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Small-eye cataract surgery: a how-to

Do it right, and these patients will be forever grateful. But know that all eyes aren’t created equal.

By: Uday Devgan, MD, FACS, FRCS
Ophthalmology Management April 1, 2015

Small-eye cataract surgery: a how-to

Do it right, and these patients will be forever grateful. But know that all eyes aren’t created equal.

By Uday Devgan, MD

The surgeon who performs cataract surgery on small eyes must be aware of the anatomic complications these eyes create. Their shorter axial length is often synonymous with a shallower anterior chamber. Because the corneal diameter is shorter, the effective lens position of the IOL might be more difficult to figure out.

But, with these challenges comes a true positive note: Small eyes are hyperopic, sometimes highly hyperopic. These patients must wear spectacles all of the time.

So, surgeons, give these patients your all, because if you succeed, removal of their cataracts will restore the angle anatomy, lower the intraocular pressure and give them the best vision they have ever had.

The Pre-op Evaluation

TYPICAL SMALL-EYE CHARACTERISTICS
FEATURES MEASUREMENTS               
Axial length < 22 mm  
Hyperopia ≥ +3D  
Anterior chamber Shallow, measured depth
≤ 2 mm
Associated narrow angles		  
ANTERIOR SEGMENT EVALUATION
ASSESSMENT CAUSE REASON
Endothelial weakness Higher chance of phaco-induced cell loss Closer proximity of phaco probe
Small size Larger astigmatic change during surgery Cutting more tissue
Anterior chamber Shallow, measured depth
≤ 2 mm
Associated narrow angles		 Crowded anterior segment
MEASURING AXIAL LENGTH
ISSUE CAUSE           
Small errors = larger refractive shift Normal eye
1 mm = 3 diopters of error		  
  Small eye
1 mm = 4-5 diopters of error		  

IOL Calculation

FORMULA GENERATIONS
Hoffer Q 3rd
Holladay 2 4th (preferred)

Holladay 2 uses white-to-white size, refraction and anterior chamber depth data to improve accuracy.

The small eye IOL choices

IOL POWER REQUIRED THREE-PIECE ACRYLIC & SILICONE IOL SINGLE-PIECE ACRYLIC IOL MAXIMUM-POWER SINGLE-PIECE ACRYLIC IOL SECOND SURGERY WITH PIGGYBACK LENS IN CILIARY SULCUS
+30 diopters • •    
+35 diopters • •    
+40 diopters     •  
> +40 diopters*     • •
* An IOL power of > +40 requires a maximum-power IOL and second surgery combined. The second IOL power is chosen after noting the post-operative refraction after the first surgery. Dr. Devgan cautions against primary polypseudophakia.

Risks and problems of cataract surgery in small eyes

RISKS/PROBLEMS EFFECT SOLUTION
Choroidal hemorrhage Potential vision loss Do not allow AC to collapse during surgery
Shallow anterior chamber Complicates capsulorhexis creation Inflate anterior chamber with cohesive viscoelastic
AC depth of <1 mm Prohibits capsulorhexis creation Partial pars plana anterior vitrectomy

During the vitrectomy, removing too much vitreous can cause too deep of an anterior chamber. OM

About the Author

Uday Devgan, MD, is chief of ophthalmology at Olive View UCLA Medical Center and in private practice at Devgan Eye Surgery in Los Angeles and Beverly Hills, Calif. His e-mail is devgan@gmail.com, or www.DevganEye.com.

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