Ординатура / Офтальмология / Английские материалы / Textbook of Vitreoretinal Diseases and Surgery_Natarajan, Hussain_2008

Textbook of Vitreoretinal Diseases and Surgery

may be marred by ectopia lentis and poorly dilating pupils. Retinal breaks are commonly located along temporal periphery. (50% or more). Giant retinal tears are reported in 11% eyes.48 Uncomplicated detachments with clear media, centrally placed lens and peripheral break/s are managed with scleral buckling while complicated detachments need pars plana vitrectomy with internal tamponade, mostly silicone oil. Eyes undergoing pars plana vitrectomy invariably need lensectomy as the lens is usually subluxated in superotemporal quadrant. In general, anatomical success rate is in the range of 80 to 90%52 (combined scleral buckling and vitrectomy).

OUTCOME OF SURGERY IN PEDIATRIC RRD

Delay in diagnosis, higher incidence of PVR, need for multiple surgeries and associated congenital anamolies affect overall outcome in these eyes. The anatomical and functional results are summarized in Table 19-4.

TABLE 19-4: Surgery for pediatric RRD—results

Scleral buckling is the preferred procedure and vitrectomy was reserved for more complicated cases and in eyes with failed scleral buckle. Single surgery attachment rate is found to be around 60 to 80% while final attachment rate is around 80 to 90% in pediatric RRD. Gonzales, et al49 reported 78% anatomical attachment rate. The best anatomical results are noted in RDs with atrophic holes or dialysis (almost 100%) followed by tractional tears (74%) and giant retinal tears (67%). Younger age, worse initial vision, more extensive detachment, large and posterior tears and presence of PVR are associated with poor anatomical outcome.

Though not very encouraging, at least some degree of visual improvement is expected in about 60 to 70% of the cases. Haring et al24 reported 20/40 or better vision in 60.6% eyes following scleral buckling. Binocular vision could be achieved in 52.4% patients. Final visual acuity correlates well with presenting vision and is adversely affected by duration of the RD and presence of PVR. Visual rehabilitation is an integral part of the management following surgery in these eyes as amblyopia is a potential cause for visual impairment. There is life long risk of recurrent RD, glaucoma and cataract

238 indicating need for frequent prolonged follow-up.

Pediatric Retinal Detachment

Summary

The incidence of RRD is low in pediatric population. Ocular trauma/surgery and congenital structural abnormalities are the commonest etiological factors in this age group. There is higher incidence of bilateral involvement. Anatomical outcome is generally good following scleral buckling or vitrectomy.

Although visual improvement is modest, the value of surgery must be considered in context with the expected natural history of these eyes as, if left untreated, most will ultimately result in phthisis with irreversible vision loss. Delay in diagnosis, more frequent macular involvement, early and frequent development of PVR, preexisting congenital anomalies, development of amblyopia and lack of health care facilities are some of the chief reasons which limit the potential of visual recovery in these children.

In view of higher frequency of vision threatening abnormalities in the fellow eye, these patients need regular follow-up throughout their life. Once detected, prompt prophylactic treatment of asymptomatic lesions should be considered.

School vision screening tests, education of high risk patients and their parents regarding the threat of detachment and symptoms of the detachment can help in early diagnosis and treatment to improve overall final outcome. Finally improved surgical techniques may also help to reduce the incidence of pediatric RRD.

References

1.Fivgas GD, Capone A Jr. Pediatric rhegmatogenous retinal detachment. Retina 2001; 21:101-6.

2.Haimann MH, Burton TC, Brown CK. Epidemiology of retinal detachment Arch Ophthalmol 1982; 100:289-92.

3.Winslow RL, Tasman W. Juvenile rhegmatogenous retinal detachment Ophthalmology. 1978; 85:607-18.

4.Yokoyama T, Kato T, Minamoto A. et al Characteristics and surgical outcomes of pediatric retinal detachment. Eye 2004;18:889-92.

5.Ghazi NG, Green WR. Pathology and pathogenesis of retinal detachment. Eye 2002; 16:411-21.

6.Weinberg DV, Lyon AT, Greenwald MJ, Mets MB. Rhegmatogenous retinal detachments in children: risk factors and surgical outcomes. Ophthalmology 2003; 110:1708-13.

7.Butler TKH, Kiet AW, Orr GM. Anatomical and visual outcome of retinal detachment surgery in children. BJO 2001; 85:1437-9.

8.Nagpal M, Nagpal K, Rishi P, Nagpal PN. Juvenile rhegmatogenous retinal detachment. Indian J Ophthalmol 2004; 52:297-302.

9.Lee RWJ, Mayer EJ. The etiology of pediatric rhegmatogenous retinal detachment-15 years experience. Eye 2008; 22:636-40.

10.Schepens CL. Chapter 4. Pathogenesis of non traumatic rhegmatogenous retinal detachment. In-Retinal Detachment and Allied Diseases, Vol 1, WB Saunders 1983;37-67.

11.Ninn-Pedersen K, Bauer B. Cataract patients in a defined Swedish population, 1986 to 1990. V. Postoperative retinal detachments. Arch Ophthalmol 1996;114:382-6.

12.Katz J, Tielsch JM. Lifetime prevalence of ocular injuries from the Baltimore Eye Survey. Arch Ophthalmol 1993; 111:1564-8.

13.Sheard RM, Mireskandari K, Ezra E, Sullivan PM. Vitreoretinal surgery after childhood ocular trauma. Eye 2007;21:793-8.

14.Eagling EM. Ocular damage after blunt trauma to the eye. Its relationship to the nature of the injury. Br J Ophthalmol 1974 58:126-40.

15.Dugel PV, Ober RR. Chapter 139. Posterior segment manifestation in closed globe contusion injury. In Ryan SJ, Wilkinson (Eds), Retina, 4th edition, Vol 3, Mosby 2006;2365-77.

16.Ryan S, Yoon Y. Chapter 138-Posterior segment trauma-open globe contusion injury In Ryan SJ, Wilkinson (Eds). Retina, 4th edition, Vol 3, Mosby 2006;2353-64.

17.Javitt JC, Street DA, Tielsch JM, et al. National outcomes of cataract extraction. Retinal detachment and endophthalmitis after outpatient cataract surgery. Cataract Patient Outcomes Research Team. Ophthalmology 1994; 101:100-5.

Textbook of Vitreoretinal Diseases and Surgery

Introduction

Retinoblastoma is the most common intraocular tumor in children. Many tumors possibly arise in infancy or childhood but do not present until later in life like melanocytoma and choroidal osteoma. The other common intraocular tumors in children include juvenile xanthogranuloma, medulloepithelioma, circumscribed choroidal hemangioma, choroidal osteoma, congenital hypertrophy of the retinal pigment epithelium, combined hamartoma of the retina and retinal pigment epithelium and tumors associated with the phacomatoses—von Hippel Lindau syndrome, tuberous sclerosis, neurofibromatosis and Wyburn Mason syndrome.

Epidemiology

Retinoblastoma is the most common intraocular malignant tumor in children with a reported incidence of 1 in 15000 to 1 in 18000 live births.1 The tumor is bilateral in 25% to 35% cases.2 Until recently, enucleation was considered the standard treatment modality for children affected by this tumor. Early diagnosis and recent advances in management like use of chemotherapy and protocol based management strategy have improved the prognosis of this potentially fatal tumor.

Clinical Presentation of Retinoblastoma (Figures 20-1A to G)

Leukocoria is the most common clinical presentation seen in about 56% of patients.3 Other less common presentations include squint, hypopyon, hyphema, vitreous hemorrhage. More advanced cases may present with tumor necrosis and sterile orbital inflammation or with extraocular extension and proptosis.4 Extraocular extension is most likely to occur at the sites of the scleral emissary veins. Atypical clinical manifestations include hypopyon with anterior segment invasion or spontaneous phthisis bulbi.5 Metastasis can occur in long standing and neglected cases and is most commonly seen in brain, skull, distant bones and lymph nodes.

The clinical appearance of the fundus lesion varies with type of tumor growth. Three patterns of tumor growth are usually recognized.4

1.Endophytic tumor: Here the tumor grows as a yellow-white mass lesion from the retinal surface towards the vitreous cavity and can eventually give rise to vitreous seeds. Retinal vessels are not seen on the surface of the tumor and there is no associated retinal detachment.

2.Exophytic tumor grows under the retinal surface giving rise to retinal detachment.

3.Diffuse infiltrating tumor involves the retinal surface as a placoid thickening. This is usually seen in older children and can present with secondary glaucoma.

In a child presenting with leucokoria, other causes like persistent hyperplastic primary vitreous,

Coats’ disease, ocular toxocariasis, endogenous endophthalmitis should be excluded before embarking on the definitive treatment of retinoblastoma.

A dilated fundus evaluation with an indirect ophthalmoscope is useful to diagnose retinoblastoma in 90% cases. An examination under anesthesia is required in every case and should include measurement of corneal dimensions, intraocular pressure, iris and anterior chamber examination for any neovascularization and anterior chamber seeding. Subtle proptosis of the affected eye could be an indicator of extraocular tumor extension and should be looked for.4 It is important to evaluate

242 the fundus thoroughly with indentation of the periphery to detect any peripheral tumor. 3 Ultrasound

Textbook of Vitreoretinal Diseases and Surgery

FIGURE 20-2:Ultrasound B-scan of the left eye of a child with retinoblastoma with the presence of an intraocular mass and high relflective spots within suggestive of intraocular calcification. On the A-scan there is presence of corresponding high spikes

TABLE 20-1: International classification of intraocular retinoblastoma

Group A: Small tumor (< 3 mm) outside macula.

Group B: Tumor > 3 mm or any macular tumor or any tumor with subretinal fluid. Group C: Localised subretinal or vitreous seeds.

Group D: Diffuse subretinal or vitreous seeds

Group E: Tumor touching the lens, neovascular glaucoma, tumor anterior to anterior vitreous face involving ciliary body or anterior segment, diffuse infiltrating retinoblastoma, opaque media from hemorrhage, tumor necrosis with aseptic orbital cellulitis, phthisis bulbi.

of management of retinoblastoma is to safeguard the life of the child. Salvage of the eye and vision are the secondary and tertiary goals respectively. Management is based on the stage of the disease at presentation—intraocular retinoblastoma, retinoblastoma with high-risk factors, orbital

246 retinoblastoma and metastatic retinoblastoma.