Compliance of Soft Contact Lens Care and Bacterial Contamination Among University Students in Palestine.

Purpose: This study investigated the contact lens care compliance, noncompliance reasons, bacterial contamination rate, and the behaviors associated with contamination among university students in Palestine. Patients and Methods: 133 Habitual soft contact lens wearers were recruited in this study and interviewed using a face-to-face questionnaire, to obtain data on demographics, contact lenses, modifiable lens care behaviors and the reasons for non-compliance. High, moderate, and low lens care behaviors were identified. Additionally, a sample of the participant's storage cases was collected for bacterial contamination testing. Results: The participants' mean age was 22.4±4.4, with female predominance (62.4%). The average compliance rate was 76.8%. Total CL care compliance (100%) was found in filling the case with adequate solution, not sharing the lenses or storage case with others, while the poorest compliance (>40%) was found in attending after-care visits, checking the solution's expiry, and re-disinfecting the lenses with a fresh solution before insertion after prolonged storage. Poor understanding of the instructions contributed significantly to a low level of compliance (P≤0.05). Gram-positive and gram-negative bacteria were detected in 19.55% of the participants' cases. Poor hand and case hygiene, no replacement of lens cases (monthly), and water exposure were linked to bacterial contamination of storage cases. Conclusion: This study indicated moderate to high compliance in CL care, averaging 76.8%. Poor compliance was found in attending after-care visits, checking the solution's expiry, and re-disinfecting the lenses with a fresh solution after an extended storage interval. 19.55% of the cases had bacterial contamination, with Staphylococcus Aureus being the most common. Poor hand and lens case hygiene and water exposure are found to be associated with lens case contamination. These findings emphasize the importance of patient education on safer lens wear modalities, proper wearing schedules, and hygiene regimens to reduce the risks of developing contact lens complications.

Prevalence and Behavioral-Based Risk Factors (Eye Cosmetic and Tobacco Use) of Symptomatic Dry Eye Disease in Four Middle Eastern Countries: Lebanon, Syria, Jordan, and Palestine.

Purpose: To estimate the prevalence of symptomatic dry eye disease (DED) in four Middle Eastern Countries and investigate the association between behavioral-based risk factors and severity of DED. Patients and Methods: Population-based cross-sectional study of 1463 participants from 4 Mediterranean countries (Lebanon, Syria, Jordan, and Palestine). The Arabic version of the Ocular Surface Disease Index (ARB-OSDI) questionnaire was used to estimate the prevalence and severity of symptomatic DED using an online format survey. The survey also included demographic questions and possible behavioral risk factors (tobacco and cosmetic use). One-Way ANOVA and multivariate regression analyses were used to investigate the association between OSDI mean scores and behavioral-based risk factors. Results: The prevalence of symptomatic DED (OSDI score ≥ 13) among the overall population (332 males and 1132 females) reached 70.2%. Tobacco and cosmetic users reported a higher significant prevalence and severity of symptomatic DED than non-users (p < 0.0001). Smoking habits (eg, smoking cigarettes or Ajami, smoking in closed areas, and daily smoking) were more likely to report symptomatic DED. Bad hygiene process during the use of any cosmetic product was behind the high prevalence and severity of symptomatic DED among the females of the study population. Conclusion: Symptomatic DED is substantial in Middle Eastern countries. It is statistically associated with cosmetic and tobacco use.

Ocular surface response and subjective symptoms associated to lens care solutions in Palestine / Respuesta de la superficie ocular y síntomas subjetivos asociados a las soluciones para el cuidado de las lentillas en Palestina

PURPOSE: To compare the biocompatibility and subjective symptoms of four multipurpose solutions marketed in Palestine with hydrogel contact lenses. METHODS: 50 habitual soft contact lens wearers were recruited in this interventional crossover study. Subjects were asked to attend the optometry clinic five times. A new pair of hydrogel lenses (Bioxifilcon-B) were fitted each time. This pair was soaked randomly overnight in one of the following four-multipurpose solutions (NEOPLUS(R), AvizorUnicaSensitive(R), ReNuMultiPlus(R) and COMPLETERevitaLens(R)) which contain different disinfecting agents (PHMB, Phx, PAPB, and PQ-1 + Alexidine, respectively), or non-preserved saline. At each visit, corneal staining, ocular redness and subjective symptoms were assessed. RESULTS: The percentage of corneal staining increased significantly (P ≤ 0.050) after soaking the lenses with PHMB (86%), PAPB (64%) and Phx (32%) based-solutions. However, a non-significant increase was noticed after the use of PQ-1 + Alexidine based solution (30%, P = 0.083). Ocular redness evaluation showed a significant increase (P ≤ 0.050) in limbal hyperemia after the use of all solutions, while bulbar redness was significantly increased after the use of biguanide-based solutions (P ≤ 0.050). The subjective assessment analysis showed a non-significant change in comfort, dryness, photophobia and scratchiness (P ≥ 0.050) at 2-h intervention using all solutions, except for the PHMB based solution which showed a significant change in subjective symptoms (P ≤ 0.050). Conclusion: The combination of Bioxifilcon-B hydrogel contact lenses and solution containing PHMB, PAPB and Phx-disinfectants induced a significant increase in corneal staining after 2h of CL-wear with a higher severity when the PHMB-based solution was used, while the PQ-1+Alexidine-based solution did not. Only the PHMB-based solution triggered a significant change in subjective symptoms which might which suggests that it might be related to the severity of staining rather than the induction of staining

OBJETIVO: Comparar la biocompatibilidad y los síntomas subjetivos de cuatro soluciones multiusos comercializadas en Palestina con lentillas de hidrogel. MÉTODOS: En este estudio intervencionista cruzado, reunimos a 50 usuarios habituales de lentillas blandas. Solicitamos a los sujetos que acudieran cinco veces a la clínica optométrica. Cada vez ajustamos un nuevo par de lentillas de hidrogel (Bioxifilcon-B). Dicho par se sumergió aleatoriamente por la noche en una de las siguientes soluciones multiuso (NEOPLUS(R), AvizorUnicaSensitive(R), ReNuMultiPlus(R) y COMPLETERevitaLens(R)), que contienen diferentes agentes desinfectantes (PHMB, Phx, PAPB, y PQ-1 + Alexidina, respectivamente), o solución salina sin conservantes. Durante cada visita, valoramos la coloración de la córnea, el enrojecimiento ocular y los síntomas subjetivos. RESULTADOS: El porcentaje de coloración de la córnea se incrementó significativamente (P ≤ 0,05) tras sumergir las lentillas en soluciones basadas en PHMB (86%), PAPB (64%) y Phx (32%). Sin embargo, se observó un incremento no significativo tras utilizar la solución basada en PQ-1 + Alexidina (30%, P = 0,083). La evaluación del enrojecimiento ocular reflejó un incremento significativo (P ≤ 0,05) de la hiperemia limbal tras el uso de todas las soluciones, mientras el enrojecimiento bulbar se incrementó significativamente tras utilizar soluciones basadas en biguanida (P ≤ 0,05). El análisis de valoración subjetiva reflejó un cambio no significativo en cuanto a comodidad, sequedad, fotofobia y picazón (P ≥ 0,05) durante la intervención de dos horas utilizando todas las soluciones, exceptuando la solución basada en PHMB, que reflejó un cambio significativo en cuanto a síntomas subjetivos (P ≤ 0,05). CONCLUSIÓN: La combinación de las lentillas de hidrogel Bioxifilcon-B y la solución con contenido de desinfectantes PHMB, PAPB y Phx indujo un incremento significativo de la coloración de la córnea tras 2 h de uso de lentillas, con una severidad superior al utilizarse la solución basada en PHMB, hecho que no se produjo con la solución basada en PQ-1 + Alexidina. Únicamente la solución basada en PHMB desencadenó un cambio significativo en cuanto a síntomas subjetivos, lo cual podría sugerir que podría guardar relación con la severidad de la coloración, en lugar de la inducción de la misma

Ocular surface response and subjective symptoms associated to lens care solutions in Palestine.

PURPOSE: To compare the biocompatibility and subjective symptoms of four multipurpose solutions marketed in Palestine with hydrogel contact lenses. METHODS: 50 habitual soft contact lens wearers were recruited in this interventional crossover study. Subjects were asked to attend the optometry clinic five times. A new pair of hydrogel lenses (Bioxifilcon-B) were fitted each time. This pair was soaked randomly overnight in one of the following four-multipurpose solutions (NEOPLUS®, AvizorUnicaSensitive®, ReNuMultiPlus® and COMPLETERevitaLens®) which contain different disinfecting agents (PHMB, Phx, PAPB, and PQ-1+Alexidine, respectively), or non-preserved saline. At each visit, corneal staining, ocular redness and subjective symptoms were assessed. RESULTS: The percentage of corneal staining increased significantly (P≤0.050) after soaking the lenses with PHMB (86%), PAPB (64%) and Phx (32%) based-solutions. However, a non-significant increase was noticed after the use of PQ-1+Alexidine based solution (30%, P=0.083). Ocular redness evaluation showed a significant increase (P≤0.050) in limbal hyperemia after the use of all solutions, while bulbar redness was significantly increased after the use of biguanide-based solutions (P≤0.050). The subjective assessment analysis showed a non-significant change in comfort, dryness, photophobia and scratchiness (P≥0.050) at 2-h intervention using all solutions, except for the PHMB based solution which showed a significant change in subjective symptoms (P≤0.050). CONCLUSION: The combination of Bioxifilcon-B hydrogel contact lenses and solution containing PHMB, PAPB and Phx-disinfectants induced a significant increase in corneal staining after 2h of CL-wear with a higher severity when the PHMB-based solution was used, while the PQ-1+Alexidine-based solution did not. Only the PHMB-based solution triggered a significant change in subjective symptoms which might which suggests that it might be related to the severity of staining rather than the induction of staining.

Characteristics of keratoconic patients at two main eye centres in Palestine: a cross-sectional study.

BACKGROUND: Keratoconus (KC) is a multifactorial, degenerative ectatic condition of the cornea. It usually manifests during late adolescence or the early twenties. A painless disease, KC may end with severe visual loss. The prevalence of KC in middle-eastern countries is much higher than in other regions of the world. This may be due to genetic and environmental risk factors and consanguinity. The goal of this study is to explore the demographic profile of Palestinian keratoconic patients. METHODS: A retrospective study was conducted in two ophthalmology centres (Tertiary Ophthalmic Centre of An-Najah National University Hospital and An-Noor Centre at the Specialized Arab Hospital). All medical charts of keratoconic patients attending both centres over the period from 2009 to 2016 were reviewed. These patients were diagnosed by ophthalmologists depending on history, examination and Pentacam. Severity was determined using the k median index from the Pentacam map. Data analysis was carried out using SPSS Version 22. RESULTS: The medical files of 936 keratoconic eyes of 505 keratoconic patients were reviewed. Their mean age at the time of diagnosis was 23.3 ranging from 8 to 62 years. Approximately 70.1% of them presented after the age of 20 years, and younger age groups were more likely to develop a severe disease stage than older ones (P = 0.001, r = - 0.108). There was a nearly equal distribution of patients between the two sexes (49.5% male, 50.5% female). On initial evaluation, the best-corrected visual acuity (BCVA) was recorded as ≥6/12 in most affected eyes (71.5%). Regarding severity, 62% presented in a mild form, while 9.9% were at a severe stage. About 88.2% presented with bilateralism. CONCLUSIONS: Most of the patients in their twenties presented with a mild bilateral form of the disease. This result is compatible with published international reports. It is recommended that the results of this study be considered when establishing a screening program in Palestine. Subsequently, patients will be identified at an appropriate time where action can be taken before disease progression take place.

Biomechanical Changes of Collagen Cross-Linking on Human Keratoconic Corneas Using Scanning Acoustic Microscopy.

PURPOSE: To assess the biomechanical changes of collagen cross-linking on keratoconic corneas in vitro. METHODS: Six keratoconic corneal buttons were included in this study. Each cornea was divided into two halves, where one half was cross-linked and the other half was treated with riboflavin only and served as control. The biomechanical changes of the corneal tissue were measured across the stroma using scanning acoustic microscopy (SAM). RESULTS: In the cross-linked corneas, there was a steady decrease in the magnitude of speed of sound from the anterior region through to the posterior regions of the stroma. The speed of sound was found to decrease slightly across the corneal thickness in the control corneas. The increase in speed of sound between the cross-linked and control corneas in the anterior region was by a factor of 1.039×. CONCLUSION: A higher speed of sound was detected in cross-linked keratoconic corneal tissue when compared with their controls, using SAM. This in vitro model can be used to compare to the cross-linking results obtained in vivo, as well as comparing the results obtained with different protocols.

Biomechanical changes after repeated collagen cross-linking on human corneas assessed in vitro using scanning acoustic microscopy.

PURPOSE: To explore the biomechanical changes induced by repeated cross-linking using scanning acoustic microscopy (SAM). METHODS: Thirty human corneas were divided into three groups. In group A, five corneas were cross-linked once. In group B, five corneas were cross-linked twice, 24 hours apart. In group C, five corneas were cross-linked three times, 24 hours apart. The contralateral controls in all groups had similar treatment but without UV-A. The speed of sound, which is directly proportional to the square root of the tissue's elastic modulus, was assessed using SAM. RESULTS: In group A, the speed of sound of the treated corneas was 1677.38 ± 10.70 ms(-1) anteriorly and 1603.90 ± 9.82 ms(-1) posteriorly, while it was 1595.23 ± 9.66 ms(-1) anteriorly and 1577.13 ± 8.16 ms(-1) posteriorly in the controls. In group B, the speed of sound of the treated corneas was 1746.33 ± 23.37 ms(-1) anteriorly and 1631.60 ± 18.92 ms(-1) posteriorly, while it was 1637.57 ± 22.15 ms(-1) anteriorly and 1612.30 ± 22.23 ms(-1) posteriorly in the controls. In group C, the speed of sound of the treated corneas was 1717.97 ± 18.92 ms(-1) anteriorly and 1616.62 ± 17.58 ms(-1) posteriorly, while it was 1628.69 ± 9.37 ms(-1) anteriorly and 1597.68 ± 11.97 ms(-1) posteriorly in the controls. The speed of sound in the anterior (200 × 200 µm) region between the cross-linked and control corneas in groups A, B, and C was increased by a factor of 1.051 (P = 0.005), 1.066 (P = 0.010), and 1.055 (P = 0.005) respectively. However, there was no significant difference among the cross-linked corneas in all groups (P = 0.067). CONCLUSIONS: A significant increase in speed of sound was found in all treated groups compared with the control group; however, the difference among the treated groups is not significant, suggesting no further cross-links are induced when collagen cross-linking treatment is repeated.

Biomechanical properties of human corneas following low- and high-intensity collagen cross-linking determined with scanning acoustic microscopy.

PURPOSE: To assess and compare changes in the biomechanical properties of the cornea following different corneal collagen cross-linking protocols using scanning acoustic microscopy (SAM). METHODS: Ten donor human corneal pairs were divided into two groups consisting of five corneal pairs in each group. In group A, five corneas were treated with low-fluence (370 nm, 3 mW/cm(2)) cross-linking (CXL) for 30 minutes. In group B, five corneas were treated with high-fluence (370 nm, 9 mW/cm(2)) CXL for 10 minutes. The contralateral control corneas in both groups had similar treatment but without ultraviolet A. The biomechanical properties of all corneas were tested using SAM. RESULTS: In group A, the mean speed of sound in the treated corneas was 1677.38 ± 10.70 ms(-1) anteriorly and 1603.90 ± 9.82 ms(-1) posteriorly, while it was 1595.23 ± 9.66 ms(-1) anteriorly and 1577.13 ± 8.16 ms(-1) posteriorly in the control corneas. In group B, the mean speed of sound of the treated corneas was 1665.06 ± 9.54 ms(-1) anteriorly and 1589.89 ± 9.73 ms(-1) posteriorly, while it was 1583.55 ± 8.22 ms(-1) anteriorly and 1565.46 ± 8.13 ms(-1) posteriorly in the untreated control corneas. The increase in stiffness between the cross-linked and control corneas in both groups was by a factor of 1.051×. CONCLUSIONS: SAM successfully detected changes in the corneal stiffness after application of collagen cross-linking. A higher speed-of-sound value was found in the treated corneas when compared with the controls. No significant difference was found in corneal stiffness between the corneas cross-linked with low- and high-intensity protocols.

Biomechanical properties of corneal tissue after ultraviolet-A-riboflavin crosslinking.

Photodynamic collagen crosslinking (CXL) using ultraviolet-A (UVA) irradiation combined with the photosensitizer riboflavin has been introduced as a new treatment for progressive keratoconus. The results of clinical studies are promising, but the efficacy of the treatment in halting the progression depends on the stability of the induced biomechanical effects. The effects of corneal CXL on corneal rigidity; collagen fiber diameter; and resistance to heat degradation, enzymatic digestion, and swelling due to hydration are reviewed in this paper. The collective results indicate that CXL using UVA and riboflavin enhances the biomechanical properties of the corneal tissue, which remain stable over time. Therefore, this treatment could become the future standard therapy for keratoconus or used to halt the progression of keratoconus and postpone the need for corneal transplantation. The increase in availability and popularity of the CXL technique accentuates the requirement for reliable and accurate techniques for measuring corneal biomechanical properties before and after treatment.

Scanning acoustic microscopy for mapping the microelastic properties of human corneal tissue.

PURPOSE: To assess the feasibility of applying scanning acoustic microscopy (SAM) on UV cross-linked corneal tissue for mapping and analyzing its biomechanical properties. MATERIALS AND METHODS: Five corneal pairs (10 corneas) were used. In each pair, one cornea was cross-linked (epithelium removed, riboflavin application for 45 min and UVA irradiation for 30 min) and the contralateral control cornea was epithelial debrided and treated only with riboflavin for 45 min. Histological sections were prepared and their mechanical properties were examined using SAM. A line profile technique and 2D analysis was used to analyze the mechanical properties of the corneas. Then the corneal paraformaldehyde and unfixed sections were examined histologically using hematoxylin and eosin (H&E) staining. RESULTS: In the frozen fresh corneal tissue, the speed of sound of the treated corneas was 1672.5 ± 36.9 ms(-1), while it was 1584.2 ± 25.9 ms(-1) in the untreated corneas. In the paraformaldehyde fixed corneal tissue, the speed of sound of the treated corneas was 1863.0 ± 12.7 ms(-1), while it was 1739.5 ± 30.4 ms(-1) in the untreated corneas. The images obtained from the SAM technique corresponded well with the histological images obtained with H&E staining. CONCLUSION: SAM is a novel tool for examining corneal tissue with a high spatial resolution, providing both histological and mechanical data.