7-year-old Vrushali Patil* loved riding bicycle as soon as she returned home from school in Taloja, Navi Mumbai. Everyday, her mother used to accompany her to the nearby playground. Once while riding the bicycle, a solid branch of a tree hit Vrushali around her left side of the head. Her mother got her first aid help and left for home.
Next day, Vrushali felt very strange with respect to her vision. She further noticed that her left eye is not straight and anxiously informed her mother about seeing everything in double. Worried mother immediately called her family doctor and informed about her daughter’s double vision problem. Her family doctor then advised to consult a paediatric squint eye specialist from Advanced Eye Hospital & Institute (AEHI), in Sanpada, Navi Mumbai.
Detailed eye check-up was conducted for Vrushali. Squint eye evaluation was conducted including Binocular Single Vision (BSV) test, Stereopsis , Prism cover test and anterior and posterior segment examination of the eye.
Binocular Single Vision is the state of simultaneous vision, which is achieved by the coordinated use of both eyes, so that separate and slightly dissimilar images arising in each eye are appreciated as a single image by the process of fusion.
Stereopsis is the ability to fuse images that stimulate horizontally disparate retinal elements within Panum’s fusional area (the area of one retina such that any point of image will fuse with a single point on the other retina) resulting in binocular appreciation of visual object in depth i.e. in the third dimension.
Mrs. Patil was referred to consult Dr. Prachi Agashe, a Paediatric Ophthalmologist and a Squint Surgeon at AEHI. She observed that Vrushali had to turn her head on one side to visualise things. A detailed evaluation showed the presence of squint as one of her eye muscle – lateral rectus had reduced movement. Therefore, Vrushali’s left eye couldn’t move away from her nose, making her eye crossed towards her nose.
Dr. Agashe diagnosed her with Sixth nerve paresis. She advised a neurologist’s opinion to rule out any other neurological issue arising out of her head injury which was thankfully normal.
Sixth nerve palsy occurs due to damage to the sixth cranial nerve that sends signal to lateral rectus. But, due to an external physical trauma like head injury or skull fracture can damage this nerve that stops sending signal to the lateral rectus muscle thereby weakening it and hence restricts the eye movement. Depending upon the severity of the damage, it gives poor eye alignment and most commonly double vision.
Dr. Prachi then prescribed her few oral steroids containing medicines. She further advised her to do alternate eye patching to stimulate the crossed eye and prevent the chances of lazy eye in the squinting eye. She asked her to follow up after two weeks.
After two weeks, Vrushali showed gradual progress. Dr. Prachi further prescribed her prism glasses and followed her up after one month.
Gradually, Vrushali’s eyes showed improvement and her double vision and squint got completely resolved Sixth nerve palsy in children can be due to various causes like infection, trauma or raised intracranial pressure. Many a times this shows good resolution with conservative means in children. However, if the squint persists beyond 6 months then a definitive squint surgery may be required.
6th nerve palsy is fairly common in children especially due to major head injuries. It is rare to have isolated 6th nerve palsy with minor head injury unassociated with other neurological signs. However, good thing is that most of these isolated lateral rectus paralyses due to 6th nerve injury tends to recover over a period of few months. It is wise to get the child evaluated with an eye doctor in the event of any eye or head injury to rule out any serious effect.
About Dr. Prachi Agashe
Dr. Prachi Agashe, (Pediatric Ophthalmology, DNB (Ophth), MBBS) is a Squint Surgeon and a Pediatric Ophthalmologist at the Advanced Eye Hospital. She has several years of experience and expertise in dealing with eye problems like Strabismus, Amblyopia (aka lazy eye), Congenital Abnormalities, Childhood Cataract, etc. Consult Dr. Prachi Agashe by booking an appointment.
About Advanced Eye Hospital and Institute:
Advanced Eye Hospital and Institute in Navi Mumbai is one of the best eye hospitals in Mumbai. Comprehensive eye check-up areas and the operation theatres are state-of-art and equipped with the best diagnostic and surgery machines. Personalized care, infection free modular operation theatres and beautiful ambiance compliment the innovative eye care service offered at AEHI. Besides Kharghar, Sanpada, Koperkhairne, Ghansoli, airoli, Nerul, Vashi and Panvel, patients from all over Mumbai and western India travel to AEHI for world class eye care management.