Wills Eye Health System & Wills Eye Institute

To optimize the real-world applicability of a health economic model estimating the cost-effectiveness of corneal cross-linking for the treatment of keratoconus in the United States.

A previously reported discrete-event simulation (DES) model was adapted to reassess the cost-effectiveness of corneal cross-linking (CXL) from the US payer perspective. The simulation of keratoconus progression, which is a key driver of model outcomes, was remodeled to more accurately reflect the real-world relationship between age and the rate of disease progression. All costs were updated to reflect 2025 values. We simulated 4,000 eyes of 2,000 patients diagnosed with keratoconus to compare the lifetime cost and quality-adjusted life years (QALYs) of those treated with CXL vs conventional management.

Given updated cost and disease progression parameters, CXL resulted in lower direct medical costs of $38,897 and 2.97 incremental QALYs over a lifetime treatment horizon. Economically justifiable price (EJP) analysis demonstrated that CXL remained cost-effective up to a drug acquisition cost of $172,369 at a $100,000/QALY cost-effectiveness threshold and $246,549 at a $150,000/QALY cost-effectiveness threshold.

After modeling a conservative cost of corneal transplantation and incorporating an age-dependent disease progression rate, our evaluation confirmed that CXL was the dominant (i.e. cost-saving and cost-effective) treatment strategy, primarily due to greatly improved patient outcomes (i.e. benefits strongly correlated with visual acuity). As novel and less invasive methods (e.g. transepithelial CXL) enter the market, it is expected that the demand for corneal cross-linking will increase given its significant clinical and economic value.

Non-human primates (NHPs) are a crucial model for studying glaucoma because of their similarities to humans in anatomy, physiology and pathology. Our goal in this study was to quantify in vivo NHP lamina cribrosa (LC) shapes at low, normal, and elevated intraocular pressures (IOPs), and compare them with literature reported values for in vivo human LCs. We imaged the optic nerve heads (ONH) of seven eyes from six rhesus macaque monkeys using spectral-domain optical coherence tomography (SD-OCT) at several IOP levels while keeping intracranial pressure at baseline. LC shape was characterized by measuring shape index (SI) and curvedness from manually delineated marks of the anterior LC surface. We found that LC shape in NHPs was more similar across individuals at normal IOP than it is in humans. This was, in part, because the NHPs LCs did not exhibit the characteristic horizontal central ridge seen in human LCs and were instead less saddle-shaped and more trough-shaped. With increasing IOP, NHPs LCs curvedness increased, without significant changes in SI, differing from the human response where SI decreases. These findings emphasize the importance of characterizing species-specific differences in anatomy and biomechanics, and the need to determine how these differences may impact susceptibility to glaucomatous damage.