Acta Ophthalmologica 2015
Outcome of surgical treatment of primary and secondary glaucoma in young children Madeleine Zetterberg,1,2 Alf Nystr€ om,2 Lada Kalaboukhova1,2 and Gunilla Magnusson1,2 1
Department of Clinical Neuroscience and Rehabilitation/Ophthalmology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden 2 The Eye Clinic at Sahlgrenska University Hospital, M€ olndal, Sweden
ABSTRACT. Purpose: To describe a paediatric cohort surgically treated for primary or secondary glaucoma (PG/SG), with regard to incidences, visual outcome and control of intraocular pressure (IOP). Methods: All children (n = 29, 42 eyes in total) surgically treated for PG or SG at the age of 4 years or younger between January 2002 and December 2010 at Sahlgrenska University Hospital in M€ olndal were retrospectively studied through medical records. Median follow-up time after initial surgery was 5.9 years (range 2.4–11.2 years). Results: The incidence of primary congenital glaucoma was 4.3 cases per 100 000 live births in the county of V€ astra G€ otaland. For glaucoma secondary to cataract surgery, the incidence was 13% with a median postoperative duration to diagnosis of glaucoma of 3.8 months (range 1.6 months to 4.3 years). Preoperative mean IOP was 31.5 (SD 8.1) mmHg, and mean IOP at last visit was 17.1 (SD 4.4) mmHg. For the entire cohort, 30% of the glaucoma eyes required more than two IOP-lowering surgical procedures during the study period. BCVA was ≥0.3 (decimal) in 45% of glaucomatous eyes at last follow-up with no statistically significant difference between PG and SG. Analysis of functional visual outcome, that is BCVA in the better eye, showed that 83% of all patients attained a BCVA of ≥0.5. Conclusions: The incidences and outcome of surgically treated paediatric glaucoma were in accordance with previous studies. Chamber angle surgery, and if necessary, tube implantation without the use of antimetabolites, is a favourable approach leaving most sites needed for future glaucoma surgery unaffected. Key words: aphakic glaucoma – congenital cataract – congenital glaucoma – glaucoma surgery – intraocular pressure – visual acuity
Acta Ophthalmol. 2015: 93: 269–275 ª 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd
doi: 10.1111/aos.12566
Introduction The term paediatric glaucoma refers to a rare, sight-threatening condition in children with increased intraocular pressure (IOP) and risk of blindness. Typical symptoms at the debut include lacrimation, photophobia, blepharospasm,
buphthalmos, corneal oedema and impaired vision (Papadopoulos et al. 2013). This condition can be classified as primary congenital glaucoma (PG) or secondary glaucoma (SG). The high intraocular pressure (IOP) in PG is due to partial or complete obstruction of the outflow of aqueous
humour. This was initially believed to result from the persistence of a thin membrane in the chamber angle, Barkan’s membrane, but later studies indicate that the pathogenic cause is an abnormal thickening of trabecular beams with tractions on the iris, that is a primary trabeculodysgenesis (Barkan 1955; Shaffer 1955; Jerndal 1972; Anderson 1981; Tawara & Inomata 1984). Secondary glaucoma can occur due to congenital or acquired ocular or systemic disorders but also as a complication to surgery for congenital cataract. Lower age at surgery confers a higher risk of this complication (Magnusson et al. 2000; Ruddle et al. 2013). Suggested mechanisms include chronic trabeculitis due to postoperative inflammation, increased outflow resistance due to lens remnants or chemical substances from the vitreous body (Kirwan & O’Keefe 2006). The risk of SG varies between 10% and 30% of all children having had cataract surgery (Mills & Robb 1994; Johnson & Keech 1996; Magnusson et al. 2000; Kirwan et al. 2010). The aim of this study was to determine the incidence of PG and the rate of SG after surgery of congenital cataract in the western part of Sweden and to report the outcome with regard to visual acuity and IOP control in young children with PG or SG treated surgically at the Eye Clinic at Sahlgrenska University Hospital, M€ olndal, between 2002 and 2010.
Materials and Methods During the period January 2002 to December 2010, a total of 29 children
269
Acta Ophthalmologica 2015
at the age of 0–4 years had surgery for glaucoma at the Sahlgrenska University Hospital in M€ olndal, one of two centres in Sweden performing this type of procedures. This age group was selected for analysis as glaucoma surgery in children 0–4 years recently was classified as National Specialised Medical Care by the Swedish National Board of Health and Welfare (Socialstyrelsen 2012). Data were collected from medical records, and the study was approved by the local ethical committee. The study adhered to the tenets of the Declaration of Helsinki. The majority of the patients (72.4%) were residents in the county of V€ astra G€ otaland, but eight children were from other, mainly the southern, parts of Sweden and referred to our clinic for IOP-lowering surgery. For diagnosis of glaucoma, at least one glaucomatous sign, such as increased axial length or corneal diameter, corneal oedema or glaucomatous disc appearance, in combination with elevated IOP was required. Subjects were denoted as primary glaucoma (PG) or secondary glaucoma (SG) based on the classification by Papadopoulos et al. (2013). In accordance with this classification, children who had congenital/acquired ocular or systemic disorders associated with glaucoma were designated as secondary glaucoma. Both the PG and the SG groups included children who had experienced cataract extraction. However, patients in the PG group were diagnosed with glaucoma prior to cataract surgery, whereas children who developed glaucoma after cataract surgery were denoted as secondary glaucoma. For determination of the incidence of primary glaucoma in the county of V€ astra G€ otaland, birth data for this region were obtained from the Regional Council Administration for population statistics. During the period 2002–2010, there were 161 441 live births in the region. Only patients with primary glaucoma born in the county of V€astra G€ otaland (n = 7) were included for this arithmetic procedure. The incidence of glaucoma secondary to cataract surgery was based on all paediatric patients experiencing cataract extraction between 2008 and 2010 at the Sahlgrenska University Hospital in M€ olndal. During this three-year period, reliable data on congenital cataract surgery could be collected through the national Swedish register
270
for paediatric cataract (Paediatric Cataract Register; PECARE). Age at last visit varied between 7 months and 14 years for the whole cohort. Mean follow-up time after diagnosis was 5.73 (SD 3.5) years and did not differ significantly between the PG and the SG groups. For three subjects, follow-up was short (less than 6 months) because one child died in Hutchinson– Gilford progeria at the age of 9 months and two children moved abroad or outside the county of V€ astra G€ otaland and medical journals could not be retrieved. To obtain a complete demographic description of all primary and secondary glaucoma cases during the study period, including underlying causes and for computation of the PG incidence in the county, no cases were excluded due to short follow-up (Table 1). For subsequent analysis of outcome measures, however, these three children were excluded, resulting in a mean follow-up after first surgery of 6.3 (SD 3.2) years for the entire cohort with a minimum follow-up time of 2.4 years (Table 2). Information on visual acuity at last follow-up could be obtained from 33 eyes (89%). Visual acuity, given as best corrected visual acuity (BCVA) in decimals, was tested using Snellen charts according to age and co-operation of the child (Kay picture test, HOTV and KM) (Kay 1983; Moutakis et al. 2004). A grading for visual function was used according to the World Health Organization’s (WHO) classification with a BCVA in decimals of
Outcome of surgical treatment of primary and secondary glaucoma in young children Madeleine Zetterberg,1,2 Alf Nystr€ om,2 Lada Kalaboukhova1,2 and Gunilla Magnusson1,2 1
Department of Clinical Neuroscience and Rehabilitation/Ophthalmology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden 2 The Eye Clinic at Sahlgrenska University Hospital, M€ olndal, Sweden
ABSTRACT. Purpose: To describe a paediatric cohort surgically treated for primary or secondary glaucoma (PG/SG), with regard to incidences, visual outcome and control of intraocular pressure (IOP). Methods: All children (n = 29, 42 eyes in total) surgically treated for PG or SG at the age of 4 years or younger between January 2002 and December 2010 at Sahlgrenska University Hospital in M€ olndal were retrospectively studied through medical records. Median follow-up time after initial surgery was 5.9 years (range 2.4–11.2 years). Results: The incidence of primary congenital glaucoma was 4.3 cases per 100 000 live births in the county of V€ astra G€ otaland. For glaucoma secondary to cataract surgery, the incidence was 13% with a median postoperative duration to diagnosis of glaucoma of 3.8 months (range 1.6 months to 4.3 years). Preoperative mean IOP was 31.5 (SD 8.1) mmHg, and mean IOP at last visit was 17.1 (SD 4.4) mmHg. For the entire cohort, 30% of the glaucoma eyes required more than two IOP-lowering surgical procedures during the study period. BCVA was ≥0.3 (decimal) in 45% of glaucomatous eyes at last follow-up with no statistically significant difference between PG and SG. Analysis of functional visual outcome, that is BCVA in the better eye, showed that 83% of all patients attained a BCVA of ≥0.5. Conclusions: The incidences and outcome of surgically treated paediatric glaucoma were in accordance with previous studies. Chamber angle surgery, and if necessary, tube implantation without the use of antimetabolites, is a favourable approach leaving most sites needed for future glaucoma surgery unaffected. Key words: aphakic glaucoma – congenital cataract – congenital glaucoma – glaucoma surgery – intraocular pressure – visual acuity
Acta Ophthalmol. 2015: 93: 269–275 ª 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd
doi: 10.1111/aos.12566
Introduction The term paediatric glaucoma refers to a rare, sight-threatening condition in children with increased intraocular pressure (IOP) and risk of blindness. Typical symptoms at the debut include lacrimation, photophobia, blepharospasm,
buphthalmos, corneal oedema and impaired vision (Papadopoulos et al. 2013). This condition can be classified as primary congenital glaucoma (PG) or secondary glaucoma (SG). The high intraocular pressure (IOP) in PG is due to partial or complete obstruction of the outflow of aqueous
humour. This was initially believed to result from the persistence of a thin membrane in the chamber angle, Barkan’s membrane, but later studies indicate that the pathogenic cause is an abnormal thickening of trabecular beams with tractions on the iris, that is a primary trabeculodysgenesis (Barkan 1955; Shaffer 1955; Jerndal 1972; Anderson 1981; Tawara & Inomata 1984). Secondary glaucoma can occur due to congenital or acquired ocular or systemic disorders but also as a complication to surgery for congenital cataract. Lower age at surgery confers a higher risk of this complication (Magnusson et al. 2000; Ruddle et al. 2013). Suggested mechanisms include chronic trabeculitis due to postoperative inflammation, increased outflow resistance due to lens remnants or chemical substances from the vitreous body (Kirwan & O’Keefe 2006). The risk of SG varies between 10% and 30% of all children having had cataract surgery (Mills & Robb 1994; Johnson & Keech 1996; Magnusson et al. 2000; Kirwan et al. 2010). The aim of this study was to determine the incidence of PG and the rate of SG after surgery of congenital cataract in the western part of Sweden and to report the outcome with regard to visual acuity and IOP control in young children with PG or SG treated surgically at the Eye Clinic at Sahlgrenska University Hospital, M€ olndal, between 2002 and 2010.
Materials and Methods During the period January 2002 to December 2010, a total of 29 children
269
Acta Ophthalmologica 2015
at the age of 0–4 years had surgery for glaucoma at the Sahlgrenska University Hospital in M€ olndal, one of two centres in Sweden performing this type of procedures. This age group was selected for analysis as glaucoma surgery in children 0–4 years recently was classified as National Specialised Medical Care by the Swedish National Board of Health and Welfare (Socialstyrelsen 2012). Data were collected from medical records, and the study was approved by the local ethical committee. The study adhered to the tenets of the Declaration of Helsinki. The majority of the patients (72.4%) were residents in the county of V€ astra G€ otaland, but eight children were from other, mainly the southern, parts of Sweden and referred to our clinic for IOP-lowering surgery. For diagnosis of glaucoma, at least one glaucomatous sign, such as increased axial length or corneal diameter, corneal oedema or glaucomatous disc appearance, in combination with elevated IOP was required. Subjects were denoted as primary glaucoma (PG) or secondary glaucoma (SG) based on the classification by Papadopoulos et al. (2013). In accordance with this classification, children who had congenital/acquired ocular or systemic disorders associated with glaucoma were designated as secondary glaucoma. Both the PG and the SG groups included children who had experienced cataract extraction. However, patients in the PG group were diagnosed with glaucoma prior to cataract surgery, whereas children who developed glaucoma after cataract surgery were denoted as secondary glaucoma. For determination of the incidence of primary glaucoma in the county of V€ astra G€ otaland, birth data for this region were obtained from the Regional Council Administration for population statistics. During the period 2002–2010, there were 161 441 live births in the region. Only patients with primary glaucoma born in the county of V€astra G€ otaland (n = 7) were included for this arithmetic procedure. The incidence of glaucoma secondary to cataract surgery was based on all paediatric patients experiencing cataract extraction between 2008 and 2010 at the Sahlgrenska University Hospital in M€ olndal. During this three-year period, reliable data on congenital cataract surgery could be collected through the national Swedish register
270
for paediatric cataract (Paediatric Cataract Register; PECARE). Age at last visit varied between 7 months and 14 years for the whole cohort. Mean follow-up time after diagnosis was 5.73 (SD 3.5) years and did not differ significantly between the PG and the SG groups. For three subjects, follow-up was short (less than 6 months) because one child died in Hutchinson– Gilford progeria at the age of 9 months and two children moved abroad or outside the county of V€ astra G€ otaland and medical journals could not be retrieved. To obtain a complete demographic description of all primary and secondary glaucoma cases during the study period, including underlying causes and for computation of the PG incidence in the county, no cases were excluded due to short follow-up (Table 1). For subsequent analysis of outcome measures, however, these three children were excluded, resulting in a mean follow-up after first surgery of 6.3 (SD 3.2) years for the entire cohort with a minimum follow-up time of 2.4 years (Table 2). Information on visual acuity at last follow-up could be obtained from 33 eyes (89%). Visual acuity, given as best corrected visual acuity (BCVA) in decimals, was tested using Snellen charts according to age and co-operation of the child (Kay picture test, HOTV and KM) (Kay 1983; Moutakis et al. 2004). A grading for visual function was used according to the World Health Organization’s (WHO) classification with a BCVA in decimals of
