Ahmed Al Habash, MD and Earl Randy Craven, MD. Conversion from Anatomically Narrowed ... Burgoyne C, Tello C, Katz LJ. Nanophthalmia and chronic angle ...
Conversion from Anatomically Narrowed Angle to Chronic Angle Closure After Phacoemulsification in Nanopthalmic Eyes Ahmed Al Habash, MD and Earl Randy Craven, MD King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
Introduction • The clinical spectrum of the small eye varies from simple microphthalmos, complex microphthalmos, nanophthalmos, and relative anterior microphthalmos.1 • Nanophthalmos is an ocular developmental disorder in which the eyes are abnormally small without ocular and systemic anomalies.2 • Eyes with nanophthalmos are characterized by a short axial length, high hyperopia, shallow anterior chamber and narrow anterior chamber angle (ACA), short corneal diameter and thick sclera.3 • The gold standard for clinically assessing the ACA is gonioscopy. However, evaluation of gonioscopic finding is subjective and depends on the examiner’s experience. • Anterior segment optical coherence tomography (AS-OCT), which is a new non-invasive, non-contact and high-resolution imaging technique to assess the anterior segment structures and ACA structures. • We would like to share in this poster a finding of 3 cases of nanophthalmos that developed a high peripheral anterior synechiea (PAS) post cataract surgery.
Case Report We report 3 cases were diagnosed as nanophthalmos with narrow angle not synechieal closed, had cataract extraction and developed high PAS afterward. First case was a 62 years old male known case of nanophthalmos, axial length 19.4mm, anterior chamber depth 2.3mm with narrow angle, had cataract surgery and developed high PAS. (Figure 1) Second case a 45 years old female known case of nanophthalmos, peripheral iridotomy done for both eyes, narrow angle not synechially closed (Figure 2). Axial length is 14.09mm. Phacoemulsification with intraocular lens implantation was done and developed after that synechial angle closure. (Figure 3) Third case is a 36 years old male known case of nanophthalmos with narrow angle had peripheral iridotomy for both eyes; axial length 16.3mm has undergone phacoemulsification with intraocular lens implantation and irido-zonulo-vitrectomy-hyalidoectomy during the same procedure because of the development of aqueous misdirection. Postoperatively the patient developed synechially closed angle with high PAS (Figure 4).
Figure 1. Patient number 1 developed high PAS with deep chamber
Figure 2. Patient number 2 pre cataract surgery with narrow angle but not synechially closed
Figure 3. Patient number 2 post phacoemulsification show narrow with areas of PAS
Figure 4. Patient number 3 post phacoemulsification with high PAS.
Discussion • This is the first description of conversion to angle closure post phacoemulsification. The mechanism appears to be a tight volume to the anterior chamber with significant shallowing resulting in PAS in the first days after cataract surgery. This was not prevented with an irido-zonulehyaloidectomy and posterior vitrectomy. This may indicate that ciliary body position is close enough to the angle to play a role. • Nanophthalmos is a part of the clinical spectrum of microphthalmos resulting from developmental arrest of the globe after closure of the embryonic fissure. It usually affects both eyes and is inherited in an autosomal-dominant, autosomal-recessive or sporadic fashion.1 • Short axial length and a narrow anterior chamber, which are characteristics of nanophthalmic eyes, are two risk factors for primary angle closure glaucoma.4 • Several possible mechanisms have been reported for angle closure. The most common cause of angle closure glaucoma is a relative pupillary block secondary to the posterior pushing mechanism, which results in peripheral anterior synechia (PAS) formation. Another possible mechanism is physical displacement of the peripheral iris by anteriorly rotated ciliary processes when an annular ciliochoroidal effusion and ciliary body 5 detachment occur in nanophthalmic eyes. • Previous studies suggest that with early recognition and appropriate treatment such as peripheral iridotomy for eyes with narrow angles, 6,7 glaucomatous optic neuropathy can be prevented with no further treatment. • The screening of an ACA is very important in the early phases of the disease, such as eyes with narrow angles, before PAS formation and/or elevation of IOP occurs.8 • Nanophthalmos occurs in a distinct group of patients with high levels of ocular comorbidity, and the results of cataract surgery are less favorable compared with the results in the general population. • Cataract surgery in nanophthalmos is often difficult because of crowding of the anterior segment. • Our theories of PAS formation after cataract surgery in nanophthalmos is Intermittent Aqueous Misdirection, Choroidal effusions and high Pressure during Surgery. • Our recommendations for preventing PAS formation are to prevent sudden decrease of pressure during surgery, anterior vitrectomy or goniosynecholysis and leaving viscoelastic in the angle.
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Financial Disclosures The Authors have no financial interests or relationship to disclose
