chord length (P < 0.05). The larger iris concavity increased risk of excessively low postoperative vault (< 100 µm) (OR = 81.10; 95%CI = 2.87 to 2296.58; P = 0.01). Conclusions: Eyes with obviously concave iris were associated with a higher rate of excessively low vault (< 100 µm). Evaluation of iris morphology may provide significant information for predicting excessive postoperative vault.

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.

Treatment of Severe Acute Bacterial Keratitis in Rabbits Using Continuous Topical Ocular Instillation with Norvancomycin.

PURPOSE: Efficacy of norvancomycin (NVCM) through continuous topical ocular instillation drug delivery (CTOIDD) system for treating severe acute bacterial keratitis infection with Staphylococcus aureus was investigated. METHODS: Rabbits with bacterial keratitis were treated using CTOIDD with NVCM (n=13), topical NVCM eye drops (n=11), and CTOIDD with saline (n=8). Clinical signs of keratitis in all groups were assessed consecutively for a week. Bacterial quantification of excised corneas was counted on the fourth and eighth days. Histopathologic examinations were performed to assess inflammatory cell infiltration on the eighth day. RESULTS: All signs of bacterial keratitis were alleviated in CTOIDD with NVCM according to criteria, and the CTOIDD-NVCM group had significantly less inflammation than CTOIDD-saline (p<0.05), and eye drop-NVCM (p<0.05). Two eyes in the eye drop-NVCM group, four eyes in the CTOIDD-saline group had corneal perforation (CP), while none of the rabbits showed CP in the CTOIDD-NVCM group. Bacterial counts were significantly less in the CTOIDD with NVCM group in comparison to the eye drop-NVCM (p<0.05), and CTOIDD-saline (p<0.05) groups. Severe inflammation and marked inflammatory cell infiltration were found in histopathologic examinations in the CTOIDD-saline and eye drop-NVCM groups, while significantly less inflammation was documented in the CTOIDD-NVCM (p<0.05) group. CONCLUSION: CTOIDD with NVCM effectively reduced the severity and treated acute bacterial S. aureus keratitis infection in a rabbit model. The presented approach of CTOIDD with NVCM appears to be a promising therapeutic approach for severe acute bacterial keratitis.

Efficacy of Sub-Tenon Micro-Perfusion of Cyclophosphamide in Rabbits with Severe Ocular Inflammation.

PURPOSE: To explore the feasibility of cyclophosphamide (CP) via a sub-Tenon micro-perfusion system (SMS) in rabbits, and assess its therapeutic efficacy in severe ocular inflammation. MATERIALS AND METHODS: Distribution and pharmacokinetics of CP were evaluated in vivo, and the concentrations of CP in plasma, vitreous humor, and retina/choroid were quantitated by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) at different time points. After induction of severe experimental uveitis, rabbits were divided into three groups (n=8 in each): the SMS group, subconjunctival injection (SI) group, and control group. Clinical inflammatory score was assessed in rabbits. Electroretinography and histopathology were performed on post-treatment day 8. Statistical analyses were performed using Mann-Whitney and Kruskal-Wallis tests. P-value less than 0.05 was considered significant. RESULTS: The concentrations of CP in vitreous humor and retina/choroid in the SMS group were significantly higher than that of the SI group at 3, 6, 10, and 24 hours (P<0.01), while plasmatic CP concentrations were comparable at all time points in the SMS group and SI group (P>0.05). The SMS group showed significantly less inflammation compared to the control group and SI group. Furthermore, the restoration of retinal structure and function were more obvious in the SMS group compared with conventional SI application. CONCLUSION: Sub-Tenon micro-perfusion of CP exhibited satisfied therapeutic efficacy in rabbits with severe ocular inflammation and may provide a promising alternative for controlling ocular inflammatory disease and immune-mediated ocular diseases.

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.

Sub-Tenon Sustained Controllable Delivery of Dexamethasone for Treating Severe Acute Experimental Uveitis.

PURPOSE: To evaluate the efficacy of dexamethasone (DXM) through sub-tenon sustained controllable drug delivery system (SSCDDS) for treating severe acute experimental uveitis. METHODS: Rabbits were treated with either DXM (treated group) or normal saline (control group) through SSCDDS. Clinical signs of uveitis were assessed at days 1, 3, 5, 7, and 14 after treatment. Histopathologic examinations were performed to evaluate inflammatory cell infiltration on posttreatment days 7 and 14. RESULTS: All signs of experimental uveitis were reduced by SSCDDS of DXM according to clinical criteria, and the treated group had significantly less inflammation than the control group (p<0.05). Histopathologic examinations showed severe inflammation and marked inflammatory cell infiltration in the control group, but minimal inflammation in the treated group. CONCLUSIONS: Sub-tenon sustained controllable delivery of DXM effectively suppresses severe acute inflammation in a rabbit model of uveitis. The proposed minimal invasive system might be a promising candidate for managing severe ocular diseases.