RHEGMATOGENOUS RETINAL DETACHMENT ASSOCIATED WITH MYELINATED NERVE FIBERS: A CASE REPORT Lingam Gopal, FRCS, Subhankarsri Paul, MS, Parveen Sen, MD, Vikas Khetan, DO, DNB
Purpose: To report the management of a case of rhegmatogenous retinal detachment associated with myelinated nerve fibers. Methods: A 7-year-old boy presented with decreased vision in the right eye for 3 months. Fundus examination revealed total retinal detachment with a large break within the myelinated nerve fibers in the right eye. The right eye underwent pars plana vitrectomy, encirclage, relaxing retinotomy, endolaser, and C3F8 injection. Results: The retina remained attached at the 6-month follow-up with visual acuity of 6/18, N10. Conclusion: An area of the retina with myelinated nerve fiber is stiff and could potentially pose problems in retinal reattachment when a retinal break is located within the same area. RETINAL CASES & BRIEF REPORTS 4:158 –159, 2010
From the Shri Bhagwan Mahavir Vitreoretinal Services, Medical and Vision Research Foundations, Sankara Nethralaya, Chennai, Tamil Nadu, India.
showed few cells in the anterior chamber and broken posterior synechiae on the anterior lens capsule. The anterior segment of the left eye was normal. Intraocular pressure with applanation tonometry was 12 mmHg in both eyes. Fundus examination of the right eye revealed total retinal detachment. A large patch of MNF was noted surrounding the disk and macula and almost encroaching on the fovea. Multiple small retinal holes surrounding a larger retinal break were noted superonasal to the disk within the sector involved by the MNF (Figure 1A and B). Systemic examination was noncontributory. Vitrectomy with encircling band, gas tamponade with 12% C3F8 mixture, and endolaser were performed on the right eye. During the fluid–air exchange, the retina involved by the MNF remained stiff and failed to flatten, despite absence of proliferative vitreoretinopathy. Hence, multiple relaxation radial cuts were performed on the edge of the breaks to flatten the retina. Silicone oil was avoided as the risk of silicone oil entering the subretinal space was high in this case because of the tautness of the retina. Twelve percent C3F8 was preferred because of its better tamponading effect. Producing laser burns around the retinal breaks was also difficult as the breaks lay within the MNFs. On postoperative follow-up at 4 weeks and then at 6 months, the best-corrected visual acuity in the right eye was 6/18, N10. The anterior segment was normal. The intraocular pressure was 16 mmHg. Fundus examination showed an attached retina. (Figure 2).
M
yelinated nerve fibers (MNFs) of the retina are reported in 0.3% to 0.6% of ophthalmic patients. Ophthalmoscopically, the myelin sheaths surrounding nerve fibers of the optic nerve head and retina have an opaque white appearance.1 Retinal breaks in areas with MNFs have been previously reported.2 We describe the management of a case of rhegmatogenous retinal detachment wherein the retinal breaks were located within the area affected by MNFs. Case Report A 7-year-old boy presented to us with a decrease in vision in the right eye for 3 months. The best-corrected visual acuity was 1/60, N36 in the right eye with ⫺7.00 D sph and 6/6, N6 without correction in the left eye. The anterior segment of the right eye Supported by the Vision Research Foundation, Chennai, India. The authors have no financial interest in any of the materials used in the study. Reprint requests: Vikas Khetan, DO, DNB, Medical and Vision Research Foundations, Sankara Nethralaya, 18, College Road, Chennai 600 006, Tamil Nadu, India; e-mail: [email protected]
Discussion MNFs have been described to have many ocular associations such as retinal breaks,2,3 epiretinal mem158
159
MYELINATED NERVE FIBRE AND RETINAL BREAK
Fig. 1. a, Preoperative photograph showing extensive myelination of nerve fibers surrounding the disk. Arrow shows the blood vessel emanating from the disk. b, Preoperative photograph showing the retinal breaks in the retina with myelinated nerve fibers. Arrow points to myelinated fibers beyond the break. There was no proliferative vitreo retinopathy preoperatively.
brane with macular edema,4 and retinal vascular anomalies.5 A large retinal defect with extensive MNFs has been reported.3 The defect was situated in the superior portion of the MNFs and choroidal vasculature was visible through it. The defect remained unchanged during 6 years of follow-up and did not lead to retinal detachment.3 Retinal breaks in areas with MNFs treated with an argon laser also have been reported.2 Vitrectomy for a patient with MNF has been reported for removal of an epiretinal membrane in an older patient.6 Our case highlights the challenges faced in settling the retina with breaks located within the area involving the MNF. A large enough area of MNF (⬃4 disk
diameters) as noted in our case can make that area very taut because the natural elasticity is lost because of myelination, and this resulted in difficulty in flattening the involved area during fluid–air exchange. We had to resort to relaxing cuts to enable the reattachment. Production of laser burns was also difficult (probably not visualized) because of the white MNF. In view of the stiffness of the area, we deliberately treated a larger area surrounding the breaks with laser to provide a greater chance of sealing the retinal breaks. Conclusion Large patches of MNF can make the retina stiff and pose problems in sealing a retinal break located within the area of MNF. Key words: myelinated nerve fiber, retinal detachment. References 1.
2. 3.
4.
5.
Fig. 2. Postoperative photograph showing the slightly lifted edge of the large retinal break. Some amount of postoperative fibrosis is made out across the retinal break creating the impression of multiple breaks (arrow).
6.
Straatsma BR, Foos RY, Heckenlively JR, Taylor GN. Myelinated retinal nerve fibers. Am J Ophthalmol 1981;91: 25–38. Eide N. Retinal breaks in an area with medullated nerve fibres. Acta Ophthalmol (Copenh) 1986;64:271–273. Moochand C, Venatesh P, Garg S. Large retinal defect associated with myelinated nerve fibers. J Pediatr Ophthalmol Strabismus 2006;43:376 –377. Karadimas P, Kapetanios A, panavotidhou E, Bouzas EA. Epiretinal membrane occurring with myelinated retinal nerve fibers and vascular abnormalities. Retina 2003;23:880 – 881. Mehta JS, Raman J, Gupta N, Sinha A. Retinal vascular anomalies in acquired myelinated nerve fibres. Acta Ophthalmol Scand 2003;81:311–312. Williams AJ, Fekrat S. Disappearance of myelinated nerve fibers after pars plana vitrectomy. Am J Ophthalmol 2006;142: 521–523.
Purpose: To report the management of a case of rhegmatogenous retinal detachment associated with myelinated nerve fibers. Methods: A 7-year-old boy presented with decreased vision in the right eye for 3 months. Fundus examination revealed total retinal detachment with a large break within the myelinated nerve fibers in the right eye. The right eye underwent pars plana vitrectomy, encirclage, relaxing retinotomy, endolaser, and C3F8 injection. Results: The retina remained attached at the 6-month follow-up with visual acuity of 6/18, N10. Conclusion: An area of the retina with myelinated nerve fiber is stiff and could potentially pose problems in retinal reattachment when a retinal break is located within the same area. RETINAL CASES & BRIEF REPORTS 4:158 –159, 2010
From the Shri Bhagwan Mahavir Vitreoretinal Services, Medical and Vision Research Foundations, Sankara Nethralaya, Chennai, Tamil Nadu, India.
showed few cells in the anterior chamber and broken posterior synechiae on the anterior lens capsule. The anterior segment of the left eye was normal. Intraocular pressure with applanation tonometry was 12 mmHg in both eyes. Fundus examination of the right eye revealed total retinal detachment. A large patch of MNF was noted surrounding the disk and macula and almost encroaching on the fovea. Multiple small retinal holes surrounding a larger retinal break were noted superonasal to the disk within the sector involved by the MNF (Figure 1A and B). Systemic examination was noncontributory. Vitrectomy with encircling band, gas tamponade with 12% C3F8 mixture, and endolaser were performed on the right eye. During the fluid–air exchange, the retina involved by the MNF remained stiff and failed to flatten, despite absence of proliferative vitreoretinopathy. Hence, multiple relaxation radial cuts were performed on the edge of the breaks to flatten the retina. Silicone oil was avoided as the risk of silicone oil entering the subretinal space was high in this case because of the tautness of the retina. Twelve percent C3F8 was preferred because of its better tamponading effect. Producing laser burns around the retinal breaks was also difficult as the breaks lay within the MNFs. On postoperative follow-up at 4 weeks and then at 6 months, the best-corrected visual acuity in the right eye was 6/18, N10. The anterior segment was normal. The intraocular pressure was 16 mmHg. Fundus examination showed an attached retina. (Figure 2).
M
yelinated nerve fibers (MNFs) of the retina are reported in 0.3% to 0.6% of ophthalmic patients. Ophthalmoscopically, the myelin sheaths surrounding nerve fibers of the optic nerve head and retina have an opaque white appearance.1 Retinal breaks in areas with MNFs have been previously reported.2 We describe the management of a case of rhegmatogenous retinal detachment wherein the retinal breaks were located within the area affected by MNFs. Case Report A 7-year-old boy presented to us with a decrease in vision in the right eye for 3 months. The best-corrected visual acuity was 1/60, N36 in the right eye with ⫺7.00 D sph and 6/6, N6 without correction in the left eye. The anterior segment of the right eye Supported by the Vision Research Foundation, Chennai, India. The authors have no financial interest in any of the materials used in the study. Reprint requests: Vikas Khetan, DO, DNB, Medical and Vision Research Foundations, Sankara Nethralaya, 18, College Road, Chennai 600 006, Tamil Nadu, India; e-mail: [email protected]
Discussion MNFs have been described to have many ocular associations such as retinal breaks,2,3 epiretinal mem158
159
MYELINATED NERVE FIBRE AND RETINAL BREAK
Fig. 1. a, Preoperative photograph showing extensive myelination of nerve fibers surrounding the disk. Arrow shows the blood vessel emanating from the disk. b, Preoperative photograph showing the retinal breaks in the retina with myelinated nerve fibers. Arrow points to myelinated fibers beyond the break. There was no proliferative vitreo retinopathy preoperatively.
brane with macular edema,4 and retinal vascular anomalies.5 A large retinal defect with extensive MNFs has been reported.3 The defect was situated in the superior portion of the MNFs and choroidal vasculature was visible through it. The defect remained unchanged during 6 years of follow-up and did not lead to retinal detachment.3 Retinal breaks in areas with MNFs treated with an argon laser also have been reported.2 Vitrectomy for a patient with MNF has been reported for removal of an epiretinal membrane in an older patient.6 Our case highlights the challenges faced in settling the retina with breaks located within the area involving the MNF. A large enough area of MNF (⬃4 disk
diameters) as noted in our case can make that area very taut because the natural elasticity is lost because of myelination, and this resulted in difficulty in flattening the involved area during fluid–air exchange. We had to resort to relaxing cuts to enable the reattachment. Production of laser burns was also difficult (probably not visualized) because of the white MNF. In view of the stiffness of the area, we deliberately treated a larger area surrounding the breaks with laser to provide a greater chance of sealing the retinal breaks. Conclusion Large patches of MNF can make the retina stiff and pose problems in sealing a retinal break located within the area of MNF. Key words: myelinated nerve fiber, retinal detachment. References 1.
2. 3.
4.
5.
Fig. 2. Postoperative photograph showing the slightly lifted edge of the large retinal break. Some amount of postoperative fibrosis is made out across the retinal break creating the impression of multiple breaks (arrow).
6.
Straatsma BR, Foos RY, Heckenlively JR, Taylor GN. Myelinated retinal nerve fibers. Am J Ophthalmol 1981;91: 25–38. Eide N. Retinal breaks in an area with medullated nerve fibres. Acta Ophthalmol (Copenh) 1986;64:271–273. Moochand C, Venatesh P, Garg S. Large retinal defect associated with myelinated nerve fibers. J Pediatr Ophthalmol Strabismus 2006;43:376 –377. Karadimas P, Kapetanios A, panavotidhou E, Bouzas EA. Epiretinal membrane occurring with myelinated retinal nerve fibers and vascular abnormalities. Retina 2003;23:880 – 881. Mehta JS, Raman J, Gupta N, Sinha A. Retinal vascular anomalies in acquired myelinated nerve fibres. Acta Ophthalmol Scand 2003;81:311–312. Williams AJ, Fekrat S. Disappearance of myelinated nerve fibers after pars plana vitrectomy. Am J Ophthalmol 2006;142: 521–523.
