Effect of material and care system combination on subclinical inflammation of the ocular surface in soft contact lens wear.

PURPOSE: To investigate the ocular subclinical inflammatory response in two soft contact lens materials when used in combination with two different care systems ('solutions'). METHODS: Fifteen established soft contact lens wearers wore each of two lenses: Acuvue® 2 (CH) and Acuvue® Oasys® (SiH) or no lenses in random sequence for one week. Two care systems were used: a peroxide system: Oxysept 1 Step® (P) for the right lens and Opti-Free® Replenish® (MPS) for the left lens. After one week of lens/no lens wear, in vivo confocal microscopy (IVCM) of corneal and conjunctival regions was carried out. Density of presumed dendritic cells (DC) and 'white spots' (WS) were quantified. Impression cytology of the bulbar and upper eyelid margin conjunctivae was carried out and samples were analysed for CD45+, CD3+ and CD11c+ cells. RESULTS: The SiH + MPS combination showed a greater inflammatory response compared to SiH + P in seven out of 12 parameters investigated (p < 0.05). The remaining five were not statistically different between the two solutions. The converse was found for the CH lens, with four of the 12 parameters showing a greater response with the P solution compared to the MPS (p < 0.05). CONCLUSION: This study suggests that the SiH lens investigated demonstrated an upregulated response when used with a MPS compared to a P solution whereas the converse is true for the CH lens which showed a reduced response when used with a MPS compared to a P solution. This finding aids in the understanding of the biological underpinnings of manifest corneal inflammatory events during contact lens wear.

Afferent Visual Manifestations of Traumatic Brain Injury.

Traumatic brain injury (TBI) causes structural and functional damage to the central nervous system including the visual pathway. Defects in the afferent visual pathways affect visual function and in severe cases cause complete visual loss. Visual dysfunction is detectable by structural and functional ophthalmic examinations that are routine in the eye clinic, including examination of the pupillary light reflex and optical coherence tomography (OCT). Assessment of pupillary light reflex is a non-invasive assessment combining afferent and efferent visual function. While a assessment using a flashlight is relatively insensitive, automated pupillometry has 95% specificity and 78.1% sensitivity in detecting TBI-related visual and cerebral dysfunction with an area under the curve of 0.69-0.78. OCT may also serve as a noninvasive biomarker of TBI severity, demonstrating changes in the retinal ganglion cell layer and nerve fiber layer throughout the range of TBI severity even in the absence of visual symptoms. This review discusses the impact of TBI on visual structure and function.

Subclinical Inflammation of the Ocular Surface in Soft Contact Lens Wear.

PURPOSE: To investigate the inflammatory response of the ocular surface with different soft contact lens (CL) replacement frequencies and materials. METHODS: Twenty soft CL wearers were required to wear 3 lens types: reusable Acuvue 2 (A2), reusable Acuvue Oasys (AO), and daily disposable Acuvue Oasys (AODD), for 1 week in random sequence in 1 eye with the nonlens-wearing eye acting as a control. Three methods were used to assess the subclinical response: tear cytokine evaluation, in vivo confocal microscopy (IVCM), and impression cytology. RESULTS: Of 13 cytokines investigated, differences were observed only for IL-12p70, which was present in greater concentrations for A2 (interocular difference 8.8 pg/mL, 95% confidence interval 5.5-12.1) and AO (8.9 [5.7-12.1]) compared with AODD (3.7 [0.6-6.8]). For IVCM, corneal presumed dendritic cell density was lower for AODD (interocular difference 1.9 [-0.1 to 3.9] cells/mm) than for both A2 (9.3 [7.2-11.4]) and AO (10.6 [8.6-12.6]). This trend was the same for the other 5 IVCM measures evaluated. The proportion of CD45 cells in the bulbar conjunctiva was lower for AODD (0.6 [-0.3 to 1.5]%) compared with A2 (4.6 [3.7-5.6]) and AO (4.8 [3.9-5.8]). Similar findings were observed for cells in the upper lid margin. CONCLUSIONS: This work has demonstrated for the first time that daily disposable CL wear produces a minimal subclinical inflammatory response compared with no lens wear over 1 week. By contrast, this inflammatory response is upregulated with reusable lenses but appears to be similar between hydrogel and silicone hydrogel materials over this short time frame.

Reading Performance and Compensatory Head Posture in Infantile Nystagmus after Null Zone Training.

This study aimed to assess the visual function, reading performance, and compensatory head posture (CHP) in schoolchildren with infantile nystagmus. A total of 18 participants aged between 13 to 18 years old were divided into spectacle (n = 9) and null zone group (n = 9) based on their visual acuity. Visual acuity (LogMAR), contrast sensitivity (Pelli-Robson), reading time and rate (Tobii TX300), and CHP were measured pre and post null zone reading training. Participants in the null zone group received 10 sessions of training (5 weeks). Visual acuity and contrast sensitivity of participants in the spectacle and null zone groups were not significantly different pre and post training. Reading performance, i.e., reading time (z = -1.36; p = 0.173) and reading rate (z = -0.06; p = 0.953), of participants in the spectacle group was not significantly different after 5 weeks. Reading time (z = -2.55; p = 0.011) and reading rate (z = -2.07; p = 0.038 of participants in the null zone group showed significant improvement post training. After 5 weeks, CHP improved in six out of the nine participants (66.7%) of the null zone group and was unchanged in all participants in the spectacle group. Null zone reading training could benefit children with infantile nystagmus in improving reading performance and compensatory head posture.