Specific precautions when operating Nanophthalmic eye
Simple microphthalmos
• Short axial length (>2 SD smaller than age-based normative)
• no other ocular malformations.
✍️ Relative anterior microphthalmos
• Normal axial length with disproportionately small anterior segment.
✍️ Nanophthalmos
• Short axial length (14–20.5 mm)
• white to white <9 mm
• Shallow AC <2.2 m
• Diffuse RCS ( retina choroid sclera) complex thickening (> 1.7 mm) with increased risk of choriodal effusion
• Normal sized lens.
✅ Pathophysiology of effusion in precautions when operating Nanophthalmic eye
• Thickened sclera compresses vortex vein, impeding normal choroidal venous drainage.
• Transcleral protein egress is hampered and lack of lymphatic drainage results in suprachoroidal fluid retention.
✅ Common complications in precautions when operating Nanophthalmic eye
• Posterior capsular rupture (4–11.7%)
• Aqueous misdirection (0–25%)
• Suprachoroidal haemorrhage(0–2.7%)
• Prolonged anterior uveitis (2.3–11.8%)
• Uveal effusion (9.3%)
✅ Preoperative considerations in precautions when operating Nanophthalmic eye
✍️ Axial length measurement
• partial coherence interferometry
• optical low coherence reflectometry is preferred over ultrasound biometry.
✍️ Hoffer Q formula is more accurate for axial length <22 mm
✍️ Intravenous mannitol helps reduce vitreous pressure.
✅ Intraoperative considerations in precautions when operating Nanophthalmic eye
✍️ General anaesthesia is preferred as it does not increase orbital volume and adequately relaxes rectus muscle tone.
✍️ High-molecular-weight OVDs aid capsulor- rhexis.
✍️ Peripheral iridotomy is warranted in the case of narrow angles and or elevated IOP.
✍️ Many surgeons do two/four quadrant prophylactic sclerotomies which serves to drain uveal exudation and relaxes scleral tension, indirectly decompressing the vortex veins.
✍️ Good suturing helps reinforce globe integrity.
✅ Postoperative care in precautions when operating Nanophthalmic eye
✍️ Correction of residual refractive error by glasses contact lenses
✍️ Inflammation control
✍️ Prevention of aqueous misdirection with use of strong cycloplegics.( postoperatively)
Precautions when operating nanophthalmic eye Videos:
Nanophthalmic eye with axial length of 19.3mm, WTW 10.5, lens thickness 5mm with shallow AC and small pupil. Use of Ahmed Surgical Gonio Lens (www.ocularinc.com) to visualize angles. Healon5 used for viscomydriasis and flattening of anterior capsule, and small pupil phaco technique demonstrated. Anterior approach iridozonulohyaloidectomy performed to prevent malignant glaucoma (which occurred postop in fellow eye). Use 720p HD setting on playback for best quality.
Precautions when operating nanophthalmic eye
