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Revista en O.A. en la web del editorDepto. de Optometría y VisiónUnidad Docente de Bioquímica y Biología MolecularFac. de Óptica y OptometríaTRUEpu

From evidence to fake news

Sin financiaciónNo data JCR 20190.812 SJR (2019) Q2, 4/12 OptometryNo data IDR 2019UE

Changes in diadenosine polyphosphates during alignment-fit and orthokeratology rigid gas permeable lens wear

The authors thank Paragon Vision Science (Mesa, AZ), Lenticon SA (Madrid, Spain), and Interlenco SA (Madrid, Spain) for donating the lenses, and Bausch & Lomb (Rochester, NY) for donating the care solutions used in the study.PURPOSE: To evaluate the levels of dinucleotides diadenosine tetraphosphate (Ap(4)A) and diadenosine pentaphosphate (Ap(5)A) in tears of patients wearing rigid gas permeable (RGP) contact lenses on a daily wear basis and of patients wearing reverse-geometry RGP lenses overnight for orthokeratology treatment. METHODS: Twenty-two young volunteers (10 females, 12 males; 23.47 ± 4.49 years) were fitted with an alignment-fit RGP lens (paflufocon B) for a month, and after a 15-day washout period they were fitted with reverse-geometry RGP lenses for corneal reshaping (paflufocon D) for another month. During each period, tears were collected at baseline day 1, 7, 15, and 28. Ap(4)A and Ap(5)A were measured by high-pressure liquid chromatography (HPLC). Additionally, corneal staining, break-up time (BUT), Schirmer test, and dryness symptoms were evaluated. RESULTS: Ap(4)A concentrations increased significantly from baseline during the whole period of daily wear of RGP lenses (P < 0.001); concentration was also significantly higher than in the orthokeratology group, which remained at baseline levels during the study period except at day 1 (P < 0.001) and day 28 (P = 0.041). While BUT and Schirmer remained unchanged in both groups, discomfort and dryness were significantly increased during alignment-fit RGP daily wear but not during the orthokeratology period. CONCLUSIONS: Daily wear of RGP lenses increased the levels of Ap(4)A due to mechanical stimulation by blinking of the corneal epithelium, and this is associated with discomfort. Also, orthokeratology did not produce symptoms or signs of ocular dryness, which could be a potential advantage over soft contact lenses in terms of contact lens-induced dryness.Supported by Ministerio de Ciencia e Innovacion Grant SAF2010-16024, RETIC Red de Patologia ocular del envejecimiento, calidad visual, y calidad de vida Grant RD07/0062/0004, and BSCHUCM Grant GR58/08

Diadenosine polyphosphates in the tears of aniridia patients

Purpose To quantify diadenosine polyphosphate levels in tears of congenital aniridia patients to estimate the ocular surface changes associated with congenital aniridia compared to normal individuals. Methods Fifteen patients diagnosed with congenital aniridia and a control group of forty volunteers were studied. Tears were collected to quantify the levels of diadenosine polyphosphates Ap4A and Ap5A by high-performance liquid chromatography (H.P.L.C). Break-up time (BUT), corneal staining, McMonnies questionnaire and the Schirmer I test were applied to both groups. Results Dinucleotides in congenital aniridia patients were higher than in control subjects. For the congenital aniridia group, under 15 years old, the values were 0.77 ± 0.01 μm and 0.17 ± 0.02 μm for Ap4A and Ap5A, respectively. The group aged from 15 to 40 years old provided concentrations of 4.37 ± 0.97 μm and 0.46 ± 0.05 μm for Ap4A and Ap5A, the group over 40 gave concentrations of 11.17 ± 5.53 μm and 0.68 ± 0.17 μm for Ap4A and Ap5A. Dinucleotide concentrations increased with age, being statistically significant different among the three age groups (p < 0.05). Congenital aniridia patients showed a normal tear secretion and no dry eye McMonnies scores, except for the group over 40 years old. BUT values decreased and corneal staining increased with age and correlated with the levels of diadenosine polyphosphates (p < 0.05). Conclusions The levels of dinucleotides in tears increase in aniridia patients compared with healthy subjects, and they seem to be related with the progression of corneal disorders in aniridia patients, both of which increase with ageing

Diadenosine Polyphosphates in Tears of Sjögren Syndrome Patients

Purpose.: To analyze the levels of diadenosine tetraphosphate (Ap4A) and diadenosine pentaphosphate (Ap5A) in tears of subjects with Sjögren syndrome and to compare them with those in a control group. Methods.: Twelve subjects with a diagnosis of Sjögren syndrome and 20 healthy control subjects were invited to participate in the present study. Schirmer strips were used to measure tear secretion (Schirmer I test) and to collect tears. Ap4A and Ap5A were measured by high-pressure liquid chromatography (HPLC), and a dry eye questionnaire (DEQ) was used to evaluate dry eye symptomatology. Results.: The mean concentrations of Ap4A and Ap5A in the Sjögren syndrome group were 2.54 ± 1.02 and 26.13 ± 6.95 μM, respectively. This group of patients was divided in two subgroups: four patients with normal tear production and eight patients with low tear production. Concentrations of Ap4A, and Ap5A in patients with normal tear production (Schirmer test result, 12.3 ± 1.2 mm) were 0.47 ± 0.20 and 8.03 ± 3.27 μM, respectively. In the patients with low tear production (Schirmer test result, 1.0 ± 0.3 mm), the concentrations were 4.09 ± 1.36 and 39.51 ± 8.46 μM, respectively and in the control group, 0.13 ± 0.03 and 0.04 ± 0.02 μM, respectively. Conclusions.: Patients with Sjögren syndrome have abnormally elevated concentrations of diadenosine polyphosphates, indicating that these compounds could be used in the diagnosis of this disease

Overnight orthokeratology: Technology, efficiency, safety, and myopia control

[Excerpt] Modern orthokeratology differs significantly from the original technique back in the 1960s. Over the last 3 decades, new materials, lens designs, manufacturing processes, fitting techniques, and instruments for the analysis of corneal changes have been developed and have contributed to its evolution. Nowadays, orthokeratology is carried out using the contact lenses during sleep hours (overnight orthoker atology (OOK)), and it is approved by FDA for the treatment of myopia, up to 6 dioptres. #ere are reports of some designs that allow treatment of myopia up to 10–12 dioptres and hyperopia up to 3 dioptres, and recent toric designs, either in the optical zone or in the periphery of the lens, allow correction of astigmatism above 1.75 dioptres up to 3.50 dioptres though those treatments are performed off label. Currently, even some cases of presbyopia may be solved with the help of OOK [1, 2]. However, the greatest impact of this technique in recent years is its application as a method for the control of myopia progression, either on its own or in combination with low-dose atropine [3, 4]. Recently, a published report written by the American Academy of Ophthalmology concludes that orthokeratology is effective for myopia control and potentially has a greater effect when it is applied in patients aged 6 to 8 years [5]. [...]- Universidad Complutense de Madrid(undefined

Accommodation response and spherical aberration during Orthokeratology

Purpose: To evaluate the changes in the accommodative response and in the corneal and internal spherical aberration during three months of wear of orthokeratology lenses from the baseline. Methods: Fifty children aged 8 to 17 were recruited for a prospective study and were fitted with orthokeratology lenses. Refraction without cycloplegia, high and low uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), accommodation lag, horizontal near phoria without correction, corneal topography, corneal and total wavefront aberration were performed at baseline, 1 day, 1 week, 1 month and 3 months. Data were analysed by Student t-test for related samples, repeated measures ANOVA test and Pearson Correlation test. Results: The spherical equivalent (SE) before and after three months was -3.33 ± 1.60 D and -0.30±0.46 D, respectively. Accommodation lag was 0.53±0.38 D and 0.20±0.33 D at baseline and at three months, respectively. A moderate correlation between lag at the baseline and its change between baseline and the 3-month visit was found (P&lt;0.05; R= 0.748). The spherical aberration (SA) increased for anterior corneal and total measurement, being statistically significant for all visits (P&lt;0.05). The internal SA decreased: -0.105±0.006 at baseline and -0.196±0.203 at 1 week (P&lt; 0.05). No difference between baseline and the follow up visits in posterior corneal SA was found (P&gt;0.05) Conclusion: The negative SA of the lens increases during OK treatment compensated for the increase of the anterior corneal surface positive SA, in addition to increasing the accommodative response

The influence of rigid gas permeable lens wear on the concentrations of dinucleotides in tears and the effect on dry eye signs and symptoms in keratoconus

Purpose: To evaluate the signs and symptoms of dry eye and dinucleotide secretion in tears of keratoconus patients (KC) and the potential effect of rigid gas permeable (RGP) contact lens wear. Methods: Twenty-three KC patients and forty control subjects were enrolled in this study. Signs of dry eye including tear volume, tear stability and corneal staining along with symptoms were assessed using the McMonnies questionnaire. Tears were collected using Schirmer strips, and dinucleotide concentrations in collected tears measured using high pressure liquid chromatography. Values obtained in KC and controls were compared. The effect of contact lens wear in KC was also assessed. Results: KC eyes showed a significantly lower tear volume compared to controls, shorter tear break up time (TBUT), higher corneal staining and higher McMonnies dry eye questionnaire scores (p < 0.05). When compared with non-wearers, KC contact lens wearers showed significantly higher symptoms, lower Schirmer and TBUT values (p < 0.05). Concentration of Ap4A (0.695 ± 0.304 μM vs. 0.185 ± 0.178 μM) and Ap5A (0.132 ± 0.128 μM vs. 0.045 ± 0.036 μM) were higher in KC compared to controls (p < 0.001) and only Ap4A was statistically higher in RGP wearers compared to non-wearers (0.794 ± 0.478 μM vs. 0.417 ± 0.313 μM) (p < 0.05). Conclusion: Signs and symptoms of dry eye as well as concentrations of Ap4A and Ap5A were markedly increased in KC patients compared to controls. Moreover, Ap4A and symptoms of dry eye were statistically higher in RGP wearers compared to non-wearers. This seems to indicate that factors such as RGP contact lens wear might exacerbate the clinical condition of dry eye.This work was supported by grants from the Ministerio de Ciencia e Innovación (SAF2010-16024 and SAF2013-44416-R) and RETICS (RD12/0034/0003). The authors want to thank Thomas Johnson and Vimala Punsammy for helping in the preparation of the manuscript