IN THIS ISSUE:
• Is There an Inflammatory Complication Risk Controversy?
Previously published reports on extended wear contact lenses are subjected to a meta-analysis. The meta-analysis suggests that the risk of experiencing an inflammatory complication with the wearing of high Dk silicone hydrogel lenses worn for up to 30 days is twice that of low Dk lenses worn for up to 7 days. (p. 247)
• Can Epidemiology Explain Risk of Infiltrates with New Lens Types?
In a research review, the author points to a new understanding of the epidemiology of contact lens related infiltrates, particularly when related to the introduction of new lens types and modalities. This is important in making an informed choice of lens modality, wear schedule and hygiene. (p. 257)
• Pseudomonas aeruginosa Loves an Accommodating Host
The author’s review identifies several key aspects that affect bacterial virulence and host response. This may be helpful in the development of future therapies to reduce the scarring and vision loss associated with microbial keratitis. (p. 273)
• Are Contact Lenses Abandoned Primarily Because of Dryness and Discomfort?
The author, in an interesting review, says YES. Despite astounding chemical engineering advances that should make contact lenses more comfortable for longer wearing periods, contact lens induced dryness and discomfort remains an enigma. (p. 279)
• The Mysteries of Lipid Deposits on Contact Lenses
In a review of the literature, the authors suggest strategies for reducing clinically significant lipid deposits on hydrogel lens materials. However, they also see the need for future creative research to unravel the complex interactions involved in the tear film and the lipids that are involved. (p. 286)
• Contact Lens Related Dryness Symptoms: Who Is at Most Risk?
Researchers study the prevalence of dryness symptoms in a population of soft contact lens wearers and non-contact lens wearers. They find that females wearing contact lenses, or those working or studying in certain indoor environments, or who are involved in intensive use of computers are at a noticeably higher risk of dryness complaints. They suggest strategies for addressing this in the coming years. (p. 296)
• Go Fly with Silicon Hydrogel Contact Lenses
Contact lens wearers often times limit use of lenses during air travel or while napping. The authors report that use of daily wear silicone hydrogel lenses can significantly improve comfort in most such challenging environments. (p. 302)
• Solution Toxicity Is “Tip Off” to Likely Inflammation
Solution toxicity produces generalized, asymptomatic mild punctate epithelial fluorescein staining that has previously been said to produce little or no clinical consequence. However, in this study mild corneal inflammatory events were three times more likely to occur in eyes exhibiting toxic staining than in those that did not. (p. 309)
• Are All Contact Lens Multipurpose Solutions Equal?
The use of a single laboratory strain of Serratia marcescens may be insufficient to provide assurance that the disinfection solution will be effective against clinical isolates. Five contact lens multipurpose solutions are put to the test. (p. 316)
• A New Tool to Reduce Contact Lens Discomfort
Contact lens osmolality likely plays a role in ocular discomfort during lens wear but it is difficult to measure. A vapor pressure osmometer measures osmolality of very small volumes, offsetting many difficulties. (p. 321)
• New Standards for Measuring Oxygen Permeability Needed?
The authors report some notable discrepancies between claimed vs. measured permeability values of the oxygen permeability of commercially available silicone hydrogel contact lenses. They call for a modified version of the polarographic technique stipulated in the international standard. (p. 328)
• More Oxygen for Keratoconics with Hybrid Lenses
While some newer hybrid contact lenses provide more oxygen over the entire cornea, they do so more in some parts of the cornea than others. (p. 334)
• Stromal but Not Epithelial Thickening Altered by Dk/t in Corneal Refractive Therapy
Overnight lens wear places a burden upon the cornea. The authors use optical coherence tomography (OCT) to measure total corneal, stromal, and epithelial thickness changes after lens wear with two lenses of identical design, but different Dk/t. Stromal swelling was affected by lens Dk/t, but epithelial thinning was not. (p. 343)
• Central Corneal Shape and Optical Performance Not Altered by Dk/t in Corneal Refractive Therapy
After one night of corneal refractive therapy using two lenses with identical design, but different Dk/t, the central corneal shape and optical performance were similar in two lens-wearing eyes. (p. 349)
• Corneal Refractive Therapy for Hyperopia
The authors report that corneal refractive therapy can be used to steepen the central cornea and flatten the paracentral region to correct hyperopia. (p. 357)
• The Perfect Contact Lens: We Are Not There Yet!
We are challenged to consider both the advances and the remaining obstacles to the perfect contact lens in an imperfect environment. (p. 365)