Ординатура / Офтальмология / Английские материалы / The Glaucomas Volume 1 Pediatric Glaucomas_Sampaolesi, Zarate_2009

High-Pass-Resolution Perimetry

in Normal Children in Congenital Glaucoma

In 1983 [10], we conducted a comparative study between differential light sensitivity perimetry and high- pass-resolution perimetry in congenital glaucoma. The population of congenital glaucoma patients was studied by performing visual field examinations with the Octopus 1-2-3 and high-pass-resolution perimetry and confocal tomography with the Heidelberg Retina Tomograph, which was used to assess optic disc parameters. The population was divided into three groups:

G I Pure congenital glaucomas; G2 Refractory glaucomas;

G3 Late congenital glaucoma (goniodysgenesis).

Introduction

Differential light sensitivity (DLS) perimetry and high- pass-resolution perimetry (HRP) in adults have been compared by several researchers [11–14], but their relationship has not been studied in children with congenital glaucoma.

Material

See Table 18.2 for a description of the material.

Methods

Visual field examinations were performed with Octopus 1-2-3 (Interzeag, the G1 program, 59 locations within 30° of the visual field) and the Ophthimus high- pass-resolution perimetry (High-Tech Vision, Malmö, Sweden; version 2.0) (50 locations were measured within the central 30°s of the visual field).

In this study, Pearson’s correlation coefficient was calculated between MD (mean defect) and NC (neural capacity), MD and GD (global deviation), and CLV (corrected loss variance) and LO (local deviation) in three groups. NC is an index estimating the total number of functioning retinal ganglion cells.

Results

The relationship between mean defect (MD) and global deviation (GD) showed in group 1 MD and GD correlated significantly: r = 0.80, p < 0.0001 (Fig. 18.4). In groups 2 and 3, the correlation was not significant.

The relationship between corrected loss variance (CLV) and local deviation (LD) was as follows. In group 1, CLV and LD correlated significantly, r = 0.78, p < 0.0001 (Fig. 18.5). In group 2, it was not significant. Group 3 had a fairly significant correlation: r = 0.45, p < 0.01.

The relationship between MD and neural capacity NC showed that in group 1, there was a significant correlation: r = 0.78, p<0.0001 (Fig. 18.6). Group 2 was not significant. Group 3 had a fairly significant correlation, r=0.42, p < 0.02.

However, when we tried to correlate the three groups together, we found two groups of cases: one located far from the zero line and the other surrounding zero. The correlation is not represented by a straight line but rather by a curve. This means that in many cases the MD is normal but the NC is pathological. The correlation between these two indices is far from perfect (Fig.18.7). In our opinion, these different methods of psychophysical tests measure different aspects of the visual field system.

Both at the 1990 IPS Meeting held in Malmö, Sweden, and now, we believe we were the first to study the visual field in children with differential light sensitivity perimetry (Octopus 2000 and 1-2-3 perimeters) and with high-pass-resolution perimetry. With both perimeters, it is possible to obtain reliable results in children between 5 and 10 years of age. To be sure of the accuracy of our results, we used a reliability factor not higher than 10.

Fig 18.4 Relationship between MD and GD in group 1

Fig. 18.6 Relationship between MD and NC in group 1

Fig 18.5 Relationship between CLV and LD in group 1

Fig. 18.7 Two groups of cases can be found: one located far from the zero line and the other surrounding it. The correlation is not represented by a straight line but rather by a curve. This means that in many cases, the MD is normal but the NC is pathological

Nonconventional Contrast Perimetry

in Congenital Glaucoma

Nowadays, nonconventional perimetry is performed using the following perimeters: frequency doubling technology (FDT) (Carl Zeiss Meditec, Jena, Germany and Zeiss, Wellch Allyn, Skaneateles Falls, NY, USA), Matrix (Zeiss), and Pulsar (Haag-Streit, Wedel, Germany).

Throughout this book, we have presented perimetries taken in children with congenital glaucoma using

conventional and nonconventional perimetry. We will give a short explanation why. The method is explained in full detail and the results correlate with lesions of the optic nerve (HRT). In 2003, we showed that in 50% of glaucoma patients with a normal visual field for conventional perimetry, there are defects marked with frequency doubling and that these are topographically perfectly correlated with the damage found in the optic nerve with confocal tomography (HRT). We will show an example here. The complete model and its results are presented in Volume II.

Fig. 18.8 Conventional perimetry (Octopus), all eyes have normal visual field

With conventional perimetry (Octopus) all eyes had a normal visual field (Fig. 18.8). With nonconventional perimetry (FDT), in group 3, all eyes had a pathological visual field. Figures 18.8 and 18.9 show the Brusini Staging System for classifying the degree of development of the perimetry lesion, firstly for conventional perimetry (Octopus), and in the second for nonconventional perimetry (FDT). The upper part shows the developmental phase. Each numbered round dot represents an eye, and the color corresponds to the developmental phase of the ON for confocal tomog-

Fig. 18.10 Glaucoma staging system 2

raphy (HRT), as can be seen in this group. Those performing only conventional perimetry will diagnose hypertension, and those who perform frequency doubling will diagnose glaucoma. In conclusion, Chap. 20 (see Figs. 20.11 and 20.13) presents a typical case of goniodysgenesis, or late congenital glaucoma, which is seen to be normal with conventional perimetry, although with nonconventional perimetry in the same field it shows ON lesions that correspond topographically to visual field lesions.

There are two very interesting studies on the application of the frequency doubling technique in pediatrics by Nesher et al. [16] and by Blumenthal et al. [17]. The authors show that the method is very useful in young patients beginning at 6 years of age, the reliability of the results increases as age increases, children are not frightened by it because the lights in the room can be switched on, because there is no dome, and finally because the stimulus is not static but moving, which attracts the child’s attention.

We believe the Brusini Glaucoma Staging System 2 to be the best method to study the progression of the visual field for conventional perimetry (Fig. 18.10) and the FDT Staging System from the same author for nonconventional perimetry (Fig. 18.11) [18, 19, 20].

References

1.Robin AL, Quigley HA, Pollack IP et al (1979) An analysis of visual fields and disk cupping in childhood glaucoma. Am J Ophthalmol 88:847–858

9.Haas A, Flammer J, Schneider U (1986) Influence of age on visual fields of normal subjects. Am J Ophthalmol 101:199–203

10.Sampaolesi R (1983) Ocular echometry and the diagnosis of congenital glaucoma and its evaluation. In: Glaucoma update II, Springer, Berlin Heidelberg New York, pp 175–184

11.Wanger P, Persson HE (1987) Pattern-reversal electroretinogramms and high-pass resolution perimetryin suspected or early glaucoma. Ophthalmology 94:1098–1103

12.Dannheim F, Abramo F, Verlohr D (1989) Comparison of

automated conventional and spatial resolution perimetry in glaucoma. In: Heijl A (ed) Perimetry update 1988/1989. Kugler & Ghedini, Amsterdam, pp 383–392

13.Lachenmayr BJ, Drance SM, Douglas GR, Mikelberg FS (1991) Light-sense, flicker and resolution perimetry in glaucoma: a comparative study. Graefe’s Arch Ophthalmol 229:246–251

14.Kono Y, Maeda M, Yamamoto T, Kitazawa Y (1993) A comparative study between high-pass resolution perimetry and differential light sensitivity perimetry in glaucoma patients. In: Mills R (ed) Perimetry update 1992/1993. Kugler, Amsterdam, pp 409–413

genital glaucoma. Arch Ophthalmol 98:1575–1576

3.Tejeiro A, Dominguez A (1990) Perimetría computarizada en el glaucoma congénito Arch Soc Esp Oftalmol LVIII:631–634

4.Sampaolesi R, Casiraghi JF (1991) Computerized visual fields in pediatric glaucoma. In: Mills RP, Heijl A (eds) Perimetry update 1990/1991.Kugler & Ghedini, Amsterdam, pp 455–464

5.Flammer J (1987) The Octopus glaucoma GI program. Glaucoma 9:67–72

6.Flammer J (1986) The concept of visual field indices. Graefes Arch Ophthalmol 224:389–392

7.Bebie H, Flammer J, Bebie T (1989) The cumulative defect curve: separation of local and diffuse components of visual field damage. Graefes Arch Ophthalmol 226:9–12

8.Wild JM, Dengler-Harles M, Searle AET, O’Neill EE, Crews SJ (1989) The influence of the learning effect on automated perimetry in patients with suspected Glaucoma. Acta Ophthalmol 67:537–545

zwischen der konfokalen Tomographie des Nervus Opticus (HRT) und der perimetrischen Frequenzverdoppelugstechnik (FDT) Klin Monatsbl Augenheilkd 220:754–766

16.Nesher R, Norman G, Stem Y, Gorck L, Epstein E, Raz Y, Assia E (2004) Frequency doubling technology threshold testing in the pediatric age group. J Glaucoma 13:278–282

17.Blumenthal EZ, Haddad A. Horani A, Anteby I (2004) The reliability of frequency-doubling perimetry in young children. Ophthalmology 111:435–439

18.Brusini P, Filacorda S (2006) Enhanced Glaucoma Staging System (GSS 2) for classifying functional damage in glaucoma. J Glaucoma 15:40–46

19.Brusini P (2006) Frequency doubling technology staging system 2. J Glaucoma 15:315–320

20.Brusini P, Johnson CA (2007) Staging functional damage in glaucoma: review of different classification methods. Surv Ophthalmol 52:156–178

This inflammatory disease in mothers may cause a chamber angle anomaly identical to that in congenital glaucoma with ocular hypertension, which responds to antiglaucoma operations. However, these cases are differentiated by cataract, deafness, cardiac anomalies, and mental retardation. Nevertheless, there are cases, generally occurring when the rubeola virus infection occurs in the first 3 months of pregnancy, where these alterations are not present and the risk of confusion is greater.

Nasolacrimal Duct Obstruction

Epiphora and blepharospasm are signs of this disease, but never photophobia. However, many cases have reached us 7 months or more after the onset of symptoms because the family consulted a neonatologist or pediatrician who mistook the diagnosis. We always give courses in the hospital neonatology and pediatrics departments to alert them to this possibility. If there is any doubt, a permeability test of the lachrymal ducts can always be made with fluorescein or probing at the lachrymal point and passing a drip. It should be remembered that in a congenital glaucoma case, there is always photophobia, tearing, blepharospasm [1, 2], increased axial length, and reversible optic nerve cupping.

Megalocornea

Megalocornea may simulate congenital glaucoma and lead to confusion in the diagnosis. In general, the corneal diameter is greater than 14 mm, which leads to the anterior chamber being deeper, and to iridodonesis, but it does not present ocular hypertension, increased axial length, or reversible ON cupping. The chamber angle is normal. There are rare cases of families in which some members have glaucoma and others megalocornea.

Obstetric Trauma

Often when the child is extracted with forceps, there is a breakage of the endothelium and the Descemet membrane (Haab’s striae). These striae are generally unilateral.

Myopia

In general, it is very difficult to differentiate myopia from congenital glaucoma [3]. Echometry can help, since in glaucoma the anterior chamber, the length of the vitreous, and axial length are noticeably increased, but the lens is less thick, which does not occur in myopia. It should also be remembered that in myopia there is no hypertension.

Corticoids and Ocular Pressure

History

The first case of glaucoma described was provoked by the use of cortisone in patients who had been treated for long periods as a result of a uveitis or spring conjunctivitis [4].

Lijó-Pavía [5] described the first case in Argentina. Similar situations were presented by Dejean et al. [6]. In 1953, Stern [7] reported acute glaucoma produced

by the application of cortisone administered locally. In 1954, Covell [8] published a paper on glaucoma produced by systemic corticosteroid therapy. In 1954, François published a study on cortisone and ocular pressure, and in 1962, Goldmann et al. [9] reported the characteristics of the disease in six patients and called it cortisone glaucoma.

Becker [10] and Armaly [11, 12] classified the population by their response to cortisone as high, medium, or low, and concluded that this response was hereditary. This interpretation is not currently accepted, because of identical twin studies conducted by Schwartz et al. [13, 14], and because the response to corticoids can be produced only in the group that reacts with high pressure [15].

Glaucoma has also been described as provoked by corticoids when they are applied internally: MacLean [16], Woods [17], Laval and Collier [18]. These authors reported that corticoids used internally can provoke or worsen glaucoma.

Discussing a study by Bárany on the exit of aqueous humor, Chandler [19] said that cortisone treatment given internally can hamper the control of simple chronic glaucoma. Berstein and Schwartz [20] found a statistically significant slight increase in ocular pressure in 48 patients who, for various reasons, were submitted to long-term corticoid treatments.

Glaucomas have also been described that originated from endogenous corticoids. Bayer [21] and Bayer and Neuner [22] showed glaucoma in patients with subtotal adrenalectomie in suprarenal glands, and Haas and Nootens in a case of Cushing’s syndrome [23].

Physiopathology

Bárany [24] showed that locally applied hyaluronidase acts on the hyaluronic acid of the trabecular meshwork, depolymerizing it and increasing the exit of aqueous humor from the anterior chamber. Corticoids have an antihyaluronidase action and thus act on the trabecular meshwork, reducing the ease of the outflow of aqueous humor.

In cortisone glaucoma, aqueous humor exit is reduced because of an alteration of the trabecular meshwork. The amount of already existing polymerized glycosaminoglycans (hyaluronic acid) in the trabecular meshwork increases, because degradation (depolymerization) fails. This alteration occurs because of the inhibition of the release of enzymes contained in the lys-

osomes in the cellular cytoplasm that are responsible for depolymerization. The inhibition of enzyme release is produced by the stabilization of the lysosome membrane provoked by corticoids (the stabilizing action of the membrane has been demonstrated experimentally). Another theory in 1975 suggested that the corticoids block phagocytosis of the trabecular meshwork by the endothelial cells (this is their normal function, called self-cleaning).

The third theory was developed by Yun et al. [25], who suggest that the increase in elastin observed in human trabecular meshwork cells, cultivated intraand extracellularly after being treated with dexamethasone, could be related to a possible obstructive mechanism in the drainage system of the aqueous humor. Quaranta and Serafini [26] showed that, in this type of glaucoma, intraocular pressure increases because in tonography the value of C is reduced.

Clinical Picture

Describing his first six cases, Goldmann [9] listed the characteristics as an open-angle glaucoma, with generally high ocular hypertension, in white eyes, with optic disc pallor but without cupping, and uncharacteristic lesions of the visual field.

In cortisone glaucomas, there are no symptoms. It is like open-angle glaucoma, with the diagnosis generally made fortuitously when measuring ocular pressure. These patients have often been treated for months or years for conjunctivitis, blepharitis, uveitis, or intolerance to contact lenses. Weekers et al. [27] also studied it from this point of view.

Development

Almost all the cases improved after 2–4 weeks, simply by interrupting corticoid use. In others, however, this improvement did not occur and in these patients, chronic irreversible glaucoma was established.

In many cases in which removing the corticoid led to normalization of ocular pressure, the visual field defects persist irreversibly. It should be remembered that today these patients are confused with normalpressure or low-tension glaucoma and become part of the great arsenal of these diagnoses that we described in Chap. 1 as glaucomas that are inactive as a result of local medication.

Treatment

Treatment can be reversible:

1.Corticoid suppression;

2.Antiglaucoma medical therapy;

3.Subconjunctival hyaluronidase.

Or irreversible:

4. Surgical therapy.

Any fistulizing surgical therapy can be chosen, but it should be stressed that Bietti and Quaranta [28] used goniotomy in eight cases of irreversible corticoid glaucoma, seven of which obtained perfect regulation of ocular pressure and thus could continue using corticoids. We currently prefer trabeculotomy and, if necessary, trabeculectomy.

Prophylaxis

Any local application of corticoids must be accompanied by precise indications and strict monitoring of ocular pressure. Careless self-medication in cases of contact lenses, conjunctivitis, etc., which is common today, and even treatment indicated by general clinicians, should be avoided (Table 19.1).

In extreme cases, the use of FML (fluorometholone) has a greater anti-inflammatory effect and does not cause ocular hypertension. Flurbiprofen (Tolerane, Plos NR), which is a corticoid and analgesic anti-inflamma- tory, is in our opinion the best medication today.

Clinical History No. 1

The following clinical history is an example of cortisone glaucoma.

This 16-year-old female, had a history of toxoplasmosis (bilateral peripheral uveitis). She received general and local corticoids for 4 years. The left eye presented a slight dysgenesis in the chamber angle, with pathological mesodermal tissue up to the spur, an anomaly not present in the right eye, with visual acuity 200/200, ocular pressure 14 mmHg, and normal daily pressure curve. The left eye has the following features, as well as the gonioscopic elements mentioned above, corresponding to the first examination at the time the patient was referred to us in 1974.

Faced with irreductible levels of tension and a reduction of visual acuity, I made a trabeculectomy. From then on, ocular pressure was regulated around 16 mmHg with the diurnal pressure curve at normal values and visual acuity reached 20/60.

The pathological anatomy of the trabeculectomy piece can be seen in Fig. 19.1.

In 1988, after missing check-ups for 3 years, she returned at age 30 because of reduced vision in the left eye. Visual acuity had fallen to less than 20/200 because of a cortisone posterior subcapsular cataract. In 1989, I inserted an intraocular lens, achieving visual acuity of 20/40, and she has maintained ocular pressure within normal limits to date, 2008.

Fig. 19.1 Pathological anatomy