Off the Cuff: The Problem is Not Too Many Schools

A prospective, nonrandomized, controlled study was conducted to explore the association between ocular dominance and degree of myopia in patients with anisometropia, and to investigate the character of visual evoked potential (VEP) in high anisometropias. A total of 1,771 young myopia cases, including 790 anisometropias, were recruited.

Researchers found no significant relation between ocular dominance and spherical equivalent (SE) refraction in all subjects. On average for subjects with anisometropia 1.0D to 1.75 D, there was no significant difference in SE power between dominant and nondominant eyes, while in the SE anisometropia ≥1.75 D group, the degree of myopia was significantly higher in nondominant eyes than in dominant eyes. The trend was more significant in the SE anisometropia ≥2.5 D group. No significant difference in higher-order aberrations was detected between dominant eye and nondominant eye either in the whole study candidates or in any anisometropia groups. In anisometropias >2.0 D, the N75 latency of nondominant eye was longer than that of dominant eye.

These results suggested that, with the increase of anisometropia, the nondominant eye had a tendency of higher refraction, and N75 wave latency of nondominant eye was longer than that of dominant eye in high anisometropias.

Whereas it is known that elevated intraocular pressure (IOP) increases the risk of glaucoma, it is not known why optic nerve heads (ONHs) vary so much in sensitivity to IOP and how this sensitivity depends on the characteristics of the ONH such as tissue mechanical properties and geometry. It is often assumed that ONHs with uncommon or atypical sensitivity to IOP, high sensitivity in normal tension glaucoma or high robustness in ocular hypertension also have atypical ONH characteristics. Here, researchers address two specific questions quantitatively: Do atypical ONH characteristics necessarily lead to atypical biomechanical responses to elevated IOP? And, do typical biomechanical responses necessarily come from ONHs with typical characteristics.

Researchers generated 100,000 ONH numerical models with randomly selected values for the characteristics, all falling within literature ranges of normal ONHs. The models were solved to predict their biomechanical response to an increase in IOP. Researchers classified ONH characteristics and biomechanical responses into typical or atypical using a percentile-based threshold, and calculated the fraction of ONHs for which the answers to the two questions were true and/or false. They then studied the effects of varying the percentile threshold.

Researchers found that when they classified the extreme 5% of individual ONH characteristics or responses as atypical, only 28% of ONHs with an atypical characteristic had an atypical response. Further, almost 29% of typical responses came from ONHs with at least one atypical characteristic. Thus, the answer to both questions is no. This answer held irrespective of the threshold for classifying typical or atypical.

The results challenge the assumption that ONHs with atypical sensitivity to IOP must have atypical characteristics. This finding suggests that the traditional approach of identifying risk factors by comparing characteristics between patient groups (e.g. ocular hypertensive vs. primary open angle glaucoma) may not be a sound strategy.

Ocular targeted therapy has been enormously advanced by implementation of new methods of drug delivery and targeting using implantable drug delivery systems (DDSs) or devices (DDDs), stimuli-responsive advanced biomaterials, multimodal nanomedicines, cell therapy modalities and medical bioMEMs. These technologies tackle several ocular diseases such as inflammation-based diseases (e.g., scleritis, keratitis, uveitis, iritis, conjunctivitis, chorioretinitis, choroiditis, retinitis and retinochoroiditis), ocular hypertension and neuropathy, age-related macular degeneration and mucopolysaccharidosis (MPS) due to accumulation of glycosaminoglycans (GAGs). Such therapies appear to provide ultimate treatments, even though much more effective, yet biocompatible, noninvasive therapies are needed to control some disabling ocular diseases/disorders. In the current study, investigators reviewed and discussed recent advancements on ocular targeted therapies.

On the ground that the pharmacokinetic and pharmacodynamic analyses of ophthalmic drugs need special techniques, most ocular DDSs/devices developments have been designed to localized therapy within the eye. Application of advanced DDSs such as subconjunctival insert/implants (e.g., latanoprost implant, Gamunex-C), episcleral implant (e.g., LX201), cationic emulsions (e.g., Cationorm™, Vekacia™, Cyclokat™), intac/punctal plug DDSs (latanoprost punctal plug delivery system, L-PPDS), and intravitreal implants (I-vitaion™, NT-501, NT- 503, MicroPump, Thethadur, IB-20089 Verisome™, Cortiject, DE-102, Retisert™, Iluvein™ and Ozurdex™) have significantly improved the treatment of ocular diseases. However, most of these DDSs/devices are applied invasively and even need surgical procedures. Of these, use of de novo technologies such as advanced stimuli-responsive nanomaterials, multimodal nanosystems (NSs)/nanoconjugates (NCs), biomacromolecualr scaffolds and bioengineered cell therapies need to be further advanced to get better compliance and higher clinical impacts.

Despite many successful battles against ocular diseases, investigators wrote that strategies to address ocular diseases that occur with aging are ongoing. They wrote further that understanding the molecular aspects of eye diseases in a holistic way and developing ultimate treatment protocols, preferably as noninvasive systems, are essential to making further strides toward that end.