Ocular Surface Disease And Glaucoma Surgery

Ocular Surface Disease(OSD)(DEWS 2007) is multifactorial disease of tears and ocular surface that results in discomfort, visual disturbances, tear film instability, damage of ocular surface,inflammation. Classification:hyposecretory(Sy Sjogren/non-Sjogren) and evaporative. Delphi panel classification grades disease stages. Etiology: age, drugs, nutrition, systemic diseases, surgery, contact lenses, environment. Anterior segment surgical approach disrupts tear film in cataract, glaucoma, refractive, corneal, vitreoretinal surgery. Glaucoma surgery affects tear film,conjunctival incisions change ocular surface structure, decrease goblet cell density, filtration bleb changes ocular surface after trabeculectomy causing chronic inflammation.

Aim of this work is to present OSD frequency in patients after glaucoma surgery examined and surgicaly treated in Glaucoma department of Eye Clinic, University Clinical Center Nis. Also to determine the existence of postoperative difference in tear film parameters and finding after trabeculectomy due to anterior segment surgical approach.

We performed retrospective-prospective observation in Eye Clinic in 60 operated glaucoma patients(60eyes) with Open Angle Glaucoma (OAG) including: primary(POAG) and secondary exfoliative (XFG)glaucoma. Ophthalmological examination in patients before and after surgery was repeated at 7, 30 and 60 day postoperatively. Ocular Surface evaluation was performed by tear break-up time (TBUT), corneal and conjunctival vital dye staining(fluorescein, Rose Bengal) according to Oxford score, Schirmer test, thereafter results were incorporated in OSD grade and type following Delphi Panel Grading Scale and International Panel of experts guidelines, Dry Eye WorkShop (DEWS, 2007).The results were processed using descriptive statistical methods SPSS.

Trabeculectomy influences tear-film changes in operated patients. OSD Grades presented statistically significant difference through time(Chi-Square=26,012;p˂0,0001). Postoperatively, IIb grade is frequent, most prevalent 30.and 60 day in both glaucoma (POAG and XFG). These occurs due to redistribution of normal/lower grades to severe IIb grade from 28.33% to 65% after second month. OSD clinical type distribution presents significant difference through postoperative time in both glaucoma POAG/XFG(Chi-Square=33,222;p˂0,0001). Before surgery mixed type is most frequent(66,67%).After  surgery Evaporative OSD type predominants(71,67%). Two months later Mixed type returned to preoperative level. Hyposecretory subjects are in low percent.

OSD is frequent diagnosis in clinical practice following glaucoma, medical or surgicaly treated. Both conditions require attention and intervention. Analysis includes quantitative tear film parameters assessment: TBUT and Schirmer test, because the change in their results as a quantitative measure can be precisely analyzed, and incorporated together with other diagnostic criteria of dry eye into type and degree of OSD. Glaucoma surgery worsens OSD to higher grade for two months and increases evaporative type. As chronic condition, it is important to treat both diseases at the same time, we want to find out time of worsening after surgery to preserve ocular surface integrity, reduce inflamattion  and improve trabeculectomy success.