Part 1. Definition
Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
Part 2. Example
Chronic rhinosinusitis (CRS) is a heterogeneous disease with an uncertain pathogenesis. Group 2 innate lymphoid cells (ILC2s) represent a recently discovered cell population which has been implicated in driving Th2 inflammation in CRS; however, their relationship with clinical disease characteristics has yet to be investigated. The aim of this study was to identify ILC2s in sinus mucosa in patients with CRS and controls and compare ILC2s across characteristics of disease. A cross-sectional study of patients with CRS undergoing endoscopic sinus surgery was conducted. Sinus mucosal biopsies were obtained during surgery and control tissue from patients undergoing pituitary tumour resection through transphenoidal approach. ILC2s were identified as CD45(+) Lin(-) CD127(+) CD4(-) CD8(-) CRTH2(CD294)(+) CD161(+) cells in single cell suspensions through flow cytometry. ILC2 frequencies, measured as a percentage of CD45(+) cells, were compared across CRS phenotype, endotype, inflammatory CRS subtype and other disease characteristics including blood eosinophils, serum IgE, asthma status and nasal symptom score. 35 patients (40% female, age 48 ± 17 years) including 13 with eosinophilic CRS (eCRS), 13 with non-eCRS and 9 controls were recruited. ILC2 frequencies were associated with the presence of nasal polyps (P = 0.002) as well as high tissue eosinophilia (P = 0.004) and eosinophil-dominant CRS (P = 0.001) (Mann-Whitney U). They were also associated with increased blood eosinophilia (P = 0.005). There were no significant associations found between ILC2s and serum total IgE and allergic disease. In the CRS with nasal polyps (CRSwNP) population, ILC2s were increased in patients with co-existing asthma (P = 0.03). ILC2s were also correlated with worsening nasal symptom score in CRS (P = 0.04).
Answer: Are group 2 innate lymphoid cells ( ILC2s ) increased in chronic rhinosinusitis with nasal polyps or eosinophilia?
Explanation: The question is based on the following sentences from the passage (i) Group 2 innate lymphoid cells (ILC2s) {ii) In the CRS with nasal polyps (CRSwNP) population, ILC2s were increased in patients with co-existing asthma (iii) As ILC2s are elevated in patients with CRSwNP, they may drive nasal polyp formation in CRS. and (iv) They were also associated with increased blood eosinophilia
Part 3. Exercise
Diabetic macular edema (DME) is the leading cause of severe visual loss in patients with diabetic retinopathy. This is so despite the fact that argon laser photocoagulation of the macula (M-ALC) has been shown to be beneficial. Recently, it has been suggested that pars plana vitrectomy (PPV) can lead to the resolution of DME and stop the deterioration of central visual acuity.', 'To explore the potential benefit of PPV for the treatment of DME.', 'PPV was carried out in 30 eyes of 21 consecutive patients (median age 71 years, range 61-88 years) with type II diabetes mellitus suffering from DME. 23 eyes had non-proliferative diabetic retinopathy (NPDR) and 7 eyes had proliferative diabetic retinopathy (PDR) in addition to DME. Posterior vitreous detachment had to be carried out in all cases. If epiretinal membranes were present (23 eyes), they were removed. In 13 eyes (initially 11 eyes) the internal limiting membrane (ILM) was also removed. Prior to PPV 8 eyes had received M-ALC. Three eyes had M-ALC after PPV. One eye developed a retinal detachment 6 weeks after PPV and was excluded form the analysis. After an initial treatment failure two eyes underwent repeat PPV with peeling of the ILM. Both eyes of another patient had 2 repeat PPVs because of recurrent vitreous hemorrhage. Median follow-up was 16 months (range 1-62 months).', 'Following PPV the macula flattened or became attached in 20/27 (74%) eyes. 15/18 (83%) eyes showed reduction or disappearance of leakage during fluorescein-angiography. Central visual acuity increased by two to six lines in 15/27 (56%) for the whole group at 6 months after PPV. For the subgroup (18 eyes) for which the evolution of visual acuity prior to PPV could be documented mean and median visual acuity had decreased markedly from 0.26 +/- 0.19 resp. 0.2 (range 0.03-0.6) to 0.12 +/- 0.09 resp. 0.1 (range 0.02-0.4) during the 12 months preceding PPV and increased to 0.28 +/- 0.23 resp. 0.2 (range 0.03-0.8) during the 12 months following PPV.
Answer:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Do improvement of visual acuity in eyes with diabetic macular edema after treatment with pars plana vitrectomy?