by Charlie Warden
(Antioch, TN. USA)
Have been battling type 2 diabetes for over 15 years. Have gone thru oral meds to insulin injections.
My a1c has been anywhere from 11.0 down to 7.3. I cant seem to be consistent with my glucose levels. Im not overweight and love to run, bike and golf. I work sometimes too much.
My biggest complaint is I have been having vision problems for 3 or 4 years. I had lazer surgery on 1 eye and the Dr. wants to do the other eye. I can tell you that after the 1st surgery I cant hardly see a straight line anymore.
I cant afford to have this problem with my second eye because I make a living with my vision. I work on very small items under a microscope. I feel like that my blurry vision started when Lantus was prescribed. I take 40u at bedtime and 14u of Novolog with each meal.
Any help would really be appreciated!!!
—Charlie Warden, Antioch, Tennessee, USA
Charlie, difficulty seeing straight lines after retinal laser is called visual distortion or metamorphopsia. It should not be dismissed as an expected inconvenience, especially because your work depends on fine central vision.
Before laser is performed on the second eye, ask for a prompt review by a retina specialist—and a second retina-specialist opinion if possible—to confirm the diagnosis, the exact laser proposed, the urgency, the expected benefit, and whether anti-VEGF injections or another approach is suitable. Do not delay treatment when high-risk proliferative retinopathy threatens severe vision loss, but do not consent without understanding why this eye needs laser.
Answer by Dr. Albana Greca, MD, MMedSc
Hello Charlie,
Your concern is understandable. Retinal laser aims to reduce future vision loss; it does not guarantee sharper vision. Results depend on the exact retinal problem.
Persistent wavy lines may come from macular edema, ischemia, an epiretinal membrane, retinal traction, cataract, disease progression, or treatment effects. Timing alone cannot prove the cause.
You need a dilated retinal exam and usually OCT to assess the macula. Retinal photographs, angiography, visual-field testing, or an Amsler grid may also help. Our overview of diabetic eye diseases and warning signs explains why blur, distortion, and loss of side vision require different evaluations.
Ask the specialist to name the procedure and diagnosis:
For center-involved macular edema with reduced vision, anti-VEGF injections are usually first-line. They can also replace PRP in some proliferative retinopathy, but require reliable follow-up. Our diabetic retinopathy treatment guide reviews injections, laser, and vitrectomy.
Lantus, or insulin glargine, is not known to directly cause chronic retinal distortion. Low, high, or rapidly changing glucose can temporarily blur vision. Persistent wavy lines require an eye examination rather than assuming Lantus is responsible.
Do not stop or reduce Lantus or NovoLog yourself. Missing insulin can cause severe hyperglycemia. Review glucose or CGM records with your diabetes clinician for highs, lows, missed doses, and meal mismatching.
An HbA1c pattern from 11% to 7.3% shows substantial variation. Sustained glucose, blood-pressure, and cholesterol improvement reduces long-term risk. Rapid HbA1c reduction can sometimes cause early worsening, so retinal monitoring is important during treatment intensification.
This does not mean glucose should remain high. The goal is safer, steady improvement with coordinated diabetes and retinal follow-up. You may also find the discussion of type 2 diabetes and blurry vision useful.
Vitamin A, bilberry, antioxidants, and aldose-reductase inhibitors are not established retinopathy treatments and must not replace laser, injections, or surgery. Excess vitamin A can be harmful.
Contact the retina specialist urgently for sudden vision loss, a new shower of floaters, flashes of light, a dark curtain or shadow, rapidly increasing distortion, severe eye pain, marked redness, or new bleeding in the vision. These may indicate bleeding, retinal tear or detachment, or another sight-threatening problem.
What I want you to remember: laser may protect the second eye from severe future loss, but the benefit and trade-offs depend on the exact retinal problem. Because the first eye has major distortion and your work requires precise vision, obtain a macular assessment and retina-specialist discussion—and a second opinion when safe—before proceeding.
Educational safety note: General education only. This cannot determine whether laser is required or replace a retina examination.
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