diff --git a/omero_search_engine/api/v1/resources/utils.py b/omero_search_engine/api/v1/resources/utils.py
index dd83193..83d66a6 100644
--- a/omero_search_engine/api/v1/resources/utils.py
+++ b/omero_search_engine/api/v1/resources/utils.py
@@ -1263,16 +1263,17 @@ def get_studies_titles(idr_name, resource, data_source=None):
     resourse_res = search_index_using_search_after(
         res_index, resource_query, None, None, None
     )
-    for item_ in resourse_res["results"]:
-        study_title["id"] = item_.get("id")
-        study_title["name"] = item_.get("name")
-        study_title["type"] = resource
-        # study_title["description"] = item_.get("description")
-        for value in item_.get("key_values"):
-            if value.get("name"):
-                value["key"] = value["name"]
-                del value["name"]
-        study_title["key_values"] = item_.get("key_values")
+    if len(resourse_res)>0:
+        for item_ in resourse_res["results"]:
+            study_title["id"] = item_.get("id")
+            study_title["name"] = item_.get("name")
+            study_title["type"] = resource
+            # study_title["description"] = item_.get("description")
+            for value in item_.get("key_values"):
+                if value.get("name"):
+                    value["key"] = value["name"]
+                    del value["name"]
+            study_title["key_values"] = item_.get("key_values")
     return study_title
 
 
diff --git a/omero_search_engine/cache_functions/elasticsearch/transform_data.py b/omero_search_engine/cache_functions/elasticsearch/transform_data.py
index 2428e73..12ebe20 100644
--- a/omero_search_engine/cache_functions/elasticsearch/transform_data.py
+++ b/omero_search_engine/cache_functions/elasticsearch/transform_data.py
@@ -287,11 +287,12 @@ def prepare_data(data, data_source, doc_type):
             row_to_insert["key_values"] = []
             data_to_be_inserted[row["id"]] = row_to_insert
         key_value = row_to_insert["key_values"]
-        key_value.append(
-            {
-                "name": row.get("mapvalue_name"),
-                "value": row.get("mapvalue_value"),
-                "index": row.get("mapvalue_index"),
+        if row.get("mapvalue_name"):
+            key_value.append(
+                {
+                    "name": row.get("mapvalue_name"),
+                    "value": row.get("mapvalue_value"),
+                    "index": row.get("mapvalue_index"),
             }
         )