PREMATURE CLOSURE OF INNER RETINAL FENESTRATION IN THE TREATMENT OF OPTIC DISK PIT MACULOPATHY Ron W. Slocumb, MD, Mark W. Johnson, MD
Purpose: To describe the results of inner retinal fenestration surgery in a patient with chronic macular detachment secondary to an optic disk pit. Methods: A 55-year-old woman had a chronic macular detachment secondary to an optic disk pit that was refractory to vitrectomy and laser photocoagulation. A partial thickness retinal fenestration that connected the schisis-like retinal cavity to the vitreous space was created surgically. Results: One day after surgery, the fenestration was shown to be patent by optical coherence tomography (OCT). However, 3 weeks postoperatively, the OCT revealed a closed fenestration and persistent macular detachment. Conclusion: A surgically created inner retinal fenestration can close within 3 weeks of surgery without resolution of the macular detachment associated with an optic disk pit. RETINAL CASES & BRIEF REPORTS 4:37–39, 2010
Recently, Spaide et al8 theorized that a surgically created inner retinal fenestration would provide a pathway for intraretinal fluid to flow into the vitreous cavity instead of into the macula and thus facilitate the resolution of optic pit maculopathy. In support of this theory, they described the case of a young man with an optic disk pit in whom extensive intraretinal fluid resolved completely over 1 year after creation of a retinal fenestration. We report the outcome of a second patient with optic disk pit maculopathy treated with surgical inner retinal fenestration.
From the Kellogg Eye Center, University of Michigan School of Medicine, Ann Arbor, Michigan.
O
ptic nerve pits are frequently associated with serous detachments of the macula.1 The macular detachment has been shown to be preceded by the formation of a schisis-like cavity secondary to the accumulation of intraretinal fluid emanating from the disk cavitation.2 The fluid within the retina then enters into the subretinal space via a defect in the outer layer of the schisis cavity, causing a macular detachment. The treatment of macular detachment associated with optic disk pits remains controversial. Laser photocoagulation to produce a fluid barrier at the temporal border of the optic disk is often unsuccessful, even with repeated treatments.1,3,4 Several reports suggest that vitrectomy combined with laser photocoagulation and gas tamponade may be more effective than laser therapy alone, particularly in eyes with substantial visual loss.5-7
Case Report A 55-year-old woman with an optic disk pit in the left eye was evaluated without visual complaints. She reported a history of serous macular detachment in the left eye 8 years earlier that resolved after 4 sessions of juxtapapillary laser photocoagulation and pars plana vitrectomy. Best-corrected visual acuity (BCVA) measured 20/20 in the right eye and 20/25 in the left eye. The results of a right fundus examination were unremarkable. A left fundus examination revealed a moderately large pit in the inferotemporal optic nerve head. A diaphanous tissue layer was seen over the pit, and a probable small defect was present within the tissue layer. There was extensive juxtapapillary laser scarring and mild schisis-like thickening of the fovea without subretinal fluid (Figure 1).
Neither of the authors has proprietary interest in the subject matter of this report. Reprint requests: Mark W. Johnson, MD, Kellogg Eye Center, 1000 Wall Street, Ann Arbor, MI 48105; e-mail: [email protected]
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Fig. 3. Vertical OCT scan through inferior papillomacular bundle in the left eye 1 day after fenestration procedure shows patent opening in the inner retina connecting the vitreous cavity with the schisis cavity.
Fig. 1. Color photograph of left fundus showing inferotemporal optic disk pit and juxtapapillary scarring secondary to previous laser photocoagulation treatment. No subretinal fluid is present.
Eight months later, the patient returned with complaints of central vision loss in the left eye. The BCVA measured 20/200 in the left eye, and there was subretinal fluid in the macula. She underwent pars plana vitrectomy with additional juxtapapillary laser treatment and gas tamponade. However, the macular detachment and intraretinal fluid persisted 3 months postoperatively (Figure 2). After informed consent, the patient agreed to undergo the inner retinal fenestration surgery described by Spaide et al.8 During pars plana vitrectomy, a bent microvitreoretinal (MVR) blade was used to create a small but definite slit in the inner retina in the inferior papillomacular bundle. The blade was extended through at least half-thickness retina to create a new communication between the vitreous cavity and the intraretinal schisis cavity. The MVR blade was moved side to side to enlarge the fenestration in the hope of avoiding postoperative closure by retinal wound healing. No subretinal fluid drainage was performed, and no air or gas tamponade was used.
Fig. 2. Horizontal OCT scan through inferior macula and papillomacular bundle in the left eye shows intraretinal and subretinal fluid persisting 3 months after vitrectomy, laser photocoagulation, and gas tamponade.
One day after surgery, OCT (Figure 3) confirmed a patent inner retinal fenestration. There was no apparent change in the amount of subretinal or intraretinal fluid. Three weeks after surgery, repeat OCT (Figure 4) showed a closed fenestration with a nodular inner retinal scar. Although the intraretinal fluid had decreased slightly, the subretinal fluid had not changed, and the BCVA remained 20/200. Seven months after surgery, the fenestration remained closed with persistent macular detachment and BCVA of 20/400. The patient elected 1 final attempt at surgical repair, which included pars plana vitrectomy and drainage of viscous submacular fluid using a 33-gauge subretinal needle and perfluoro-octane liquid. Endolaser photocoagulation was used to retreat the papillomacular bundle in areas where there was persistent intraretinal fluid. The power level was carefully titrated to achieve a visible, but not overly hot, burn, and treatment was avoided within 200 m of the optic disk. On final follow-up examination, 8 months after the final surgery, BCVA measured 20/80, and all intraretinal and subretinal fluid was resolved (Figure 5).
Discussion The pathogenesis of the maculopathy associated with optic pits and other cavitary disk anomalies is not completely understood. The most likely sources of the fluid that accumulates in and under the retina in this
Fig. 4. Horizontal OCT scan of the left eye 3 weeks postoperatively shows closure of the inner retinal fenestration and persistence of intraretinal and subretinal fluid.
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Fig. 5. Horizontal OCT scan of the left eye 6 weeks after the final vitrectomy shows complete resolution of intraretinal and subretinal fluid.
condition are the vitreous cavity and the perioptic subarachnoid space. Johnson and Johnson9 described a mechanical model in which either liquid vitreous or cerebrospinal fluid can be pumped under pressure into the retinal stroma via the optic pit, leading to schisislike intraretinal fluid. Ultimately, the fluid can track through defects in the outer retina to produce the macular detachment. Spaide et al8 hypothesized that, if some of the fluid flow into the retina could be redirected into the vitreous cavity via a surgically created inner retinal fenestration, the macular fluid might be slowly reabsorbed by the retinal pigment epithelium. Although we were able to surgically create a fenestration connecting the schisis-like space to the vitreous cavity in our patient, the OCT imaging confirmed that the fenestration had closed by 3 weeks postoperatively. This short duration of fenestration patency was insufficient for resolution of the chronic intraretinal and submacular fluid. In contrast, Spaide et al8 observed gradual resolution of schisis-like fluid over a period of 1 year after similar surgery in a 15-year-old boy with extensive intraretinal (but no subretinal) fluid. There are several possible explanations for these discrepant outcomes. For example, closure of the fenestration may be hindered or prevented in eyes with a fluid flow rate that is higher and more constant than that of our patient. Flow dynamics may vary with such factors as the source of fluid, the size of the congenital anomalous fluid pathways, and the presence or absence of subretinal fluid. Alternatively, surgical fac-
tors such as the size and exact location of the fenestration may be important. It is possible that this procedure is more effective in eyes with intraretinal fluid alone compared with eyes with intraretinal and subretinal fluid. However, it is worth noting that no information is provided in the report by Spaide et al8 regarding the patency of the fenestration during the postoperative period. It is, therefore, possible that the fenestration closed in their patient as in our patient and that the slow resolution of intraretinal fluid occurred spontaneously and was merely coincidental to the surgical procedure. It is apparent from our case that closure of a surgical inner retinal fenestration can occur before any significant change in the subretinal or intraretinal fluid associated with a cavitary disk anomaly. Given only two published cases of this surgical procedure, additional research is needed to determine its efficacy and to evaluate the cause and incidence of fenestration closure. Key words: optic pit, optic disk, optic disk pit maculopathy, retinal fenestration, vitrectomy. References 1.
2.
3. 4. 5.
6.
7.
8.
9.
Gass JD. Serous detachment of the macula secondary to congenital pit of the optic nerve head. Am J Ophthalmol 1969; 67:821– 841. Lincoff H, Lopez R, Kreissig I, Yannuzzi L, Cox M, Burton T. Retinoschisis associated with optic nerve pits. Arch Ophthalmol 1988;106:61– 67. Gass JDM. Stereoscopic Atlas of Macular Diseases: Diagnosis and Treatment. 4th ed. St. Louis, MO: Mosby; 1997:976 –982. Tobe T, Nishimura T, Uyama M. Laser photocoagulation for pit-macular syndrome. Ganka Rinshoiho 1991;85:124 –130. Cox MS, Witherspoon CD, Morris RE, Flynn HW. Evolving techniques in the treatment of macular detachment caused by optic nerve pits. Ophthalmology 1988;95:889 – 896. Postel EA, Pulido JS, McNamara JA, Johnson MW. The etiology and treatment of macular detachment associated with optic nerve pits and related anomalies. Trans Am Ophthalmol Soc 1998;96:73– 88. Snead MP, James N, Jacobs PM. Vitrectomy, argon laser, and gas tamponade for serous retinal detachment associated with an optic disc pit: a case report. Br J Ophthalmol 1991;75:381–382. Spaide RF, Fischer Y, Ober M, Stoller G. Surgical hypothesis: inner retinal fenestration as a treatment for optic disc pit maculopathy. Retina 2006;26:89 –91. Johnson TM, Johnson MW. Pathogenic implications of subretinal gas migration through pits and atypical colobomas of the optic nerve. Arch Ophthalmol 2004;122:1793–1800.
Purpose: To describe the results of inner retinal fenestration surgery in a patient with chronic macular detachment secondary to an optic disk pit. Methods: A 55-year-old woman had a chronic macular detachment secondary to an optic disk pit that was refractory to vitrectomy and laser photocoagulation. A partial thickness retinal fenestration that connected the schisis-like retinal cavity to the vitreous space was created surgically. Results: One day after surgery, the fenestration was shown to be patent by optical coherence tomography (OCT). However, 3 weeks postoperatively, the OCT revealed a closed fenestration and persistent macular detachment. Conclusion: A surgically created inner retinal fenestration can close within 3 weeks of surgery without resolution of the macular detachment associated with an optic disk pit. RETINAL CASES & BRIEF REPORTS 4:37–39, 2010
Recently, Spaide et al8 theorized that a surgically created inner retinal fenestration would provide a pathway for intraretinal fluid to flow into the vitreous cavity instead of into the macula and thus facilitate the resolution of optic pit maculopathy. In support of this theory, they described the case of a young man with an optic disk pit in whom extensive intraretinal fluid resolved completely over 1 year after creation of a retinal fenestration. We report the outcome of a second patient with optic disk pit maculopathy treated with surgical inner retinal fenestration.
From the Kellogg Eye Center, University of Michigan School of Medicine, Ann Arbor, Michigan.
O
ptic nerve pits are frequently associated with serous detachments of the macula.1 The macular detachment has been shown to be preceded by the formation of a schisis-like cavity secondary to the accumulation of intraretinal fluid emanating from the disk cavitation.2 The fluid within the retina then enters into the subretinal space via a defect in the outer layer of the schisis cavity, causing a macular detachment. The treatment of macular detachment associated with optic disk pits remains controversial. Laser photocoagulation to produce a fluid barrier at the temporal border of the optic disk is often unsuccessful, even with repeated treatments.1,3,4 Several reports suggest that vitrectomy combined with laser photocoagulation and gas tamponade may be more effective than laser therapy alone, particularly in eyes with substantial visual loss.5-7
Case Report A 55-year-old woman with an optic disk pit in the left eye was evaluated without visual complaints. She reported a history of serous macular detachment in the left eye 8 years earlier that resolved after 4 sessions of juxtapapillary laser photocoagulation and pars plana vitrectomy. Best-corrected visual acuity (BCVA) measured 20/20 in the right eye and 20/25 in the left eye. The results of a right fundus examination were unremarkable. A left fundus examination revealed a moderately large pit in the inferotemporal optic nerve head. A diaphanous tissue layer was seen over the pit, and a probable small defect was present within the tissue layer. There was extensive juxtapapillary laser scarring and mild schisis-like thickening of the fovea without subretinal fluid (Figure 1).
Neither of the authors has proprietary interest in the subject matter of this report. Reprint requests: Mark W. Johnson, MD, Kellogg Eye Center, 1000 Wall Street, Ann Arbor, MI 48105; e-mail: [email protected]
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Fig. 3. Vertical OCT scan through inferior papillomacular bundle in the left eye 1 day after fenestration procedure shows patent opening in the inner retina connecting the vitreous cavity with the schisis cavity.
Fig. 1. Color photograph of left fundus showing inferotemporal optic disk pit and juxtapapillary scarring secondary to previous laser photocoagulation treatment. No subretinal fluid is present.
Eight months later, the patient returned with complaints of central vision loss in the left eye. The BCVA measured 20/200 in the left eye, and there was subretinal fluid in the macula. She underwent pars plana vitrectomy with additional juxtapapillary laser treatment and gas tamponade. However, the macular detachment and intraretinal fluid persisted 3 months postoperatively (Figure 2). After informed consent, the patient agreed to undergo the inner retinal fenestration surgery described by Spaide et al.8 During pars plana vitrectomy, a bent microvitreoretinal (MVR) blade was used to create a small but definite slit in the inner retina in the inferior papillomacular bundle. The blade was extended through at least half-thickness retina to create a new communication between the vitreous cavity and the intraretinal schisis cavity. The MVR blade was moved side to side to enlarge the fenestration in the hope of avoiding postoperative closure by retinal wound healing. No subretinal fluid drainage was performed, and no air or gas tamponade was used.
Fig. 2. Horizontal OCT scan through inferior macula and papillomacular bundle in the left eye shows intraretinal and subretinal fluid persisting 3 months after vitrectomy, laser photocoagulation, and gas tamponade.
One day after surgery, OCT (Figure 3) confirmed a patent inner retinal fenestration. There was no apparent change in the amount of subretinal or intraretinal fluid. Three weeks after surgery, repeat OCT (Figure 4) showed a closed fenestration with a nodular inner retinal scar. Although the intraretinal fluid had decreased slightly, the subretinal fluid had not changed, and the BCVA remained 20/200. Seven months after surgery, the fenestration remained closed with persistent macular detachment and BCVA of 20/400. The patient elected 1 final attempt at surgical repair, which included pars plana vitrectomy and drainage of viscous submacular fluid using a 33-gauge subretinal needle and perfluoro-octane liquid. Endolaser photocoagulation was used to retreat the papillomacular bundle in areas where there was persistent intraretinal fluid. The power level was carefully titrated to achieve a visible, but not overly hot, burn, and treatment was avoided within 200 m of the optic disk. On final follow-up examination, 8 months after the final surgery, BCVA measured 20/80, and all intraretinal and subretinal fluid was resolved (Figure 5).
Discussion The pathogenesis of the maculopathy associated with optic pits and other cavitary disk anomalies is not completely understood. The most likely sources of the fluid that accumulates in and under the retina in this
Fig. 4. Horizontal OCT scan of the left eye 3 weeks postoperatively shows closure of the inner retinal fenestration and persistence of intraretinal and subretinal fluid.
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OPTIC DISK MACULOPATHY FENESTRATION
Fig. 5. Horizontal OCT scan of the left eye 6 weeks after the final vitrectomy shows complete resolution of intraretinal and subretinal fluid.
condition are the vitreous cavity and the perioptic subarachnoid space. Johnson and Johnson9 described a mechanical model in which either liquid vitreous or cerebrospinal fluid can be pumped under pressure into the retinal stroma via the optic pit, leading to schisislike intraretinal fluid. Ultimately, the fluid can track through defects in the outer retina to produce the macular detachment. Spaide et al8 hypothesized that, if some of the fluid flow into the retina could be redirected into the vitreous cavity via a surgically created inner retinal fenestration, the macular fluid might be slowly reabsorbed by the retinal pigment epithelium. Although we were able to surgically create a fenestration connecting the schisis-like space to the vitreous cavity in our patient, the OCT imaging confirmed that the fenestration had closed by 3 weeks postoperatively. This short duration of fenestration patency was insufficient for resolution of the chronic intraretinal and submacular fluid. In contrast, Spaide et al8 observed gradual resolution of schisis-like fluid over a period of 1 year after similar surgery in a 15-year-old boy with extensive intraretinal (but no subretinal) fluid. There are several possible explanations for these discrepant outcomes. For example, closure of the fenestration may be hindered or prevented in eyes with a fluid flow rate that is higher and more constant than that of our patient. Flow dynamics may vary with such factors as the source of fluid, the size of the congenital anomalous fluid pathways, and the presence or absence of subretinal fluid. Alternatively, surgical fac-
tors such as the size and exact location of the fenestration may be important. It is possible that this procedure is more effective in eyes with intraretinal fluid alone compared with eyes with intraretinal and subretinal fluid. However, it is worth noting that no information is provided in the report by Spaide et al8 regarding the patency of the fenestration during the postoperative period. It is, therefore, possible that the fenestration closed in their patient as in our patient and that the slow resolution of intraretinal fluid occurred spontaneously and was merely coincidental to the surgical procedure. It is apparent from our case that closure of a surgical inner retinal fenestration can occur before any significant change in the subretinal or intraretinal fluid associated with a cavitary disk anomaly. Given only two published cases of this surgical procedure, additional research is needed to determine its efficacy and to evaluate the cause and incidence of fenestration closure. Key words: optic pit, optic disk, optic disk pit maculopathy, retinal fenestration, vitrectomy. References 1.
2.
3. 4. 5.
6.
7.
8.
9.
Gass JD. Serous detachment of the macula secondary to congenital pit of the optic nerve head. Am J Ophthalmol 1969; 67:821– 841. Lincoff H, Lopez R, Kreissig I, Yannuzzi L, Cox M, Burton T. Retinoschisis associated with optic nerve pits. Arch Ophthalmol 1988;106:61– 67. Gass JDM. Stereoscopic Atlas of Macular Diseases: Diagnosis and Treatment. 4th ed. St. Louis, MO: Mosby; 1997:976 –982. Tobe T, Nishimura T, Uyama M. Laser photocoagulation for pit-macular syndrome. Ganka Rinshoiho 1991;85:124 –130. Cox MS, Witherspoon CD, Morris RE, Flynn HW. Evolving techniques in the treatment of macular detachment caused by optic nerve pits. Ophthalmology 1988;95:889 – 896. Postel EA, Pulido JS, McNamara JA, Johnson MW. The etiology and treatment of macular detachment associated with optic nerve pits and related anomalies. Trans Am Ophthalmol Soc 1998;96:73– 88. Snead MP, James N, Jacobs PM. Vitrectomy, argon laser, and gas tamponade for serous retinal detachment associated with an optic disc pit: a case report. Br J Ophthalmol 1991;75:381–382. Spaide RF, Fischer Y, Ober M, Stoller G. Surgical hypothesis: inner retinal fenestration as a treatment for optic disc pit maculopathy. Retina 2006;26:89 –91. Johnson TM, Johnson MW. Pathogenic implications of subretinal gas migration through pits and atypical colobomas of the optic nerve. Arch Ophthalmol 2004;122:1793–1800.
