Abnormal sclerocytes in nanophthalmos

Clinical update in nanophthalmos: Features, diseases and complications associated

Nanophthalmos is a rare congenital condition of the eyeball that is characterised by a smaller size of the anterior and posterior segments without associated ocular malformations. Typical features that have traditionally been described in these eyes are short axial length, thickened sclera, cornea with a smaller diameter, narrow anterior chamber, and an increased lens to globe volume ratio. However, at present, there is still a lack of recognised diagnostic criteria for nanophthalmos and a classification of its severity. Its clinical relevance stems from the increased risk of multiple ocular conditions, such as high hyperopia, amblyopia, angle-closure glaucoma, retinal detachment, and cataracts. Likewise, in relation to surgery in these eyes, there are particularities in cataract and glaucoma surgery and with a greater risk of associated intra- and postoperative complications. In this way, the treatment of nanophthalmos focuses on controlling the associated eye conditions and reducing and controlling surgical complications. This review aims to update what has been published in recent years regarding nanophthalmos.

Clinical spectrum and treatment outcomes of patients with nanophthalmos

PURPOSE

To study the varied demographic, visual and clinical presentation of patients with nanophthalmos.

METHODS

Retrospective chart review of 144 consecutive subjects with nanophthalmos from January 2010 to January 2018 was done. Demographic details, visual acuity, refractive status, clinical parameters and surgical data were collected.

RESULTS

Mean age at presentation was 48.76 ± 15.99 years (5-74 years) and 55.6% were females. Median BCVA was 0.78 (6/36 Snellen equivalent) and median spherical equivalent was +10.0 (5.7-12.5) . Amblyopia was seen in 30.0% patients. Legal blindness was present in 16.7% of the study population. The mean IOP was 18.38 ± 9.38 mmHg. Angle closure disease was present in 67.7% and 35.7% had angle closure glaucoma. Presence of peripheral anterior synechia had higher odds (OR = 3.66; 95% CI, 1.71-7.84) of associated glaucoma. The mean axial length, 17.64 ± 1.74 mm was inversely correlated to the mean Retinochoroidal Sclera(RCS) thickness of 1.99 ± 0.25 mm (r = -0.28, p value < 0.001).All patients who had undergone surgery for glaucoma (n = 11) had associated intra or postoperative complication. Cataract surgery by manual small incision had more complications than Phacoemulsification (p value = 0.001). Occurrence of uveal effusion was significantly lower in eyes which underwent sclerostomy (p = 0.04) CONCLUSION: Nanophthalmos is a rare disorder with varying degree of visual impairment & amblyopia. High incidence of angle closure glaucoma was observed. Surgical management for glaucoma is often challenging with frequent complications. Cataract surgery by phacoemulsification had significantly lower complications than SICS and performing a concomitant sclerostomy reduced the occurrence of uveal effusions.

Atypical features of nanophthalmic macula--a spectral domain OCT study

Background

To report atypical features on Spectral domain optical coherence tomography (SD-OCT) in a case of non-familial pure adult nanophthalmos.

Case presentation

A 39 year old male hyperope was found to have biometric and fundus findings typical of nanophthalmos. The additional atypical features included serous pigment epithelial detachment (PED) in right eye and a cuff of subretinal fluid with underlying yellow deposits along superotemporal arcade in the left eye. Fundus flourescein angiogram showed hyperfluorescence due to window defect, dye pooling due to serous PED in right eye and leak superior to disc in right eye and superotemporally in left eye. Cirrus-SD OCT horizontal line scan passing through the fovea showed extensive inner limiting membrane corrugations causing distorted foveal contour in both eyes. A large juxtafoveal serous PED and a small extrafoval PED were seen with folds in the retinal pigment epithelium (RPE)-choriocapillary layer in the right eye.

Conclusion

Structural disruptions in the RPE-choriocapillary complex in the form of folds or juxtafoveal serous PED and RPE folds can be atypical features of nanophthalmic macula better discerned on high resolution OCT.

Optical coherence tomography findings of retinal folds in nanophthalmos

Aim. To report the optical coherence tomography (OCT) findings in three members of the same family with nanophthalmos associated with elevated papillomacular retinal fold. Methods. Complete ophthalmic examination as well as ultrasonography and OCT was performed in all patients. Results. Axial lengths ranged from 16.75 mm to 17.48 mm and refractive errors ranged from +17.50 D to +20.50 D. Main fundus findings were the hyperopic crowded, cupless optic disc, and retinal fold through papillomacular region. Macular OCT scans revealed retinal fold with normal retinal pigment epithelium and choriocapillaris. Interpretation. It is presumed that the retinal folds in nanophthalmos result from a redundancy of the retinal layer caused by retarded growth of the scleral, choroidal, and retinal pigment epithelial layers. The anatomic information provided by the current study is consistent with this thesis.

Choroidal Effusion with Serous Retinal Detachment as a Complication of Strabismus Surgery

A 12-year-old girl was referred because of unilateral visual loss in the right eye 5 days after uneventful strabismus surgery for a divergent squint. She had hypermetropia of +8 diopters and the axial length of both eyes was below normal for that age. Investigation with funduscopy, central visual field examination, optical coherence tomography, and fluorescein angiography revealed choroidal edema in the affected eye. The macular edema responded well to parabulbar and topical steroids and vision recovered completely within 2 weeks. Strabismus surgery in highly hypermetropic eyes with a small axial length can be complicated by choroidal edema.

Changes of scleral sulfated proteoglycans in three cases of nanophthalmos

PURPOSE

To examine the composition of scleral sulfated proteoglycans in three nanophthalmic eyes by electron microscopic histochemistry.

METHODS

Scleral tissues from three cases of nanophthalmos were collected from the Niigata University Hospital for transmission electron microscopic examination. Sulfated proteoglycans were studied using the cuprolinic blue (CB) dye binding method in conjunction with enzymatic digestion.

RESULTS

Compared with the controls, the nanophthalmic sclerae were much thicker, and the collagen fibrils showed a less orderly arrangement. Twisting or fraying of collagen fibrils was noted in some areas, and fine fibrous materials surrounded the abnormal fibrils. CB-positive proteoglycan filaments were found around the collagen fibrils and in the fine fibrous materials in the nanophthalmic specimens. The number of proteoglycan filaments was smaller than that in the normal specimens. After enzymatic digestion, the CB-positive filaments were identified as dermatan/chondroitin sulfate proteoglycans. Although the number of dermatan sulfate filaments in nanophthalmos sclerae was similar to that in the controls, there were many fewer chondroitin sulfate filaments.

CONCLUSION

A loss of chondroitin sulfate proteoglycan was observed in nanophthalmic sclerae. The alteration may be related to the abnormal organization of collagen fibrils and the onset of uveal effusion.

Management of glaucoma in patients with nanophthalmos

AIMS

In this retrospective study, we aimed to evaluate the results of glaucoma surgery in patients with nanophthalmos.

METHODS

Twenty-eight bilateral nanophthalmic patients, of whom 20 patients underwent trabeculectomy+Mitomycin-C (MMC)+inferior sclerotomy between 1996 and 2004, were included in this study. Records of patients with nanophthalmos were reviewed. Intraocular pressure (IOP), glaucoma medications, surgical success, visual acuity and complications were analyzed.

RESULTS

The mean IOP was 34.6+/-5.3 mm Hg preoperatively. At the final follow-up visit, the mean IOP dropped to 21.41+/-7.34 mm Hg (P<0.05). The cumulative probability of success was 85% at 1 year, 78.5% at 2 years, 76.9% at 3 years, 70.6% at 4 years and 47% at 5 years after surgery. Visual acuity decreased in 13 (65%) patients but no eye lost vision. Sequels of choroidal detachment (five patients 25%) and retinal folds (four patients 20%) were the most frequent reason for visual decrease. Uveal effusion (10 patients 50%) and cataract formation (seven patients 35%) were major late postoperative complications.

CONCLUSIONS

Results indicate that trabeculectomy+MMC+inferior sclerotomy procedure was effective and safe for glaucoma control in patients with nanophthalmos, but uveal effusion is a major problem and cataract surgery is expected in the long run.

Angle closure in younger patients

PURPOSE

Angle-closure glaucoma is rare in children and young adults; only scattered cases associated with specific clinical entities have been reported. We evaluated the findings in patients aged 40 or younger with angle closure in our database.

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

Our database was searched for patients aged 40 years or younger with angle closure. Data recorded included age at initial consultation, age at the time of diagnosis, gender, slit-lamp examination, gonioscopy, ultrasound biomicroscopy (from 1993 onward), clinical diagnosis, and therapy. Patients with prior incisional surgery were excluded, as were patients with anterior chamber proliferative mechanisms leading to angle closure.

RESULTS

Sixty-seven patients (49 females, 18 males) met entry criteria. Mean age at the time of consultation was 34.4 +/- 9.4 (standard deviation) years (range, 3-68 years). Diagnoses included plateau iris syndrome (35 patients); iridociliary cysts (8 patients); retinopathy of prematurity (7 patients); uveitis (5 patients); isolated nanophthalmos (3 patients); relative pupillary block (2 patients); Weill-Marchesani syndrome (3 patients); and 1 patient each with Marfan syndrome, miotic-induced angle closure, persistent hyperplastic primary vitreous, and idiopathic lens subluxation.

CONCLUSIONS

The etiology of angle closure in young individuals differs from the older population and is typically associated with structural/developmental ocular anomalies rather than relative pupillary block. After laser iridotomy, these eyes should be monitored for recurrent angle closure and the need for additional laser or incisional surgical intervention.

Autosomal dominant nanophthalmos (NNO1) with high hyperopia and angle-closure glaucoma maps to chromosome 11

Nanophthalmos is an uncommon developmental ocular disorder characterized by a small eye, as indicated by short axial length, high hyperopia (severe farsightedness), high lens/eye volume ratio, and a high incidence of angle-closure glaucoma. We performed clinical and genetic evaluations of members of a large family in which nanophthalmos is transmitted in an autosomal dominant manner. Ocular examinations of 22 affected family members revealed high hyperopia (range +7.25-+13.00 diopters; mean +9.88 diopters) and short axial length (range 17.55-19.28 mm; mean 18.13 mm). Twelve affected family members had angle-closure glaucoma or occludable anterior-chamber angles. Linkage analysis of a genome scan demonstrated highly significant evidence that nanophthalmos in this family is the result of a defect in a previously unidentified locus (NNO1) on chromosome 11. The gene was localized to a 14.7-cM interval between D11S905 and D11S987, with a maximum LOD score of 5. 92 at a recombination fraction of .00 for marker D11S903 and a multipoint maximum LOD score of 6.31 for marker D11S1313. NNO1 is the first human locus associated with nanophthalmos or with an angle-closure glaucoma phenotype, and the identification of the NNO1 locus is the first step toward the cloning of the gene. A cloned copy of the gene will enable examination of the relationship, if any, between nanophthalmos and less severe forms of hyperopia and between nanophthalmos and other conditions in which angle-closure glaucoma is a feature.

The nanophthalmic macula

AIMS

To define an unusual macular appearance found in association with nanophthalmos.

METHODS

A case review.

RESULTS

Seven children (aged 8 months to 17 years) with nanophthalmos were examined. They all exhibited the same clinical findings of an unusual yellow macula appearance with retinal folds and crowded optic discs. Visual electrophysiology performed in four cases was normal.

CONCLUSION

A distinctive yellow macular pigmentation with associated chorioretinal folds and crowded optic discs is present in nanophthalmos. It is proposed that the retinal folds are due to a disparity between scleral and retinal growth while the macula discoloration is due to a congenital abnormality in arrangement or position of the luteal pigment and is not degenerative. Included in this case series is the second case in the literature of nanophthalmos associated with Kenny's syndrome. Inheritance of nanophthalmos appears to be autosomal recessive.

Autosomal dominant simple microphthalmos

Congenital bilateral microphthalmos is a rare malformation of the eye, which ranges from extreme to mild reduction of total axial length. Microphthalmos may occur as an isolated ocular abnormality or as part of a systemic disorder, and different classifications of the condition have been attempted. We describe a large pedigree with 14 persons in four generations affected with bilateral microphthalmos without other ocular or systemic signs. An autosomal dominant trait with complete penetrance is proposed. Five subjects underwent a complete ophthalmological evaluation. The total axial length was measured by A scan ultrasonography in all persons. Ultrasonography showed a reduction of the total axial length (range 18.4-19.7 mm) and a reduced vitreous cavity length (range 11.4-13.5 mm) in all investigated patients. All the patients had microcornea (range 8-9.7 mm). No other ocular anomalies or associated systemic malformations were found. A review of published reports also suggests that simple, partial, posterior, pure microphthalmos and nanophthalmos are similar clinical entities sharing total axial length and vitreous cavity length reduction. Therefore, the term simple microphthalmos is proposed to identify these clinical conditions.