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The Natural History of Glaucoma and Ocular Hypertension After Pediatric Cataract Surgery
The Natural History of Glaucoma and Ocular Hypertension After Pediatric Cataract Surgery James E. Egbert, MD,a Stephen P. Christiansen, MD,b Martha M. Wright, MD,b Terri L. Young, MD,c and C. Gail Summers, MDb,d Introduction: We sought to define the prevalence and natural history of ocular hypertension and glaucoma for at least a 10-year period after pediatric cataract surgery. Methods: We conducted a prospective observational study of patients who received pediatric cataract surgery. Inclusion criteria included 2 directed ophthalmologic examinations performed at a minimum of 5 and 10 years after surgery. Results: A total of 63 patients (22 with bilateral cataracts and 41 with unilateral cataracts) were examined at a median of 15.1 year (range, 10.3-21.3 years) after surgery. A majority of the subjects had glaucoma or ocular hypertension (ie, 59%; 37/63). Nineteen percent (12/63) had glaucoma (5/22 with bilateral cataracts and 7/41 with unilateral cataracts). Approximately half (7/12) had developed glaucoma during the first 5-year observational period and the remainder (5/12) developed it during the following observational period. Forty percent (25/63) of the patients had ocular hypertension in at least one aphakic eye (9/23 with bilateral cataracts and 16/40 with unilateral cataracts). The rate of progression from ocular hypertension to glaucoma over a mean observational period of 7.2 years (range, 6.2-8.1 years) was 23% (5/22). Discussion: Patients who receive surgery for pediatric cataracts are at very high risk of developing ocular hypertension and glaucoma. Patients can develop late-onset glaucoma and ocular hypertension more than 10 years after surgery. Years of ocular hypertension may precede the diagnosis of late-onset glaucoma. (J AAPOS 2006;10:54-57) phakic glaucoma after surgery for pediatric cataract is a common cause of glaucoma in the pediatric age group.1 Most studies of glaucoma after pediatric cataract surgery are retrospective chart reviews.2-11 These studies have estimated the risk of glaucoma after pediatric cataract surgery and the influence of age at surgery, type of cataract, corneal diameter, length of time after surgery, and the presence or absence of an intraocular lens. However, few reports have used diagnostic criteria commonly used in the literature for adult-onset glaucoma to differentiate between subjects with ocular hypertension and glaucoma.12,13 Moreover, few prospective studies exist, and none have estimated the risk of progression to glaucoma in pediatric aphakic patients with ocular hypertension.12,14
A
From the aDepartment of Surgery, Division of Ophthalmology, Santa Clara Valley Medical Center, San Jose, California; bUniversity of Minnesota, Department of Ophthalmology, Minneapolis, Minnesota; cUniversity of Pennsylvania, Division of Ophthalmology, Philadelphia, Pennsylvania; and dUniversity of Minnesota, Department of Pediatrics, Minneapolis, Minnesota. Submitted April 2, 2003. Revision accepted July 8, 2005. Reprint requests: James E. Egbert, MD, Department of Surgery Division of Ophthalmology, 751 South Bascom Avenue, San Jose, CA 95128-2699 (e-mail address: James.Egbert@ hhs.co.santa-clara.ca.us). Copyright © 2006 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2006/$35.00 ⫹ 0 doi:10.1016/j.jaapos.2005.07.002
54
February 2006
Previously, we reported the results of a prospective study designed to estimate the prevalence of ocular hypertension and glaucoma after surgery for pediatric cataracts.12 We found 9% of subjects had glaucoma and 37% of subjects had ocular hypertension after a minimum of 5 years after an automated lensectomy and vitrectomy for pediatric cataracts. We now report long-term data from this ongoing prospective study, including the change in prevalence of ocular hypertension and glaucoma with time, the rate of progression from ocular hypertension to glaucoma and the influence subject variables have upon the development of ocular hypertension and glaucoma.
MATERIALS AND METHODS This study used a retrospective review of medical records to identify subjects to be studied prospectively. Permission for performing the retrospective and prospective portions of this study was obtained from the Institutional Review Board of the University of Minnesota. A computerized search of medical records was performed to identify pediatric subjects younger than 10 years of age who underwent an automated lensectomy and anterior vitrectomy for congenital or pediatric cataracts from 1978 through 1987 by the Pediatric Ophthalmology Service at the University of Minnesota.12 No subject received an IOL at the time of cataract surgery. Exclusion criteria included coexisting ocular or systemic anomalies associated with glaucoma, inJournal of AAPOS
Journal of AAPOS Volume 10 Number 1 February 2006
cluding trauma, uveitis, microphthalmia, radiation therapy for intraocular or intraorbital tumors, retinopathy of prematurity, congenital glaucoma, Reiger syndrome, aniridia, Peters anomaly, or retinal detachment. The age and corneal diameter in the horizontal meridian at the time of surgery were noted. Ophthalmology examinations documented in the records were reviewed and intraocular pressures, occurrence of complications, and the onset of glaucoma treatment were recorded. All subjects identified by the search of medical records were invited to participate in a long-term prospective study of ocular hypertension and glaucoma after pediatric cataract surgery. All subjects have subsequently received 2 directed ophthalmology examinations for glaucoma, which occurred at minimum of 5 and 10 years after surgery. These 2 glaucoma-directed study examinations are henceforth referred to as the 5- and 10-year examinations. The results from the 5-year examination were reported previously.12 The results of the 5- and 10-year examinations were documented on a data acquisition form. The form included measurements of the corneal diameter, intraocular pressure, cycloplegic refraction, an optic nerve head examination and a request for photographs of the optic nerve. Subjects were encouraged to return to the University of Minnesota for the study examinations. If this was not possible, the data acquisition forms were completed by the subject’s local ophthalmologist. The data acquisition form and optic nerve photographs were sent to the study coordinator for interpretation by the authors. A calibrated Goldmann tonometer, Tonopen (Mentor O&O, Inc, Norwell, MA), or a pneumatonometer measured the intraocular pressure. The intraocular pressure determination was considered valid if the child was able to cooperate without duress or squeezing of the eyelids. When optic nerve photographs were obtained, these were used to estimate the cup: disk ratio. For all subjects, the diagnosis of glaucoma required the intraocular pressure to be greater than 21 mm Hg and the optic nerve head to have one or more of the following features consistent with glaucoma. A difference in the cup: disk ratio of 0.2 or greater on clinical examination, a cup: disk ratio greater than 0.5, an increase in cup: disk ratio of 0.2 or greater on sequential clinical examinations or any increase in cup: disk ratio on sequentially obtained optic nerve photographs. For instance, a subject with bilateral aphakia, an intraocular pressure greater than 21 mm Hg in each eye and bilateral cup: disk ratios of 0.6 would be diagnosed with glaucoma in each eye. Subjects receiving glaucoma medications at the time of the study examination required the presence of optic nerve head abnormalities to be diagnosed as having glaucoma. When subjects were diagnosed with glaucoma, they continued to be classified as having glaucoma throughout the study. A diagnosis of ocular hypertension required the intraocular pressure to be greater than 21 mm Hg with an absence of the aforementioned optic nerve abnormalities.
Egbert et al
55
Because the outcomes of right and left eyes were highly correlated in individuals with bilateral cataracts, the analysis for subjects with bilateral cataracts were by subject rather than by eye. For subjects with a different diagnosis between the 2 eyes, the more severe diagnosis was used to classify the patient. For instance, a subject with glaucoma in one eye and ocular hypertension in the contralateral eye or, a subject with a normal examination in one eye and ocular hypertension in the contralateral eye, received a diagnosis of glaucoma and ocular hypertension, respectively. Groups were compared with respect to continuous variables by means of Wilcoxon’s rank-sum test. P ⬍ 0.05 was indicative of a statistically significant difference. Previously, we reported the results of the 5-year examination.12 We now report the results of the 10-year examination.
RESULTS We enrolled 63 subjects who had lensectomy and automated vitrectomy for pediatric cataract (22 with bilateral cataracts and 41 with unilateral cataracts). The 10-year examination occurred at a median of 15.1 years (range, 10.33-21.25 years) after surgery. The mean duration between the 5- and 10-year examinations was 7.1 years (range, 5.1– 8.4 years). Of the 62 previously reported subjects, 60 (97%) continued to participate in the study.12 These included 21 (95%) of 22 subjects with bilateral cataracts and 39 (98%) of 40 subjects with unilateral cataracts. The 2 subjects who did not continue with the study were diagnosed with ocular hypertension (bilateral cataracts), and a normal examination (unilateral cataract) at the 5-year examination. Three subjects (one with bilateral cataracts, 2 with unilateral cataracts) were not included in the previous study documenting the 5-year examination results but are included in this report. All 3 subjects received a 5- and 10-year examination. One subject with bilateral cataracts had a normal examination at the 5-year examination but was diagnosed with ocular hypertension in both eyes at the 10-year examination. A second subject with a unilateral cataract was diagnosed with glaucoma at the 5-year examination and the contralateral phakic eye was normal. The third subject had a unilateral cataract and a normal examination at the 5-year examination but had ocular hypertension at the ten-year examination. The contralateral phakic eye for this subject was normal. Of the 63 subjects, 45 were examined at the University of Minnesota, and 18 were examined by their local ophthalmologists. All subjects were able to cooperate with intraocular pressure measurement and optic nerve examination. Thirty-one of 63 (49%; 13 with bilateral cataracts and 18 with unilateral cataracts) had optic nerve photographs obtained at the 5- and 10-year examinations. Corneal diameter, cycloplegic refractive error, and visual acuity were recorded less than 50% of the time and hence, these variables were not analyzed. The prevalence of ocular hypertension or glaucoma at the 10-year examination was 59% (37/63). Patients with
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bilateral cataracts had a prevalence of either disorder of 64% (14/22). Patients with unilateral cataracts had a prevalence for either disorder of 56% (23/41). Twelve of 63 subjects (19%) had glaucoma (5/22 with bilateral cataracts and 7/41 with unilateral cataracts). Seven subjects (2 bilateral cataracts, 5 unilateral cataract) had glaucoma at the 5-year examination for a prevalence of 11%. Five additional subjects (3 bilateral cataracts, 2 unilateral cataracts) had glaucoma at the 10-year examination. All 5 subjects who had newly diagnosed glaucoma at the 10-year examination had ocular hypertension at the 5-year examination. The rate of progression from ocular hypertension to glaucoma over a mean observational period of 7.2 years (range, 6.2-8.1 years), was 23% (5/22). Two of the 5 subjects who progressed from ocular hypertension to glaucoma received glaucoma medications after being diagnosed with ocular hypertension. The remaining 3 subjects received no treatment until the diagnosis of glaucoma was made. None of the subjects with unilateral cataracts had developed glaucoma in the noncataractous eye. Smaller preoperative corneal diameters were observed more frequently in subjects who developed glaucoma than in normal subjects (P ⬍ 0.005). However, at least 5 subjects with a corneal diameter in the range of 10-12 mm at the time of surgery developed glaucoma. The smallest corneal diameter in subjects who had normal examinations was 9.5 mm and was present in 2 subjects. There was no statistically significant difference in age at surgery between subjects with glaucoma and normal subjects. The prevalence of ocular hypertension at the 10-year examination was 40% (25/63; 9 with bilateral cataracts and 16 with unilateral cataracts). Twenty-two subjects had ocular hypertension at the 5-year examination for a prevalence of 35%. Eight subjects with a normal intraocular pressure at the 5-year examination had ocular hypertension at the 10-year examination (2 bilateral cataracts, and 6 unilateral cataracts). The rate of progression from a normal examination at the five-year examination to ocular hypertension at the 10-year examination was 24% (8/34) over a mean observational period of 7.2 years (5.1-8.4 years). There was no statistically significant difference in age or corneal diameter at the time of cataract extraction between subjects with ocular hypertension and normal subjects. Eight patients with unilateral cataracts had ocular hypertension in the noncataractous phakic eye. The maximum intraocular pressure recorded was 25 mm Hg for 3, 24 mm Hg for 1, 23 mm Hg for 3, and 22 mmg for 1. Seven of the 8 subjects had abnormalities in the aphakic eye. Four had ocular hypertension, and 3 had glaucoma in the aphakic eye. No patient with unilateral cataracts had glaucoma in the noncataractous phakic eye.
DISCUSSION This ongoing prospective study of aphakic glaucoma after automated lensectomy and vitrectomy for cataracts in the
Journal of AAPOS Volume 10 Number 1 February 2006
pediatric age group demonstrates a high prevalence of ocular hypertension and glaucoma 5 and 10 years after surgery. The prevalence of either disorder at the 5-year examination was 47%.1 At the 10-year examination, a majority of subjects (59%) had glaucoma or ocular hypertension. Seven subjects had glaucoma at the 5-year examination for a prevalence of 11%.12 At the 10-year examination, 9% (5/56) of the remaining subject pool without glaucoma developed glaucoma, suggesting that the rate of developing glaucoma does not decrease during the first 10 years after pediatric cataract surgery. Therefore, the patient who has not developed glaucoma 5 years after surgery may still develop the disease during subsequent years of observation. All 5 subjects who were diagnosed with glaucoma at the 10-year examination had ocular hypertension at the 5-year examination. The rate of progression from ocular hypertension to aphakic glaucoma was 23% during a mean observational period of 7.2 years. Given the high prevalence of ocular hypertension after surgery for pediatric cataracts, a 23% rate of progression to glaucoma is alarming. We were unable to locate any previous study of the rate of progression from ocular hypertension to glaucoma in children after surgery for pediatric cataracts. Further prospective observations of these subjects will allow us to determine whether the rate of developing glaucoma will increase, decrease, or remain the same in subsequent years. Recently, the rate of progression from ocular hypertension to open-angle glaucoma in phakic adults participating in the ocular hypertension treatment study was reported. The rate of progression was 9.5% over the course of 5 years.15 The subjects in this study had a high prevalence of ocular hypertension after surgery for pediatric cataracts. At the 5-year examination, 37% of subjects had ocular hypertension.12 At the 10-year examination 24% (8/33) of patients with previously normal findings had ocular hypertension. Further observation will determine whether patients who had a normal examination at the 10-year examination will subsequently develop ocular hypertension and glaucoma. Eight of 41 subjects with unilateral aphakia had ocular hypertension in the contralateral phakic eye. None had received treatment to the hypertensive phakic eye because of the presence of a normal optic nerve, the intermittent nature of the hypertension, and the fact that the maximum intraocular pressure recorded was 25 mm Hg. Abnormalities in the noncataractous eye of patients with unilateral cataracts have been reported.16 In a retrospective study of 97 pediatric patients receiving monocular cataract surgery two patients had congenital glaucoma in the normal eye.16. A family history for glaucoma was not obtained for our subjects. All subjects were able to cooperate with measurement of intraocular pressure and optic nerve head examination. Many were able to cooperate with nonsedated optic nerve head photography. Sequential optic nerve head photo-
Journal of AAPOS Volume 10 Number 1 February 2006
graphs increased our ability to diagnose changes in the optic nerve head compared with numerical or hand drawn representations of the optic nerve head. The use of highspeed film allowed us to obtain clear photographs of the optic nerve head in subjects with nystagmus. Photographs given to parents and retained in the medical records can enhance continuing care if multiple physicians are involved or if care is transferred to another physician. The placement of IOLs in children with pediatric cataracts has become more common. Some authors have hypothesized that the IOL may protect pediatric patients from developing pseudophakic glaucoma.11 The first published report from a multicenter prospective study of IOL implantation in children younger than 6 months of age documented a high rate of complications and pseudophakic glaucoma.17 The subjects in our study did not receive an IOL at the time of pediatric cataract surgery. We did not include secondary IOL placement on the data acquisition form. This information will be requested in future examinations. It is not known when, if ever, a child who has had surgery for cataracts is no longer at risk for ocular hypertension or glaucoma. Children can develop glaucoma more than 10 years after uneventful cataract surgery. Many subjects with a normal examination 5 years after surgery subsequently developed ocular hypertension. We recommend that children who have received surgery for cataracts receive regular directed examinations for ocular hypertension and glaucoma throughout their lives. References 1. Taylor RH, Ainsworth JR, Evans AR, Levin AV. The epidemiology of pediatric glaucoma: the Toronto experience. J AAPOS 1999;3:308-15. 2. Francois J. Late results of congenital cataract surgery. Ophthalmology 1979;86:1586-98.
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3. Phelps CD, Arafat NI. Open-angle glaucoma following surgery for congenital cataracts. Arch Ophthalmol 1977;95:1985-7. 4. Chrousos GA, Parks MM, O’Neill JF. Incidence of chronic glaucoma, retinal detachment and secondary membrane surgery in pediatric aphakic patients. Ophthalmology 1984;91:1238-41. 5. Keech RV, Tongue AC, Scott WE. Complications after surgery for congenital and infantile cataracts. Am J Ophthalmol 1989;108:136-41. 6. Pressman SH, Crouch ER Jr. Pediatric aphakic glaucoma. Ann Ophthalmol 1983;15:568-73. 7. Robb RM, Petersen RA. Outcome of treatment for bilateral congenital cataracts. Ophthalmic Surg 1992;23:650-6. 8. Parks MM, Johnson DA, Reed GW. Long-term visual results and complications in children with aphakia. A function of cataract type. Ophthalmology. 1993;100:826-41. 9. Mills MD, Robb RM. Glaucoma following childhood cataract surgery. J Pediatr Ophthalmol Strabismus 1994;31:355-60. 10. Magnusson G, Abrahamsson M, Sjostrand J. Glaucoma following congenital cataract surgery: an 18-year longitudinal follow-up. Acta Ophthalmol Scand 2000;78:65-70. 11. Asrani S, Freedman S, Hasselblad V, Buckley EG, Egbert J, Dahan E, Gimbel H, Johnson D, McClatchey S, Parks M, Plager D, Maselli E. Does primary intraocular lens implantation prevent “aphakic” glaucoma in children?. J AAPOS 2000;4:33-9. 12. Egbert JE, Wright MM, Dahlhauser KF, Keithahn MAZ, Letson RD, Summers CG. A prospective study of ocular hypertension and glaucoma after pediatric cataract surgery. Ophthalmology 1995;102: 1098-101. 13. Mori M, Keeech RV, Scott WE. Glaucoma and ocular hypertension in pediatric patients with cataracts. J AAPOS 1997;1:98-101. 14. Simon JW, Megta N, Simmons ST, Catalano RA, Lininger LL. Glaucoma after pediatric lensectony/vitrectomy. Ophthalmology 1991;98:671-4. 15. Kass MA, Heuer DK, Higginbotham EJ, Johnson CA, Keltner JL, Miller JP, Parrish RK, Wilson MR, Gordon MO. The ocular hypertension treatment study. Arch Ophthalmol 2002;120:701-13. 16. Summers CG, Letson RD. Is the phakic eye normal in monocular pediatric aphakia? J Pediatric Ophthalmol Strabismus 1992;29:324-7. 17. Plager DA, Yang S, Neely D, Sprunger D, Sondhi N. Complications in the first year following cataract surgery with and without IOL in infants and older children. J AAPOS 2002;6:9-14.
A
From the aDepartment of Surgery, Division of Ophthalmology, Santa Clara Valley Medical Center, San Jose, California; bUniversity of Minnesota, Department of Ophthalmology, Minneapolis, Minnesota; cUniversity of Pennsylvania, Division of Ophthalmology, Philadelphia, Pennsylvania; and dUniversity of Minnesota, Department of Pediatrics, Minneapolis, Minnesota. Submitted April 2, 2003. Revision accepted July 8, 2005. Reprint requests: James E. Egbert, MD, Department of Surgery Division of Ophthalmology, 751 South Bascom Avenue, San Jose, CA 95128-2699 (e-mail address: James.Egbert@ hhs.co.santa-clara.ca.us). Copyright © 2006 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/2006/$35.00 ⫹ 0 doi:10.1016/j.jaapos.2005.07.002
54
February 2006
Previously, we reported the results of a prospective study designed to estimate the prevalence of ocular hypertension and glaucoma after surgery for pediatric cataracts.12 We found 9% of subjects had glaucoma and 37% of subjects had ocular hypertension after a minimum of 5 years after an automated lensectomy and vitrectomy for pediatric cataracts. We now report long-term data from this ongoing prospective study, including the change in prevalence of ocular hypertension and glaucoma with time, the rate of progression from ocular hypertension to glaucoma and the influence subject variables have upon the development of ocular hypertension and glaucoma.
MATERIALS AND METHODS This study used a retrospective review of medical records to identify subjects to be studied prospectively. Permission for performing the retrospective and prospective portions of this study was obtained from the Institutional Review Board of the University of Minnesota. A computerized search of medical records was performed to identify pediatric subjects younger than 10 years of age who underwent an automated lensectomy and anterior vitrectomy for congenital or pediatric cataracts from 1978 through 1987 by the Pediatric Ophthalmology Service at the University of Minnesota.12 No subject received an IOL at the time of cataract surgery. Exclusion criteria included coexisting ocular or systemic anomalies associated with glaucoma, inJournal of AAPOS
Journal of AAPOS Volume 10 Number 1 February 2006
cluding trauma, uveitis, microphthalmia, radiation therapy for intraocular or intraorbital tumors, retinopathy of prematurity, congenital glaucoma, Reiger syndrome, aniridia, Peters anomaly, or retinal detachment. The age and corneal diameter in the horizontal meridian at the time of surgery were noted. Ophthalmology examinations documented in the records were reviewed and intraocular pressures, occurrence of complications, and the onset of glaucoma treatment were recorded. All subjects identified by the search of medical records were invited to participate in a long-term prospective study of ocular hypertension and glaucoma after pediatric cataract surgery. All subjects have subsequently received 2 directed ophthalmology examinations for glaucoma, which occurred at minimum of 5 and 10 years after surgery. These 2 glaucoma-directed study examinations are henceforth referred to as the 5- and 10-year examinations. The results from the 5-year examination were reported previously.12 The results of the 5- and 10-year examinations were documented on a data acquisition form. The form included measurements of the corneal diameter, intraocular pressure, cycloplegic refraction, an optic nerve head examination and a request for photographs of the optic nerve. Subjects were encouraged to return to the University of Minnesota for the study examinations. If this was not possible, the data acquisition forms were completed by the subject’s local ophthalmologist. The data acquisition form and optic nerve photographs were sent to the study coordinator for interpretation by the authors. A calibrated Goldmann tonometer, Tonopen (Mentor O&O, Inc, Norwell, MA), or a pneumatonometer measured the intraocular pressure. The intraocular pressure determination was considered valid if the child was able to cooperate without duress or squeezing of the eyelids. When optic nerve photographs were obtained, these were used to estimate the cup: disk ratio. For all subjects, the diagnosis of glaucoma required the intraocular pressure to be greater than 21 mm Hg and the optic nerve head to have one or more of the following features consistent with glaucoma. A difference in the cup: disk ratio of 0.2 or greater on clinical examination, a cup: disk ratio greater than 0.5, an increase in cup: disk ratio of 0.2 or greater on sequential clinical examinations or any increase in cup: disk ratio on sequentially obtained optic nerve photographs. For instance, a subject with bilateral aphakia, an intraocular pressure greater than 21 mm Hg in each eye and bilateral cup: disk ratios of 0.6 would be diagnosed with glaucoma in each eye. Subjects receiving glaucoma medications at the time of the study examination required the presence of optic nerve head abnormalities to be diagnosed as having glaucoma. When subjects were diagnosed with glaucoma, they continued to be classified as having glaucoma throughout the study. A diagnosis of ocular hypertension required the intraocular pressure to be greater than 21 mm Hg with an absence of the aforementioned optic nerve abnormalities.
Egbert et al
55
Because the outcomes of right and left eyes were highly correlated in individuals with bilateral cataracts, the analysis for subjects with bilateral cataracts were by subject rather than by eye. For subjects with a different diagnosis between the 2 eyes, the more severe diagnosis was used to classify the patient. For instance, a subject with glaucoma in one eye and ocular hypertension in the contralateral eye or, a subject with a normal examination in one eye and ocular hypertension in the contralateral eye, received a diagnosis of glaucoma and ocular hypertension, respectively. Groups were compared with respect to continuous variables by means of Wilcoxon’s rank-sum test. P ⬍ 0.05 was indicative of a statistically significant difference. Previously, we reported the results of the 5-year examination.12 We now report the results of the 10-year examination.
RESULTS We enrolled 63 subjects who had lensectomy and automated vitrectomy for pediatric cataract (22 with bilateral cataracts and 41 with unilateral cataracts). The 10-year examination occurred at a median of 15.1 years (range, 10.33-21.25 years) after surgery. The mean duration between the 5- and 10-year examinations was 7.1 years (range, 5.1– 8.4 years). Of the 62 previously reported subjects, 60 (97%) continued to participate in the study.12 These included 21 (95%) of 22 subjects with bilateral cataracts and 39 (98%) of 40 subjects with unilateral cataracts. The 2 subjects who did not continue with the study were diagnosed with ocular hypertension (bilateral cataracts), and a normal examination (unilateral cataract) at the 5-year examination. Three subjects (one with bilateral cataracts, 2 with unilateral cataracts) were not included in the previous study documenting the 5-year examination results but are included in this report. All 3 subjects received a 5- and 10-year examination. One subject with bilateral cataracts had a normal examination at the 5-year examination but was diagnosed with ocular hypertension in both eyes at the 10-year examination. A second subject with a unilateral cataract was diagnosed with glaucoma at the 5-year examination and the contralateral phakic eye was normal. The third subject had a unilateral cataract and a normal examination at the 5-year examination but had ocular hypertension at the ten-year examination. The contralateral phakic eye for this subject was normal. Of the 63 subjects, 45 were examined at the University of Minnesota, and 18 were examined by their local ophthalmologists. All subjects were able to cooperate with intraocular pressure measurement and optic nerve examination. Thirty-one of 63 (49%; 13 with bilateral cataracts and 18 with unilateral cataracts) had optic nerve photographs obtained at the 5- and 10-year examinations. Corneal diameter, cycloplegic refractive error, and visual acuity were recorded less than 50% of the time and hence, these variables were not analyzed. The prevalence of ocular hypertension or glaucoma at the 10-year examination was 59% (37/63). Patients with
56
Egbert et al
bilateral cataracts had a prevalence of either disorder of 64% (14/22). Patients with unilateral cataracts had a prevalence for either disorder of 56% (23/41). Twelve of 63 subjects (19%) had glaucoma (5/22 with bilateral cataracts and 7/41 with unilateral cataracts). Seven subjects (2 bilateral cataracts, 5 unilateral cataract) had glaucoma at the 5-year examination for a prevalence of 11%. Five additional subjects (3 bilateral cataracts, 2 unilateral cataracts) had glaucoma at the 10-year examination. All 5 subjects who had newly diagnosed glaucoma at the 10-year examination had ocular hypertension at the 5-year examination. The rate of progression from ocular hypertension to glaucoma over a mean observational period of 7.2 years (range, 6.2-8.1 years), was 23% (5/22). Two of the 5 subjects who progressed from ocular hypertension to glaucoma received glaucoma medications after being diagnosed with ocular hypertension. The remaining 3 subjects received no treatment until the diagnosis of glaucoma was made. None of the subjects with unilateral cataracts had developed glaucoma in the noncataractous eye. Smaller preoperative corneal diameters were observed more frequently in subjects who developed glaucoma than in normal subjects (P ⬍ 0.005). However, at least 5 subjects with a corneal diameter in the range of 10-12 mm at the time of surgery developed glaucoma. The smallest corneal diameter in subjects who had normal examinations was 9.5 mm and was present in 2 subjects. There was no statistically significant difference in age at surgery between subjects with glaucoma and normal subjects. The prevalence of ocular hypertension at the 10-year examination was 40% (25/63; 9 with bilateral cataracts and 16 with unilateral cataracts). Twenty-two subjects had ocular hypertension at the 5-year examination for a prevalence of 35%. Eight subjects with a normal intraocular pressure at the 5-year examination had ocular hypertension at the 10-year examination (2 bilateral cataracts, and 6 unilateral cataracts). The rate of progression from a normal examination at the five-year examination to ocular hypertension at the 10-year examination was 24% (8/34) over a mean observational period of 7.2 years (5.1-8.4 years). There was no statistically significant difference in age or corneal diameter at the time of cataract extraction between subjects with ocular hypertension and normal subjects. Eight patients with unilateral cataracts had ocular hypertension in the noncataractous phakic eye. The maximum intraocular pressure recorded was 25 mm Hg for 3, 24 mm Hg for 1, 23 mm Hg for 3, and 22 mmg for 1. Seven of the 8 subjects had abnormalities in the aphakic eye. Four had ocular hypertension, and 3 had glaucoma in the aphakic eye. No patient with unilateral cataracts had glaucoma in the noncataractous phakic eye.
DISCUSSION This ongoing prospective study of aphakic glaucoma after automated lensectomy and vitrectomy for cataracts in the
Journal of AAPOS Volume 10 Number 1 February 2006
pediatric age group demonstrates a high prevalence of ocular hypertension and glaucoma 5 and 10 years after surgery. The prevalence of either disorder at the 5-year examination was 47%.1 At the 10-year examination, a majority of subjects (59%) had glaucoma or ocular hypertension. Seven subjects had glaucoma at the 5-year examination for a prevalence of 11%.12 At the 10-year examination, 9% (5/56) of the remaining subject pool without glaucoma developed glaucoma, suggesting that the rate of developing glaucoma does not decrease during the first 10 years after pediatric cataract surgery. Therefore, the patient who has not developed glaucoma 5 years after surgery may still develop the disease during subsequent years of observation. All 5 subjects who were diagnosed with glaucoma at the 10-year examination had ocular hypertension at the 5-year examination. The rate of progression from ocular hypertension to aphakic glaucoma was 23% during a mean observational period of 7.2 years. Given the high prevalence of ocular hypertension after surgery for pediatric cataracts, a 23% rate of progression to glaucoma is alarming. We were unable to locate any previous study of the rate of progression from ocular hypertension to glaucoma in children after surgery for pediatric cataracts. Further prospective observations of these subjects will allow us to determine whether the rate of developing glaucoma will increase, decrease, or remain the same in subsequent years. Recently, the rate of progression from ocular hypertension to open-angle glaucoma in phakic adults participating in the ocular hypertension treatment study was reported. The rate of progression was 9.5% over the course of 5 years.15 The subjects in this study had a high prevalence of ocular hypertension after surgery for pediatric cataracts. At the 5-year examination, 37% of subjects had ocular hypertension.12 At the 10-year examination 24% (8/33) of patients with previously normal findings had ocular hypertension. Further observation will determine whether patients who had a normal examination at the 10-year examination will subsequently develop ocular hypertension and glaucoma. Eight of 41 subjects with unilateral aphakia had ocular hypertension in the contralateral phakic eye. None had received treatment to the hypertensive phakic eye because of the presence of a normal optic nerve, the intermittent nature of the hypertension, and the fact that the maximum intraocular pressure recorded was 25 mm Hg. Abnormalities in the noncataractous eye of patients with unilateral cataracts have been reported.16 In a retrospective study of 97 pediatric patients receiving monocular cataract surgery two patients had congenital glaucoma in the normal eye.16. A family history for glaucoma was not obtained for our subjects. All subjects were able to cooperate with measurement of intraocular pressure and optic nerve head examination. Many were able to cooperate with nonsedated optic nerve head photography. Sequential optic nerve head photo-
Journal of AAPOS Volume 10 Number 1 February 2006
graphs increased our ability to diagnose changes in the optic nerve head compared with numerical or hand drawn representations of the optic nerve head. The use of highspeed film allowed us to obtain clear photographs of the optic nerve head in subjects with nystagmus. Photographs given to parents and retained in the medical records can enhance continuing care if multiple physicians are involved or if care is transferred to another physician. The placement of IOLs in children with pediatric cataracts has become more common. Some authors have hypothesized that the IOL may protect pediatric patients from developing pseudophakic glaucoma.11 The first published report from a multicenter prospective study of IOL implantation in children younger than 6 months of age documented a high rate of complications and pseudophakic glaucoma.17 The subjects in our study did not receive an IOL at the time of pediatric cataract surgery. We did not include secondary IOL placement on the data acquisition form. This information will be requested in future examinations. It is not known when, if ever, a child who has had surgery for cataracts is no longer at risk for ocular hypertension or glaucoma. Children can develop glaucoma more than 10 years after uneventful cataract surgery. Many subjects with a normal examination 5 years after surgery subsequently developed ocular hypertension. We recommend that children who have received surgery for cataracts receive regular directed examinations for ocular hypertension and glaucoma throughout their lives. References 1. Taylor RH, Ainsworth JR, Evans AR, Levin AV. The epidemiology of pediatric glaucoma: the Toronto experience. J AAPOS 1999;3:308-15. 2. Francois J. Late results of congenital cataract surgery. Ophthalmology 1979;86:1586-98.
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3. Phelps CD, Arafat NI. Open-angle glaucoma following surgery for congenital cataracts. Arch Ophthalmol 1977;95:1985-7. 4. Chrousos GA, Parks MM, O’Neill JF. Incidence of chronic glaucoma, retinal detachment and secondary membrane surgery in pediatric aphakic patients. Ophthalmology 1984;91:1238-41. 5. Keech RV, Tongue AC, Scott WE. Complications after surgery for congenital and infantile cataracts. Am J Ophthalmol 1989;108:136-41. 6. Pressman SH, Crouch ER Jr. Pediatric aphakic glaucoma. Ann Ophthalmol 1983;15:568-73. 7. Robb RM, Petersen RA. Outcome of treatment for bilateral congenital cataracts. Ophthalmic Surg 1992;23:650-6. 8. Parks MM, Johnson DA, Reed GW. Long-term visual results and complications in children with aphakia. A function of cataract type. Ophthalmology. 1993;100:826-41. 9. Mills MD, Robb RM. Glaucoma following childhood cataract surgery. J Pediatr Ophthalmol Strabismus 1994;31:355-60. 10. Magnusson G, Abrahamsson M, Sjostrand J. Glaucoma following congenital cataract surgery: an 18-year longitudinal follow-up. Acta Ophthalmol Scand 2000;78:65-70. 11. Asrani S, Freedman S, Hasselblad V, Buckley EG, Egbert J, Dahan E, Gimbel H, Johnson D, McClatchey S, Parks M, Plager D, Maselli E. Does primary intraocular lens implantation prevent “aphakic” glaucoma in children?. J AAPOS 2000;4:33-9. 12. Egbert JE, Wright MM, Dahlhauser KF, Keithahn MAZ, Letson RD, Summers CG. A prospective study of ocular hypertension and glaucoma after pediatric cataract surgery. Ophthalmology 1995;102: 1098-101. 13. Mori M, Keeech RV, Scott WE. Glaucoma and ocular hypertension in pediatric patients with cataracts. J AAPOS 1997;1:98-101. 14. Simon JW, Megta N, Simmons ST, Catalano RA, Lininger LL. Glaucoma after pediatric lensectony/vitrectomy. Ophthalmology 1991;98:671-4. 15. Kass MA, Heuer DK, Higginbotham EJ, Johnson CA, Keltner JL, Miller JP, Parrish RK, Wilson MR, Gordon MO. The ocular hypertension treatment study. Arch Ophthalmol 2002;120:701-13. 16. Summers CG, Letson RD. Is the phakic eye normal in monocular pediatric aphakia? J Pediatric Ophthalmol Strabismus 1992;29:324-7. 17. Plager DA, Yang S, Neely D, Sprunger D, Sondhi N. Complications in the first year following cataract surgery with and without IOL in infants and older children. J AAPOS 2002;6:9-14.