diff --git a/app/services/ocr_service.py b/app/services/ocr_service.py
index 7b928ea..47b65d9 100644
--- a/app/services/ocr_service.py
+++ b/app/services/ocr_service.py
@@ -527,7 +527,7 @@ class MineruOCRService(OCRServiceBase):
             messages = [{"role": "user", "content": [{"type": "image_url", "image_url": {"url": image_url}}, {"type": "text", "text": prompt}]}]
 
             response = self.openai_client.chat.completions.create(
-                model="PaddleOCR-VL-0.9B",  # Use exact model name from vLLM server
+                model="PaddleOCR-VL-0.9B",
                 messages=messages,
                 temperature=0.0,
             )
@@ -555,9 +555,9 @@ class MineruOCRService(OCRServiceBase):
 
         formula_text = self._recognize_formula_with_paddleocr_vl(original_image)
 
-        if formula_text.startswith("\[") or formula_text.startswith("\("):
-            formula_text = formula_text.replace("\[", "$$").replace("\(", "$$")
-            formula_text = formula_text.replace("\]", "$$").replace("\)", "$$")
+        if formula_text.startswith(r"\[") or formula_text.startswith(r"\("):
+            formula_text = formula_text.replace(r"\[", "$$").replace(r"\(", "$$")
+            formula_text = formula_text.replace(r"\]", "$$").replace(r"\)", "$$")
         else:
             formula_text = f"$${formula_text}$$"
 
@@ -614,15 +614,10 @@ class MineruOCRService(OCRServiceBase):
             if "results" in result and "image" in result["results"]:
                 markdown_content = result["results"]["image"].get("md_content", "")
 
-            print(f"[DEBUG] Markdown content from Mineru: {markdown_content[:200]}...")
-
             # Check if markdown contains formula image references
             if "![](images/" in markdown_content:
-                print(f"[DEBUG] Detected image reference, calling PaddleOCR-VL...")
                 # Use PaddleOCR-VL to recognize the formula
                 markdown_content = self._extract_and_recognize_formulas(markdown_content, image)
-            else:
-                print(f"[DEBUG] No image reference found in markdown")
 
             # Apply postprocessing to fix OCR errors
             markdown_content = _postprocess_markdown(markdown_content)