Possibly ...
Do you use iCloud Messaging? (where all your messages are synced through iCloud ... check your iCloud settings to see if Messages is turned ON). If you are using this service, then you're out of luck since Messages in iCloud is not a backup -- any changes you make are synced to iCloud, so all the deletions are replicated in iCloud.
If you do not use iCloud Messaging, have you performed a backup after these photos were deleted? If you did, then your backup will contain your messages, but the backup would reflect the deletions if it was done afterwards.
If you have not backed up since deleting these photos, then do not perform a backup now (doing so will remove any chance of recovery). Instead, restore your iPhone through iTunes and load the backup that preceded you deleting these photos. Once you do this, you should find the photos that you deleted, within your messages. Note that doing this will lose any data you accumulated since that backup was performed, so you'll have to weigh the importance of these photos vs. the importance of the data since your last backup.