Toric Trifocal Intraocular Lens for Refractive Lens Exchange: A Multi-center, Multi-surgeon Large Cohort Study.

PURPOSE: To assess the outcomes of a novel toric trifocal intraocular lens (IOL) for refractive lens exchange (RLE) in a large series of eyes with corneal astigmatism. METHODS: Consecutive eyes that underwent RLE with the PanOptix Toric IOL (Alcon Laboratories, Inc) were included. Outcomes measures included postoperative distance (UDVA), 60 cm intermediate (UIVA), and 40 cm near (UNVA) uncorrected visual acuity, manifest refraction, spherical and defocus equivalent, efficacy and safety indices, and vector analyses of refractive and toric IOL accuracy. RESULTS: A total of 4,933 eyes had a median follow-up of 3 months. UDVA of 20/20 and 20/40 was obtained in 65% and 99% of eyes monocularly and 87% and 100% binocularly, respectively. UIVA at 60 cm of 20/25 and 20/40 was achieved in 70% and 99% of eyes monocularly and in 77% and 100% binocularly, respectively. UNVA at 40 cm of 20/25 and 20/40 was achieved in 85% and 96% of eyes monocularly and in 95% and 100% binocularly, respectively. A total of 67%, 89%, 97%, and 99% of eyes had a SEQ within 0.25, 0.50, 0.75, and 1.00 diopter (D) of intended target (R2 = 0.99). Postoperative refractive astigmatism of 0.50, 0.75, and 1.00 D or less was achieved in 86%, 95%, and 98% of eyes. The vector analysis correction index and index of success were 1.04 ± 0.35 and 0.41 ± 0.31 for toric IOL accuracy and 1.00 ± 0.46 and 0.36 ± 0.55 for refractive accuracy, respectively. The 3- and 12-month post-RLE excimer laser enhancement rates were 1.1% (95% CI: 0.8% to 1.4%) and 7.6% (95% CI: 6.9% to 8.3%), respectively. CONCLUSIONS: The PanOptix Toric IOL performed well for a wide range of axial lengths and corneal astigmatism in eyes that had RLE. Most patients achieved effective uncorrected binocular near, intermediate, and distance vision for daily functioning. [J Refract Surg. 2023;39(5):302-310.].

Does Adjunctive Under-flap CXL Reduce Regression for Hyperopic LASIK?

PURPOSE: To investigate whether adding accelerated under-flap corneal cross-linking to hyperopic laser in situ keratomileusis (LASIK-ufCXL) affects postoperative stability and regression, visual and refractive outcomes, and subjective quality of vision. METHODS: This prospective comparative contralateral eye study included 51 patients with hyperopia (102 eyes) who received LASIK-ufCXL in the eye with highest defocus equivalent (DEQ) or randomized when DEQ equal, with the contralateral control eye receiving LASIK alone. After excimer ablation, 0.25% riboflavin was instilled on the stromal bed for 3 minutes. The flap was repositioned, followed by a total irradiation dose of 3.24 J ultraviolet A (UV-A) light administered to the corneal surface, using 18 mW/cm2 UV-A for 3 minutes. Postoperative hyperopic regression (stability) was the primary outcome measure, defined by the difference in spherical equivalent (SEQ) at 1 week and 24 months postoperatively. Secondary measures reported uncorrected distance visual acuity, corrected distance visual acuity, cylinder vector analysis, subjective quality of vision, subjective night vision disturbances, and corneal haze. RESULTS: At 24 months, the SEQ stability (P = .4273) and the magnitude of hyperopic regression (P = .5613) did not significantly differ between groups, with a small trend showing hyper-opic regression of 0.50 diopters or greater being less frequent in LASIK-ufCXL eyes. There were no significant differences in accuracy, efficacy, and safety (P > .05), with a small trend of more residual refractive astigmatism in the LASIK-ufCXL group (P = .3216, Cohen's d: -0.29). Subjective quality of vision trended inferior in LASIK-ufCXL eyes (P = .2237, Cohen's d: -0.25), with a greater haze grading (P = .0466, Cohen's d: 0.41). CONCLUSIONS: Postoperative regression and stability were statistically equivalent between hyperopic LASIK vs LASIK-ufCXL, with identical safety. There were small clinical trends of lower efficacy, accuracy, and subjective quality of vision in LASIK-ufCXL eyes. [J Refract Surg. 2022;38(12):770-779.].

Characterization of a novel parainfluenza virus, caviid parainfluenza virus 3, from laboratory guinea pigs (Cavia porcellus).

A novel Respirovirus was isolated from nasopharyngeal swab specimens from clinically normal laboratory guinea pigs, and was characterized and named caviid parainfluenza virus 3 (CavPIV-3). The CavPIV-3 is enveloped, is 100 to 300 nm in diameter, and has a characteristic 15-nm-diameter chevron-shaped virus ribonucleocapsid protein. Sequence analysis of the fusion glycoprotein of CavPIV-3 revealed it to be 94% identical to human and guinea pig parainfluenza 3 (PIV-3) viruses and 80% identical to bovine PIV-3. To determine whether CavPIV-3 causes clinical disease in laboratory guinea pigs and to compare the serologic response of guinea pigs to CavPIV-3 and to other paramyxoviruses, an infection study was performed, in which groups of guinea pigs were inoculated with CavPIV-3, Sendai virus, simian virus 5 (SV-5), murine pneumonia virus (PVM), or bovine PIV-3 virus. During the course of the study, guinea pigs were maintained in an infectious disease suite, housed in Micro-Isolator cages, and were only manipulated under a laminar flow hood. Clinical signs of disease were not observed in any of the paramyxovirus-inoculated guinea pigs during the eight-week course of the study, and histologic signs of disease were not evident at necropsy eight weeks after inoculation. Guinea pigs inoculated with CavPIV-3, Sendai virus, PVM, and bovine PIV-3 developed robust homologous or heterologous serologic responses. In contrast, guinea pigs inoculated with SV-5 developed modest or equivocal serologic responses, as assessed by use of an enzyme-linked immunosorbent assay. Further, use of the SV-5 enzyme-linked immunosorbent assay resulted in the highest degree of non-specific reactivity among all of the paramyxovirus assays. In summary, CavPIV-3 is a novel guinea pig Respirovirus that subclinically infects laboratory guinea pigs, resulting in a robust serologic response, but no observed clinical or histologic disease. The CavPIV-3 fusion glycoprotein gene sequence is available from GenBank as accession No. AF394241, and the CavPIV-3 virus is available from the American Type Culture Collection as accession No. DR-1547.

Vaccinating adolescents against meningococcal disease in Canada: a cost-effectiveness analysis.

BACKGROUND: One dose of serogroup C meningococcal conjugate vaccine (MCV-C) at 12 months of age is the most common immunization schedule in Canada, but immunity may wane over time. OBJECTIVES: To assess the cost-effectiveness of a booster dose at 12 years of age with either MCV-C or a quadrivalent ACYW135 meningococcal conjugate vaccine (MCV-4). METHODS: A simulation model for assessing both the direct and indirect effects of vaccination was developed. Age- and serogroup-specific incidence and fatality rates were derived from Canadian surveillance data. Vaccine efficacy was estimated from data from the U.K. and Spain, assuming an age-dependent decline of vaccine efficacy over time. Expected vaccine coverage rates were 90% at 12 months, and 70% at 12 years. Herd immunity was modeled using UK data. Vaccine purchase price per dose was $23 for MCV-C and $70 for MCV-4. Costs and health outcomes were discounted at 3% per year. Results, expressed in 2004 Canadian $ and from a societal perspective, were presented for a steady state situation and a population of 1 million. RESULTS: Under the "no vaccination" base scenario, 5.7 cases of vaccine-preventable meningococcal disease would occur each year. Vaccination at 12 months using MCV-C would reduce the burden of disease by 32%. Adding MCV-C at 12 years of age would reduce the number of cases by 55% at no marginal cost, while using MCV-4 would result in a disease reduction of 78% for a marginal cost of $31000 per QALY gained. Comparing MCV-4 with MCV-C as a booster dose, the incremental cost-effectiveness ratio would be $113000 per QALY. The efficacy of C-MCV vaccination at 12 months and the differential price between the two vaccines were the parameters having the strongest impact on the cost/QALY ratios. Any increase in the incidence of serogroup Y will improve the marginal cost-effectiveness ratio associated with MCV-4. CONCLUSION: Adolescent revaccination would be beneficial. Using C-MCV would be the most cost-effective option, while using MCV-4 would be more effective but would also require more investment.

Relative efficacy of different immunization schedules for the prevention of serogroup C meningococcal disease: a model-based evaluation.

Different immunization strategies have been implemented for the control of serogroup C meningococcal disease (CMD) in Canada and in other developed countries. Results from effectiveness studies of conjugate vaccines in the UK and Spain indicate waning immunity over time. To estimate the life-time protection conferred by different immunization schedules, a simulation model was constructed based on the current epidemiologic situation in Canada. Results showed that the efficacy of any immunization schedule was highly influenced by the rate at which immunity waned and that the benefit of a booster dose increased with increasing rates of waning immunity. Schedules including several doses in early infancy provided little additional benefit over programs starting with 1 dose at the age of 12 months. One-dose programs provided low levels of protection, unless the vaccine was administered at the age of 12 months, and a waning immunity rate of 1% per year or less was assumed. The most effective schedule was 5 doses given at age 2 months, 4 months, 1 year, 12 years, and 18 years, but was only marginally better than 2 doses provided at 12 months and 12 years of age. Existing routine immunization schedules may not be optimal and should be designed to achieve the highest level of protection using the lowest number of doses.