Study design
In this retrospecitve clinical study, we included 28 eyes of 14 patients with severe DED due to Sjogren syndrome. The diagnosis of primary and secondary Sjögren’s syndrome were made by a specialized rheumatologist in accordance with the criteria proposed by the American-European Consensus Group which identifies six criteria: “(I) ocular symptoms (dry eye symptoms, foreign body sensation, use of artificial tears three or more times per day); (II) oral symptoms (dry mouth, swollen salivary glands, need for liquids to swallow dry foods); (III) ocular signs (Schirmer test < 5 mm/5′, positive ocular surface staining); (IV) histopathology of salivary glands positive for focal lymphocytic sialadenitis; (V) oral signs (unstimulated whole salivary flow ≤1.5 mL/15′, abnormal parotid sialography, abnormal salivary scintigraphy); (VI) positivity of autoantibodies Anti-SSA (Ro) or Anti-SSB (La). The diagnosis of SS is reached with any four of the six criteria, including either item IV or VI; or with any three of the four objective criteria (III, IV, V, VI)” [16]. All patients with SS were receiving therapy with hydroxychloroquine (200 mg, once a day).
The study adhered to the tenets of the declaration of Helsinki and Institutional Review Board (the ethical committee of Alexandria University Faculty of Medicine) approval was obtained. We included cases with ocular surface disease index (OSDI) score ≥ 33, chronic dry eye > 6 months, Schirmer’s test values of < 5 mm after 5 minutes, and fluorescein score ≥ 3. Patients with previous refractive surgery, previous cataract or refractive surgeries, active ocular surface disease except dry eye, blinking abnormalities, contact lens wearers, and previous herpetic keratitis were excluded. Each patient received unilateral lacrimal gland injection of PRP while the other eye served as control group. Both groups received preservative free eye drops as needed and stopped at the day of examination.
Following the OSDI questionnaire, noninvasive testing for tear meniscus height (TMH), non-invasive tears break up time (NITBUT), lipid layer thickness (LLT) and meibography parameters were done prior to invasive testing, including Shirmer test I and CFS.
Study assessment and parameters
Complete ophthalmic examination in the form of best corrected visual acuity, ocular adnexa and anterior segment examination by slit lamp biomicroscopy were performed. Subjective questionnaire of all patients using the Ocular Surface Disease Index (OSDI) were performed. An OSDI score of 12 was considered to be an indication of a normal healthy eye, a score of 13–22 was considered to be an indication of a mild dry eye condition, 23–32 was considered to be a sign of moderate dye eye condition, and a score of more than 33 indicated severe eye dryness [17], only patients with OSDI > 33 were included in the study. We used ocular surface analyzer SBM Sistemi machine (LS-3, Sun Kingdom co.,ltd, China) for assessment of the average of noninvasive tear breakup times (NIBUT) in seconds, tear meniscus height (TMH) in millimeters, lipid layer thickness (LLT) in nanometers; and infrared Meibography for Meiboscore calculation where the meibomian gland loss area was assessed for partial or complete loss of the MGs and scored using the following grades for each eyelid: 0, no loss of MGs; 1, area loss less than one-third of the total MG area; 2, area loss between one-third and two-thirds; 3, area loss more than two-thirds [18]. Lacrimal volume was assessed using Schirmer I test without anesthesia; regular Schirmer stripes (IO Schirme Eye Care Products, Delhi), were folded and gently placed to the temporal angle as far as practicable over the lower lid edge. During the procedure, the patient was advised to hold the eyes closed. The strips were calculated using the millimeter scale of each strip after 5 min of wetting. Corneal fluorescein staining (CFS) was tested according to the area (A) and density (D) classification of corneal fluorescein staining where the AD classification was graded using the scale reported by Miyata et al. (2003) (A) – 0, no punctate staining; 1, staining involving less than one-third of the cornea; 2, staining involving one-third to two-thirds of the cornea; 3, staining involving more than two-thirds of the cornea. (D) – 0, No punctate staining; 1, sparse density; 2, moderate density; 3, high density and overlapping lesions [19].
Platelet rich plasma preparation
The patient’s blood was extracted into 10-mL sterile tubes containing 1 mL 3.8% sodium citrate acting as an anticoagulant. Centrifugation of total blood at optimal condition was used to achieve enrichment of platelets in plasma fraction. A first centrifugation with low forces (10 min at soft spin from 300 g) separates the whole blood into three layers: an upper layer that contains mostly platelets and white blood cells (WBC) called platelet-poor plasma (PPP); an intermediate thin layer of whitish color called buffy coat (BC), rich in WBC; and a bottom layer that consists mostly of red blood cells (RBC). The upper layer and superficial buffy coat was transferred into another sterile tube for a second centrifugation step at higher speeds (10 min at hard spin from 1200 g) to concentrate platelets. The upper two-thirds of the volume (PPP) were discarded, while the lower one-third was homogenized by gently shaking the tube to create PRP. Then, 1 ml of pure PRP were collected and platelets were activated adding 10% calcium chloride (CaCl2) in a proportion 0.05:1 mL (CaCl2: PRP) just before application. 1 ml of PRP was injected transcutaneous into the external one-third of the orbital rim at a depth of 4 mm to the superior area [14, 15, 20]. Injections were performed by one surgeon (IYA) and the surgeon who performed the injection was not the same as the one who evaluated the patient. Postoperative care included observation of the area. There were no negative side effects, including erythema, edema or severe pain, and analgesics that may alter platelet function were avoided.
Follow up
Both injected eye and control group were followed up at 1, 2, and 3 months after initiation of therapy for symptoms and ocular surface parameters changes. Our follow up measures included NIBUT, TMH, LLT, Meiboscore, Schirmer test I and CFS.
Statistical analysis
Statistical analyses were performed by SPSS version 25 (Statistical Packages for the Social Sciences, Chicago, Illinois, USA). Qualitative data were described using number and percent. We described quantitative data using mean and standard deviation. The Kolmogorov-Smirnov test was used to assess the normality. To compare both groups and baseline data to each point of follow up in the injected eye group, either paired t-test or the Wilcoxon signed ranks test were carried out. P-value of < 0.05 was considered to be statistically significant.