AI Summary & Key Takeaways
AI InsightAll these changes reverse to normal after switching to preservative free drop
📌 3 Key Takeaways
Abstract
Purpose: To investigate the toxic effect of benzalkonium chloride, a preservative that is commonly used in ophthalmic solutions, on ocular surface and on tear film functions and also reversibility of this effect. Material and Method: Tshirtyeight eyes of 19 patients using timolol maleat (0.5%) because of primary open angle glaucoma (POAG) or ocular hipertension were included in the study. The changes in the tear film functions and the ocular surface were evaluated by Schirmer I test, fluorescein break up time (BUT), rose bengal stainning and impression cytology. Then the medication was switched to preservative free timolol maleat and all tests were repeated at 1st and 2nd months. In addition intraocular pressures were measured at each follow up. Results: The mean of Schirmer I tests while using timolol maleat with preservative was 7.05 mm/5 min. It increased to 9.8 mm/5 min when patients were switched to preservative free drop (p<0.002). At the beginning the fluorescein BUT was 8.29 sec and was increased to 13.18 sec while using preservative free drop (p<0.01). While 19% of the eyes were stainned with rose bengal when the patients were using preservative containing eye drop, it decreased to the level of 5% at the 2nd month of preservative free drop usage (p=0.001). Impression cytology evaluation showed that 50% of the eyes were at stage 0 while using timolol maleat with preservative. It increased to 76.3% after 2 months of preservative free drop usage (p=0.02). There was no significant difference between the effectiveness of medications with and without preservative (p>0.05). Conclusion: Chronic exposure to benzalkonium chloride results in worsenning of tear film function tests increase in biological stainning of ocular surface, squamous metaplasia in conjunctiva and loss of goblet cells. All these changes reverse to normal after switching to preservative free drop
Özet
Amaç: Oftalmik solüsyonlarda sıklıkla kullanılan bir prezervatif olan benzalkonyum klorürün oküler yüzey ve gözyaşi filmi fonksiyonları üzerindeki toksik etkisini ve bu etkinin geri dönüşebilirliğini incelemek. Gereç ve Yöntem: Çalışmaya primer açık açılı glokom (PAAG) veya oküler hipertansiyon (OHT) nedeniyle timolol maleat (%0.5) kullanan 19 hastanın 38 gözü çalışmaya alındı. Gözyaşı filmi fonksiyonları ve oküler yüzey değişiklikler Schirmer I testi, floresein kırılma zamanı (FKZ), rose bengal ile boyanma, impresyon sitolojisi ile değerlendirildi. Daha sonra medikasyon prezervansız timolol maleat ile değiştirildi ve bütün testler 1. ve 2. aylarda tekrarlandı. Ayrıca her takipte hastaların göziçi basıncı (GIB) ölçüldü. Bulgular: Prezervanlı timolol maleat kullanırken Schirmer I testi ortalamas 7.05 mm/5dak idi (p 0.05). Sonuç: Kronik benzalkonyum klorür maruziyeti gözyaşı filmi fonksiyon testlerinde bozulma, oküler yüzey biyolojik boyanmasında artış, konjonktivada skuamoz metaplazi ve goblet hücre kaybı ile sonuçlanmaktadır. Bütün bu değişiklikler prezevansız damlaya geçildikten sonra normale dönmeye başlamaktadır.