CT of Acquired Hyperopia with Choroidal Folds

Transcription

1 11 07 CT of quired Hyperopia with Choroidal Folds Gary K. Stima 1 Rihard P. Mills2 Roger. Dailey3 W. Thomas Shults 4 Robert E. Kalina 2 Seven patients with an opthalmologi diagnosis of aquired hyperopia with horoidal folds were evaluated by high-resolution axial CT of the orbits. Coronal, oblique oronal, and para sagittal reformations were obtained and the thikness of the opti nerve and morphologi appearane of the globes were assessed by measurement and subjetive appearane. Flattening of the globe, whih aused the globe to assume an ellipsoid shape, was seen in all 11 affeted eyes. Mild to moderate opti nerve enlargement was also demonstrated in most patients. In six of 11 affeted eyes a visible spae was noted between the opti nerve and its sheath, implying expansion of the subarahnoid perineural ompartment. These findings were not demonstrated in a ontrol group of five patients sanned in a similar manner. Sans of a phantom revealed no evidene of CT-generated distortion. These findings may help to identify hyperopia with horoidal folds as a benign disease and eventually help to establish its ause. Reeived Marh 31, 1986; aepted after revision pril 20, Presented at the annual meeting of the merian Soiety of Neuroradiology, San Diego, January Department of Radiology, S8-05, University of Washington, Seattle, W 98195, and First Hill Diagnosti Imaging Center, ylston ve., Seattle, W ddress reprint requests to G. K. Stima at First Hill Diagnosti Imaging Center. 2 Department of Ophthalmology, RJ-10, University of Washington, Seattle, W Department of Ophthalmology, Oregon Health Sienes University, Portland, OR Good Samaritan Hospital, Neurologial Sienes Center, Portland, OR JNR 8: , November/Deember /87/ merian Soiety of Neuroradiology quired hyperopia with horoidal folds is a benign ondition haraterized linially by the aute development of a unilateral or bilateral hyperopi shift in refrative error, ausing some patients to experiene blurred vision. Only 13 ases of this rare disease, whih affets primarily middle-aged men, have been reported [1, 2]. Visual auity is improved to normal or near normal by plus lenses, and both the refrative error and ophthalmosopi findings tend to remain stable over time. The ophthalmosopi examination shows horoidal folds in the fundus (Fig. 1 ). These are best demonstrated by fluoresein angiography (Fig. 18). Sonographi measurements reveal a flattening of the globe in the anteroposterior diameter. Choroidal folds have been desribed extensively in the ophthalmology literature [3-14], inluding two reports that disussed the assoiation of horoidal folds with aquired hyperopia [1, 2]. Reently, follow-up studies have indiated the benign ourse of this disease [2]. The availability of high-resolution CT sanners has greatly improved the ability to evaluate the orbit by providing thin slies, artifat redution algorithms, and software that improves radiographi ontrast of the markedly varying densities of orbital strutures. Suh fators enable the identifiation of previously undeteted abnormalities in aquired hyperopia with horoidal folds. We evaluated seven patients with aquired hyperopia with horoidal folds by high-resolution orbit CT to assess the hanges in shape of the globe and to attempt to determine the ause of this disease. Subjets and Methods Seven patients were diagnosed as having aquired hyperopia with horoidal folds on the basis of linial history, ophthalmosopy, and refration. The patients were followed for an average of 4.5 years (range, 0-7 years), and the details of the linial ophthalmosopi findings were reported elsewhere [2]. Some of these patients had CT sans previously, but

2 1108 STIMC ET L. JNR :8, November/Deember 1987 Fig. 1.-Case 3. Choroidal folds in newly aquired hyperopia in right eye only., Fundosopi view. Folds are alternating dark and light bands radiating from opti disk., Fluoresein angiography best shows horoidal folds as alternating dark and light lines. 8 thin-slie tehnique was not available and no abnormalities were demonstrated. Five ontrol patients were also evaluated. These ontrol patients were sanned to evaluate trauma (two patients), possible tumor (one patient), photophobia (one patient), and orbital pseudotumor (one patient). Patients, ontrols, and a speially onstruted phantom were sanned using 1.5-mm ontiguous axial slies without IV ontrast material on a GE 9800 CT sanner (five patients) or with ontrast on a GE 8800 (two patients) CT sanner. Coronal reformations were obtained at the level of the globe and at midone. Parasagittal reformations were obtained along the axes of the opti nerves, and oblique oronal reformations were obtained perpendiular to eah opti nerve at its midpoint. For the majority of patients, the head was tilted bak about 10 beyond the inferior orbital meatal line to plae the petrous ridges below the level of the san and to present the entire opti nerve within the axial plane. To maximally streth the opti nerve [15], half the patients were instruted to look superiorly about 30. Subjetive impressions of flattening of the globe, thikening of the opti nerve image, visualization of the subarahnoid spae along the opti nerve, and sleral thikening were made by two observers. Sans of a onstruted phantom globe and nerve were also obtained in the same manner to ensure that no artifatual hanges in size or shape were reated by the different reformations used. Soring of the subjetive findings were as follows: flattening of the pole of the globe was graded as 0 (normal, 1 (flattened but onvex), 2 (flat), 3 (onave indentation of the globe). Widening of the nerve head at the globe was graded as 0 (uniform nerve, no widening), 1 (fusiform dilatation), 2 (lubbed). Visualization of low density in the perineural spae was graded as 0 (low density, not seen), 1 (possibly seen), 2 (definite visualization of perineural low density as ontrasted to the nerve). Uveosleral thikening was graded a 0 (not seen), 1 (possibly seen), 2 (definite thikening). Results Our CT observations are summarized in Table 1. We found flattening of the posterior globe, mild to moderate opti nerve enlargement, and, in six of 11 affeted eyes, a disernible spae between the sheath and nerve, suggesting fluid aumulation in the subarahnoid spae. Suh abnormalities were not seen in five ontrol patients and an orbit phantom. In the seven patients with a diagnosis of hyperopia with horoidal folds, flattening of the posterior globe was deteted in all 11 affeted eyes. In five of the affeted eyes, the posterior globe was onvex but of flatter urvature than the normal globe (Fig. 2). In six of the affeted eyes, the posterior aspet of the globe was either flat or indented (Fig. 3) in the region of the opti nerve insertion. oth axial and sagittal views were effetive in demonstrating these findings. In the ontrol patients, a suggestion of slight flattening was seen in only one of nine eyes examined. Sans of the phantom showed no evidene of flattening or distortion in any projetion. Widening of the nerve head at its insertion to the globe was identified as lubbed in two of the affeted eyes (Fig. 4) and as fusiform dilatation in the remaining nine. None of the ontrol eyes suggested a finding of nerve dilatation. The axial views were slightly better than the sagittal reonstrutions in identifying this finding. visible subarahnoid spae along the opti nerve was definitely seen in two of the affeted eyes (Fig. 5) and was possibly seen in an additional four. Suh a visualization of subarahnoid spae was not identified in any of the ontrol

3 JNR:8, November/Deember 1987 CT OF CQUIRED HYPEROPI 1109 TLE 1: CT Findings in Patients with quired Hyperopia Case No. Enlarged Flat Pole Wide Nerve Head Subarahnoid Eye Spae Comment xial Sagittal xial Sagittal xial Sagittal R Unaffeted L ffeted 2 R ffeted L ffeted 3 R ffeted L Unaffeted 4 R Previously affeted L ffeted 5 R ffeted L ffeted 6 R Newly affeted L ffeted 7 R ffeted L Clinially unaffeted Note.-Flat pole of globe soring: 0 = normal; 1 = flattened but onvex; 2 = flat ; 3 = onave indentation of globe. Widening of nerve head at globe: 0 = uniform (no widening), 1 = fusiform dilatation, 2 = lubbed. Enlarged subarahnoid spae: 0 = low density is not seen, 1 = possibly seen, 2 = definitive visualization of perineural low density as ontrasted to the nerve. R = right; L = left. flattening of the globe and no enlargement of the subarahnoid spae of the opti nerve. Disussion Fig. 2.-Case 1. Convex but abnormal posterior aspet of globe. xial view of orbit in 60-year-old man who noted dereasing myopia in left eye requiring x 90 orretion. Choroidal folds were in left eye only. Myopi right globe is round; left globe shows flattened onvex urvature (grade 1). eyes and no artifat was seen on the phantom opti nerve views to suggest the presene of a border. xial views were slightly better than parasagittal views in identifying this enlarged subarahnoid spae. Sans that plaed the opti nerve exatly in the axial plane allowed more reliable interpretation of the findings. -mode ehography was done in six of the seven patients and showed flattening of the posterior poles. -mode ehography provided axial length data in four of the seven ases. However, the 30 test used for detetion of perineural fluid was done in only one ase, and the results were equivoal. Uveosleral thikening was not present in any of the patients with hyperopia and horoidal folds. One ontrol patient, with orbital pseudotumor, was identified by uveosleral thikening on the CT san, typial linial symptoms of orbital pain, and response to steroid therapy. Choroidal folds were seen on ophthalmosopy but there was no evidene of aquired hyperopia. The high-resolution san demonstrated no quired hyperopia with horoidal folds is a benign disease that results in relatively sudden onset of signifiant hyperopi hange in refrative error. Choroidal folds are demonstrated on ophthalmosopi examination. One established, the disease does not appear to progress. In one patient the previously uninvolved eye developed hyperopia and horoidal folds at a later time. In two myopi patients, the hyperopi shift restored unorreted vision to near normal. The ause of this disease is not known. The CT identifiation of flattening of the globe and possible enlargement of the subarahnoid sheath near the opti nerve head and along the nerve raises the possibility that the ause of the disease is at least initially an edematous proess [16, 17]. The flattening of the globe identified in some patients was dramati and exeeded the hange expeted to ause the refrative error. The diagnosti possibilities when an abnormal shape of the globe is identified have been reported [18]. quired hyperopia with horoidal folds should be added to this differential list. The differential diagnoses of flattening of the posterior globe also inlude orbital neoplasm profound hypotony, and posterior sleritis. In hypotony (dereased intraoular pressure), the ontration of the extraoular musles deforms the globe into a square shape. In posterior sleritis, the slera is thikened. The finding of CT visualization of a luent zone between opti nerve sheath and nerve suggests an inreased olletion of subarahnoid fluid in the perineural spae. Confirmatory

4 1110 STIMC ET L. JNR :8, November/Deember 1987 Fig. 3.-Case 5. Flat or indented posterior aspet of globe. xial () and sagittal (, right eye; C, left eye) CT views of orbit in 26-year-old man with blurred vision, hyperopia, and bilateral horoidal folds. Flattening and indentation (grade 3) of posterior poles of globes and dereased antero- posterior diameter bilaterally. Opti nerves widen at entrane to globe. Low density peripherally along margin of left opti nerve, best seen on axial view (arrows), suggests presene of fluid in perineural spae (grade 2). Reprinted with permission from Ophfhalmology [2]. Fig. 4.-Case 2. Widening of nerve head at insertion. xial () and sagittal (, right eye; C, left eye) CT views of orbit in 47-year-old man with hyperopia and bilateral horoidal folds. 80th globes show dereased anteroposterior diameter and posterior flattening (grade 2). Left opti nerve is lubbed at insertion to globe (grade 2). Figures 48 and 4C reprinted with permission from Ophthalmology [2]. Fig. 5.-Case 7. Visible subarahnoid spae. 52-year-old man with severe hyperopia in right eye with horoidal folds; mild hyperopia and no horoidal folds in left eye., xial view, and, right sagittal view show dereased anteroposterior diameter of right globe (grade 2) and enlarged opti nerve sheath. Low density in perineural spae (arrows) appears to represent fluid (grade 2). C, Coronal view shows enlargement of right opti nerve sheath. Figures 5 and 58 reprinted with permission from Ophthalmology [2]. ultrasoni data were unfortunately not available on most of our patients. 30 test using quantitative -san ehography was equivoal (differentiation of sheath and nerve ehoes was not lear) in the one patient on whom it was performed. In ases of suspeted sheath enlargement due to fluid aumulation, suh testing may show dereased width of the perineural subarahnoid spae when the sheath is strethed during abdution of the eye. Proof of perineural subarahnoid fluid aumulation through surgial exploration was not eleted beause of the benign nature of the ondition. lthough our observations of globe size and onfiguration were generally in agreement with ophthalmosopi, sonographi, and linial findings, they of1en required some interpretation as to whether the orneal vault (the "ap" that protrudes from the otherwise spherial globe) was inluded in the san, whether the patient had inherent faial asymmetry, and whether reformations obtained were in the optimal plane. The subjetive appearane allowed a better ompensation for suh fators and the abnormal findings were more easily identified (Table 1) than with diret measurement. Sans of the phantom showed no artifatual hanges in the shape of the nerves or globes, and demonstrated the auray of the measurement proesses. Hyperopia with horoidal folds is a benign disease of unknown origin. Our investigations have shown flattening of the posterior globe, enlargement of the opti nerve head, and a

5 JNR :8, November/Deember 1987 CT OF CQUIRED HYPEROPI 1111 disernible subarahnoid spae around the opti nerve. These findings may help identify this disease as benign, and may eventually help to establish its ause. CKNOWLEDGMENT We thank Debborah urh for oordinating the sanning and assisting with measurements and analysis. REFERENCES 1. Kalina RE, Mills RP. quired hyperopia with horoidal folds. Ophthalmology 1980;87 : Dailey R, Mills RP, Stima GK, Shults WT, Kalina RE. The natural history and CT appearane of aquired hyperopia with horoidal folds. Ophthalmology 1986;93 : Hyvarinen L, Walsh F. enign horoidal folds. m J Ophtha/mol 1970;70: Kroll J, Norton EDW. Regression of horoidal folds. Trans m ad Ophtha/mol Otolaryngol 1970;74: ird C, Sanders MD. Choroidal folds in assoiation with papilloedema. r J Ophtha/mo/1973;57: Newell FW. Choroidal folds. m J Ophtha/mo/1973;75: Cappaert WE, Purnell EW, Frank KE. Use of -setor san ultrasound in the diagnosis of benign horoidal fold s. m J Ophthalmol 1977;87 : Cangemi FE, Trempe DL, Walsh J. Choroidal folds. m J Ophthalmol 1978;86: Wolter JR. Parallel horizontal horoidal folds seondary to an orbital tumor. m J Ophthalmo/1974;77 : ullok JD, Egbert PR o Experimental horoidal folds. m J Ophthalmol 1974;78 : Fribert TR, Grove S. Choroidal folds and refrative errors assoiated with orbital tumors. rh Ophthalmo/1983;101 : Newell FW. Fundus hanges in persistent and reurrent horoidal folds. r J Ophtha/mo/1984;68: Ossoinig KC, Cennamo G, Frazier-yrne S. Ehographi differential diagnosis of opti nerve lesions. Do Ophthalmol Pro Series 1981;29 : Norton EWD. harateristi fluoresein angiographi pattern in horidal folds. Pro R So Med 1969;62 : Unsold R, Newton TH, Hoyt WF. CT examination tehnique of the opti nerve. J Comput ssist Tomogr 1980;4 : Hupp SL, ukley EG, yrne SF, et a/. Post-traumati venous obstrutive retinopathy assoiated with enlarged opti nerve sheath. rh Ophtha/mol 1984;102: Rothfus WE, Curtin HD, Siamovitis TL, Kennerdell JS. Opti nerve/sheath enlargement. Radiology 1984;150: Osborne DR, Foulks GN. Computed tomographi analysis of deformity and dimensional hanges in the eyeball. Radiology 1984;153 :